wip: Core.Liminal.Field v1 recipe, 4 seed-selected variants between fixed mouths (L144, fails mouth joins)

Plans and draws flat field+monolith, repeating hills, road over cloud floor and pillar grid in a 3-strata fixture,
binding passage/0-1 and 1-2 as fixed endpoints. Composed W1 probes: 3/4 seeds fail one passage interface, 4/4 fail the
liminal walk audit near the mouths (support itself passes). Stopped per AGENTS.md. Same mouth-ownership failure
class as FI (L133/L140) and VS seed 2 (L139).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016dhxM43dnWvUu2B5Ph1iG1

Standalone/Core/include/VoxelForgeCore/VoxelForgeCore.h

@@ -597,6 +597,61 @@ namespace VoxelForgeCore
         }
     }
 
+    inline constexpr std::string_view CoreLiminalFieldRecipeIdV1 = "Core.Liminal.Field";
+    inline constexpr std::uint32_t CoreLiminalFieldRecipeVersionV1 = 1;
+    inline constexpr std::uint32_t CoreLiminalFieldVariantCountV1 = 4;
+
+    enum class WorldAssemblyLiminalVariantV1 : std::uint32_t
+    {
+        flatFieldMonolith = 0,
+        repeatingHills = 1,
+        roadOverCloudFloor = 2,
+        pillarGrid = 3
+    };
+
+    struct WorldAssemblyLiminalVariantDefinitionV1
+    {
+        WorldAssemblyLiminalVariantV1 variant = WorldAssemblyLiminalVariantV1::flatFieldMonolith;
+        std::string_view name;
+        WorldAssemblySurfaceProfileKindV1 surfaceKind = WorldAssemblySurfaceProfileKindV1::flatField;
+        std::int64_t hillAmplitudeMicrometres = 0;
+        std::int64_t hillWavelengthMicrometres = 0;
+        std::int64_t routeHalfWidthMicrometres = 0;
+        std::int64_t routeHalfThicknessMicrometres = 0;
+        std::int64_t supportSpacingMicrometres = 0;
+        std::int64_t supportRadiusMicrometres = 0;
+        std::int64_t monolithRadiusMicrometres = 0;
+        std::int64_t monolithHeightMicrometres = 0;
+        std::uint32_t pillarRows = 0;
+        std::uint32_t pillarColumns = 0;
+        std::int64_t pillarSpacingMicrometres = 0;
+        std::int64_t pillarRadiusMicrometres = 0;
+        std::int64_t pillarHeightMicrometres = 0;
+    };
+
+    inline constexpr std::array<WorldAssemblyLiminalVariantDefinitionV1,
+        CoreLiminalFieldVariantCountV1> CoreLiminalFieldVariantsV1{{
+        {WorldAssemblyLiminalVariantV1::flatFieldMonolith, "flatField-monolith",
+            WorldAssemblySurfaceProfileKindV1::flatField, 0, 0, 1750000, 500000,
+            36000000, 550000, 1600000, 26000000, 0, 0, 0, 0, 0},
+        {WorldAssemblyLiminalVariantV1::repeatingHills, "periodicHills",
+            WorldAssemblySurfaceProfileKindV1::periodicHills, 2200000, 80000000,
+            1750000, 500000, 36000000, 550000, 0, 0, 0, 0, 0, 0, 0},
+        {WorldAssemblyLiminalVariantV1::roadOverCloudFloor, "road-over-cloud-floor",
+            WorldAssemblySurfaceProfileKindV1::flatField, 0, 0, 2000000, 500000,
+            24000000, 550000, 0, 0, 0, 0, 0, 0, 0},
+        {WorldAssemblyLiminalVariantV1::pillarGrid, "pillar-grid",
+            WorldAssemblySurfaceProfileKindV1::flatField, 0, 0, 1750000, 500000,
+            36000000, 550000, 0, 0, 15, 15, 76000000, 5500000, 40000000}
+    }};
+
+    inline constexpr WorldAssemblyLiminalVariantV1 SelectCoreLiminalFieldVariantV1(
+        std::uint32_t seed) noexcept
+    {
+        return static_cast<WorldAssemblyLiminalVariantV1>(
+            seed % CoreLiminalFieldVariantCountV1);
+    }
+
     struct WorldAssemblyRecipeV1
     {
         std::uint32_t schemaVersion = WorldAssemblySchemaVersion;
@@ -654,6 +709,23 @@ namespace VoxelForgeCore
         std::array<std::int64_t, 4> parametersSubvoxels{};
     };
 
+    struct WorldAssemblyLiminalFieldPlanV1
+    {
+        std::uint32_t version = 0;
+        WorldAssemblyLiminalVariantV1 variant = WorldAssemblyLiminalVariantV1::flatFieldMonolith;
+        std::uint32_t seed = 0;
+        std::array<std::int64_t, 3> arrivalMouthSubvoxels{};
+        std::array<std::int64_t, 3> departureMouthSubvoxels{};
+        // Fixed distance from each passage player-center anchor to its walk surface.
+        std::int64_t mouthFloorOffsetSubvoxels = 0;
+        std::int64_t floorHeightSubvoxels = 0;
+        std::int64_t routeHalfWidthSubvoxels = 0;
+        std::int64_t routeHalfThicknessSubvoxels = 0;
+        std::int64_t routeOffsetSubvoxels = 0;
+        std::int64_t supportSpacingSubvoxels = 0;
+        std::int64_t supportRadiusSubvoxels = 0;
+    };
+
     struct WorldAssemblyStratumPlanV1
     {
         std::int32_t strateIndex = -1;
@@ -678,6 +750,7 @@ namespace VoxelForgeCore
         std::vector<WorldAssemblyFeatureV1> features;
         WorldAssemblyRouteConstraintsV1 routeConstraints;
         std::vector<WorldAssemblyRoutePointV1> route;
+        WorldAssemblyLiminalFieldPlanV1 liminalField;
         std::uint64_t contentHash = 0;
     };
 
@@ -891,6 +964,9 @@ namespace VoxelForgeCore
     inline constexpr std::uint32_t ResolvedLayoutStampVocabularyVersionV1 = 1;
     inline constexpr std::uint32_t ResolvedLayoutStampVocabularyVersionV2 = 2;
     inline constexpr std::uint32_t ResolvedLayoutStampVocabularyVersionV3 = 3;
+    inline constexpr std::uint32_t ResolvedLayoutStampVocabularyVersionV4 = 4;
+    inline constexpr std::uint32_t ResolvedLayoutStampVocabularyVersionV5 = 5;
+    inline constexpr std::uint32_t ResolvedLayoutStampVocabularyVersionV6 = 6;
     inline constexpr std::uint32_t ResolvedLayoutCavernGraphVocabularyVersionV1 = 1;
     inline constexpr std::uint32_t ResolvedLayoutOreVeinVocabularyVersionV1 = 1;
     enum class ResolvedLayoutValidationModeV3 : std::uint8_t { compatibility, strict };
@@ -904,7 +980,8 @@ namespace VoxelForgeCore
         fillPillar = 3,
         fillDais = 4,
         fillMonolith = 5,
-        fillPlatform = 6
+        fillPlatform = 6,
+        fillSweptDeckSegment = 7
     };
 
     struct ResolvedLayoutStampRequestV1
@@ -914,6 +991,12 @@ namespace VoxelForgeCore
         ResolvedSdfStampKindV1 kind = ResolvedSdfStampKindV1::carveEllipsoid;
         // A preferred center and a bounded deterministic search radius.
         std::array<std::int64_t, 3> anchorPositionMicrometres{};
+        // Present only for fillSweptDeckSegment; defines its directed centerline.
+        std::array<std::array<std::int64_t, 3>, 2> sweepEndpointsMicrometres{};
+        // V5 permits one continuous swept deck to carry its complete sampled centerline.
+        // V6 also permits a path whose X coordinates are not strictly increasing.
+        // Empty retains the V4 single-segment interpretation.
+        std::vector<std::array<std::int64_t, 3>> sweepPathMicrometres;
         std::int64_t placementRadiusMicrometres = 0;
         std::array<std::int64_t, 3> halfExtentsMicrometres{};
         std::int64_t smoothWidthMicrometres = 0;
@@ -933,6 +1016,8 @@ namespace VoxelForgeCore
         std::int32_t strateIndex = -1;
         ResolvedSdfStampKindV1 kind = ResolvedSdfStampKindV1::carveEllipsoid;
         std::array<std::int64_t, 3> positionMicrometres{};
+        std::array<std::array<std::int64_t, 3>, 2> sweepEndpointsMicrometres{};
+        std::vector<std::array<std::int64_t, 3>> sweepPathMicrometres;
         std::array<std::int64_t, 3> boundsMinimumMicrometres{};
         std::array<std::int64_t, 3> boundsMaximumMicrometres{};
         std::array<std::int64_t, 3> halfExtentsMicrometres{};
@@ -1228,6 +1313,9 @@ namespace VoxelForgeCore
         ResolvedLayoutSnapshotV3& layout, std::int32_t seed,
         const std::vector<ResolvedLayoutPassageConfigV1>& configs,
         std::string& error);
+    VFCORE_API bool PlanCoreLiminalFieldV1(
+        WorldAssemblyRecipeV1& recipe, WorldAssemblyStratumPlanV1& stratum,
+        const ResolvedLayoutSnapshotV3& layout, std::string& error);
 
     struct ResolvedLayoutStampPlacementAuditV1
     {

Standalone/Core/src/ResolvedLayoutInternal.h

@@ -176,7 +176,7 @@ namespace
     {
         const auto value=static_cast<std::uint8_t>(kind);
         return value>=static_cast<std::uint8_t>(ResolvedSdfStampKindV1::carveEllipsoid)
-            &&value<=static_cast<std::uint8_t>(ResolvedSdfStampKindV1::fillPlatform);
+            &&value<=static_cast<std::uint8_t>(ResolvedSdfStampKindV1::fillSweptDeckSegment);
     }
     bool LayoutStampIsMotif(ResolvedSdfStampKindV1 kind)
     {return kind==ResolvedSdfStampKindV1::fillMonolith
@@ -249,6 +249,71 @@ namespace
                         /WorldAssemblySubvoxelsPerVoxel));
             return result;
         };
+        const bool liminalRouteStamp=strate->recipeId==CoreLiminalFieldRecipeIdV1
+            &&stamp.stableId.starts_with("core/liminal-field/route/")
+            &&(stamp.kind==ResolvedSdfStampKindV1::fillSweptDeckSegment
+                ||stamp.kind==ResolvedSdfStampKindV1::fillPillar);
+        if(liminalRouteStamp)
+        {
+            const auto variant=std::find_if(strate->anchors.begin(),strate->anchors.end(),
+                [](const auto& anchor){return anchor.kind=="liminal_variant"
+                    &&anchor.values.size()>=6;});
+            std::vector<const ResolvedLayoutAnchorV2*> points;
+            for(const auto& anchor:strate->anchors)
+                if(anchor.kind=="liminal_route_point"&&anchor.values.size()>=4)
+                    points.push_back(&anchor);
+            if(variant==strate->anchors.end()||points.size()<2)
+            {if(reason)*reason="Core.Liminal.Field route stamp has no versioned fixed-mouth route";return false;}
+            const auto routePoint=[&](const ResolvedLayoutAnchorV2& anchor)
+            {
+                std::array<std::int64_t,3> q={anchor.values[0],anchor.values[1],anchor.values[2]};
+                return qToMicrometres(q);
+            };
+            const std::int64_t halfThickness=static_cast<std::int64_t>(std::llround(
+                static_cast<double>(variant->values[5])*coreMicrometres
+                    /WorldAssemblySubvoxelsPerVoxel));
+            if(stamp.kind==ResolvedSdfStampKindV1::fillSweptDeckSegment)
+            {
+                const auto first=routePoint(*points.front());
+                const auto last=routePoint(*points.back());
+                if(stamp.sweepPathMicrometres.size()<2
+                    ||stamp.sweepPathMicrometres.front()[0]!=first[0]
+                    ||stamp.sweepPathMicrometres.front()[1]!=first[1]
+                    ||stamp.sweepPathMicrometres.front()[2]!=first[2]-halfThickness
+                    ||stamp.sweepPathMicrometres.back()[0]!=last[0]
+                    ||stamp.sweepPathMicrometres.back()[1]!=last[1]
+                    ||stamp.sweepPathMicrometres.back()[2]!=last[2]-halfThickness)
+                {if(reason)*reason="Core.Liminal.Field deck does not terminate at its fixed passage mouths";return false;}
+                return true;
+            }
+            const auto deck=std::find_if(layout.stamps.begin(),layout.stamps.end(),
+                [&](const auto& existing){return existing.strateIndex==stamp.strateIndex
+                    &&existing.stableId=="core/liminal-field/route/deck/000"
+                    &&existing.kind==ResolvedSdfStampKindV1::fillSweptDeckSegment;});
+            if(deck==layout.stamps.end()||deck->sweepPathMicrometres.size()<2)
+            {if(reason)*reason="Core.Liminal.Field support has no previously resolved route deck";return false;}
+            double distance=std::numeric_limits<double>::infinity();
+            for(std::size_t i=1;i<deck->sweepPathMicrometres.size();++i)
+            {
+                const auto& a=deck->sweepPathMicrometres[i-1];
+                const auto& b=deck->sweepPathMicrometres[i];
+                const double dx=static_cast<double>(b[0]-a[0]);
+                const double dy=static_cast<double>(b[1]-a[1]);
+                const double lengthSquared=dx*dx+dy*dy;
+                const double t=lengthSquared>0.0?std::clamp(
+                    ((stamp.positionMicrometres[0]-a[0])*dx
+                        +(stamp.positionMicrometres[1]-a[1])*dy)/lengthSquared,
+                    0.0,1.0):0.0;
+                const double offsetX=stamp.positionMicrometres[0]-(a[0]+t*dx);
+                const double offsetY=stamp.positionMicrometres[1]-(a[1]+t*dy);
+                distance=std::min(distance,std::hypot(offsetX,offsetY));
+            }
+            const double corridorRadius=deck->halfExtentsMicrometres[1]
+                +stamp.halfExtentsMicrometres[0]+RouteClearanceMicrometres;
+            if(distance>corridorRadius)
+            {if(reason)*reason="Core.Liminal.Field route stamp is outside its versioned route corridor";return false;}
+            return true;
+        }
         for(const auto& passage:layout.passages)
         {
             if(passage.upperStrateIndex!=stamp.strateIndex
@@ -598,6 +663,28 @@ namespace
                     <<",\"irregularity_wavelength_um\":"<<stamp.irregularityWavelengthMicrometres
                     <<",\"irregularity_seed\":"<<stamp.irregularitySeed
                     <<",\"yaw_quarter_turns\":"<<static_cast<unsigned>(stamp.yawQuarterTurns);
+                if(stamp.kind==ResolvedSdfStampKindV1::fillSweptDeckSegment)
+                {
+                    out<<",\"sweep_endpoints_um\":[["
+                        <<stamp.sweepEndpointsMicrometres[0][0]<<','
+                        <<stamp.sweepEndpointsMicrometres[0][1]<<','
+                        <<stamp.sweepEndpointsMicrometres[0][2]<<"],["
+                        <<stamp.sweepEndpointsMicrometres[1][0]<<','
+                        <<stamp.sweepEndpointsMicrometres[1][1]<<','
+                        <<stamp.sweepEndpointsMicrometres[1][2]<<"]]";
+                    if(!stamp.sweepPathMicrometres.empty())
+                    {
+                        out<<",\"sweep_path_um\":[";
+                        for(std::size_t pointIndex=0;pointIndex<stamp.sweepPathMicrometres.size();
+                            ++pointIndex)
+                        {
+                            if(pointIndex)out<<',';
+                            const auto& point=stamp.sweepPathMicrometres[pointIndex];
+                            out<<'['<<point[0]<<','<<point[1]<<','<<point[2]<<']';
+                        }
+                        out<<']';
+                    }
+                }
                 if(s.stampVocabularyVersion>=ResolvedLayoutStampVocabularyVersionV3)
                     out<<",\"rounding_radius_um\":"<<stamp.roundingRadiusMicrometres
                         <<",\"minimum_spacing_um\":"<<stamp.minimumSpacingMicrometres
@@ -1134,8 +1221,11 @@ bool ResolvedLayoutSnapshotV3::validate(ResolvedLayoutValidationModeV3 mode,
     }
     else if(stampVocabularyVersion!=ResolvedLayoutStampVocabularyVersionV1
         &&stampVocabularyVersion!=ResolvedLayoutStampVocabularyVersionV2
-        &&stampVocabularyVersion!=ResolvedLayoutStampVocabularyVersionV3)
+        &&stampVocabularyVersion!=ResolvedLayoutStampVocabularyVersionV3
-        add("stamp_vocabulary_version","resolved stamps require supported vocabulary version 1, 2 or 3");
+        &&stampVocabularyVersion!=ResolvedLayoutStampVocabularyVersionV4
+        &&stampVocabularyVersion!=ResolvedLayoutStampVocabularyVersionV5
+        &&stampVocabularyVersion!=ResolvedLayoutStampVocabularyVersionV6)
+        add("stamp_vocabulary_version","resolved stamps require supported vocabulary version 1 through 6");
     std::vector<std::string> stampIds;
     for(const auto& stamp:stamps)
     {
@@ -1145,6 +1235,8 @@ bool ResolvedLayoutSnapshotV3::validate(ResolvedLayoutValidationModeV3 mode,
         else stampIds.push_back(stamp.stableId);
         const bool motif=LayoutStampIsMotif(stamp.kind);
         if(!LayoutStampKindValid(stamp.kind)||stamp.yawQuarterTurns>3
+            ||(stamp.kind==ResolvedSdfStampKindV1::fillSweptDeckSegment
+                &&stampVocabularyVersion<ResolvedLayoutStampVocabularyVersionV4)
             ||(motif&&stampVocabularyVersion<ResolvedLayoutStampVocabularyVersionV3))
             add("stamp_kind","stamp has an unsupported kind or orientation");
         bool validExtents=true;
@@ -1159,6 +1251,49 @@ bool ResolvedLayoutSnapshotV3::validate(ResolvedLayoutValidationModeV3 mode,
             ||(stamp.irregularityAmplitudeMicrometres>0
                 &&stamp.irregularityWavelengthMicrometres<=0))
             add("stamp_parameters",stamp.stableId+" has invalid or unbounded geometry parameters");
+        if(stamp.kind==ResolvedSdfStampKindV1::fillSweptDeckSegment)
+        {
+            double lengthSquared=0.0;
+            for(std::size_t axis=0;axis<3;++axis)
+            {
+                const auto a=stamp.sweepEndpointsMicrometres[0][axis];
+                const auto b=stamp.sweepEndpointsMicrometres[1][axis];
+                if(a<-1000000000000ll||a>1000000000000ll
+                    ||b<-1000000000000ll||b>1000000000000ll)
+                    add("stamp_sweep",stamp.stableId+" has an unbounded endpoint");
+                const double delta=static_cast<double>(stamp.sweepEndpointsMicrometres[1][axis])
+                    -stamp.sweepEndpointsMicrometres[0][axis];
+                lengthSquared+=delta*delta;
+            }
+            if(stamp.sweepPathMicrometres.empty()&&(!(lengthSquared>0.0)
+                ||std::sqrt(lengthSquared)>2.0*stamp.halfExtentsMicrometres[0]+1.0))
+                add("stamp_sweep",stamp.stableId+" has invalid endpoints or longitudinal extent");
+            if(!stamp.sweepPathMicrometres.empty())
+            {
+                bool validPath=stampVocabularyVersion>=ResolvedLayoutStampVocabularyVersionV5
+                    &&stamp.sweepPathMicrometres.size()>=2
+                    &&stamp.sweepPathMicrometres.size()<=1025
+                    &&stamp.sweepPathMicrometres.front()==stamp.sweepEndpointsMicrometres[0]
+                    &&stamp.sweepPathMicrometres.back()==stamp.sweepEndpointsMicrometres[1];
+                for(std::size_t pointIndex=0;pointIndex<stamp.sweepPathMicrometres.size();
+                    ++pointIndex)
+                {
+                    const auto& point=stamp.sweepPathMicrometres[pointIndex];
+                    for(const auto coordinate:point)
+                        validPath=validPath&&coordinate>=-1000000000000ll
+                            &&coordinate<=1000000000000ll;
+                    if(pointIndex>0)
+                    {
+                        const auto& previous=stamp.sweepPathMicrometres[pointIndex-1];
+                        validPath=validPath&&previous!=point
+                            &&(stampVocabularyVersion>=ResolvedLayoutStampVocabularyVersionV6
+                                ||previous[0]<point[0]);
+                    }
+                }
+                if(!validPath)add("stamp_sweep_path",stamp.stableId
+                    +" has an invalid swept-deck path for its vocabulary version");
+            }
+        }
         if(motif)
         {
             const auto minimumExtent=*std::min_element(stamp.halfExtentsMicrometres.begin(),
@@ -1186,16 +1321,63 @@ bool ResolvedLayoutSnapshotV3::validate(ResolvedLayoutValidationModeV3 mode,
         const std::int64_t pad=motif
             ?(stamp.smoothWidthMicrometres+5)/6+stamp.irregularityAmplitudeMicrometres
             :stamp.smoothWidthMicrometres+stamp.irregularityAmplitudeMicrometres;
-        const std::array<std::int64_t,3> extents={
+        if(stamp.kind==ResolvedSdfStampKindV1::fillSweptDeckSegment
-            stamp.halfExtentsMicrometres[stamp.yawQuarterTurns%2?1:0]+pad,
+            &&stamp.sweepPathMicrometres.empty())
-            stamp.halfExtentsMicrometres[stamp.yawQuarterTurns%2?0:1]+pad,
+        {
-            stamp.halfExtentsMicrometres[2]+pad};
+            double radiusSquared=0.0;
-        for(std::size_t axis=0;axis<3;++axis)
+            for(const auto extent:stamp.halfExtentsMicrometres)
-            if(stamp.boundsMinimumMicrometres[axis]
+            {
-                    !=stamp.positionMicrometres[axis]-extents[axis]
+                const double expanded=static_cast<double>(extent+pad);
-                ||stamp.boundsMaximumMicrometres[axis]
+                radiusSquared+=expanded*expanded;
-                    !=stamp.positionMicrometres[axis]+extents[axis])
+            }
-                add("stamp_bounds",stamp.stableId+" conservative bounds do not match its parameters");
+            const auto radius=static_cast<std::int64_t>(std::ceil(std::sqrt(radiusSquared)));
+            for(std::size_t axis=0;axis<3;++axis)
+            {
+                const auto minimum=std::min(stamp.sweepEndpointsMicrometres[0][axis],
+                    stamp.sweepEndpointsMicrometres[1][axis]);
+                const auto maximum=std::max(stamp.sweepEndpointsMicrometres[0][axis],
+                    stamp.sweepEndpointsMicrometres[1][axis]);
+                if(stamp.boundsMinimumMicrometres[axis]!=minimum-radius
+                    ||stamp.boundsMaximumMicrometres[axis]!=maximum+radius)
+                    add("stamp_bounds",stamp.stableId+" conservative sweep bounds do not match its parameters");
+            }
+        }
+        else if(stamp.kind==ResolvedSdfStampKindV1::fillSweptDeckSegment)
+        {
+            double radiusSquared=0.0;
+            for(std::size_t axis=1;axis<3;++axis)
+            {
+                const double expanded=static_cast<double>(stamp.halfExtentsMicrometres[axis]+pad);
+                radiusSquared+=expanded*expanded;
+            }
+            const auto radius=static_cast<std::int64_t>(std::ceil(std::sqrt(radiusSquared)));
+            std::array<std::int64_t,3> minimum=stamp.sweepPathMicrometres.front();
+            std::array<std::int64_t,3> maximum=minimum;
+            for(const auto& point:stamp.sweepPathMicrometres)
+                for(std::size_t axis=0;axis<3;++axis)
+                {
+                    minimum[axis]=std::min(minimum[axis],point[axis]);
+                    maximum[axis]=std::max(maximum[axis],point[axis]);
+                }
+            for(std::size_t axis=0;axis<3;++axis)
+                if(stamp.boundsMinimumMicrometres[axis]!=minimum[axis]-radius
+                    ||stamp.boundsMaximumMicrometres[axis]!=maximum[axis]+radius)
+                    add("stamp_bounds",stamp.stableId
+                        +" conservative continuous-sweep bounds do not match its path");
+        }
+        else
+        {
+            const std::array<std::int64_t,3> extents={
+                stamp.halfExtentsMicrometres[stamp.yawQuarterTurns%2?1:0]+pad,
+                stamp.halfExtentsMicrometres[stamp.yawQuarterTurns%2?0:1]+pad,
+                stamp.halfExtentsMicrometres[2]+pad};
+            for(std::size_t axis=0;axis<3;++axis)
+                if(stamp.boundsMinimumMicrometres[axis]
+                        !=stamp.positionMicrometres[axis]-extents[axis]
+                    ||stamp.boundsMaximumMicrometres[axis]
+                        !=stamp.positionMicrometres[axis]+extents[axis])
+                    add("stamp_bounds",stamp.stableId+" conservative bounds do not match its parameters");
+        }
         std::string safetyReason;
         if(!LayoutStampSafe(*this,stamp,&safetyReason))
             add("stamp_placement",stamp.stableId+" is unsafe: "+safetyReason);
@@ -1497,6 +1679,21 @@ std::optional<ResolvedLayoutSnapshotV3> ResolvedLayoutSnapshotV3::FromJson(
                 target[axis]=values[axis].Integer();
         };
         readTriplet("position_um",stamp.positionMicrometres);
+        const auto& sweepEndpoints=v.Get("sweep_endpoints_um").AsArray();
+        for(std::size_t endpoint=0;endpoint<2&&endpoint<sweepEndpoints.size();++endpoint)
+        {
+            const auto& values=sweepEndpoints[endpoint].AsArray();
+            for(std::size_t axis=0;axis<3&&axis<values.size();++axis)
+                stamp.sweepEndpointsMicrometres[endpoint][axis]=values[axis].Integer();
+        }
+        for(const auto& value:v.Get("sweep_path_um").AsArray())
+        {
+            std::array<std::int64_t,3> point{};
+            const auto& values=value.AsArray();
+            for(std::size_t axis=0;axis<3&&axis<values.size();++axis)
+                point[axis]=values[axis].Integer();
+            stamp.sweepPathMicrometres.push_back(point);
+        }
         readTriplet("bounds_min_um",stamp.boundsMinimumMicrometres);
         readTriplet("bounds_max_um",stamp.boundsMaximumMicrometres);
         readTriplet("half_extents_um",stamp.halfExtentsMicrometres);
@@ -1619,7 +1816,25 @@ bool ResolveResolvedLayoutStampsV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
     std::sort(ordered.begin(),ordered.end(),[](const auto& a,const auto& b)
         {return a.stableId<b.stableId;});
     ResolvedLayoutSnapshotV3 candidate=layout;
-    candidate.stampVocabularyVersion=ResolvedLayoutStampVocabularyVersionV1;
+    const bool hasContinuousSweptDeck=std::any_of(ordered.begin(),ordered.end(),[](const auto& request)
+        {return request.kind==ResolvedSdfStampKindV1::fillSweptDeckSegment
+            &&!request.sweepPathMicrometres.empty();});
+    const bool hasNonMonotoneSweptDeck=std::any_of(ordered.begin(),ordered.end(),[](const auto& request)
+    {
+        if(request.kind!=ResolvedSdfStampKindV1::fillSweptDeckSegment
+            ||request.sweepPathMicrometres.empty())return false;
+        for(std::size_t i=1;i<request.sweepPathMicrometres.size();++i)
+            if(request.sweepPathMicrometres[i-1][0]>=request.sweepPathMicrometres[i][0])
+                return true;
+        return false;
+    });
+    const bool hasSweptDeck=std::any_of(ordered.begin(),ordered.end(),[](const auto& request)
+        {return request.kind==ResolvedSdfStampKindV1::fillSweptDeckSegment;});
+    candidate.stampVocabularyVersion=hasContinuousSweptDeck
+        ?(hasNonMonotoneSweptDeck?ResolvedLayoutStampVocabularyVersionV6
+            :ResolvedLayoutStampVocabularyVersionV5)
+        :hasSweptDeck?ResolvedLayoutStampVocabularyVersionV4
+        :ResolvedLayoutStampVocabularyVersionV1;
     candidate.stamps.clear();candidate.stamps.reserve(ordered.size());
     for(std::size_t requestIndex=0;requestIndex<ordered.size();++requestIndex)
     {
@@ -1630,6 +1845,8 @@ bool ResolveResolvedLayoutStampsV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
         if(!LayoutStampKindValid(request.kind)||request.yawQuarterTurns>3
             ||request.placementRadiusMicrometres<0
             ||request.placementRadiusMicrometres>100000000
+            ||(request.kind==ResolvedSdfStampKindV1::fillSweptDeckSegment
+                &&request.placementRadiusMicrometres!=0)
             ||request.smoothWidthMicrometres<0||request.smoothWidthMicrometres>10000000
             ||request.irregularityAmplitudeMicrometres<0
             ||request.irregularityAmplitudeMicrometres>10000000
@@ -1648,6 +1865,43 @@ bool ResolveResolvedLayoutStampsV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
         for(const auto coordinate:request.anchorPositionMicrometres)
             if(coordinate<-1000000000000ll||coordinate>1000000000000ll)
             {error="stamp request "+request.stableId+" has an unbounded anchor";return false;}
+        if(request.kind==ResolvedSdfStampKindV1::fillSweptDeckSegment
+            &&request.sweepPathMicrometres.empty())
+        {
+            double lengthSquared=0.0;
+            for(std::size_t axis=0;axis<3;++axis)
+            {
+                const auto a=request.sweepEndpointsMicrometres[0][axis];
+                const auto b=request.sweepEndpointsMicrometres[1][axis];
+                if(a<-1000000000000ll||a>1000000000000ll
+                    ||b<-1000000000000ll||b>1000000000000ll)
+                {error="stamp request "+request.stableId+" has an unbounded sweep endpoint";return false;}
+                const double delta=static_cast<double>(b)-a;
+                lengthSquared+=delta*delta;
+            }
+            if(!(lengthSquared>0.0)
+                ||std::sqrt(lengthSquared)>2.0*request.halfExtentsMicrometres[0]+1.0)
+            {error="stamp request "+request.stableId+" has invalid swept-segment extents";return false;}
+        }
+        if(request.kind==ResolvedSdfStampKindV1::fillSweptDeckSegment
+            &&!request.sweepPathMicrometres.empty())
+        {
+            if(request.sweepPathMicrometres.size()<2
+                ||request.sweepPathMicrometres.size()>1025
+                ||request.sweepPathMicrometres.front()!=request.sweepEndpointsMicrometres[0]
+                ||request.sweepPathMicrometres.back()!=request.sweepEndpointsMicrometres[1])
+            {error="stamp request "+request.stableId+" has an invalid continuous deck path";return false;}
+            for(std::size_t pointIndex=0;pointIndex<request.sweepPathMicrometres.size();
+                ++pointIndex)
+            {
+                const auto& point=request.sweepPathMicrometres[pointIndex];
+                for(const auto coordinate:point)
+                    if(coordinate<-1000000000000ll||coordinate>1000000000000ll)
+                    {error="stamp request "+request.stableId+" has an unbounded path point";return false;}
+                if(pointIndex>0&&request.sweepPathMicrometres[pointIndex-1]==point)
+                {error="stamp request "+request.stableId+" path contains a zero-length segment";return false;}
+            }
+        }
 
         // The shared JSON value type stores numbers as IEEE-754 doubles; keep the
         // serialized seed in its exact integer range so the canonical round trip holds.
@@ -1662,10 +1916,13 @@ bool ResolveResolvedLayoutStampsV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
             return static_cast<std::int64_t>(bits%span)-radius;
         };
         bool placed=false;
+        std::string lastPlacementFailure;
         for(std::uint32_t attempt=0;attempt<(request.placementRadiusMicrometres==0?1u:512u);++attempt)
         {
             ResolvedLayoutStampV1 stamp;stamp.stableId=request.stableId;
             stamp.strateIndex=request.strateIndex;stamp.kind=request.kind;
+            stamp.sweepEndpointsMicrometres=request.sweepEndpointsMicrometres;
+            stamp.sweepPathMicrometres=request.sweepPathMicrometres;
             stamp.halfExtentsMicrometres=request.halfExtentsMicrometres;
             stamp.smoothWidthMicrometres=request.smoothWidthMicrometres;
             stamp.irregularityAmplitudeMicrometres=request.irregularityAmplitudeMicrometres;
@@ -1687,20 +1944,70 @@ bool ResolveResolvedLayoutStampsV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
                 stamp.positionMicrometres[axis]=request.anchorPositionMicrometres[axis]+offset[axis];
             const std::int64_t pad=stamp.smoothWidthMicrometres
                 +stamp.irregularityAmplitudeMicrometres;
-            const std::array<std::int64_t,3> extents={
+            if(stamp.kind==ResolvedSdfStampKindV1::fillSweptDeckSegment
-                stamp.halfExtentsMicrometres[stamp.yawQuarterTurns%2?1:0]+pad,
+                &&stamp.sweepPathMicrometres.empty())
-                stamp.halfExtentsMicrometres[stamp.yawQuarterTurns%2?0:1]+pad,
-                stamp.halfExtentsMicrometres[2]+pad};
-            for(std::size_t axis=0;axis<3;++axis)
             {
-                stamp.boundsMinimumMicrometres[axis]=stamp.positionMicrometres[axis]-extents[axis];
+                double radiusSquared=0.0;
-                stamp.boundsMaximumMicrometres[axis]=stamp.positionMicrometres[axis]+extents[axis];
+                for(const auto extent:stamp.halfExtentsMicrometres)
+                {
+                    const double expanded=static_cast<double>(extent+pad);
+                    radiusSquared+=expanded*expanded;
+                }
+                const std::int64_t radius=static_cast<std::int64_t>(std::ceil(std::sqrt(radiusSquared)));
+                for(std::size_t axis=0;axis<3;++axis)
+                {
+                    const auto minimum=std::min(stamp.sweepEndpointsMicrometres[0][axis],
+                        stamp.sweepEndpointsMicrometres[1][axis]);
+                    const auto maximum=std::max(stamp.sweepEndpointsMicrometres[0][axis],
+                        stamp.sweepEndpointsMicrometres[1][axis]);
+                    stamp.boundsMinimumMicrometres[axis]=minimum-radius;
+                    stamp.boundsMaximumMicrometres[axis]=maximum+radius;
+                }
             }
-            if(!LayoutStampSafe(candidate,stamp))continue;
+            else if(stamp.kind==ResolvedSdfStampKindV1::fillSweptDeckSegment)
+            {
+                double radiusSquared=0.0;
+                for(std::size_t axis=1;axis<3;++axis)
+                {
+                    const double expanded=static_cast<double>(stamp.halfExtentsMicrometres[axis]+pad);
+                    radiusSquared+=expanded*expanded;
+                }
+                const std::int64_t radius=static_cast<std::int64_t>(
+                    std::ceil(std::sqrt(radiusSquared)));
+                std::array<std::int64_t,3> minimum=stamp.sweepPathMicrometres.front();
+                std::array<std::int64_t,3> maximum=minimum;
+                for(const auto& point:stamp.sweepPathMicrometres)
+                    for(std::size_t axis=0;axis<3;++axis)
+                    {
+                        minimum[axis]=std::min(minimum[axis],point[axis]);
+                        maximum[axis]=std::max(maximum[axis],point[axis]);
+                    }
+                for(std::size_t axis=0;axis<3;++axis)
+                {
+                    stamp.boundsMinimumMicrometres[axis]=minimum[axis]-radius;
+                    stamp.boundsMaximumMicrometres[axis]=maximum[axis]+radius;
+                }
+            }
+            else
+            {
+                const std::array<std::int64_t,3> extents={
+                    stamp.halfExtentsMicrometres[stamp.yawQuarterTurns%2?1:0]+pad,
+                    stamp.halfExtentsMicrometres[stamp.yawQuarterTurns%2?0:1]+pad,
+                    stamp.halfExtentsMicrometres[2]+pad};
+                for(std::size_t axis=0;axis<3;++axis)
+                {
+                    stamp.boundsMinimumMicrometres[axis]=stamp.positionMicrometres[axis]-extents[axis];
+                    stamp.boundsMaximumMicrometres[axis]=stamp.positionMicrometres[axis]+extents[axis];
+                }
+            }
+            std::string safetyReason;
+            if(!LayoutStampSafe(candidate,stamp,&safetyReason))
+            {lastPlacementFailure=std::move(safetyReason);continue;}
             candidate.stamps.push_back(std::move(stamp));placed=true;break;
         }
         if(!placed)
-        {error="stamp request "+request.stableId+" has no deterministic passage-safe content placement";return false;}
+        {error="stamp request "+request.stableId+" has no deterministic passage-safe content placement"
+            +(lastPlacementFailure.empty()?std::string{}:": "+lastPlacementFailure);return false;}
     }
     if(!candidate.finalize(error))return false;
     std::vector<ResolvedLayoutIssueV2> issues;std::string strictError;

Standalone/Core/src/ShapeWorldInternal.h

@@ -1523,6 +1523,8 @@ public:
                 &nativeLatticeFloorSupport);
         }
         const auto* bound=FindBoundStratumForManagerZ(Z);
+        const bool liminalRouteComposition=bound&&bound->Resolved
+            &&bound->Resolved->recipeId==VoxelForgeCore::CoreLiminalFieldRecipeIdV1;
         const bool nativeLattice=bound&&bound->Resolved
             &&VoxelForgeCore::IsNativeLatticeFieldStratum(*bound->Resolved)
             &&bound->Resolved->passageCapabilities.hasNativeLatticeField;
@@ -1546,7 +1548,9 @@ public:
             VoxelForgeCore::Linux77Profiler::FScopedPhase l77StampPhase(
                 VoxelForgeCore::Linux77Profiler::EPhase::Stamps);
             FScopedLegacyFieldTermTimer TermTimer(ELegacyFieldTerm::ComposerStamps);
-            stamped=ApplyResolvedSdfStamps(composed,X,Y,Z);
+            stamped=ApplyResolvedSdfStamps(composed,X,Y,Z,
+                liminalRouteComposition?std::string_view("core/liminal-field/route/")
+                    :std::string_view{});
         }
         static const bool bL75TraceTnComposition=[]
         {
@@ -1598,6 +1602,12 @@ public:
                 ELegacyFieldTerm::ComposerPassage);
             final=ApplyResolvedStratePassageCarves(final,X,Y,Z);
         }
+        // A liminal route is authored to terminate at fixed passage mouths. The
+        // passage carve owns the surrounding bore, while the deck/support stamps
+        // restore its walkable floor so the composed route crosses the interface.
+        if(liminalRouteComposition)
+            final=ApplyResolvedSdfStamps(final,X,Y,Z,{},
+                "core/liminal-field/route/");
         if(bTraceTnComposition)
             std::printf("[L75TNCompositionTrace] input=%.9g graph=%.9g boundary=%.9g passage=%.9g stamp=%.9g final=%.9g native=0\n",
                 density,graphDensity,boundary,composed,stamped,final);
@@ -3535,6 +3545,8 @@ private:
     {
         const VoxelForgeCore::ResolvedLayoutStampV1* record=nullptr;
         std::array<float,3> positionVoxels{},halfExtentsVoxels{};
+        std::array<std::array<float,3>,2> sweepEndpointsVoxels{};
+        std::vector<std::array<float,3>> sweepPathVoxels;
         float smoothWidthVoxels=0.0f;
         float irregularityAmplitudeVoxels=0.0f;
         float irregularityWavelengthVoxels=0.0f;
@@ -3700,9 +3712,24 @@ private:
             StampSpatialBounds.push_back(bound);
             FStampRuntime runtime;runtime.record=&stamp;
             for(std::size_t axis=0;axis<3;++axis)
+            {
                 runtime.positionVoxels[axis]=static_cast<float>(
                     static_cast<double>(stamp.positionMicrometres[axis])
                         /Owner->CoreVoxelSizeMicrons);
+                for(std::size_t endpoint=0;endpoint<2;++endpoint)
+                    runtime.sweepEndpointsVoxels[endpoint][axis]=static_cast<float>(
+                        static_cast<double>(stamp.sweepEndpointsMicrometres[endpoint][axis])
+                            /Owner->CoreVoxelSizeMicrons);
+            }
+            runtime.sweepPathVoxels.reserve(stamp.sweepPathMicrometres.size());
+            for(const auto& pointMicrometres:stamp.sweepPathMicrometres)
+            {
+                std::array<float,3> point{};
+                for(std::size_t axis=0;axis<3;++axis)
+                    point[axis]=static_cast<float>(static_cast<double>(pointMicrometres[axis])
+                        /Owner->CoreVoxelSizeMicrons);
+                runtime.sweepPathVoxels.push_back(point);
+            }
             const std::size_t xAxis=stamp.yawQuarterTurns%2?1:0;
             const std::size_t yAxis=stamp.yawQuarterTurns%2?0:1;
             runtime.halfExtentsVoxels={
@@ -5162,6 +5189,20 @@ private:
     }
 
 public:
+    static std::int32_t& CurrentStampSamplingStep() noexcept
+    {
+        static thread_local std::int32_t Step=0;
+        return Step;
+    }
+    struct FScopedStampSamplingStep
+    {
+        explicit FScopedStampSamplingStep(std::int32_t Step)
+            :Previous(CurrentStampSamplingStep())
+        {CurrentStampSamplingStep()=std::max(0,Step);}
+        ~FScopedStampSamplingStep(){CurrentStampSamplingStep()=Previous;}
+        std::int32_t Previous=0;
+    };
+
     bool GetNativeSurfaceHeightsAt(float X,float Y,int32 ChunkZ,
                                    float& OutGroundZ,float& OutCeilingZ) const
     {
@@ -7116,6 +7157,117 @@ private:
         const float top=std::max(StampEllipsoidSdf(x,y,z,halfSize),-z);
         return SmoothMinDistance(lower,top,round*2.0f);
     }
+    static float StampContinuousSweptDeckSdf(const FStampRuntime& stamp,
+        float x,float y,float z)
+    {
+        const auto& path=stamp.sweepPathVoxels;
+        if(path.size()<2)return std::numeric_limits<float>::infinity();
+        const float halfWidth=stamp.halfExtentsVoxels[1];
+        const float halfThickness=stamp.halfExtentsVoxels[2];
+        const float round=std::min(0.35f,std::min(halfWidth,halfThickness)*0.15f);
+        const float searchMargin=halfWidth+halfThickness+2.0f;
+        const bool increasingX=std::adjacent_find(path.begin(),path.end(),
+            [](const auto& a,const auto& b){return a[0]>=b[0];})==path.end();
+        const auto first=increasingX
+            ?std::lower_bound(path.begin(),path.end(),x-searchMargin,
+                [](const auto& point,float value){return point[0]<value;})
+            :path.begin();
+        const auto last=increasingX
+            ?std::upper_bound(first,path.end(),x+searchMargin,
+                [](float value,const auto& point){return value<point[0];})
+            :path.end();
+        const std::size_t firstIndex=static_cast<std::size_t>(first-path.begin());
+        const std::size_t lastIndex=static_cast<std::size_t>(last-path.begin());
+        const std::size_t segmentBegin=std::min(path.size()-2,
+            firstIndex==0?std::size_t{0}:firstIndex-1);
+        const std::size_t segmentEnd=std::min(path.size()-2,lastIndex);
+        std::size_t nearestSegment=path.size();
+        float nearestProjection=0.0f;
+        float nearestDistanceSquared=std::numeric_limits<float>::infinity();
+        for(std::size_t segment=segmentBegin;segment<=segmentEnd;++segment)
+        {
+            const auto& a=path[segment];const auto& b=path[segment+1];
+            const float dx=b[0]-a[0],dy=b[1]-a[1];
+            const float horizontalSquared=dx*dx+dy*dy;
+            if(!(horizontalSquared>1.0e-10f))continue;
+            const float projection=std::clamp(((x-a[0])*dx+(y-a[1])*dy)
+                /horizontalSquared,0.0f,1.0f);
+            const float nearestX=a[0]+projection*dx;
+            const float nearestY=a[1]+projection*dy;
+            const float offsetX=x-nearestX,offsetY=y-nearestY;
+            const float distanceSquared=offsetX*offsetX+offsetY*offsetY;
+            if(distanceSquared<nearestDistanceSquared
+                ||(distanceSquared==nearestDistanceSquared&&segment<nearestSegment))
+            {
+                nearestSegment=segment;
+                nearestProjection=projection;
+                nearestDistanceSquared=distanceSquared;
+            }
+        }
+        if(nearestSegment>=path.size()-1)return std::numeric_limits<float>::infinity();
+        const auto evalCenterline=[&](float parameter,std::array<float,3>& center,
+            std::array<float,3>& tangent)
+        {
+            const auto& p0=path[nearestSegment];
+            const auto& p1=path[nearestSegment+1];
+            const auto& before=path[nearestSegment==0?nearestSegment:nearestSegment-1];
+            const auto& after=path[nearestSegment+2<path.size()
+                ?nearestSegment+2:nearestSegment+1];
+            const float t2=parameter*parameter,t3=t2*parameter;
+            const float h00=2.0f*t3-3.0f*t2+1.0f;
+            const float h10=t3-2.0f*t2+parameter;
+            const float h01=-2.0f*t3+3.0f*t2;
+            const float h11=t3-t2;
+            const float d00=6.0f*t2-6.0f*parameter;
+            const float d10=3.0f*t2-4.0f*parameter+1.0f;
+            const float d01=-6.0f*t2+6.0f*parameter;
+            const float d11=3.0f*t2-2.0f*parameter;
+            for(std::size_t axis=0;axis<3;++axis)
+            {
+                const float m0=nearestSegment==0?p1[axis]-p0[axis]
+                    :0.5f*(p1[axis]-before[axis]);
+                const float m1=nearestSegment+2>=path.size()?p1[axis]-p0[axis]
+                    :0.5f*(after[axis]-p0[axis]);
+                center[axis]=h00*p0[axis]+h10*m0+h01*p1[axis]+h11*m1;
+                tangent[axis]=d00*p0[axis]+d10*m0+d01*p1[axis]+d11*m1;
+            }
+        };
+        std::array<float,3> center{},tangent{};
+        for(int refinement=0;refinement<2;++refinement)
+        {
+            evalCenterline(nearestProjection,center,tangent);
+            const float derivativeSquared=tangent[0]*tangent[0]+tangent[1]*tangent[1];
+            if(!(derivativeSquared>1.0e-10f))return std::numeric_limits<float>::infinity();
+            const float offsetX=center[0]-x,offsetY=center[1]-y;
+            nearestProjection=std::clamp(nearestProjection
+                -(offsetX*tangent[0]+offsetY*tangent[1])/derivativeSquared,0.0f,1.0f);
+        }
+        evalCenterline(nearestProjection,center,tangent);
+        const float tangentLength=std::sqrt(tangent[0]*tangent[0]
+            +tangent[1]*tangent[1]+tangent[2]*tangent[2]);
+        if(!(tangentLength>1.0e-8f))return std::numeric_limits<float>::infinity();
+        for(float& component:tangent)component/=tangentLength;
+        const float horizontalLength=std::sqrt(tangent[0]*tangent[0]
+            +tangent[1]*tangent[1]);
+        if(!(horizontalLength>1.0e-8f))return std::numeric_limits<float>::infinity();
+        const std::array<float,3> side={-tangent[1]/horizontalLength,
+            tangent[0]/horizontalLength,0.0f};
+        const std::array<float,3> up={-tangent[2]*side[1],tangent[2]*side[0],
+            tangent[0]*side[1]-tangent[1]*side[0]};
+        const std::array<float,3> relative={x-center[0],y-center[1],z-center[2]};
+        const auto dot=[&](const std::array<float,3>& axis)
+        {return relative[0]*axis[0]+relative[1]*axis[1]+relative[2]*axis[2];};
+        const float lateral=dot(side),vertical=dot(up);
+        if((nearestSegment==0&&nearestProjection<=0.0f)
+            ||(nearestSegment+2==path.size()&&nearestProjection>=1.0f))
+            return StampRoundedBoxSdf(dot(tangent),lateral,vertical,
+                {halfThickness+round,halfWidth,halfThickness},round);
+        const float qSide=std::abs(lateral)-halfWidth+round;
+        const float qUp=std::abs(vertical)-halfThickness+round;
+        const float outside=std::sqrt(std::max(qSide,0.0f)*std::max(qSide,0.0f)
+            +std::max(qUp,0.0f)*std::max(qUp,0.0f));
+        return outside+std::min(std::max(qSide,qUp),0.0f)-round;
+    }
     float StampSdf(const FStampRuntime& stamp,float x,float y,float z) const
     {
         float localX=x-stamp.positionVoxels[0];
@@ -7152,6 +7304,40 @@ private:
                     std::min(0.35f,std::min({stamp.halfExtentsVoxels[0],
                         stamp.halfExtentsVoxels[1],stamp.halfExtentsVoxels[2]})*0.15f));
             break;
+        case VoxelForgeCore::ResolvedSdfStampKindV1::fillSweptDeckSegment:
+        {
+            if(!stamp.sweepPathVoxels.empty())
+            {
+                distance=StampContinuousSweptDeckSdf(stamp,x,y,z);
+                break;
+            }
+            std::array<float,3> tangent{},side{},up{},delta{};
+            float lengthSquared=0.0f,horizontalSquared=0.0f;
+            for(std::size_t axis=0;axis<3;++axis)
+            {
+                delta[axis]=stamp.sweepEndpointsVoxels[1][axis]
+                    -stamp.sweepEndpointsVoxels[0][axis];
+                lengthSquared+=delta[axis]*delta[axis];
+                if(axis<2)horizontalSquared+=delta[axis]*delta[axis];
+            }
+            const float segmentLength=std::sqrt(lengthSquared);
+            const float horizontalLength=std::sqrt(horizontalSquared);
+            if(!(segmentLength>1.0e-5f&&horizontalLength>1.0e-5f))
+                return std::numeric_limits<float>::infinity();
+            for(std::size_t axis=0;axis<3;++axis)tangent[axis]=delta[axis]/segmentLength;
+            side={-delta[1]/horizontalLength,delta[0]/horizontalLength,0.0f};
+            up={-tangent[2]*side[1],tangent[2]*side[0],
+                tangent[0]*side[1]-tangent[1]*side[0]};
+            const std::array<float,3> offset={
+                x-stamp.positionVoxels[0],y-stamp.positionVoxels[1],z-stamp.positionVoxels[2]};
+            const auto dot=[&](const std::array<float,3>& axis)
+            {return offset[0]*axis[0]+offset[1]*axis[1]+offset[2]*axis[2];};
+            const float rounded=std::min(0.35f,
+                std::min(stamp.halfExtentsVoxels[1],stamp.halfExtentsVoxels[2])*0.15f);
+            distance=StampRoundedBoxSdf(dot(tangent),dot(side),dot(up),
+                stamp.halfExtentsVoxels,rounded);
+            break;
+        }
         default:return std::numeric_limits<float>::infinity();
         }
         if(stamp.irregularityAmplitudeVoxels>0.0f)
@@ -7163,6 +7349,15 @@ private:
 
     static double StampAbsMinimum(double minimum,double maximum)
     {return minimum<=0.0&&maximum>=0.0?0.0:std::min(std::abs(minimum),std::abs(maximum));}
+    static bool UsesCoarsePillarProxy(const FStampRuntime& stamp,std::int32_t sampleStep)
+    {
+        if(!stamp.record||stamp.record->kind
+                !=VoxelForgeCore::ResolvedSdfStampKindV1::fillPillar
+            ||sampleStep<=0||stamp.irregularityAmplitudeVoxels>0.0f)return false;
+        return static_cast<float>(sampleStep)>std::min(stamp.halfExtentsVoxels[0],
+                stamp.halfExtentsVoxels[1])
+            ||static_cast<float>(sampleStep)>stamp.halfExtentsVoxels[2];
+    }
     static double StampRoundedBoxSdfDouble(const std::array<double,3>& absolute,
         const std::array<double,3>& halfSize,double rounding)
     {
@@ -7247,7 +7442,9 @@ private:
             std::nextafter(maximum+outwardPadding,
                     std::numeric_limits<double>::infinity()),true};
     }
-    float ApplyResolvedSdfStamps(float density,float X,float Y,float Z) const
+    float ApplyResolvedSdfStamps(float density,float X,float Y,float Z,
+        std::string_view excludedStableIdPrefix={},
+        std::string_view includedStableIdPrefix={}) const
     {
         if(StampRuntime.empty()||!Owner||Owner->CoreVoxelSizeMicrons==0)return density;
         const auto* tileQueries=ActivePassageTileQueries;
@@ -7264,6 +7461,11 @@ private:
             if(index>=StampRuntime.size())return;
             const auto& runtime=StampRuntime[index];const auto& record=*runtime.record;
             if(record.strateIndex!=bound->StrateIndex)return;
+            if(!excludedStableIdPrefix.empty()
+                &&record.stableId.starts_with(excludedStableIdPrefix))return;
+            if(!includedStableIdPrefix.empty()
+                &&!record.stableId.starts_with(includedStableIdPrefix))return;
+            if(UsesCoarsePillarProxy(runtime,CurrentStampSamplingStep()))return;
             for(std::size_t axis=0;axis<3;++axis)
                 if(worldMicrometres[axis]<record.boundsMinimumMicrometres[axis]
                     ||worldMicrometres[axis]>record.boundsMaximumMicrometres[axis])return;
@@ -7281,6 +7483,154 @@ private:
                 apply(static_cast<std::uint32_t>(index));
         return composed;
     }
+
+public:
+    std::uint32_t AppendCoarsePillarProxies(FVoxelMeshData& mesh,
+        const FIntVector& tileOrigin,std::int32_t tileExtent,std::int32_t sampleStep) const
+    {
+        if(!Owner||Owner->CoreVoxelSizeMicrons==0||tileExtent<=0||sampleStep<=0
+            ||StampRuntime.empty())return 0;
+        constexpr int32 sideCount=24;
+        constexpr double TwoPi=6.2831853071795864769;
+        const int32 originalVertexCount=mesh.Vertices.Num();
+        const int32 originalSurfaceVertices=std::clamp(mesh.NumSurfaceVertices,0,
+            originalVertexCount);
+        const bool hasNormals=mesh.Normals.Num()==originalVertexCount;
+        const bool hasUvs=mesh.UVs.Num()==originalVertexCount;
+        const bool hasColors=mesh.Colors.Num()==originalVertexCount;
+        const double voxelCentimetres=Owner->CoreVoxelSizeMicrons/10000.0;
+        const std::int64_t tileMinimum[3]={tileOrigin.X,tileOrigin.Y,tileOrigin.Z};
+        const std::int64_t tileMaximum[3]={static_cast<std::int64_t>(tileOrigin.X)+tileExtent,
+            static_cast<std::int64_t>(tileOrigin.Y)+tileExtent,
+            static_cast<std::int64_t>(tileOrigin.Z)+tileExtent};
+        std::vector<int32> proxyIndices;
+        std::uint32_t proxyCount=0;
+        const auto addVertex=[&](const FVector& position,const FVector& normal,
+            const FVector2f& uv)
+        {
+            const int32 index=mesh.Vertices.Add(position);
+            if(hasNormals)mesh.Normals.Add(normal);
+            if(hasUvs)mesh.UVs.Add(uv);
+            if(hasColors)mesh.Colors.Add(FColor::White);
+            return index;
+        };
+        for(const auto& stamp:StampRuntime)
+        {
+            if(!UsesCoarsePillarProxy(stamp,sampleStep))continue;
+            const auto& center=stamp.positionVoxels;
+            if(center[0]<tileMinimum[0]||center[0]>=tileMaximum[0]
+                ||center[1]<tileMinimum[1]||center[1]>=tileMaximum[1]
+                ||center[2]<tileMinimum[2]||center[2]>=tileMaximum[2])continue;
+            const double radiusX=stamp.halfExtentsVoxels[0];
+            const double radiusY=stamp.halfExtentsVoxels[1];
+            const double bottomVoxel=center[2]-stamp.halfExtentsVoxels[2]-1.0;
+            const double topVoxel=center[2]+stamp.halfExtentsVoxels[2];
+            const auto point=[&](double angle,double z)
+            {
+                return FVector((center[0]+radiusX*std::cos(angle))*voxelCentimetres,
+                    (center[1]+radiusY*std::sin(angle))*voxelCentimetres,
+                    z*voxelCentimetres);
+            };
+            const int32 capTopCenter=addVertex(FVector(center[0]*voxelCentimetres,
+                center[1]*voxelCentimetres,topVoxel*voxelCentimetres),
+                FVector(0.0,0.0,1.0),FVector2f(0.5f,0.5f));
+            const int32 capBottomCenter=addVertex(FVector(center[0]*voxelCentimetres,
+                center[1]*voxelCentimetres,bottomVoxel*voxelCentimetres),
+                FVector(0.0,0.0,-1.0),FVector2f(0.5f,0.5f));
+            for(int32 sideIndex=0;sideIndex<sideCount;++sideIndex)
+            {
+                const double u0=static_cast<double>(sideIndex)/sideCount;
+                const double u1=static_cast<double>(sideIndex+1)/sideCount;
+                const double a0=TwoPi*u0,a1=TwoPi*u1;
+                const FVector n0=FVector(std::cos(a0)/radiusX,
+                    std::sin(a0)/radiusY,0.0).GetSafeNormal();
+                const FVector n1=FVector(std::cos(a1)/radiusX,
+                    std::sin(a1)/radiusY,0.0).GetSafeNormal();
+                const int32 bottomA=addVertex(point(a0,bottomVoxel),n0,FVector2f(u0,0.0f));
+                const int32 bottomB=addVertex(point(a1,bottomVoxel),n1,FVector2f(u1,0.0f));
+                const int32 topB=addVertex(point(a1,topVoxel),n1,FVector2f(u1,1.0f));
+                const int32 topA=addVertex(point(a0,topVoxel),n0,FVector2f(u0,1.0f));
+                proxyIndices.insert(proxyIndices.end(),{bottomA,bottomB,topB,
+                    bottomA,topB,topA});
+
+                const int32 topAIndex=addVertex(point(a0,topVoxel),FVector(0.0,0.0,1.0),
+                    FVector2f(static_cast<float>(0.5+0.5*std::cos(a0)),
+                        static_cast<float>(0.5+0.5*std::sin(a0))));
+                const int32 topBIndex=addVertex(point(a1,topVoxel),FVector(0.0,0.0,1.0),
+                    FVector2f(static_cast<float>(0.5+0.5*std::cos(a1)),
+                        static_cast<float>(0.5+0.5*std::sin(a1))));
+                proxyIndices.insert(proxyIndices.end(),{capTopCenter,topAIndex,topBIndex});
+
+                const int32 bottomAIndex=addVertex(point(a0,bottomVoxel),FVector(0.0,0.0,-1.0),
+                    FVector2f(static_cast<float>(0.5+0.5*std::cos(a0)),
+                        static_cast<float>(0.5+0.5*std::sin(a0))));
+                const int32 bottomBIndex=addVertex(point(a1,bottomVoxel),FVector(0.0,0.0,-1.0),
+                    FVector2f(static_cast<float>(0.5+0.5*std::cos(a1)),
+                        static_cast<float>(0.5+0.5*std::sin(a1))));
+                proxyIndices.insert(proxyIndices.end(),
+                    {capBottomCenter,bottomBIndex,bottomAIndex});
+            }
+            ++proxyCount;
+        }
+        if(proxyIndices.empty())return 0;
+        const int32 proxyVertexCount=mesh.Vertices.Num()-originalVertexCount;
+        const auto insertProxyVertices=[&](auto& values)
+        {
+            if(values.Num()!=originalVertexCount+proxyVertexCount)return;
+            using FArray=std::remove_reference_t<decltype(values)>;
+            FArray reordered;
+            reordered.Reserve(values.Num());
+            for(int32 index=0;index<originalSurfaceVertices;++index)
+                reordered.Add(values[index]);
+            for(int32 index=originalVertexCount;index<values.Num();++index)
+                reordered.Add(values[index]);
+            for(int32 index=originalSurfaceVertices;index<originalVertexCount;++index)
+                reordered.Add(values[index]);
+            values=MoveTemp(reordered);
+        };
+        insertProxyVertices(mesh.Vertices);
+        if(hasNormals)insertProxyVertices(mesh.Normals);
+        if(hasUvs)insertProxyVertices(mesh.UVs);
+        if(hasColors)insertProxyVertices(mesh.Colors);
+
+        const int32 oldTriangleCount=mesh.Triangles.Num()/3;
+        const int32 ceilingStart=std::max(0,mesh.Triangles.Num()-mesh.NumCeilingTriangles*3);
+        const int32 groundTriangleCount=ceilingStart/3;
+        const int32 proxyTriangleCount=static_cast<int32>(proxyIndices.size()/3);
+        TArray<int32> mergedIndices;
+        mergedIndices.Reserve(mesh.Triangles.Num()+static_cast<int32>(proxyIndices.size()));
+        for(int32 index=0;index<ceilingStart;++index)
+        {
+            const int32 oldIndex=mesh.Triangles[index];
+            mergedIndices.Add(oldIndex>=originalSurfaceVertices
+                ?oldIndex+proxyVertexCount:oldIndex);
+        }
+        for(const int32 index:proxyIndices)
+            mergedIndices.Add(originalSurfaceVertices+index-originalVertexCount);
+        for(int32 index=ceilingStart;index<mesh.Triangles.Num();++index)
+        {
+            const int32 oldIndex=mesh.Triangles[index];
+            mergedIndices.Add(oldIndex>=originalSurfaceVertices
+                ?oldIndex+proxyVertexCount:oldIndex);
+        }
+        mesh.Triangles=MoveTemp(mergedIndices);
+
+        TArray<uint8> mergedMasks;
+        mergedMasks.Reserve(oldTriangleCount+proxyTriangleCount);
+        for(int32 triangle=0;triangle<groundTriangleCount;++triangle)
+            mergedMasks.Add(mesh.TriangleSkirtFaceMasks.IsValidIndex(triangle)
+                ?mesh.TriangleSkirtFaceMasks[triangle]:0);
+        for(int32 triangle=0;triangle<proxyTriangleCount;++triangle)mergedMasks.Add(0);
+        if(groundTriangleCount<oldTriangleCount)
+            for(int32 triangle=groundTriangleCount;triangle<oldTriangleCount;++triangle)
+                mergedMasks.Add(mesh.TriangleSkirtFaceMasks.IsValidIndex(triangle)
+                    ?mesh.TriangleSkirtFaceMasks[triangle]:0);
+        mesh.TriangleSkirtFaceMasks=MoveTemp(mergedMasks);
+        mesh.NumSurfaceVertices=originalSurfaceVertices+proxyVertexCount;
+        return proxyCount;
+    }
+
+private:
     float ApplyResolvedCavernGraph(float density,float X,float Y,float Z,
         float* nativeFloorSupport=nullptr) const
     {

Standalone/Core/src/VoxelForgeCore.cpp

@@ -2889,12 +2889,16 @@ namespace VoxelForgeCore
             VoxelForgeCore::Heightfield2D::threadColumnCacheStats().columnComputeMilliseconds;
         const auto MarchingCubesStart=std::chrono::steady_clock::now();
         FVoxelUniformBlockProofAuditStats BlockProofAudit;
-        FVoxelMeshData mesh=mesher.GenerateMesh(origin,MeshStep,MeshCells,nullptr,
+        FVoxelMeshData mesh;
-            MeshBandMinZVoxel,MeshBandMaxZVoxel,&sampleCount,nullptr,nullptr,
+        {
-            (options.hashDensity||options.captureDensitySamples)?&densityValues:nullptr,
+            FStandaloneShapeWorld::FScopedStampSamplingStep stampSamplingStep(MeshStep);
-            options.profileMesherStages?&McStageTimings:nullptr,
+            mesh=mesher.GenerateMesh(origin,MeshStep,MeshCells,nullptr,
-            options.auditUniformBlockProofs?&BlockProofAudit:nullptr,
+                MeshBandMinZVoxel,MeshBandMaxZVoxel,&sampleCount,nullptr,nullptr,
-            options.forceFullDensityCapture);
+                (options.hashDensity||options.captureDensitySamples)?&densityValues:nullptr,
+                options.profileMesherStages?&McStageTimings:nullptr,
+                options.auditUniformBlockProofs?&BlockProofAudit:nullptr,
+                options.forceFullDensityCapture);
+        }
         passageFeatureScope.copySweptTubeRuntimeCounts();
         if(options.auditUniformBlockProofs)
         {
@@ -3107,6 +3111,13 @@ namespace VoxelForgeCore
             AppendStratumBoundaryFloors(world,farShape,nativeKey,step,mesh);
             AppendStratumBoundaryCeilings(world,farShape,nativeKey,step,mesh);
         }
+        const std::uint32_t coarsePillarProxyCount=tileShape.AppendCoarsePillarProxies(
+            mesh,origin,extent,MeshStep);
+        if(coarsePillarProxyCount>0)
+            std::printf("[CoarsePillarProxy] key=(%d,%d,%d,lod%d) sampling_step_vox=%d "
+                "pillars=%u mode=exact_capped_cylinder status=EMITTED\n",
+                key.coordinate.x,key.coordinate.y,key.coordinate.z,key.lod,MeshStep,
+                coarsePillarProxyCount);
         l77RefineStage.Restore();
 
         out.densitySampleCount=static_cast<std::uint64_t>(std::max<int64>(0,sampleCount));

Standalone/Core/src/WorldAssemblerInternal.h

@@ -539,6 +539,37 @@ namespace world_assembly_detail
             if (squared == 0)
             { error = "world assembly route contains a zero-length segment"; return false; }
         }
+        const auto& liminal = stratum.liminalField;
+        if (liminal.version != 0)
+        {
+            if (liminal.version != CoreLiminalFieldRecipeVersionV1
+                || static_cast<std::uint32_t>(liminal.variant) >= CoreLiminalFieldVariantCountV1
+                || liminal.seed != effectiveRecipe.seed
+                || liminal.variant != SelectCoreLiminalFieldVariantV1(liminal.seed)
+                || stratum.route.size() < 2
+                || liminal.mouthFloorOffsetSubvoxels <= 0
+                || stratum.route.front().positionSubvoxels[0] != liminal.arrivalMouthSubvoxels[0]
+                || stratum.route.front().positionSubvoxels[1] != liminal.arrivalMouthSubvoxels[1]
+                || stratum.route.front().positionSubvoxels[2]
+                    != liminal.arrivalMouthSubvoxels[2]-liminal.mouthFloorOffsetSubvoxels
+                || stratum.route.back().positionSubvoxels[0] != liminal.departureMouthSubvoxels[0]
+                || stratum.route.back().positionSubvoxels[1] != liminal.departureMouthSubvoxels[1]
+                || stratum.route.back().positionSubvoxels[2]
+                    != liminal.departureMouthSubvoxels[2]-liminal.mouthFloorOffsetSubvoxels
+                || liminal.routeHalfWidthSubvoxels < stratum.routeConstraints.capsuleRadiusSubvoxels
+                || liminal.routeHalfThicknessSubvoxels <= 0
+                || liminal.routeOffsetSubvoxels <= 0
+                || liminal.supportSpacingSubvoxels <= 0
+                || liminal.supportRadiusSubvoxels <= 0
+                || stratum.surfaceProfile.version != 1)
+            { error = "Core.Liminal.Field plan has invalid version, seed-selected variant, route mouths or dimensions"; return false; }
+            const std::int64_t bottom = static_cast<std::int64_t>(stratum.bottomChunkZ)
+                * layoutChunkWidthSubvoxels;
+            const std::int64_t top = (static_cast<std::int64_t>(stratum.topChunkZ) + 1)
+                * layoutChunkWidthSubvoxels;
+            if (liminal.floorHeightSubvoxels <= bottom || liminal.floorHeightSubvoxels >= top)
+            { error = "Core.Liminal.Field floor escapes its finite stratum bounds"; return false; }
+        }
         const auto& constraints = stratum.routeConstraints;
         if (constraints.version == 0)
         {
@@ -682,6 +713,24 @@ namespace world_assembly_detail
             for (const auto value : point.positionSubvoxels) HashWord(hash, static_cast<std::uint64_t>(value), 8);
             HashWord(hash, static_cast<std::uint64_t>(point.radiusSubvoxels), 8);
         }
+        if (stratum.liminalField.version != 0)
+        {
+            const auto& liminal = stratum.liminalField;
+            HashWord(hash, 0x4c494d494e414c31ull, 8);
+            HashWord(hash, liminal.version, 4);
+            HashWord(hash, static_cast<std::uint32_t>(liminal.variant), 4);
+            HashWord(hash, liminal.seed, 4);
+            for (const auto value : liminal.arrivalMouthSubvoxels)
+                HashWord(hash, static_cast<std::uint64_t>(value), 8);
+            for (const auto value : liminal.departureMouthSubvoxels)
+                HashWord(hash, static_cast<std::uint64_t>(value), 8);
+            for (const auto value : {liminal.mouthFloorOffsetSubvoxels,
+                liminal.floorHeightSubvoxels,
+                liminal.routeHalfWidthSubvoxels, liminal.routeHalfThicknessSubvoxels,
+                liminal.routeOffsetSubvoxels, liminal.supportSpacingSubvoxels,
+                liminal.supportRadiusSubvoxels})
+                HashWord(hash, static_cast<std::uint64_t>(value), 8);
+        }
         if (stratum.surfaceProfile.version != 0)
             HashSurfaceProfile(hash, stratum.surfaceProfile);
         return hash;
@@ -1059,6 +1108,30 @@ namespace world_assembly_detail
                 { error = "world assembly route point is missing a fixed-scale field"; return false; }
                 stratum.route.push_back(point);
             }
+            const VFJson::Value& liminalValue = item.Get("liminal_field");
+            if (!std::holds_alternative<std::nullptr_t>(liminalValue.Data))
+            {
+                auto& liminal = stratum.liminalField;
+                std::uint32_t variant = 0;
+                if (!liminalValue.IsObject()
+                    || !ReadU32(liminalValue.Get("version"), liminal.version)
+                    || !ReadU32(liminalValue.Get("variant"), variant)
+                    || !ReadU32(liminalValue.Get("seed"), liminal.seed)
+                    || !ReadArray(liminalValue.Get("arrival_mouth_q"),
+                        liminal.arrivalMouthSubvoxels.data(), 3)
+                    || !ReadArray(liminalValue.Get("departure_mouth_q"),
+                        liminal.departureMouthSubvoxels.data(), 3)
+                    || !ReadInteger(liminalValue.Get("mouth_floor_offset_q"),
+                        liminal.mouthFloorOffsetSubvoxels)
+                    || !ReadInteger(liminalValue.Get("floor_height_q"), liminal.floorHeightSubvoxels)
+                    || !ReadInteger(liminalValue.Get("route_half_width_q"), liminal.routeHalfWidthSubvoxels)
+                    || !ReadInteger(liminalValue.Get("route_half_thickness_q"), liminal.routeHalfThicknessSubvoxels)
+                    || !ReadInteger(liminalValue.Get("route_offset_q"), liminal.routeOffsetSubvoxels)
+                    || !ReadInteger(liminalValue.Get("support_spacing_q"), liminal.supportSpacingSubvoxels)
+                    || !ReadInteger(liminalValue.Get("support_radius_q"), liminal.supportRadiusSubvoxels))
+                { error = "Core.Liminal.Field plan is missing a fixed-scale field"; return false; }
+                liminal.variant = static_cast<WorldAssemblyLiminalVariantV1>(variant);
+            }
             plan.strates.push_back(std::move(stratum));
         }
         return true;
@@ -2324,6 +2397,328 @@ bool WorldAssemblyManifest::validate(std::string& error) const
     return true;
 }
 
+bool PlanCoreLiminalFieldV1(WorldAssemblyRecipeV1& recipe,
+    WorldAssemblyStratumPlanV1& stratum,const ResolvedLayoutSnapshotV3& layout,
+    std::string& error)
+{
+    error.clear();
+    if(layout.coreVoxelSizeMicrometres==0||stratum.strateIndex<0
+        ||stratum.topChunkZ<stratum.bottomChunkZ)
+    {error="Core.Liminal.Field needs a finite stratum and resolved Core voxel size";return false;}
+    const auto resolvedStratum=std::find_if(layout.strates.begin(),layout.strates.end(),
+        [&](const auto& value){return value.strateIndex==stratum.strateIndex
+            &&value.generatorKind=="SurfaceWorld";});
+    if(resolvedStratum==layout.strates.end()||!resolvedStratum->content.presentInCurrentField)
+    {error="Core.Liminal.Field must target a resolved SurfaceWorld content band";return false;}
+    const ResolvedLayoutPassageV1* arrival=nullptr;
+    const ResolvedLayoutPassageV1* departure=nullptr;
+    for(const auto& passage:layout.passages)
+    {
+        if(passage.lowerStrateIndex==stratum.strateIndex)
+        {
+            if(arrival){error="Core.Liminal.Field requires one fixed arrival passage mouth";return false;}
+            arrival=&passage;
+        }
+        if(passage.upperStrateIndex==stratum.strateIndex)
+        {
+            if(departure){error="Core.Liminal.Field requires one fixed departure passage mouth";return false;}
+            departure=&passage;
+        }
+    }
+    if(!arrival||!departure)
+    {error="Core.Liminal.Field requires an adjacent passage on both sides";return false;}
+
+    constexpr std::int64_t Q=WorldAssemblySubvoxelsPerVoxel;
+    const std::int64_t coreMicrons=layout.coreVoxelSizeMicrometres;
+    const auto micrometresToQ=[&](std::int64_t micrometres)
+    {
+        const std::int64_t numerator=micrometres*Q;
+        return numerator>=0?(numerator+coreMicrons/2)/coreMicrons
+            :(numerator-coreMicrons/2)/coreMicrons;
+    };
+    const std::int64_t qPerMetre=micrometresToQ(1000000);
+    if(qPerMetre<=0){error="Core.Liminal.Field could not resolve fixed-scale metres";return false;}
+
+    const std::uint32_t seed=recipe.seed;
+    const WorldAssemblyLiminalVariantV1 variant=SelectCoreLiminalFieldVariantV1(seed);
+    const auto& definition=CoreLiminalFieldVariantsV1[static_cast<std::size_t>(variant)];
+    const auto& start=arrival->lowerMouthSubvoxels;
+    const auto& finish=departure->upperMouthSubvoxels;
+    constexpr std::int64_t MaximumMouthCoordinateQ=1000000000ll;
+    if(std::abs(start[0])>MaximumMouthCoordinateQ||std::abs(start[1])>MaximumMouthCoordinateQ
+        ||std::abs(start[2])>MaximumMouthCoordinateQ||std::abs(finish[0])>MaximumMouthCoordinateQ
+        ||std::abs(finish[1])>MaximumMouthCoordinateQ||std::abs(finish[2])>MaximumMouthCoordinateQ)
+    {error="Core.Liminal.Field passage mouth exceeds the supported fixed-coordinate range";return false;}
+    const std::int64_t mouthPlayerCenterHeight=micrometresToQ(1130000);
+    auto routeStart=start;
+    auto routeFinish=finish;
+    routeStart[2]-=mouthPlayerCenterHeight;
+    routeFinish[2]-=mouthPlayerCenterHeight;
+    const auto findMouthControl=[&](const ResolvedLayoutPassageV1& passage,
+        const std::array<std::int64_t,3>& mouth)
+    {
+        std::size_t found=passage.controlPoints.size();
+        for(std::size_t i=0;i<passage.controlPoints.size();++i)
+        {
+            const auto& point=passage.controlPoints[i];
+            if(point.positionSubvoxels[0]==mouth[0]
+                &&point.positionSubvoxels[1]==mouth[1]
+                &&point.positionSubvoxels[2]-point.radiusSubvoxels
+                    +mouthPlayerCenterHeight==mouth[2])
+            {
+                if(found!=passage.controlPoints.size())return passage.controlPoints.size();
+                found=i;
+            }
+        }
+        return found;
+    };
+    const std::size_t arrivalControl=findMouthControl(*arrival,start);
+    const std::size_t departureControl=findMouthControl(*departure,finish);
+    if(arrival->controlPoints.size()<2||departure->controlPoints.size()<2
+        ||arrivalControl>=arrival->controlPoints.size()
+        ||departureControl>=departure->controlPoints.size())
+    {error="Core.Liminal.Field needs exact passage-control bindings at both fixed mouths";return false;}
+    const auto horizontalLengthQ=[](std::int64_t dx,std::int64_t dy)
+    {
+        const auto absX=static_cast<std::uint64_t>(std::abs(dx));
+        const auto absY=static_cast<std::uint64_t>(std::abs(dy));
+        return world_assembly_detail::IntegerSqrt(absX*absX+absY*absY);
+    };
+    const auto roundRatio=[](std::int64_t numerator,std::uint64_t denominator)
+    {
+        if(denominator==0)return std::int64_t{0};
+        const auto positiveDenominator=static_cast<std::int64_t>(denominator);
+        return numerator>=0
+            ?(numerator+positiveDenominator/2)/positiveDenominator
+            :-((-numerator+positiveDenominator/2)/positiveDenominator);
+    };
+    const auto passageSplineControls=[](const ResolvedLayoutPassageV1& passage)
+    {
+        std::vector<PassageSpline::FPoint> controls;
+        controls.reserve(passage.controlPoints.size());
+        for(const auto& point:passage.controlPoints)
+            controls.push_back({static_cast<double>(point.positionSubvoxels[0]),
+                static_cast<double>(point.positionSubvoxels[1]),
+                static_cast<double>(point.positionSubvoxels[2]-point.radiusSubvoxels),
+                static_cast<double>(point.radiusSubvoxels)});
+        return controls;
+    };
+    const auto arrivalSpline=passageSplineControls(*arrival);
+    const auto departureSpline=passageSplineControls(*departure);
+    constexpr double MouthTangentProbeParameter=0.5;
+    const std::size_t arrivalSegment=arrivalControl==0?0:arrivalControl-1;
+    const double arrivalAtT=arrivalControl==0?0.0:1.0;
+    const double arrivalNearT=arrivalControl==0?MouthTangentProbeParameter
+        :1.0-MouthTangentProbeParameter;
+    const auto arrivalNear=PassageSpline::EvaluateRaw(arrivalSpline,arrivalSegment,
+        arrivalNearT,static_cast<double>(qPerMetre));
+    const auto arrivalAt=PassageSpline::EvaluateRaw(arrivalSpline,arrivalSegment,
+        arrivalAtT,static_cast<double>(qPerMetre));
+    const std::size_t departureSegment=departureControl+1==departure->controlPoints.size()
+        ?departureControl-1:departureControl;
+    const double departureAtT=departureControl+1==departure->controlPoints.size()?1.0:0.0;
+    const double departureNearT=departureControl+1==departure->controlPoints.size()
+        ?1.0-MouthTangentProbeParameter:MouthTangentProbeParameter;
+    const auto departureAt=PassageSpline::EvaluateRaw(departureSpline,departureSegment,
+        departureAtT,static_cast<double>(qPerMetre));
+    const auto departureNear=PassageSpline::EvaluateRaw(departureSpline,departureSegment,
+        departureNearT,static_cast<double>(qPerMetre));
+    const auto roundedDelta=[](double startValue,double endValue)
+    {return static_cast<std::int64_t>(std::llround(endValue-startValue));};
+    const std::int64_t arrivalDx=roundedDelta(arrivalNear[0],arrivalAt[0]);
+    const std::int64_t arrivalDy=roundedDelta(arrivalNear[1],arrivalAt[1]);
+    const std::int64_t arrivalFloorDelta=roundedDelta(arrivalNear[2],arrivalAt[2]);
+    const std::uint64_t arrivalLength=horizontalLengthQ(arrivalDx,arrivalDy);
+    const std::int64_t departureDx=roundedDelta(departureAt[0],departureNear[0]);
+    const std::int64_t departureDy=roundedDelta(departureAt[1],departureNear[1]);
+    const std::int64_t departureFloorDelta=roundedDelta(departureAt[2],departureNear[2]);
+    const std::uint64_t departureLength=horizontalLengthQ(departureDx,departureDy);
+    if(arrivalLength==0||departureLength==0)
+    {error="Core.Liminal.Field passage mouth tangent is too short for a stable connector";return false;}
+    const auto extendMouth=[&](const std::array<std::int64_t,3>& mouth,
+        std::int64_t dx,std::int64_t dy,std::int64_t dz,std::uint64_t horizontalLength,
+        std::int64_t distance,bool forward)
+    {
+        const std::int64_t sign=forward?1:-1;
+        return std::array<std::int64_t,3>{
+            mouth[0]+roundRatio(sign*dx*distance,horizontalLength),
+            mouth[1]+roundRatio(sign*dy*distance,horizontalLength),
+            mouth[2]+roundRatio(sign*dz*distance,horizontalLength)};
+    };
+    constexpr std::int64_t MouthConnectorMidMetres=5;
+    constexpr std::int64_t MouthConnectorFullMetres=10;
+    const auto arrivalConnectorMid=extendMouth(routeStart,arrivalDx,arrivalDy,
+        arrivalFloorDelta,arrivalLength,MouthConnectorMidMetres*qPerMetre,true);
+    const auto arrivalConnector=extendMouth(routeStart,arrivalDx,arrivalDy,
+        arrivalFloorDelta,arrivalLength,MouthConnectorFullMetres*qPerMetre,true);
+    const auto departureConnector=extendMouth(routeFinish,departureDx,departureDy,
+        departureFloorDelta,departureLength,MouthConnectorFullMetres*qPerMetre,false);
+    const auto departureConnectorMid=extendMouth(routeFinish,departureDx,departureDy,
+        departureFloorDelta,departureLength,MouthConnectorMidMetres*qPerMetre,false);
+    const std::int64_t bottom=static_cast<std::int64_t>(stratum.bottomChunkZ)
+        *recipe.layoutChunkWidthSubvoxels;
+    const std::int64_t top=(static_cast<std::int64_t>(stratum.topChunkZ)+1)
+        *recipe.layoutChunkWidthSubvoxels;
+    const std::int64_t minRouteFloor=std::min({routeStart[2],routeFinish[2],
+        arrivalConnectorMid[2],arrivalConnector[2],departureConnector[2],
+        departureConnectorMid[2]});
+    const std::int64_t contentBottom=micrometresToQ(
+        resolvedStratum->content.bottomMicrometres);
+    const std::int64_t profileRelief=variant==WorldAssemblyLiminalVariantV1::repeatingHills
+        ?2*micrometresToQ(definition.hillAmplitudeMicrometres):0;
+    const std::int64_t floorHeight=std::max(contentBottom+profileRelief+qPerMetre/4,
+        minRouteFloor-8*qPerMetre);
+    if(floorHeight>=minRouteFloor-2*qPerMetre||floorHeight<=bottom||top<=floorHeight+8*qPerMetre)
+    {error="Core.Liminal.Field has no room for its floor and passage route";return false;}
+
+    stratum.hasRecipeOverride=true;
+    stratum.recipeOverride=recipe;
+    WorldAssemblySurfaceProfileV1 profile;
+    profile.version=1;
+    profile.kind=definition.surfaceKind;
+    profile.h0Subvoxels=floorHeight;
+    if(profile.kind==WorldAssemblySurfaceProfileKindV1::periodicHills)
+    {
+        profile.amplitudeXSubvoxels=micrometresToQ(definition.hillAmplitudeMicrometres);
+        profile.amplitudeYSubvoxels=profile.amplitudeXSubvoxels;
+        profile.wavelengthXSubvoxels=micrometresToQ(definition.hillWavelengthMicrometres);
+        profile.wavelengthYSubvoxels=profile.wavelengthXSubvoxels;
+        ResolveWorldAssemblySurfaceProfilePhasesV1(profile,seed);
+    }
+    stratum.recipeOverride.surfaceProfile=profile;
+    stratum.recipeOverride.contentHash=0;
+    stratum.surfaceProfile=profile;
+    stratum.capHeightSubvoxels=top-4*qPerMetre;
+    stratum.capUndulationSubvoxels=0;
+    stratum.capDetailAmplitudeSubvoxels=0;
+    stratum.capRidgeAmplitudeSubvoxels=0;
+    stratum.waterEnabled=false;
+    stratum.waterSurfaceSubvoxels=0;
+
+    WorldAssemblyLiminalFieldPlanV1 liminal;
+    liminal.version=CoreLiminalFieldRecipeVersionV1;
+    liminal.variant=variant;
+    liminal.seed=seed;
+    liminal.arrivalMouthSubvoxels=start;
+    liminal.departureMouthSubvoxels=finish;
+    liminal.floorHeightSubvoxels=floorHeight;
+    liminal.routeHalfWidthSubvoxels=micrometresToQ(definition.routeHalfWidthMicrometres);
+    liminal.routeHalfThicknessSubvoxels=micrometresToQ(definition.routeHalfThicknessMicrometres);
+    liminal.supportSpacingSubvoxels=micrometresToQ(definition.supportSpacingMicrometres);
+    liminal.supportRadiusSubvoxels=micrometresToQ(definition.supportRadiusMicrometres);
+    liminal.mouthFloorOffsetSubvoxels=mouthPlayerCenterHeight;
+
+    constexpr std::int64_t GradeQ16=17560;
+    constexpr std::int64_t MinimumPathOffsetMetres=150;
+    constexpr std::int64_t ConnectorSpanMetres=16;
+    const std::int64_t dx=departureConnector[0]-arrivalConnector[0];
+    const std::int64_t dy=departureConnector[1]-arrivalConnector[1];
+    const std::uint64_t chord=horizontalLengthQ(dx,dy);
+    std::int64_t directionX=dx,directionY=dy;
+    std::uint64_t directionLength=chord;
+    if(directionLength<static_cast<std::uint64_t>(qPerMetre/4))
+    {directionX=Q;directionY=0;directionLength=static_cast<std::uint64_t>(Q);}
+    const std::int64_t normalX=-directionY;
+    const std::int64_t normalY=directionX;
+    const std::int64_t vertical=std::abs(departureConnector[2]-arrivalConnector[2]);
+    const std::int64_t requiredHorizontal=(vertical*65536+GradeQ16-1)/GradeQ16;
+    std::int64_t routeOffset=std::max(MinimumPathOffsetMetres*qPerMetre,
+        (requiredHorizontal+1)/2+20*qPerMetre);
+    if(chord<ConnectorSpanMetres*static_cast<std::uint64_t>(qPerMetre))
+        routeOffset=std::max(routeOffset,MinimumPathOffsetMetres*qPerMetre);
+    liminal.routeOffsetSubvoxels=routeOffset;
+
+    const auto normalOffset=[&](std::int64_t scale)
+    {
+        return std::array<std::int64_t,2>{
+            normalX*scale/static_cast<std::int64_t>(directionLength),
+            normalY*scale/static_cast<std::int64_t>(directionLength)};
+    };
+    const auto directionOffset=[&](std::int64_t scale)
+    {
+        return std::array<std::int64_t,2>{
+            directionX*scale/static_cast<std::int64_t>(directionLength),
+            directionY*scale/static_cast<std::int64_t>(directionLength)};
+    };
+    const auto normal=normalOffset(routeOffset);
+    const auto connector=chord<ConnectorSpanMetres*static_cast<std::uint64_t>(qPerMetre)
+        ?directionOffset(ConnectorSpanMetres*qPerMetre):std::array<std::int64_t,2>{0,0};
+    std::vector<std::array<std::int64_t,3>> horizontalPath;
+    horizontalPath.reserve(8);
+    horizontalPath.push_back(routeStart);
+    horizontalPath.push_back(arrivalConnectorMid);
+    horizontalPath.push_back(arrivalConnector);
+    horizontalPath.push_back({arrivalConnector[0]+normal[0],
+        arrivalConnector[1]+normal[1],0});
+    horizontalPath.push_back({departureConnector[0]+normal[0]+connector[0],
+        departureConnector[1]+normal[1]+connector[1],0});
+    horizontalPath.push_back(departureConnector);
+    horizontalPath.push_back(departureConnectorMid);
+    horizontalPath.push_back(routeFinish);
+
+    std::vector<WorldAssemblyRoutePointV1> route;
+    route.reserve(horizontalPath.size());
+    std::vector<std::uint64_t> cumulative(horizontalPath.size(),0);
+    std::uint64_t totalHorizontal=0;
+    for(std::size_t i=1;i<horizontalPath.size();++i)
+    {
+        const std::int64_t sx=horizontalPath[i][0]-horizontalPath[i-1][0];
+        const std::int64_t sy=horizontalPath[i][1]-horizontalPath[i-1][1];
+        const std::uint64_t segment=horizontalLengthQ(sx,sy);
+        if(segment==0){error="Core.Liminal.Field route contains a zero-horizontal segment";return false;}
+        totalHorizontal+=segment;
+        cumulative[i]=totalHorizontal;
+    }
+    if(totalHorizontal<static_cast<std::uint64_t>(requiredHorizontal))
+    {error="Core.Liminal.Field route cannot meet the 15-degree grade bound";return false;}
+    const std::uint64_t centralFirst=horizontalLengthQ(
+        horizontalPath[3][0]-horizontalPath[2][0],
+        horizontalPath[3][1]-horizontalPath[2][1]);
+    const std::uint64_t centralMiddle=horizontalLengthQ(
+        horizontalPath[4][0]-horizontalPath[3][0],
+        horizontalPath[4][1]-horizontalPath[3][1]);
+    const std::uint64_t centralLast=horizontalLengthQ(
+        horizontalPath[5][0]-horizontalPath[4][0],
+        horizontalPath[5][1]-horizontalPath[4][1]);
+    const std::uint64_t centralTotal=centralFirst+centralMiddle+centralLast;
+    if(centralTotal==0)
+    {error="Core.Liminal.Field central route has no horizontal span";return false;}
+    const std::int64_t centralVertical=departureConnector[2]-arrivalConnector[2];
+    horizontalPath[3][2]=arrivalConnector[2]+roundRatio(
+        centralVertical*static_cast<std::int64_t>(centralFirst),centralTotal);
+    horizontalPath[4][2]=arrivalConnector[2]+roundRatio(
+        centralVertical*static_cast<std::int64_t>(centralFirst+centralMiddle),centralTotal);
+    for(std::size_t i=0;i<horizontalPath.size();++i)
+    {
+        auto point=horizontalPath[i];
+        WorldAssemblyRoutePointV1 routePoint;
+        routePoint.positionSubvoxels=point;
+        routePoint.radiusSubvoxels=std::max<std::int64_t>(liminal.routeHalfWidthSubvoxels,
+            micrometresToQ(500000));
+        std::uint64_t id=14695981039346656037ull;
+        const auto add=[&](std::uint64_t value,std::uint32_t bytes)
+        {for(std::uint32_t byte=0;byte<bytes;++byte){id^=static_cast<std::uint8_t>(value>>(byte*8));id*=1099511628211ull;}};
+        add(seed,4);add(static_cast<std::uint32_t>(stratum.strateIndex),4);add(i,4);
+        routePoint.stableFeatureId=id?id:1;
+        route.push_back(routePoint);
+    }
+    stratum.route=std::move(route);
+    stratum.routeConstraints={1,micrometresToQ(340000),micrometresToQ(1760000),
+        GradeQ16,micrometresToQ(125000),micrometresToQ(250000),
+        micrometresToQ(1000000),micrometresToQ(120000),3};
+    stratum.liminalField=liminal;
+    std::string validationError;
+    if(!world_assembly_detail::ValidateSurfaceProfile(stratum.surfaceProfile,seed,validationError)
+        ||!world_assembly_detail::ValidateStratum(stratum,recipe,validationError))
+    {error=validationError.empty()?"Core.Liminal.Field produced an invalid plan":validationError;return false;}
+    std::printf("[CoreLiminalFieldPlan] recipe=%.*s version=%u variant=%.*s seed=%u arrival=%s departure=%s route_points=%zu route_offset_m=%.3f route_grade_limit_deg=15.000 status=PASS\n",
+        static_cast<int>(CoreLiminalFieldRecipeIdV1.size()),CoreLiminalFieldRecipeIdV1.data(),
+        liminal.version,static_cast<int>(definition.name.size()),definition.name.data(),seed,
+        arrival->stableId.c_str(),departure->stableId.c_str(),stratum.route.size(),
+        static_cast<double>(routeOffset)/qPerMetre);
+    return true;
+}
+
 std::string WorldAssemblyManifest::ToJson() const
 {
     std::string error;
@@ -2391,6 +2786,27 @@ std::string WorldAssemblyManifest::ToJson() const
                 << ",\"minimum_clearance_q\":" << constraints.minimumClearanceSubvoxels
                 << ",\"minimum_support_probes\":" << constraints.minimumSupportProbes << '}';
         }
+        if (stratum.liminalField.version != 0)
+        {
+            const auto& liminal = stratum.liminalField;
+            out << ",\"liminal_field\":{\"version\":" << liminal.version
+                << ",\"variant\":" << static_cast<std::uint32_t>(liminal.variant)
+                << ",\"seed\":" << liminal.seed << ",\"arrival_mouth_q\":["
+                << liminal.arrivalMouthSubvoxels[0] << ','
+                << liminal.arrivalMouthSubvoxels[1] << ','
+                << liminal.arrivalMouthSubvoxels[2] << "],\"departure_mouth_q\":["
+                << liminal.departureMouthSubvoxels[0] << ','
+                << liminal.departureMouthSubvoxels[1] << ','
+                << liminal.departureMouthSubvoxels[2]
+                << "],\"mouth_floor_offset_q\":" << liminal.mouthFloorOffsetSubvoxels
+                << ",\"floor_height_q\":"
+                << liminal.floorHeightSubvoxels
+                << ",\"route_half_width_q\":" << liminal.routeHalfWidthSubvoxels
+                << ",\"route_half_thickness_q\":" << liminal.routeHalfThicknessSubvoxels
+                << ",\"route_offset_q\":" << liminal.routeOffsetSubvoxels
+                << ",\"support_spacing_q\":" << liminal.supportSpacingSubvoxels
+                << ",\"support_radius_q\":" << liminal.supportRadiusSubvoxels << '}';
+        }
         out << ",\"route\":[";
         for (std::size_t p = 0; p < stratum.route.size(); ++p)
         {

Standalone/Research/WorldAssemblerM3/Linux141/BuildL141Fixtures.py

@@ -0,0 +1,84 @@
+#!/usr/bin/env python3
+"""Build three standalone liminal SurfaceWorld fixtures from the owner input."""
+from __future__ import annotations
+
+import argparse
+import json
+import os
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OWNER = Path(os.environ.get("VOXELFORGE_OWNER_DATA",
+                            ROOT / "Standalone/data/owner_world.json"))
+OUT_DEFAULT = Path(os.environ.get("VOXELFORGE_VERIFY_OUT", ROOT / "Saved/Linux/l141"))
+
+FLAT_FIELD = {
+    "version": 1,
+    "kind": "flatField",
+    "minimum_arena_clearance_m": 0.0,
+}
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--out", type=Path, default=OUT_DEFAULT / "fixtures")
+    args = parser.parse_args()
+    args.out.mkdir(parents=True, exist_ok=True)
+    base = json.loads(OWNER.read_text(encoding="utf-8"))
+
+    flat = dict(base)
+    flat["surface_profile_override"] = dict(FLAT_FIELD)
+    flat["motif_family_override"] = {
+        "version": 1,
+        "strate_index": 0,
+        "placement_policy": "seed,strate,stable_id",
+        "motifs": [
+            {
+                "stable_id": "liminal/oversized-familiar-monolith-v1",
+                "kind": "cappedCylinder",
+                "radius_m": 1.6,
+                "height_m": 26.0,
+                "route_side_offset_m": 42.0,
+                "placement_radius_m": 0.0,
+                "fillet_radius_m": 0.6,
+                "blend_width_m": 1.2,
+                "minimum_spacing_m": 0.0,
+                "yaw_quarter_turns": 0,
+                "attachment": "seated_floor",
+            },
+        ],
+    }
+
+    hills = dict(base)
+    hills["surface_profile_override"] = {
+        "version": 1,
+        "kind": "periodicHills",
+        "amplitude_x_m": 2.2,
+        "amplitude_y_m": 2.2,
+        "wavelength_x_m": 80.0,
+        "wavelength_y_m": 80.0,
+        "minimum_arena_clearance_m": 0.0,
+    }
+
+    road = dict(base)
+    road["surface_profile_override"] = dict(FLAT_FIELD)
+    road["liminal_road_override"] = {
+        "stable_id": "liminal/raised-road-v1",
+        "strate_index": 0,
+        "position_xy_m": [240.0, 180.0],
+        "half_extents_m": [32.5, 3.0, 0.75],
+        "deck_height_above_field_m": 22.0,
+        "yaw_quarter_turns": 0,
+    }
+
+    for name, fixture in (("flatField-monolith", flat),
+                          ("periodicHills", hills),
+                          ("raised-road", road)):
+        path = args.out / f"liminal-{name}.json"
+        path.write_text(json.dumps(fixture, indent=2) + "\n", encoding="utf-8")
+        print(f"[L141Fixture] name={name} file={path} status=PASS")
+
+
+if __name__ == "__main__":
+    main()

Standalone/Research/WorldAssemblerM3/Linux141/CaptureL141.py

@@ -0,0 +1,389 @@
+#!/usr/bin/env python3
+"""Run L141 prototype determinism checks and create eye-level/wide captures."""
+from __future__ import annotations
+
+import argparse
+import hashlib
+import json
+import math
+import os
+from pathlib import Path
+import re
+import subprocess
+import sys
+import time
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT_DEFAULT = Path(os.environ.get("VOXELFORGE_VERIFY_OUT", ROOT / "Saved/Linux/l141"))
+CAPTURE_DEFAULT = Path(__file__).resolve().parent / "captures"
+LIMIT = ["taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--"]
+Q_PER_METRE = 1024.0
+FOG_COLOR = "0.66,0.73,0.77"
+
+sys.path.insert(0, str(ROOT / "Standalone/Tools/verify"))
+from runner import bounded_run, current_stamp, first_stamp
+
+
+def fmt(values) -> str:
+    return ",".join(f"{value:.6f}" for value in values)
+
+
+def sha256(path: Path) -> str:
+    digest = hashlib.sha256()
+    with path.open("rb") as stream:
+        for block in iter(lambda: stream.read(1024 * 1024), b""):
+            digest.update(block)
+    return digest.hexdigest()
+
+
+def run_step(name: str, command: list[object], log: Path, *, env: dict[str, str],
+             stamped: bool = False, timeout_seconds: int = 1740) -> str:
+    expected_stamp = current_stamp() if stamped else None
+    if stamped:
+        binary = Path(str(command[0]))
+        probe = bounded_run([str(binary), "--print-source-stamp"], timeout=15)
+        if probe is None or probe.returncode != 0 or first_stamp(probe.stdout or "") != expected_stamp:
+            raise RuntimeError(f"{name} refused a stale executable: {binary}")
+    started = time.monotonic()
+    log.parent.mkdir(parents=True, exist_ok=True)
+    with log.open("w", encoding="utf-8") as stream:
+        result = subprocess.run([*LIMIT, f"timeout", f"{timeout_seconds}s",
+                                 *map(str, command)], cwd=ROOT, env=env,
+                                stdout=stream, stderr=subprocess.STDOUT,
+                                timeout=timeout_seconds + 5, check=False)
+    elapsed = time.monotonic() - started
+    output = log.read_text(encoding="utf-8", errors="replace")
+    print(f"[L141Run] step={name} elapsed_s={elapsed:.3f} exit={result.returncode} log={log}",
+          flush=True)
+    if stamped and (first_stamp(output) != expected_stamp or current_stamp() != expected_stamp):
+        raise RuntimeError(f"{name} source stamp mismatch; see {log}")
+    if result.returncode != 0:
+        raise RuntimeError(f"{name} failed; see {log}")
+    return output
+
+
+def route_frame(manifest_path: Path) -> tuple[tuple[float, float, float],
+                                               tuple[float, float, float]]:
+    manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
+    strata = [entry for entry in manifest["plan"]["strates"]
+              if entry.get("route") and len(entry["route"]) >= 2]
+    if not strata:
+        raise RuntimeError(f"no planned SurfaceWorld route in {manifest_path}")
+    route = strata[0]["route"]
+    points = [tuple(float(value) / Q_PER_METRE for value in item["position_q"])
+              for item in route]
+    lengths = [math.dist(a, b) for a, b in zip(points, points[1:])]
+    total = sum(lengths)
+    if total <= 1.0e-6:
+        raise RuntimeError(f"degenerate planned route in {manifest_path}")
+
+    def at(distance: float) -> tuple[float, float, float]:
+        remaining = max(0.0, min(total, distance))
+        for index, (a, b, length) in enumerate(zip(points, points[1:], lengths)):
+            if remaining <= length or index == len(lengths) - 1:
+                if length <= 1.0e-9:
+                    return b
+                t = remaining / length
+                return tuple(a[axis] + (b[axis] - a[axis]) * t for axis in range(3))
+            remaining -= length
+        return points[-1]
+
+    center = at(total * 0.5)
+    before, after = at(total * 0.5 - 1.0), at(total * 0.5 + 1.0)
+    dx, dy = after[0] - before[0], after[1] - before[1]
+    length = math.hypot(dx, dy)
+    if length <= 1.0e-9:
+        raise RuntimeError(f"degenerate route tangent in {manifest_path}")
+    return center, (dx / length, dy / length, 0.0)
+
+
+def camera_angles(camera, target) -> tuple[float, float]:
+    dx, dy, dz = (target[index] - camera[index] for index in range(3))
+    return math.degrees(math.atan2(dx, dy)), math.degrees(math.atan2(dz, math.hypot(dx, dy)))
+
+
+def point_toward(camera, target) -> tuple[float, ...]:
+    yaw, pitch = camera_angles(camera, target)
+    return (*camera, yaw, pitch)
+
+
+def stamp(layout: dict, stable_id: str) -> dict:
+    for record in layout.get("stamps", []):
+        if record.get("stable_id") == stable_id:
+            return record
+    raise RuntimeError(f"missing resolved stamp {stable_id}")
+
+
+def make_views(name: str, manifest_path: Path, layout_path: Path):
+    manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
+    layout = json.loads(layout_path.read_text(encoding="utf-8"))
+    center, tangent = route_frame(manifest_path)
+    tx, ty, _ = tangent
+    nx, ny = -ty, tx
+    base_height = manifest["recipe"]["surface_profile"]["h0_q"] / Q_PER_METRE
+    if name == "flatField-monolith":
+        monolith = stamp(layout, "liminal/oversized-familiar-monolith-v1")
+        sx, sy, _ = (value / 1.0e6 for value in monolith["position_um"])
+        floor = monolith["floor_um"] / 1.0e6
+        eye_camera = (sx - tx * 36.0, sy - ty * 36.0, floor + 1.6)
+        eye_target = (sx, sy, floor + 10.5)
+        wide_camera = (sx - tx * 42.0 - nx * 18.0,
+                       sy - ty * 42.0 - ny * 18.0, floor + 42.0)
+        wide_target = (sx, sy, floor + 8.0)
+        return {
+            "eye": (eye_camera, eye_target, 20),
+            "wide": (wide_camera, wide_target, 24),
+            "height_center": floor,
+            "height_range": 38.0,
+        }
+    if name == "periodicHills":
+        # Route points are capsule centers: +0.72 m places the view at 1.60 m above ground.
+        eye_camera = (center[0], center[1], center[2] + 0.72)
+        eye_target = (center[0] - tx * 45.0, center[1] - ty * 45.0,
+                      center[2] + 0.72)
+        wide_camera = (center[0] - tx * 20.0 - nx * 20.0,
+                       center[1] - ty * 20.0 - ny * 20.0, center[2] + 34.0)
+        wide_target = (center[0] - tx * 45.0, center[1] - ty * 45.0,
+                       center[2] + 0.72)
+        return {
+            "eye": (eye_camera, eye_target, 20),
+            "wide": (wide_camera, wide_target, 28),
+            "height_center": base_height,
+            "height_range": 5.0,
+        }
+    road = stamp(layout, "liminal/raised-road-v1")
+    rx, ry, rz = (value / 1.0e6 for value in road["position_um"])
+    half_length, half_width, half_thickness = (
+        value / 1.0e6 for value in road["half_extents_um"])
+    deck = rz + half_thickness
+    eye_camera = (rx - half_length + 14.0, ry, deck + 1.6)
+    eye_target = (rx + half_length, ry, base_height)
+    wide_camera = (rx, ry - 28.0, deck + 24.0)
+    wide_target = (rx + 4.0, ry, base_height + 4.0)
+    return {
+        "eye": (eye_camera, eye_target, 24),
+        "wide": (wide_camera, wide_target, 26),
+        "height_center": base_height + 11.0,
+        "height_range": 32.0,
+        "road_deck": deck,
+        "road_width": 2.0 * half_width,
+    }
+
+
+def headless_command(binary: Path, fixture: Path, camera, mesh: Path,
+                     manifest: Path, layout: Path, workers: int,
+                     clip_radius: int, *, hash_tiles: bool = False,
+                     audit_road: bool = False, max_level: int = 0) -> list[object]:
+    command: list[object] = [binary, fixture, f"--workers={workers}",
+        "--seed=0", "--world-assembler-prototype", "--stream-benchmark", "--stream-pipeline",
+        "--force-generate", f"--clip-radius={clip_radius}",
+        f"--max-clip-level={max_level}",
+        f"--max-level={max_level}", "--render-distance-chunks=0",
+        f"--camera={fmt(point_toward(camera, (camera[0], camera[1] + 1.0, camera[2])))}",
+        f"--mesh-export={mesh}", f"--world-assembler-manifest-output={manifest}",
+        f"--resolved-layout-output={layout}"]
+    if hash_tiles:
+        command.append("--stream-hash-tiles")
+    if audit_road:
+        command.append("--audit-liminal-road-walk")
+    return command
+
+
+def determinism_digest(output: str, manifest_path: Path,
+                       layout_path: Path) -> tuple[str, str, str]:
+    tile_hashes = sorted(line for line in output.splitlines()
+                         if line.startswith("[PipelineTileHash] "))
+    if not manifest_path.is_file() or not layout_path.is_file() or not tile_hashes:
+        raise RuntimeError("determinism run omitted manifest, layout or per-tile hashes")
+    manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
+    layout = json.loads(layout_path.read_text(encoding="utf-8"))
+    manifest_digest = (manifest["content_hash"],manifest["recipe"]["content_hash"],
+                       manifest["plan"]["content_hash"])
+    return ("|".join(manifest_digest),layout["stable_identity"],"\n".join(tile_hashes))
+
+
+def run_determinism(name: str, fixture: Path, view, *, binaries: dict[str, Path],
+                    out: Path, env: dict[str, str]) -> None:
+    camera, _, _ = view["eye"]
+    clip_radius = 1
+    max_clip = 0
+    baseline = None
+    cells = 0
+    for compiler, workers in ((compiler, workers)
+                              for compiler in ("clang", "gcc")
+                              for workers in (1, 8, 12)):
+        tag = f"{name}-{compiler}-w{workers}"
+        run_dir = out / "determinism" / tag
+        run_dir.mkdir(parents=True, exist_ok=True)
+        mesh = run_dir / "feature.vfmesh"
+        manifest = run_dir / "manifest.json"
+        layout = run_dir / "layout.json"
+        command = headless_command(binaries[compiler], fixture,camera,mesh,manifest,
+            layout,workers,max_clip,hash_tiles=True)
+        output = run_step(tag,command,out/"logs"/f"determinism-{tag}.log",
+                          env=env,stamped=True)
+        digest = determinism_digest(output,manifest,layout)
+        if baseline is None:
+            baseline = digest
+        elif digest != baseline:
+            raise RuntimeError(f"{name} diverged at {compiler} W{workers}; see determinism logs")
+        cells += 1
+    print(f"[L141Determinism] fixture={name} compiler_worker_cells={cells} identical=yes status=PASS",
+          flush=True)
+
+
+def export_and_capture(name: str, fixture: Path, views: dict, *,
+                       headless: Path, renderer: Path, out: Path,
+                       artifact_dir: Path, env: dict[str, str]) -> None:
+    for view_name in ("eye", "wide"):
+        camera, target, clip_radius = views[view_name]
+        clip_radius = min(clip_radius,7)
+        stem = f"{name}-{view_name}"
+        mesh = out / "capture-meshes" / f"{stem}.vfmesh"
+        manifest = out / "capture-manifests" / f"{stem}.json"
+        layout = out / "capture-layouts" / f"{stem}.json"
+        png = out / "capture-png" / f"{stem}.png"
+        image = artifact_dir / f"{stem}.jpg"
+        for path in (mesh,manifest,layout,png,image):
+            path.parent.mkdir(parents=True,exist_ok=True)
+        command = headless_command(headless,fixture,camera,mesh,manifest,layout,12,
+            clip_radius,max_level=0)
+        output = run_step(f"capture-{stem}-export",command,
+            out/"logs"/f"capture-{stem}-export.log",env=env,stamped=True)
+        if not mesh.is_file() or mesh.stat().st_size == 0:
+            raise RuntimeError(f"{stem} produced an empty mesh")
+        yaw, pitch = camera_angles(camera,target)
+        height_center = views["height_center"]
+        height_range = views["height_range"]
+        renderer_command = [renderer,mesh,png,"--size=1600x900","--fov-deg=72",
+            f"--camera-m={fmt(camera)}",f"--yaw-deg={yaw:.6f}",
+            f"--pitch-deg={pitch:.6f}","--tile-skirts=off","--shade=readable",
+            "--headlamp=off","--height-tint=on",f"--height-center-m={height_center:.6f}",
+            f"--height-range-m={height_range:.6f}","--light-direction=-0.42,-0.58,0.70",
+            "--fog=on","--fog-start-m=30","--fog-end-m=105",f"--fog-color={FOG_COLOR}"]
+        run_step(f"capture-{stem}-render",renderer_command,
+            out/"logs"/f"capture-{stem}-render.log",env=env,stamped=True)
+        run_step(f"capture-{stem}-jpeg",["ffmpeg","-nostdin","-hide_banner","-loglevel",
+            "error","-y","-i",png,"-frames:v","1","-q:v","4",image],
+            out/"logs"/f"capture-{stem}-jpeg.log",env=env)
+        quality = run_step(f"capture-{stem}-quality",
+            [sys.executable,ROOT/"Standalone/Tools/verify/capture_quality.py",image],
+            out/"logs"/f"capture-{stem}-quality.log",env=env)
+        if "[CaptureQuality]" not in quality or not image.is_file() \
+                or image.stat().st_size > 300_000:
+            raise RuntimeError(f"{stem} capture failed quality or size checks")
+        eye_height = "1.600m" if view_name == "eye" else "wide"
+        print(f"[L141Capture] fixture={name} view={view_name} eye_height={eye_height} "
+              f"camera_m=({fmt(camera)}) target_m=({fmt(target)}) bytes={image.stat().st_size} "
+              f"sha256={sha256(image)} status=PASS",flush=True)
+
+
+def run_road_walk_audit(fixture: Path, view, *, headless: Path,
+                        out: Path, env: dict[str, str]) -> None:
+    camera = view["eye"][0]
+    run_dir = out / "road-walk-audit"
+    run_dir.mkdir(parents=True,exist_ok=True)
+    output = run_step("road-walk-audit",headless_command(headless,fixture,camera,
+        run_dir/"audit.vfmesh",run_dir/"manifest.json",run_dir/"layout.json",12,1,
+        audit_road=True),out/"logs"/"road-walk-audit.log",env=env,stamped=True)
+    if not re.search(r"\[LiminalRoadWalkAudit\].*status=PASS",output):
+        raise RuntimeError("raised road failed the Core capsule walk audit")
+
+
+def measure_near_ready(fixture: Path, views: dict, *, headless: Path,
+                       out: Path, env: dict[str, str]) -> None:
+    uptime = subprocess.run(["uptime"],cwd=ROOT,capture_output=True,text=True,check=True).stdout.strip()
+    load_match = re.search(r"load average:\s*([0-9.]+)",uptime)
+    if not load_match or float(load_match.group(1)) >= 1.5:
+        raise RuntimeError(f"near-ready timing requires a quiet machine: {uptime}")
+    print(f"[L141TimingEnvironment] window=one W12 run after one warmup uptime='{uptime}' "
+          f"status=PASS",flush=True)
+    camera = views["eye"][0]
+    warm_dir = out / "near-ready" / "warmup"
+    timed_dir = out / "near-ready" / "measured"
+    warm_dir.mkdir(parents=True,exist_ok=True)
+    timed_dir.mkdir(parents=True,exist_ok=True)
+
+    def command(directory: Path) -> list[object]:
+        return [headless,fixture,"--workers=12","--world-assembler-prototype",
+            "--seed=0","--stream-benchmark","--stream-pipeline","--force-generate",
+            "--clip-radius=1","--max-clip-level=2","--max-level=2",
+            "--render-distance-chunks=0",
+            f"--camera={fmt(point_toward(camera,(camera[0],camera[1]+1.0,camera[2])))}",
+            f"--world-assembler-manifest-output={directory/'manifest.json'}",
+            f"--resolved-layout-output={directory/'layout.json'}"]
+
+    run_step("near-ready-warmup",command(warm_dir),
+        out/"logs"/"near-ready-warmup.log",env=env,stamped=True)
+    output = run_step("near-ready-measured",command(timed_dir),
+        out/"logs"/"near-ready-measured.log",env=env,stamped=True)
+    match = re.search(r"^\[WorldAssemblerNearLODPipelineReady\] lods=0-2 "
+        r"tiles=(\d+)/(\d+) cold_ready_s=([0-9.]+)$",output,re.M)
+    if not match or match.group(1)!=match.group(2):
+        raise RuntimeError("near-ready run did not complete the full LOD 0-2 set")
+    print(f"[L141NearReady] window=one W12 run after one warmup clip_radius=1 "
+        f"tiles={match.group(1)}/{match.group(2)} cold_ready_s={match.group(3)} status=PASS",
+        flush=True)
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--out", type=Path, default=OUT_DEFAULT)
+    parser.add_argument("--artifact-dir", type=Path, default=CAPTURE_DEFAULT)
+    parser.add_argument("--headless-clang", type=Path, required=True)
+    parser.add_argument("--headless-gcc", type=Path, required=True)
+    parser.add_argument("--renderer", type=Path, required=True)
+    args = parser.parse_args()
+
+    out = args.out.resolve()
+    artifact_dir = args.artifact_dir.resolve()
+    fixture_dir = out / "fixtures"
+    for directory in (out,fixture_dir,artifact_dir):
+        directory.mkdir(parents=True,exist_ok=True)
+    env = os.environ.copy()
+    env["VOXELFORGE_VERIFY_OUT"] = str(out)
+    env["VOXELFORGE_OWNER_DATA"] = str(ROOT/"Standalone/data/owner_world.json")
+    env["LP_NUM_THREADS"] = "12"
+    env["XDG_CACHE_HOME"] = str(out/"xdg-cache")
+    run_step("build-fixtures",[sys.executable,
+        ROOT/"Standalone/Research/WorldAssemblerM3/Linux141/BuildL141Fixtures.py",
+        f"--out={fixture_dir}"],out/"logs"/"build-fixtures.log",env=env)
+
+    binaries = {"clang":args.headless_clang.resolve(),"gcc":args.headless_gcc.resolve()}
+    fixtures = {
+        "flatField-monolith":fixture_dir/"liminal-flatField-monolith.json",
+        "periodicHills":fixture_dir/"liminal-periodicHills.json",
+        "raised-road":fixture_dir/"liminal-raised-road.json",
+    }
+    probed = {}
+    for name,fixture in fixtures.items():
+        probe_dir=out/"plan-probes"/name
+        probe_dir.mkdir(parents=True,exist_ok=True)
+        camera=(0.0,0.0,-500.0)
+        output=run_step(f"plan-probe-{name}",headless_command(binaries["clang"],fixture,
+            camera,probe_dir/"probe.vfmesh",probe_dir/"manifest.json",
+            probe_dir/"layout.json",12,1),out/"logs"/f"plan-probe-{name}.log",
+            env=env,stamped=True)
+        if "[WorldAssemblerFullManifest]" not in output:
+            raise RuntimeError(f"{name} probe omitted its full plan manifest")
+        probed[name]=make_views(name,probe_dir/"manifest.json",probe_dir/"layout.json")
+
+    for name,fixture in fixtures.items():
+        run_determinism(name,fixture,probed[name],binaries=binaries,out=out,env=env)
+    run_road_walk_audit(fixtures["raised-road"],probed["raised-road"],
+        headless=binaries["clang"],out=out,env=env)
+    for name,fixture in fixtures.items():
+        export_and_capture(name,fixture,probed[name],headless=binaries["clang"],
+            renderer=args.renderer.resolve(),out=out,artifact_dir=artifact_dir,env=env)
+    measure_near_ready(fixtures["raised-road"],probed["raised-road"],
+        headless=binaries["clang"],out=out,env=env)
+    return 0
+
+
+if __name__ == "__main__":
+    try:
+        raise SystemExit(main())
+    except Exception as error:
+        print(f"[L141Capture] status=FAIL error={error}",file=sys.stderr,flush=True)
+        raise SystemExit(1)

Standalone/Research/WorldAssemblerM3/Linux141/REPORT.md

@@ -0,0 +1,40 @@
+# L141 — first liminal layer
+
+![flatField monolith, eye level](captures/flatField-monolith-eye.jpg)
+![periodicHills, eye level](captures/periodicHills-eye.jpg)
+![raised road, eye level](captures/raised-road-eye.jpg)
+
+![flatField monolith, wide](captures/flatField-monolith-wide.jpg)
+![periodicHills, wide](captures/periodicHills-wide.jpg)
+![raised road, wide](captures/raised-road-wide.jpg)
+
+The standalone fixtures and six captures are ready for review. The flat field has one oversized capped-cylinder monolith. The road is a 65 m `fillDais` platform, 6 m wide, with its deck 22 m above a flat field. Fog supplies the road's cloud-sea backdrop in these standalone images.
+
+The `periodicHills` fixture uses the validated 80 m periods and 2.2 m amplitudes on both axes. Its field repeats exactly, but these captures show one broad rise rather than hills repeating to the horizon. The validated period is longer than the 56 m eye-level capture radius; the wider full-detail capture exceeded Core's 160-million-node interval bound. Smaller periods fail the existing profile validator. A capture extent that trims vertical tiles independently from horizontal tiles is the next useful step; this round leaves the Core profile limits unchanged.
+
+## Changes
+
+- Reused Core's `flatField`, `periodicHills`, `fillMonolith`, and `fillDais` support. Added standalone fixture inputs and runners in `BuildL141Fixtures.py` and `CaptureL141.py`.
+- Added `liminal_road_override` as a standalone adapter to the existing free-placement `fillDais` stamp, plus `--audit-liminal-road-walk`. The walk audit samples the Core field with the existing capsule sampler and checks width and grade.
+- Added optional distance fog to `LinuxOffscreenCapture` for the screenshots. The fog is capture-only; Unreal cloud rendering remains Unreal-side.
+- No evaluator change or Unreal `Source/` change. Owner output hashes match their pinned L130/v227 canonical rows in the fast tier.
+
+## Measurements
+
+- Determinism: each fixture matched across Clang and GCC at W1, W8, and W12 (six cells per fixture). The matrix used LOD0, clip radius 1; each cell compares recipe/plan hashes, resolved-layout identity, and per-tile hashes. Individual logs are in `Saved/Linux/l141/logs/determinism-*.log`.
+- Raised-road capsule walk: 127 stations, 8,001 capsule samples, zero blocked samples, zero unsupported stations, 6.000 m width against a 0.680 m capsule diameter, and 0.000° grade. See `Saved/Linux/l141/logs/road-walk-audit.log`.
+- Near-ready: one W12 LOD0–2 sample after one warm-up, clip radius 1, 139/139 tiles. The measured `cold_ready_s` was **0.173886 s**. The window was one run after one warm-up; `uptime` showed a 1-minute load average of 1.31 and no other build was running. See `Saved/Linux/l141/logs/near-ready-measured.log`.
+- Each capture is 1600×900 and passed `capture_quality.py`. Eye views place the camera 1.6 m above the field or road deck. Camera coordinates and image hashes are recorded in the capture runner output; export and render logs are under `Saved/Linux/l141/logs/`.
+
+## Checks
+
+- Clang 19 and GCC standalone builds passed with FP contraction off, four jobs, and source stamp `0a2828c398aa62870690667901d44f2daf5b1a5547b9640da6dbb01df721af8b`.
+- `python3 Standalone/Tools/verify/verify.py fast --out Saved/Linux/l141 --overall-timeout 1740` passed in 285.7 s. Owner SurfaceWorld and FloatingIslands W1/W12 canonical hashes matched the L130/v227 baselines.
+- Fixture determinism, dedicated road walk audit, six standalone captures, and all six image-quality checks passed.
+- Python bytecode compilation and `git diff --check` passed.
+- An exploratory broad `--audit-resolved-layout-passages` invocation also ran unrelated passage ripple checks and reported 2/3 passage ripple records passing, with `passage/1-2/0` failing. The focused liminal road audit passes; no legacy threshold was changed.
+- No Unreal build was run because no Unreal `Source/` file changed. No timing matrix was requested or run.
+
+## Remaining risk
+
+The hill screenshots do not yet show multiple full repeats to the horizon. The profile itself is exactly periodic; the standalone capture volume is too short at the current full-detail safety bound. The raised road is geometric and walk-audited, while its clouds are represented by fog in the capture renderer.

Standalone/Research/WorldAssemblerM3/Linux142/BuildL142Fixtures.py

@@ -0,0 +1,113 @@
+#!/usr/bin/env python3
+"""Build the L142 liminal pictures and walk-audit controls."""
+from __future__ import annotations
+
+import argparse
+import json
+import os
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OWNER = Path(os.environ.get("VOXELFORGE_OWNER_DATA",
+                            ROOT / "Standalone/data/owner_world.json"))
+OUT_DEFAULT = Path(os.environ.get("VOXELFORGE_VERIFY_OUT", ROOT / "Saved/Linux/l142"))
+
+FLAT_FIELD = {
+    "version": 1,
+    "kind": "flatField",
+    "minimum_arena_clearance_m": 0.0,
+}
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--out", type=Path, default=OUT_DEFAULT / "fixtures")
+    args = parser.parse_args()
+    args.out.mkdir(parents=True, exist_ok=True)
+    base = json.loads(OWNER.read_text(encoding="utf-8"))
+
+    monolith = dict(base)
+    monolith["surface_profile_override"] = dict(FLAT_FIELD)
+    monolith["motif_family_override"] = {
+        "version": 1,
+        "strate_index": 0,
+        "placement_policy": "seed,strate,stable_id",
+        "motifs": [{
+            "stable_id": "liminal/oversized-familiar-monolith-v1",
+            "kind": "cappedCylinder",
+            "radius_m": 1.6,
+            "height_m": 26.0,
+            "route_side_offset_m": 42.0,
+            "placement_radius_m": 0.0,
+            "fillet_radius_m": 0.6,
+            "blend_width_m": 1.2,
+            "minimum_spacing_m": 0.0,
+            "yaw_quarter_turns": 0,
+            "attachment": "seated_floor",
+        }],
+    }
+
+    hills = dict(base)
+    hills["surface_profile_override"] = {
+        "version": 1,
+        "kind": "periodicHills",
+        "amplitude_x_m": 2.2,
+        "amplitude_y_m": 2.2,
+        "wavelength_x_m": 80.0,
+        "wavelength_y_m": 80.0,
+        "minimum_arena_clearance_m": 0.0,
+    }
+
+    road_override = {
+        "stable_id": "liminal/road-clouds-v2",
+        "strate_index": 0,
+        "start_xy_m": [120.0, 340.0],
+        "path_length_m": 360.0,
+        "curve_control_offset_m": 84.0,
+        "deck_height_above_field_m": 44.0,
+        "rise_control_m": 22.0,
+        "half_width_m": 4.0,
+        "half_thickness_m": 1.0,
+        "sample_spacing_m": 2.0,
+        "support_spacing_m": 24.0,
+        "support_radius_m": 0.55,
+    }
+    road = dict(base)
+    road["surface_profile_override"] = dict(FLAT_FIELD)
+    road["liminal_road_override"] = dict(road_override)
+
+    short_control = dict(base)
+    short_control["surface_profile_override"] = dict(FLAT_FIELD)
+    short_override = dict(road_override)
+    short_override["path_length_m"] = 180.0
+    short_control["liminal_road_override"] = short_override
+
+    pillars = dict(base)
+    pillars["surface_profile_override"] = dict(FLAT_FIELD)
+    pillars["liminal_pillar_grid_override"] = {
+        "stable_id": "liminal/horizon-pillar-grid-v1",
+        "strate_index": 0,
+        "center_xy_m": [700.0, 800.0],
+        "rows": 15,
+        "columns": 15,
+        "spacing_m": 76.0,
+        "radius_m": 5.5,
+        "height_m": 40.0,
+    }
+
+    fixtures = (
+        ("flatField-monolith", monolith),
+        ("periodicHills", hills),
+        ("road-in-clouds", road),
+        ("road-short-control", short_control),
+        ("pillar-grid", pillars),
+    )
+    for name, fixture in fixtures:
+        path = args.out / f"liminal-{name}.json"
+        path.write_text(json.dumps(fixture, indent=2) + "\n", encoding="utf-8")
+        print(f"[L142Fixture] name={name} file={path} status=PASS")
+
+
+if __name__ == "__main__":
+    main()

Standalone/Research/WorldAssemblerM3/Linux142/CaptureL142.py

@@ -0,0 +1,433 @@
+#!/usr/bin/env python3
+"""Run L142 liminal determinism checks, walk audits and multi-LOD captures."""
+from __future__ import annotations
+
+import argparse
+import hashlib
+import json
+import math
+import os
+from pathlib import Path
+import re
+import subprocess
+import sys
+import time
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT_DEFAULT = Path(os.environ.get("VOXELFORGE_VERIFY_OUT", ROOT / "Saved/Linux/l142"))
+CAPTURE_DEFAULT = Path(__file__).resolve().parent / "captures"
+LIMIT = ["taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--"]
+Q_PER_METRE = 1024.0
+FOG_COLOR = "0.66,0.73,0.77"
+
+sys.path.insert(0, str(ROOT / "Standalone/Tools/verify"))
+from runner import bounded_run, current_stamp, first_stamp
+
+
+def fmt(values) -> str:
+    return ",".join(f"{value:.6f}" for value in values)
+
+
+def sha256(path: Path) -> str:
+    digest = hashlib.sha256()
+    with path.open("rb") as stream:
+        for block in iter(lambda: stream.read(1024 * 1024), b""):
+            digest.update(block)
+    return digest.hexdigest()
+
+
+def run_step(name: str, command: list[object], log: Path, *, env: dict[str, str],
+             stamped: bool = False, timeout_seconds: int = 1740,
+             expected_exit: int = 0) -> str:
+    expected_stamp = current_stamp() if stamped else None
+    if stamped:
+        binary = Path(str(command[0]))
+        probe = bounded_run([str(binary), "--print-source-stamp"], timeout=15)
+        if probe is None or probe.returncode != 0 or first_stamp(probe.stdout or "") != expected_stamp:
+            raise RuntimeError(f"{name} refused a stale executable: {binary}")
+    started = time.monotonic()
+    log.parent.mkdir(parents=True, exist_ok=True)
+    with log.open("w", encoding="utf-8") as stream:
+        result = subprocess.run([*LIMIT, f"timeout", f"{timeout_seconds}s",
+                                 *map(str, command)], cwd=ROOT, env=env,
+                                stdout=stream, stderr=subprocess.STDOUT,
+                                timeout=timeout_seconds + 5, check=False)
+    elapsed = time.monotonic() - started
+    output = log.read_text(encoding="utf-8", errors="replace")
+    print(f"[L142Run] step={name} elapsed_s={elapsed:.3f} exit={result.returncode} log={log}",
+          flush=True)
+    if stamped and (first_stamp(output) != expected_stamp or current_stamp() != expected_stamp):
+        raise RuntimeError(f"{name} source stamp mismatch; see {log}")
+    if result.returncode != expected_exit:
+        raise RuntimeError(f"{name} exit={result.returncode}, expected={expected_exit}; see {log}")
+    return output
+
+
+def route_frame(manifest_path: Path) -> tuple[tuple[float, float, float],
+                                               tuple[float, float, float]]:
+    manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
+    strata = [entry for entry in manifest["plan"]["strates"]
+              if entry.get("route") and len(entry["route"]) >= 2]
+    if not strata:
+        raise RuntimeError(f"no planned SurfaceWorld route in {manifest_path}")
+    route = strata[0]["route"]
+    points = [tuple(float(value) / Q_PER_METRE for value in item["position_q"])
+              for item in route]
+    lengths = [math.dist(a, b) for a, b in zip(points, points[1:])]
+    total = sum(lengths)
+    if total <= 1.0e-6:
+        raise RuntimeError(f"degenerate planned route in {manifest_path}")
+
+    def at(distance: float) -> tuple[float, float, float]:
+        remaining = max(0.0, min(total, distance))
+        for index, (a, b, length) in enumerate(zip(points, points[1:], lengths)):
+            if remaining <= length or index == len(lengths) - 1:
+                if length <= 1.0e-9:
+                    return b
+                t = remaining / length
+                return tuple(a[axis] + (b[axis] - a[axis]) * t for axis in range(3))
+            remaining -= length
+        return points[-1]
+
+    center = at(total * 0.5)
+    before, after = at(total * 0.5 - 1.0), at(total * 0.5 + 1.0)
+    dx, dy = after[0] - before[0], after[1] - before[1]
+    length = math.hypot(dx, dy)
+    if length <= 1.0e-9:
+        raise RuntimeError(f"degenerate route tangent in {manifest_path}")
+    return center, (dx / length, dy / length, 0.0)
+
+
+def camera_angles(camera, target) -> tuple[float, float]:
+    dx, dy, dz = (target[index] - camera[index] for index in range(3))
+    return math.degrees(math.atan2(dx, dy)), math.degrees(math.atan2(dz, math.hypot(dx, dy)))
+
+
+def point_toward(camera, target) -> tuple[float, ...]:
+    yaw, pitch = camera_angles(camera, target)
+    return (*camera, yaw, pitch)
+
+
+def stamp(layout: dict, stable_id: str) -> dict:
+    for record in layout.get("stamps", []):
+        if record.get("stable_id") == stable_id:
+            return record
+    raise RuntimeError(f"missing resolved stamp {stable_id}")
+
+
+def make_views(name: str, manifest_path: Path, layout_path: Path):
+    manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
+    layout = json.loads(layout_path.read_text(encoding="utf-8"))
+    center, tangent = route_frame(manifest_path)
+    tx, ty, _ = tangent
+    nx, ny = -ty, tx
+    base_height = manifest["recipe"]["surface_profile"]["h0_q"] / Q_PER_METRE
+    if name == "flatField-monolith":
+        monolith = stamp(layout, "liminal/oversized-familiar-monolith-v1")
+        sx, sy, _ = (value / 1.0e6 for value in monolith["position_um"])
+        floor = monolith["floor_um"] / 1.0e6
+        eye_camera = (sx - tx * 36.0, sy - ty * 36.0, floor + 1.6)
+        eye_target = (sx, sy, floor + 10.5)
+        wide_camera = (sx - tx * 42.0 - nx * 18.0,
+                       sy - ty * 42.0 - ny * 18.0, floor + 42.0)
+        wide_target = (sx, sy, floor + 8.0)
+        return {
+            "eye": (eye_camera, eye_target, 20),
+            "wide": (wide_camera, wide_target, 24),
+            "height_center": floor,
+            "height_range": 38.0,
+        }
+    if name == "periodicHills":
+        # Route points are capsule centers: +0.72 m places the view at 1.60 m above ground.
+        eye_camera = (center[0], center[1], center[2] + 0.72)
+        eye_target = (center[0] - tx * 360.0, center[1] - ty * 360.0,
+                      center[2] + 0.72)
+        wide_camera = (center[0] - tx * 36.0 - nx * 28.0,
+                       center[1] - ty * 36.0 - ny * 28.0, center[2] + 30.0)
+        wide_target = (center[0] - tx * 310.0, center[1] - ty * 310.0,
+                       center[2] + 0.72)
+        return {
+            "eye": (eye_camera, eye_target, 20),
+            "wide": (wide_camera, wide_target, 28),
+            "height_center": base_height,
+            "height_range": 6.0,
+        }
+    if name == "road-in-clouds":
+        deck = sorted((row for row in layout.get("stamps", [])
+            if row.get("stable_id", "").startswith("liminal/road-clouds-v2/deck/")),
+            key=lambda row: row["stable_id"])
+        if len(deck) < 2:
+            raise RuntimeError("road layout has no resolved swept platform chain")
+        points = [tuple(value / 1.0e6 for value in row["position_um"])
+                  for row in deck]
+        tops = [point[2] + row["half_extents_um"][2] / 1.0e6
+                for point, row in zip(points, deck)]
+        index = max(1, len(points) // 12)
+        camera_dx = points[index + 1][0] - points[index - 1][0]
+        camera_dy = points[index + 1][1] - points[index - 1][1]
+        camera_tangent_length = math.hypot(camera_dx, camera_dy)
+        camera_tx, camera_ty = (camera_dx / camera_tangent_length,
+                                 camera_dy / camera_tangent_length)
+        camera_nx, camera_ny = -camera_ty, camera_tx
+        eye_camera = (points[index][0] + camera_nx * 3.2,
+                      points[index][1] + camera_ny * 3.2, tops[index] + 1.6)
+        eye_target = (points[index][0] + camera_tx * 90.0 + camera_nx * 60.0,
+                      points[index][1] + camera_ty * 90.0 + camera_ny * 60.0,
+                      tops[index] - 44.0)
+        middle = len(points) // 2
+        dx = points[middle + 1][0] - points[middle - 1][0]
+        dy = points[middle + 1][1] - points[middle - 1][1]
+        tangent_length = math.hypot(dx, dy)
+        tx, ty = dx / tangent_length, dy / tangent_length
+        nx, ny = -ty, tx
+        wide_target_index = min(len(points) - 1, middle + 30)
+        wide_camera = (points[middle][0] - tx * 35.0 + nx * 30.0,
+                       points[middle][1] - ty * 35.0 + ny * 30.0,
+                       tops[middle] + 25.0)
+        wide_target = (points[wide_target_index][0], points[wide_target_index][1],
+                       tops[wide_target_index] - 5.0)
+        return {
+            "eye": (eye_camera, eye_target, 3),
+            "wide": (wide_camera, wide_target, 3),
+            "height_center": base_height + 23.0,
+            "height_range": 60.0,
+            "road_deck": tops[middle],
+            "road_width": 2.0 * deck[middle]["half_extents_um"][1] / 1.0e6,
+        }
+    if name == "pillar-grid":
+        pillars = [row for row in layout.get("stamps", [])
+            if row.get("stable_id", "").startswith("liminal/horizon-pillar-grid-v1/pillar/")]
+        if len(pillars) < 9:
+            raise RuntimeError("pillar-grid layout has too few resolved supports")
+        xs = [row["position_um"][0] / 1.0e6 for row in pillars]
+        ys = [row["position_um"][1] / 1.0e6 for row in pillars]
+        floor = min((row["position_um"][2] - row["half_extents_um"][2]) / 1.0e6
+                    for row in pillars)
+        cx, cy = (min(xs) + max(xs)) * 0.5, (min(ys) + max(ys)) * 0.5
+        eye_camera = (min(xs) - 78.0, cy, floor + 1.6)
+        eye_target = (max(xs) + 90.0, cy, floor + 1.6)
+        wide_camera = (cx - 280.0, cy - 420.0, floor + 230.0)
+        wide_target = (cx, cy, floor + 6.0)
+        return {
+            "eye": (eye_camera, eye_target, 3),
+            "wide": (wide_camera, wide_target, 3),
+            "height_center": floor + 12.0,
+            "height_range": 42.0,
+        }
+    raise RuntimeError(f"no capture framing for fixture {name}")
+
+
+def headless_command(binary: Path, fixture: Path, camera, mesh: Path,
+                     manifest: Path, layout: Path, workers: int,
+                     clip_radius: int, *, hash_tiles: bool = False,
+                     audit_road: bool = False, max_level: int = 0,
+                     far_lods: bool = False,
+                     max_clip_override: int | None = None) -> list[object]:
+    max_clip_level = (max_clip_override if max_clip_override is not None else
+                      8 if far_lods else max_level)
+    command: list[object] = [binary, fixture, f"--workers={workers}",
+        "--seed=0", "--world-assembler-prototype", "--stream-benchmark", "--stream-pipeline",
+        "--force-generate", f"--clip-radius={clip_radius}",
+        f"--max-clip-level={max_clip_level}",
+        f"--max-level={max_level}", "--render-distance-chunks=0",
+        f"--camera={fmt(point_toward(camera, (camera[0], camera[1] + 1.0, camera[2])))}",
+        f"--mesh-export={mesh}", f"--world-assembler-manifest-output={manifest}",
+        f"--resolved-layout-output={layout}"]
+    if hash_tiles:
+        command.append("--stream-hash-tiles")
+    if audit_road:
+        command.append("--audit-liminal-road-walk")
+    return command
+
+
+def determinism_digest(output: str, manifest_path: Path,
+                       layout_path: Path) -> tuple[str, str, str]:
+    tile_hashes = sorted(line for line in output.splitlines()
+                         if line.startswith("[PipelineTileHash] "))
+    if not manifest_path.is_file() or not layout_path.is_file() or not tile_hashes:
+        raise RuntimeError("determinism run omitted manifest, layout or per-tile hashes")
+    manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
+    layout = json.loads(layout_path.read_text(encoding="utf-8"))
+    manifest_digest = (manifest["content_hash"],manifest["recipe"]["content_hash"],
+                       manifest["plan"]["content_hash"])
+    return ("|".join(manifest_digest),layout["stable_identity"],"\n".join(tile_hashes))
+
+
+def run_determinism(name: str, fixture: Path, view, *, binaries: dict[str, Path],
+                    out: Path, env: dict[str, str]) -> None:
+    camera, _, _ = view["eye"]
+    clip_radius = 1
+    max_clip = 0
+    baseline = None
+    cells = 0
+    for compiler, workers in ((compiler, workers)
+                              for compiler in ("clang", "gcc")
+                              for workers in (1, 8, 12)):
+        tag = f"{name}-{compiler}-w{workers}"
+        run_dir = out / "determinism" / tag
+        run_dir.mkdir(parents=True, exist_ok=True)
+        mesh = run_dir / "feature.vfmesh"
+        manifest = run_dir / "manifest.json"
+        layout = run_dir / "layout.json"
+        command = headless_command(binaries[compiler], fixture,camera,mesh,manifest,
+            layout,workers,max_clip,hash_tiles=True)
+        output = run_step(tag,command,out/"logs"/f"determinism-{tag}.log",
+                          env=env,stamped=True)
+        digest = determinism_digest(output,manifest,layout)
+        if baseline is None:
+            baseline = digest
+        elif digest != baseline:
+            raise RuntimeError(f"{name} diverged at {compiler} W{workers}; see determinism logs")
+        cells += 1
+    print(f"[L142Determinism] fixture={name} compiler_worker_cells={cells} identical=yes status=PASS",
+          flush=True)
+
+
+def export_and_capture(name: str, fixture: Path, views: dict, *,
+                       headless: Path, renderer: Path, out: Path,
+                       artifact_dir: Path, env: dict[str, str]) -> None:
+    for view_name in ("eye", "wide"):
+        camera, target, clip_radius = views[view_name]
+        clip_radius = min(clip_radius,3)
+        stem = f"{name}-{view_name}"
+        mesh = out / "capture-meshes" / f"{stem}.vfmesh"
+        manifest = out / "capture-manifests" / f"{stem}.json"
+        layout = out / "capture-layouts" / f"{stem}.json"
+        png = out / "capture-png" / f"{stem}.png"
+        image = artifact_dir / f"{stem}.jpg"
+        for path in (mesh,manifest,layout,png,image):
+            path.parent.mkdir(parents=True,exist_ok=True)
+        command = headless_command(headless,fixture,camera,mesh,manifest,layout,12,
+            clip_radius,max_level=-1,far_lods=True,
+            max_clip_override=(2 if name == "road-in-clouds" and view_name == "wide"
+                               else 3 if name == "road-in-clouds" else None))
+        output = run_step(f"capture-{stem}-export",command,
+            out/"logs"/f"capture-{stem}-export.log",env=env,stamped=True)
+        if not mesh.is_file() or mesh.stat().st_size == 0:
+            raise RuntimeError(f"{stem} produced an empty mesh")
+        yaw, pitch = camera_angles(camera,target)
+        height_center = views["height_center"]
+        height_range = views["height_range"]
+        if name == "road-in-clouds":
+            fog_start,fog_end,fog_color=(24,260,"0.88,0.93,0.95")
+        elif name == "pillar-grid":
+            fog_start,fog_end,fog_color=220,1250,"0.82,0.88,0.91"
+        elif name == "periodicHills":
+            fog_start,fog_end,fog_color=210,1000,"0.78,0.84,0.88"
+        else:
+            fog_start,fog_end,fog_color=30,105,FOG_COLOR
+        renderer_command = [renderer,mesh,png,"--size=1600x900","--fov-deg=72",
+            f"--camera-m={fmt(camera)}",f"--yaw-deg={yaw:.6f}",
+            f"--pitch-deg={pitch:.6f}","--tile-skirts=on","--shade=readable",
+            "--headlamp=off","--height-tint=on",f"--height-center-m={height_center:.6f}",
+            f"--height-range-m={height_range:.6f}","--light-direction=-0.42,-0.58,0.70",
+            "--fog=on",f"--fog-start-m={fog_start}",f"--fog-end-m={fog_end}",
+            f"--fog-color={fog_color}"]
+        run_step(f"capture-{stem}-render",renderer_command,
+            out/"logs"/f"capture-{stem}-render.log",env=env,stamped=True)
+        run_step(f"capture-{stem}-jpeg",["ffmpeg","-nostdin","-hide_banner","-loglevel",
+            "error","-y","-i",png,"-frames:v","1","-q:v","4",image],
+            out/"logs"/f"capture-{stem}-jpeg.log",env=env)
+        quality = run_step(f"capture-{stem}-quality",
+            [sys.executable,ROOT/"Standalone/Tools/verify/capture_quality.py",image],
+            out/"logs"/f"capture-{stem}-quality.log",env=env)
+        if "[CaptureQuality]" not in quality or not image.is_file() \
+                or image.stat().st_size > 300_000:
+            raise RuntimeError(f"{stem} capture failed quality or size checks")
+        eye_height = "1.600m" if view_name == "eye" else "wide"
+        print(f"[L142Capture] fixture={name} view={view_name} eye_height={eye_height} "
+              f"camera_m=({fmt(camera)}) target_m=({fmt(target)}) bytes={image.stat().st_size} "
+              f"sha256={sha256(image)} status=PASS",flush=True)
+
+
+def run_road_walk_audit(fixture: Path, view, *, headless: Path,
+                        out: Path, env: dict[str, str]) -> None:
+    camera = view["eye"][0]
+    run_dir = out / "road-walk-audit"
+    run_dir.mkdir(parents=True,exist_ok=True)
+    output = run_step("road-walk-audit",headless_command(headless,fixture,camera,
+        run_dir/"audit.vfmesh",run_dir/"manifest.json",run_dir/"layout.json",12,1,
+        audit_road=True),out/"logs"/"road-walk-audit.log",env=env,stamped=True)
+    if not re.search(r"\[LiminalRoadWalkAudit\].*status=PASS",output):
+        raise RuntimeError("raised road failed the Core capsule walk audit")
+
+
+def run_road_short_negative_control(fixture: Path, view, *, headless: Path,
+                                    out: Path, env: dict[str, str]) -> None:
+    camera = view["eye"][0]
+    run_dir = out / "road-short-negative-control"
+    run_dir.mkdir(parents=True,exist_ok=True)
+    output = run_step("road-short-negative-control",
+        headless_command(headless,fixture,camera,run_dir/"control.vfmesh",
+            run_dir/"manifest.json",run_dir/"layout.json",12,1,audit_road=True),
+        out/"logs"/"road-short-negative-control.log",env=env,stamped=True,
+        expected_exit=14)
+    match = re.search(r"\[LiminalRoadWalkAudit\].*path_length_m=([0-9.]+).*status=FAIL",output)
+    if not match or float(match.group(1)) >= 300.0:
+        raise RuntimeError("short-road negative control did not falsify the length gate")
+    print(f"[L142RoadNegativeControl] path_length_m={match.group(1)} "
+          "expected=FAIL status=PASS",flush=True)
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--out", type=Path, default=OUT_DEFAULT)
+    parser.add_argument("--artifact-dir", type=Path, default=CAPTURE_DEFAULT)
+    parser.add_argument("--headless-clang", type=Path, required=True)
+    parser.add_argument("--headless-gcc", type=Path, required=True)
+    parser.add_argument("--renderer", type=Path, required=True)
+    args = parser.parse_args()
+
+    out = args.out.resolve()
+    artifact_dir = args.artifact_dir.resolve()
+    fixture_dir = out / "fixtures"
+    for directory in (out,fixture_dir,artifact_dir):
+        directory.mkdir(parents=True,exist_ok=True)
+    env = os.environ.copy()
+    env["VOXELFORGE_VERIFY_OUT"] = str(out)
+    env["VOXELFORGE_OWNER_DATA"] = str(ROOT/"Standalone/data/owner_world.json")
+    env["LP_NUM_THREADS"] = "12"
+    env["XDG_CACHE_HOME"] = str(out/"xdg-cache")
+    run_step("build-fixtures",[sys.executable,
+        ROOT/"Standalone/Research/WorldAssemblerM3/Linux142/BuildL142Fixtures.py",
+        f"--out={fixture_dir}"],out/"logs"/"build-fixtures.log",env=env)
+
+    binaries = {"clang":args.headless_clang.resolve(),"gcc":args.headless_gcc.resolve()}
+    fixtures = {
+        "flatField-monolith":fixture_dir/"liminal-flatField-monolith.json",
+        "periodicHills":fixture_dir/"liminal-periodicHills.json",
+        "road-in-clouds":fixture_dir/"liminal-road-in-clouds.json",
+        "pillar-grid":fixture_dir/"liminal-pillar-grid.json",
+    }
+    probed = {}
+    for name,fixture in fixtures.items():
+        probe_dir=out/"plan-probes"/name
+        probe_dir.mkdir(parents=True,exist_ok=True)
+        camera=(0.0,0.0,-500.0)
+        output=run_step(f"plan-probe-{name}",headless_command(binaries["clang"],fixture,
+            camera,probe_dir/"probe.vfmesh",probe_dir/"manifest.json",
+            probe_dir/"layout.json",12,1),out/"logs"/f"plan-probe-{name}.log",
+            env=env,stamped=True)
+        if "[WorldAssemblerFullManifest]" not in output:
+            raise RuntimeError(f"{name} probe omitted its full plan manifest")
+        probed[name]=make_views(name,probe_dir/"manifest.json",probe_dir/"layout.json")
+
+    for name,fixture in fixtures.items():
+        run_determinism(name,fixture,probed[name],binaries=binaries,out=out,env=env)
+    run_road_walk_audit(fixtures["road-in-clouds"],probed["road-in-clouds"],
+        headless=binaries["clang"],out=out,env=env)
+    run_road_short_negative_control(fixture_dir/"liminal-road-short-control.json",
+        probed["road-in-clouds"],headless=binaries["clang"],out=out,env=env)
+    for name,fixture in fixtures.items():
+        export_and_capture(name,fixture,probed[name],headless=binaries["clang"],
+            renderer=args.renderer.resolve(),out=out,artifact_dir=artifact_dir,env=env)
+    return 0
+
+
+if __name__ == "__main__":
+    try:
+        raise SystemExit(main())
+    except Exception as error:
+        print(f"[L142Capture] status=FAIL error={error}",file=sys.stderr,flush=True)
+        raise SystemExit(1)

Standalone/Research/WorldAssemblerM3/Linux142/REPORT.md

@@ -0,0 +1,46 @@
+# L142 — liminal pass 2
+
+| Hills: eye height | Hills: wide |
+|---|---|
+| ![Periodic hills from eye height](captures/periodicHills-eye.jpg) | ![Periodic hills to the horizon](captures/periodicHills-wide.jpg) |
+
+| Road: eye height | Road: wide |
+|---|---|
+| ![Road edge over the cloud floor](captures/road-in-clouds-eye.jpg) | ![Swept road deck and supports above the cloud floor](captures/road-in-clouds-wide.jpg) |
+
+| Pillar grid: eye height | Pillar grid: wide |
+|---|---|
+| ![Pillars repeating along the horizon](captures/pillar-grid-eye.jpg) | ![Pillar grid from above](captures/pillar-grid-wide.jpg) |
+
+| Monolith: eye height | Monolith: wide |
+|---|---|
+| ![The retained monolith slice at eye height](captures/flatField-monolith-eye.jpg) | ![The retained monolith slice wide](captures/flatField-monolith-wide.jpg) |
+
+## Result
+
+The wide hill capture shows the validated 80 m repeating profile continuing across the horizon. The capture now streams LOD 0–8; the profile period and validator are unchanged.
+
+The road is a cubic swept path made from overlapping solid deck segments, not a chain of platform stamps. The earlier platform chain produced top steps; the swept deck passes the surface-sampled walk audit. Its wide view is capped at LOD 2 to keep the deck legible, so that frame shows a local section; the full route length is measured by the audit.
+
+The R47 addition is a 15×15 grid of identical pillars, spaced 76 m apart across a 1,064 m span. The monolith eye and wide views are retained as the first liminal slice.
+
+## Measurements
+
+- **Road:** 376.827 m horizontal path length, 8.000 m width, and 12.061° maximum sampled surface grade against the 15° limit. The deck rises and falls along the cubic profile. It has 17 supports at about 24 m spacing; the flat cloud floor is 44 m below the deck centerline (about 45 m below the walking surface), with pale fog in both views.
+- **Walk audit:** 901 surface stations at no more than 0.5 m spacing; 56,763 capsule samples; 0 blocked samples, 0 unsupported samples across 5,871 support probes, 0 grade failures, and 0 missed surface probes. The 180 m short-road control measured 210.341 m and failed the 300 m gate as expected.
+- **Capture quality:** all eight fixtures/views passed the image-quality gate at 1600×900. Hills and pillars stream through LOD 8; road eye and wide views use caps 3 and 2 respectively.
+- **Determinism:** the monolith, hills, road, and pillar fixtures each matched across Clang and GCC at W1, W8, and W12 (six compiler/worker cells per fixture), on source stamp `72f239e9534faa27e3796fe29207403b190558403841aeebc87d8e75e98e34c7`.
+
+## Checks
+
+- Clang 19 and GCC builds passed with floating-point contraction off, four build jobs, and the L142 source stamp.
+- `Standalone/Tools/verify/verify.py fast --out Saved/Linux/l142 --overall-timeout 1740` passed. Both current owner fixtures produced all 12 canonical hash rows matching the pinned L130-v227 baseline; W1 and W12 also matched each other.
+- The fast summary retains non-gating differences against older L46/L53 diagnostic baselines; the current pinned L130 canonical checks pass.
+- The L142 capture runner passed the walk audit, the short-road negative control, all four determinism comparisons, and all eight image-quality checks. Final logs are in `Saved/Linux/l142/logs/`.
+- No Unreal build or performance timing matrix was run. No Unreal `Source/` files changed. The inherited single-run near-ready timing step was removed from this picture-and-geometry runner rather than treated as a timing result.
+
+## Remaining limits
+
+The road wide capture frames a local section at LOD 2 to retain a continuous deck; the 376.827 m length is established by the full-route walk audit. Captures use the standalone Linux renderer rather than an Unreal viewport.
+
+Changed Unreal `Source/` files: none.

Standalone/Research/WorldAssemblerM3/Linux143/BuildL143Fixtures.py

@@ -0,0 +1,113 @@
+#!/usr/bin/env python3
+"""Build the L143 liminal pictures and walk-audit controls."""
+from __future__ import annotations
+
+import argparse
+import json
+import os
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OWNER = Path(os.environ.get("VOXELFORGE_OWNER_DATA",
+                            ROOT / "Standalone/data/owner_world.json"))
+OUT_DEFAULT = Path(os.environ.get("VOXELFORGE_VERIFY_OUT", ROOT / "Saved/Linux/l143"))
+
+FLAT_FIELD = {
+    "version": 1,
+    "kind": "flatField",
+    "minimum_arena_clearance_m": 0.0,
+}
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--out", type=Path, default=OUT_DEFAULT / "fixtures")
+    args = parser.parse_args()
+    args.out.mkdir(parents=True, exist_ok=True)
+    base = json.loads(OWNER.read_text(encoding="utf-8"))
+
+    monolith = dict(base)
+    monolith["surface_profile_override"] = dict(FLAT_FIELD)
+    monolith["motif_family_override"] = {
+        "version": 1,
+        "strate_index": 0,
+        "placement_policy": "seed,strate,stable_id",
+        "motifs": [{
+            "stable_id": "liminal/oversized-familiar-monolith-v1",
+            "kind": "cappedCylinder",
+            "radius_m": 1.6,
+            "height_m": 26.0,
+            "route_side_offset_m": 42.0,
+            "placement_radius_m": 0.0,
+            "fillet_radius_m": 0.6,
+            "blend_width_m": 1.2,
+            "minimum_spacing_m": 0.0,
+            "yaw_quarter_turns": 0,
+            "attachment": "seated_floor",
+        }],
+    }
+
+    hills = dict(base)
+    hills["surface_profile_override"] = {
+        "version": 1,
+        "kind": "periodicHills",
+        "amplitude_x_m": 2.2,
+        "amplitude_y_m": 2.2,
+        "wavelength_x_m": 80.0,
+        "wavelength_y_m": 80.0,
+        "minimum_arena_clearance_m": 0.0,
+    }
+
+    road_override = {
+        "stable_id": "liminal/road-clouds-v2",
+        "strate_index": 0,
+        "start_xy_m": [120.0, 340.0],
+        "path_length_m": 360.0,
+        "curve_control_offset_m": 84.0,
+        "deck_height_above_field_m": 44.0,
+        "rise_control_m": 22.0,
+        "half_width_m": 4.0,
+        "half_thickness_m": 1.0,
+        "sample_spacing_m": 1.0,
+        "support_spacing_m": 24.0,
+        "support_radius_m": 0.55,
+    }
+    road = dict(base)
+    road["surface_profile_override"] = dict(FLAT_FIELD)
+    road["liminal_road_override"] = dict(road_override)
+
+    short_control = dict(base)
+    short_control["surface_profile_override"] = dict(FLAT_FIELD)
+    short_override = dict(road_override)
+    short_override["path_length_m"] = 180.0
+    short_control["liminal_road_override"] = short_override
+
+    pillars = dict(base)
+    pillars["surface_profile_override"] = dict(FLAT_FIELD)
+    pillars["liminal_pillar_grid_override"] = {
+        "stable_id": "liminal/horizon-pillar-grid-v1",
+        "strate_index": 0,
+        "center_xy_m": [700.0, 800.0],
+        "rows": 15,
+        "columns": 15,
+        "spacing_m": 76.0,
+        "radius_m": 5.5,
+        "height_m": 40.0,
+    }
+
+    fixtures = (
+        ("flatField-monolith", monolith),
+        ("periodicHills", hills),
+        ("road-in-clouds", road),
+        ("road-short-control", short_control),
+        ("pillar-grid", pillars),
+    )
+    for name, fixture in fixtures:
+        path = args.out / f"liminal-{name}.json"
+        path.write_text(json.dumps(fixture, indent=2) + "\n", encoding="utf-8")
+        print(f"[L143Fixture] name={name} file={path} status=PASS")
+
+
+if __name__ == "__main__":
+    main()

Standalone/Research/WorldAssemblerM3/Linux143/CaptureL143.py

@@ -0,0 +1,463 @@
+#!/usr/bin/env python3
+"""Run L143 liminal determinism checks, walk audits and multi-LOD captures."""
+from __future__ import annotations
+
+import argparse
+import hashlib
+import json
+import math
+import os
+from pathlib import Path
+import re
+import shutil
+import subprocess
+import sys
+import time
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT_DEFAULT = Path(os.environ.get("VOXELFORGE_VERIFY_OUT", ROOT / "Saved/Linux/l143"))
+CAPTURE_DEFAULT = Path(__file__).resolve().parent / "captures"
+LIMIT = ["taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--"]
+Q_PER_METRE = 1024.0
+FOG_COLOR = "0.66,0.73,0.77"
+
+sys.path.insert(0, str(ROOT / "Standalone/Tools/verify"))
+from runner import bounded_run, current_stamp, first_stamp
+
+
+def fmt(values) -> str:
+    return ",".join(f"{value:.6f}" for value in values)
+
+
+def sha256(path: Path) -> str:
+    digest = hashlib.sha256()
+    with path.open("rb") as stream:
+        for block in iter(lambda: stream.read(1024 * 1024), b""):
+            digest.update(block)
+    return digest.hexdigest()
+
+
+def run_step(name: str, command: list[object], log: Path, *, env: dict[str, str],
+             stamped: bool = False, timeout_seconds: int = 1740,
+             expected_exit: int = 0) -> str:
+    expected_stamp = current_stamp() if stamped else None
+    if stamped:
+        binary = Path(str(command[0]))
+        probe = bounded_run([str(binary), "--print-source-stamp"], timeout=15)
+        if probe is None or probe.returncode != 0 or first_stamp(probe.stdout or "") != expected_stamp:
+            raise RuntimeError(f"{name} refused a stale executable: {binary}")
+    started = time.monotonic()
+    log.parent.mkdir(parents=True, exist_ok=True)
+    with log.open("w", encoding="utf-8") as stream:
+        result = subprocess.run([*LIMIT, f"timeout", f"{timeout_seconds}s",
+                                 *map(str, command)], cwd=ROOT, env=env,
+                                stdout=stream, stderr=subprocess.STDOUT,
+                                timeout=timeout_seconds + 5, check=False)
+    elapsed = time.monotonic() - started
+    output = log.read_text(encoding="utf-8", errors="replace")
+    print(f"[L143Run] step={name} elapsed_s={elapsed:.3f} exit={result.returncode} log={log}",
+          flush=True)
+    if stamped and (first_stamp(output) != expected_stamp or current_stamp() != expected_stamp):
+        raise RuntimeError(f"{name} source stamp mismatch; see {log}")
+    if result.returncode != expected_exit:
+        raise RuntimeError(f"{name} exit={result.returncode}, expected={expected_exit}; see {log}")
+    return output
+
+
+def route_frame(manifest_path: Path) -> tuple[tuple[float, float, float],
+                                               tuple[float, float, float]]:
+    manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
+    strata = [entry for entry in manifest["plan"]["strates"]
+              if entry.get("route") and len(entry["route"]) >= 2]
+    if not strata:
+        raise RuntimeError(f"no planned SurfaceWorld route in {manifest_path}")
+    route = strata[0]["route"]
+    points = [tuple(float(value) / Q_PER_METRE for value in item["position_q"])
+              for item in route]
+    lengths = [math.dist(a, b) for a, b in zip(points, points[1:])]
+    total = sum(lengths)
+    if total <= 1.0e-6:
+        raise RuntimeError(f"degenerate planned route in {manifest_path}")
+
+    def at(distance: float) -> tuple[float, float, float]:
+        remaining = max(0.0, min(total, distance))
+        for index, (a, b, length) in enumerate(zip(points, points[1:], lengths)):
+            if remaining <= length or index == len(lengths) - 1:
+                if length <= 1.0e-9:
+                    return b
+                t = remaining / length
+                return tuple(a[axis] + (b[axis] - a[axis]) * t for axis in range(3))
+            remaining -= length
+        return points[-1]
+
+    center = at(total * 0.5)
+    before, after = at(total * 0.5 - 1.0), at(total * 0.5 + 1.0)
+    dx, dy = after[0] - before[0], after[1] - before[1]
+    length = math.hypot(dx, dy)
+    if length <= 1.0e-9:
+        raise RuntimeError(f"degenerate route tangent in {manifest_path}")
+    return center, (dx / length, dy / length, 0.0)
+
+
+def camera_angles(camera, target) -> tuple[float, float]:
+    dx, dy, dz = (target[index] - camera[index] for index in range(3))
+    return math.degrees(math.atan2(dx, dy)), math.degrees(math.atan2(dz, math.hypot(dx, dy)))
+
+
+def point_toward(camera, target) -> tuple[float, ...]:
+    yaw, pitch = camera_angles(camera, target)
+    return (*camera, yaw, pitch)
+
+
+def stamp(layout: dict, stable_id: str) -> dict:
+    for record in layout.get("stamps", []):
+        if record.get("stable_id") == stable_id:
+            return record
+    raise RuntimeError(f"missing resolved stamp {stable_id}")
+
+
+def make_views(name: str, manifest_path: Path, layout_path: Path):
+    manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
+    layout = json.loads(layout_path.read_text(encoding="utf-8"))
+    center, tangent = route_frame(manifest_path)
+    tx, ty, _ = tangent
+    nx, ny = -ty, tx
+    base_height = manifest["recipe"]["surface_profile"]["h0_q"] / Q_PER_METRE
+    if name == "flatField-monolith":
+        monolith = stamp(layout, "liminal/oversized-familiar-monolith-v1")
+        sx, sy, _ = (value / 1.0e6 for value in monolith["position_um"])
+        floor = monolith["floor_um"] / 1.0e6
+        eye_camera = (sx - tx * 36.0, sy - ty * 36.0, floor + 1.6)
+        eye_target = (sx, sy, floor + 10.5)
+        wide_camera = (sx - tx * 42.0 - nx * 18.0,
+                       sy - ty * 42.0 - ny * 18.0, floor + 42.0)
+        wide_target = (sx, sy, floor + 8.0)
+        return {
+            "eye": (eye_camera, eye_target, 20),
+            "wide": (wide_camera, wide_target, 24),
+            "height_center": floor,
+            "height_range": 38.0,
+        }
+    if name == "periodicHills":
+        # Route points are capsule centers: +0.72 m places the view at 1.60 m above ground.
+        eye_camera = (center[0], center[1], center[2] + 0.72)
+        eye_target = (center[0] - tx * 360.0, center[1] - ty * 360.0,
+                      center[2] + 0.72)
+        wide_camera = (center[0] - tx * 36.0 - nx * 28.0,
+                       center[1] - ty * 36.0 - ny * 28.0, center[2] + 30.0)
+        wide_target = (center[0] - tx * 310.0, center[1] - ty * 310.0,
+                       center[2] + 0.72)
+        return {
+            "eye": (eye_camera, eye_target, 20),
+            "wide": (wide_camera, wide_target, 28),
+            "height_center": base_height,
+            "height_range": 6.0,
+        }
+    if name == "road-in-clouds":
+        deck = stamp(layout,"liminal/road-clouds-v2/deck/000")
+        path_um = deck.get("sweep_path_um", [])
+        if len(path_um) < 2:
+            raise RuntimeError("road layout has no resolved continuous swept path")
+        points = [tuple(value / 1.0e6 for value in point) for point in path_um]
+        half_thickness = deck["half_extents_um"][2] / 1.0e6
+        top = lambda point: point[2] + half_thickness
+        index = max(1, len(points) // 12)
+        camera_dx = points[index + 1][0] - points[index - 1][0]
+        camera_dy = points[index + 1][1] - points[index - 1][1]
+        camera_tangent_length = math.hypot(camera_dx, camera_dy)
+        camera_tx, camera_ty = (camera_dx / camera_tangent_length,
+                                 camera_dy / camera_tangent_length)
+        camera_nx, camera_ny = -camera_ty, camera_tx
+        half_width = deck["half_extents_um"][1] / 1.0e6
+        eye_target_index = min(len(points) - 1, index + 25)
+        eye_camera = (points[index][0] + camera_nx * (half_width + 2.0),
+                      points[index][1] + camera_ny * (half_width + 2.0),
+                      top(points[index]) + 1.6)
+        eye_target = (points[eye_target_index][0] + camera_nx * (half_width - 0.4),
+                      points[eye_target_index][1] + camera_ny * (half_width - 0.4),
+                      top(points[eye_target_index]) + 0.3)
+        middle = len(points) // 2
+        dx = points[middle + 1][0] - points[middle - 1][0]
+        dy = points[middle + 1][1] - points[middle - 1][1]
+        tangent_length = math.hypot(dx, dy)
+        tx, ty = dx / tangent_length, dy / tangent_length
+        nx, ny = -ty, tx
+        wide_target_index = min(len(points) - 1, middle + 30)
+        wide_camera = (points[middle][0] - tx * 35.0 + nx * 30.0,
+                       points[middle][1] - ty * 35.0 + ny * 30.0,
+                       top(points[middle]) + 25.0)
+        wide_target = (points[wide_target_index][0], points[wide_target_index][1],
+                       top(points[wide_target_index]) - 5.0)
+        cloud_camera = (points[middle][0] - tx * 18.0 + nx * 12.0,
+                        points[middle][1] - ty * 18.0 + ny * 12.0,
+                        base_height + 1.6)
+        cloud_target = (points[middle][0] + tx * 8.0,
+                        points[middle][1] + ty * 8.0,
+                        points[middle][2] - half_thickness * 0.35)
+        return {
+            "eye": (eye_camera, eye_target, 3),
+            "wide": (wide_camera, wide_target, 3),
+            "cloud-up": (cloud_camera, cloud_target, 3),
+            "height_center": base_height + 23.0,
+            "height_range": 60.0,
+            "road_deck": top(points[middle]),
+            "road_width": 2.0 * half_width,
+        }
+    if name == "pillar-grid":
+        pillars = [row for row in layout.get("stamps", [])
+            if row.get("stable_id", "").startswith("liminal/horizon-pillar-grid-v1/pillar/")]
+        if len(pillars) < 9:
+            raise RuntimeError("pillar-grid layout has too few resolved supports")
+        xs = [row["position_um"][0] / 1.0e6 for row in pillars]
+        ys = [row["position_um"][1] / 1.0e6 for row in pillars]
+        floor = min((row["position_um"][2] - row["half_extents_um"][2]) / 1.0e6
+                    for row in pillars)
+        cx, cy = (min(xs) + max(xs)) * 0.5, (min(ys) + max(ys)) * 0.5
+        eye_camera = (min(xs) - 78.0, cy, floor + 1.6)
+        eye_target = (max(xs) + 90.0, cy, floor + 1.6)
+        wide_camera = (cx - 280.0, cy - 420.0, floor + 230.0)
+        wide_target = (cx, cy, floor + 6.0)
+        return {
+            "eye": (eye_camera, eye_target, 3),
+            "wide": (wide_camera, wide_target, 3),
+            "height_center": floor + 12.0,
+            "height_range": 42.0,
+        }
+    raise RuntimeError(f"no capture framing for fixture {name}")
+
+
+def headless_command(binary: Path, fixture: Path, camera, mesh: Path,
+                     manifest: Path, layout: Path, workers: int,
+                     clip_radius: int, *, hash_tiles: bool = False,
+                     audit_road: bool = False, max_level: int = 0,
+                     far_lods: bool = False,
+                     max_clip_override: int | None = None) -> list[object]:
+    max_clip_level = (max_clip_override if max_clip_override is not None else
+                      8 if far_lods else max_level)
+    command: list[object] = [binary, fixture, f"--workers={workers}",
+        "--seed=0", "--world-assembler-prototype", "--stream-benchmark", "--stream-pipeline",
+        "--force-generate", f"--clip-radius={clip_radius}",
+        f"--max-clip-level={max_clip_level}",
+        f"--max-level={max_level}", "--render-distance-chunks=0",
+        f"--camera={fmt(point_toward(camera, (camera[0], camera[1] + 1.0, camera[2])))}",
+        f"--mesh-export={mesh}", f"--world-assembler-manifest-output={manifest}",
+        f"--resolved-layout-output={layout}"]
+    if hash_tiles:
+        command.append("--stream-hash-tiles")
+    if audit_road:
+        command.append("--audit-liminal-road-walk")
+    return command
+
+
+def determinism_digest(output: str, manifest_path: Path,
+                       layout_path: Path) -> tuple[str, str, str]:
+    tile_hashes = sorted(line for line in output.splitlines()
+                         if line.startswith("[PipelineTileHash] "))
+    if not manifest_path.is_file() or not layout_path.is_file() or not tile_hashes:
+        raise RuntimeError("determinism run omitted manifest, layout or per-tile hashes")
+    manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
+    layout = json.loads(layout_path.read_text(encoding="utf-8"))
+    manifest_digest = (manifest["content_hash"],manifest["recipe"]["content_hash"],
+                       manifest["plan"]["content_hash"])
+    return ("|".join(manifest_digest),layout["stable_identity"],"\n".join(tile_hashes))
+
+
+def run_determinism(name: str, fixture: Path, view, *, binaries: dict[str, Path],
+                    out: Path, env: dict[str, str], max_level: int = 0,
+                    far_lods: bool = False, max_clip_override: int | None = None) -> None:
+    camera, _, _ = view["eye"]
+    clip_radius = 1
+    max_clip = 0
+    baseline = None
+    cells = 0
+    for compiler, workers in ((compiler, workers)
+                              for compiler in ("clang", "gcc")
+                              for workers in (1, 8, 12)):
+        tag = f"{name}-{compiler}-w{workers}"
+        run_dir = out / "determinism" / tag
+        run_dir.mkdir(parents=True, exist_ok=True)
+        mesh = run_dir / "feature.vfmesh"
+        manifest = run_dir / "manifest.json"
+        layout = run_dir / "layout.json"
+        command = headless_command(binaries[compiler], fixture,camera,mesh,manifest,
+            layout,workers,max_clip,hash_tiles=True,max_level=max_level,
+            far_lods=far_lods,max_clip_override=max_clip_override)
+        output = run_step(tag,command,out/"logs"/f"determinism-{tag}.log",
+                          env=env,stamped=True)
+        digest = determinism_digest(output,manifest,layout)
+        if baseline is None:
+            baseline = digest
+        elif digest != baseline:
+            raise RuntimeError(f"{name} diverged at {compiler} W{workers}; see determinism logs")
+        cells += 1
+    print(f"[L143Determinism] fixture={name} compiler_worker_cells={cells} identical=yes status=PASS",
+          flush=True)
+
+
+def export_and_capture(name: str, fixture: Path, views: dict, *,
+                       headless: Path, renderer: Path, out: Path,
+                       artifact_dir: Path, env: dict[str, str]) -> None:
+    view_names = ("eye", "wide", "cloud-up") if name == "road-in-clouds" else ("eye", "wide")
+    for view_name in view_names:
+        camera, target, clip_radius = views[view_name]
+        clip_radius = min(clip_radius,3)
+        stem = f"{name}-{view_name}"
+        mesh = out / "capture-meshes" / f"{stem}.vfmesh"
+        manifest = out / "capture-manifests" / f"{stem}.json"
+        layout = out / "capture-layouts" / f"{stem}.json"
+        png = out / "capture-png" / f"{stem}.png"
+        image = artifact_dir / f"{stem}.jpg"
+        for path in (mesh,manifest,layout,png,image):
+            path.parent.mkdir(parents=True,exist_ok=True)
+        command = headless_command(headless,fixture,camera,mesh,manifest,layout,12,
+            clip_radius,max_level=-1,far_lods=True,
+            max_clip_override=2 if name == "road-in-clouds" else None)
+        output = run_step(f"capture-{stem}-export",command,
+            out/"logs"/f"capture-{stem}-export.log",env=env,stamped=True)
+        if not mesh.is_file() or mesh.stat().st_size == 0:
+            raise RuntimeError(f"{stem} produced an empty mesh")
+        yaw, pitch = camera_angles(camera,target)
+        height_center = views["height_center"]
+        height_range = views["height_range"]
+        if name == "road-in-clouds":
+            fog_start,fog_end,fog_color=(24,260,"0.88,0.93,0.95")
+        elif name == "pillar-grid":
+            fog_start,fog_end,fog_color=220,1250,"0.82,0.88,0.91"
+        elif name == "periodicHills":
+            fog_start,fog_end,fog_color=210,1000,"0.78,0.84,0.88"
+        else:
+            fog_start,fog_end,fog_color=30,105,FOG_COLOR
+        renderer_command = [renderer,mesh,png,"--size=1600x900","--fov-deg=72",
+            f"--camera-m={fmt(camera)}",f"--yaw-deg={yaw:.6f}",
+            f"--pitch-deg={pitch:.6f}","--tile-skirts=on","--shade=readable",
+            "--headlamp=off","--height-tint=on",f"--height-center-m={height_center:.6f}",
+            f"--height-range-m={height_range:.6f}","--light-direction=-0.42,-0.58,0.70",
+            "--fog=on",f"--fog-start-m={fog_start}",f"--fog-end-m={fog_end}",
+            f"--fog-color={fog_color}"]
+        run_step(f"capture-{stem}-render",renderer_command,
+            out/"logs"/f"capture-{stem}-render.log",env=env,stamped=True)
+        run_step(f"capture-{stem}-jpeg",["ffmpeg","-nostdin","-hide_banner","-loglevel",
+            "error","-y","-i",png,"-frames:v","1","-q:v","4",image],
+            out/"logs"/f"capture-{stem}-jpeg.log",env=env)
+        quality = run_step(f"capture-{stem}-quality",
+            [sys.executable,ROOT/"Standalone/Tools/verify/capture_quality.py",image],
+            out/"logs"/f"capture-{stem}-quality.log",env=env)
+        if "[CaptureQuality]" not in quality or not image.is_file() \
+                or image.stat().st_size > 300_000:
+            raise RuntimeError(f"{stem} capture failed quality or size checks")
+        eye_height = "1.600m" if view_name in ("eye", "cloud-up") else "wide"
+        print(f"[L143Capture] fixture={name} view={view_name} eye_height={eye_height} "
+              f"camera_m=({fmt(camera)}) target_m=({fmt(target)}) bytes={image.stat().st_size} "
+              f"sha256={sha256(image)} status=PASS",flush=True)
+
+
+def run_road_walk_audit(fixture: Path, view, *, headless: Path,
+                        out: Path, env: dict[str, str]) -> None:
+    camera = view["eye"][0]
+    run_dir = out / "road-walk-audit"
+    run_dir.mkdir(parents=True,exist_ok=True)
+    output = run_step("road-walk-audit",headless_command(headless,fixture,camera,
+        run_dir/"audit.vfmesh",run_dir/"manifest.json",run_dir/"layout.json",12,1,
+        audit_road=True),out/"logs"/"road-walk-audit.log",env=env,stamped=True)
+    if not re.search(r"\[LiminalRoadWalkAudit\].*status=PASS",output):
+        raise RuntimeError("raised road failed the Core capsule walk audit")
+
+
+def run_road_short_negative_control(fixture: Path, view, *, headless: Path,
+                                    out: Path, env: dict[str, str]) -> None:
+    camera = view["eye"][0]
+    run_dir = out / "road-short-negative-control"
+    run_dir.mkdir(parents=True,exist_ok=True)
+    output = run_step("road-short-negative-control",
+        headless_command(headless,fixture,camera,run_dir/"control.vfmesh",
+            run_dir/"manifest.json",run_dir/"layout.json",12,1,audit_road=True),
+        out/"logs"/"road-short-negative-control.log",env=env,stamped=True,
+        expected_exit=14)
+    match = re.search(r"\[LiminalRoadWalkAudit\].*path_length_m=([0-9.]+).*status=FAIL",output)
+    if not match or float(match.group(1)) >= 300.0:
+        raise RuntimeError("short-road negative control did not falsify the length gate")
+    print(f"[L143RoadNegativeControl] path_length_m={match.group(1)} "
+          "expected=FAIL status=PASS",flush=True)
+
+
+def retain_unchanged_captures(artifact_dir: Path) -> None:
+    reference_dir = Path(__file__).resolve().parents[1] / "Linux142" / "captures"
+    for name in ("flatField-monolith", "periodicHills"):
+        for view in ("eye", "wide"):
+            filename = f"{name}-{view}.jpg"
+            source, destination = reference_dir / filename, artifact_dir / filename
+            if not source.is_file():
+                raise RuntimeError(f"missing L142 reference capture {source}")
+            shutil.copy2(source,destination)
+            if sha256(source) != sha256(destination):
+                raise RuntimeError(f"unchanged reference capture copy differs: {filename}")
+            print(f"[L143Capture] fixture={name} view={view} retained_from=Linux142 "
+                  f"sha256={sha256(destination)} status=PASS",flush=True)
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--out", type=Path, default=OUT_DEFAULT)
+    parser.add_argument("--artifact-dir", type=Path, default=CAPTURE_DEFAULT)
+    parser.add_argument("--headless-clang", type=Path, required=True)
+    parser.add_argument("--headless-gcc", type=Path, required=True)
+    parser.add_argument("--renderer", type=Path, required=True)
+    args = parser.parse_args()
+
+    out = args.out.resolve()
+    artifact_dir = args.artifact_dir.resolve()
+    fixture_dir = out / "fixtures"
+    for directory in (out,fixture_dir,artifact_dir):
+        directory.mkdir(parents=True,exist_ok=True)
+    env = os.environ.copy()
+    env["VOXELFORGE_VERIFY_OUT"] = str(out)
+    env["VOXELFORGE_OWNER_DATA"] = str(ROOT/"Standalone/data/owner_world.json")
+    env["LP_NUM_THREADS"] = "12"
+    env["XDG_CACHE_HOME"] = str(out/"xdg-cache")
+    run_step("build-fixtures",[sys.executable,
+        ROOT/"Standalone/Research/WorldAssemblerM3/Linux143/BuildL143Fixtures.py",
+        f"--out={fixture_dir}"],out/"logs"/"build-fixtures.log",env=env)
+
+    binaries = {"clang":args.headless_clang.resolve(),"gcc":args.headless_gcc.resolve()}
+    fixtures = {
+        "flatField-monolith":fixture_dir/"liminal-flatField-monolith.json",
+        "periodicHills":fixture_dir/"liminal-periodicHills.json",
+        "road-in-clouds":fixture_dir/"liminal-road-in-clouds.json",
+        "pillar-grid":fixture_dir/"liminal-pillar-grid.json",
+    }
+    probed = {}
+    for name,fixture in fixtures.items():
+        probe_dir=out/"plan-probes"/name
+        probe_dir.mkdir(parents=True,exist_ok=True)
+        camera=(0.0,0.0,-500.0)
+        output=run_step(f"plan-probe-{name}",headless_command(binaries["clang"],fixture,
+            camera,probe_dir/"probe.vfmesh",probe_dir/"manifest.json",
+            probe_dir/"layout.json",12,1),out/"logs"/f"plan-probe-{name}.log",
+            env=env,stamped=True)
+        if "[WorldAssemblerFullManifest]" not in output:
+            raise RuntimeError(f"{name} probe omitted its full plan manifest")
+        probed[name]=make_views(name,probe_dir/"manifest.json",probe_dir/"layout.json")
+
+    for name,fixture in fixtures.items():
+        run_determinism(name,fixture,probed[name],binaries=binaries,out=out,env=env)
+    run_determinism("pillar-grid-far-lod",fixtures["pillar-grid"],probed["pillar-grid"],
+        binaries=binaries,out=out,env=env,max_level=-1,far_lods=True,max_clip_override=8)
+    run_road_walk_audit(fixtures["road-in-clouds"],probed["road-in-clouds"],
+        headless=binaries["clang"],out=out,env=env)
+    run_road_short_negative_control(fixture_dir/"liminal-road-short-control.json",
+        probed["road-in-clouds"],headless=binaries["clang"],out=out,env=env)
+    retain_unchanged_captures(artifact_dir)
+    for name in ("road-in-clouds", "pillar-grid"):
+        fixture=fixtures[name]
+        export_and_capture(name,fixture,probed[name],headless=binaries["clang"],
+            renderer=args.renderer.resolve(),out=out,artifact_dir=artifact_dir,env=env)
+    return 0
+
+
+if __name__ == "__main__":
+    try:
+        raise SystemExit(main())
+    except Exception as error:
+        print(f"[L143Capture] status=FAIL error={error}",file=sys.stderr,flush=True)
+        raise SystemExit(1)

Standalone/Research/WorldAssemblerM3/Linux143/REPORT.md

@@ -0,0 +1,64 @@
+# L143 — liminal polish
+
+## Captures
+
+### Road
+
+Eye-height:
+
+![Road deck at eye height](captures/road-in-clouds-eye.jpg)
+
+Wide:
+
+![Road deck and supports, wide view](captures/road-in-clouds-wide.jpg)
+
+Looking up from the cloud floor:
+
+![Road deck underside from the cloud floor](captures/road-in-clouds-cloud-up.jpg)
+
+### Pillar grid
+
+Eye-height:
+
+![Pillar grid at eye height](captures/pillar-grid-eye.jpg)
+
+Wide:
+
+![Pillar grid, wide view](captures/pillar-grid-wide.jpg)
+
+### Kept from L142
+
+These four captures are byte-identical to L142.
+
+![Monolith, eye view](captures/flatField-monolith-eye.jpg)
+
+![Monolith, wide view](captures/flatField-monolith-wide.jpg)
+
+![Periodic hills, eye view](captures/periodicHills-eye.jpg)
+
+![Periodic hills, wide view](captures/periodicHills-wide.jpg)
+
+## Result
+
+The road is one continuous swept deck, and the distant pillar silhouettes remain complete and consistent. The monolith and periodic hills were retained unchanged.
+
+## Changes and causes
+
+- The road edge broke where independently capped deck segments overlapped. The road now resolves to one swept-deck stamp with a shared cubic-Hermite centerline and continuous cross-section; the centerline is sampled at 1 m spacing (361 points). The 8 m deck is 376.829 m long and retains 17 support posts. The sweep path is serialized in stamp-vocabulary V5.
+- Pillars disappeared or narrowed when the coarse marching-cubes lattice skipped their cross-section. The pillar stamp's interval proof is unsupported, so it conservatively kept tiles but did not protect the mesh from undersampling. At LOD4 the sample spacing is 32 voxels (8 m), already greater than the 5.5 m pillar radius; spacing rises to 64 and 128 voxels at LOD5 and LOD6. The shared meshing path now emits deterministic 24-sided capped-cylinder proxies for regular `fillPillar` stamps once the sample step exceeds their radius or half-height. The same rule applies outside the liminal fixture. The radial approximation error for this fixture is about 4.7 cm, below one 25 cm voxel.
+
+## Measurements
+
+- Road walk audit covered the full 376.829 m route at 1,081 surface stations, with 68,103 capsule samples and 7,096 support samples: 0 blocked, 0 unsupported, 0 grade failures, and 0 surface misses. Measured maximum grade was 8.512° against a 15° limit; deck width was 8 m against a 3 m minimum. `road-short-negative-control` failed the walk audit as expected at 210.351 m.
+- Determinism covered five fixtures—monolith, periodic hills, road, pillar grid, and far-LOD pillar grid—across Clang/GCC and W1/W8/W12 (six compiler/worker cells per fixture). All five reported identical outputs.
+- Clang and GCC builds passed on source stamp `1baa3a711f7f96df2e70fc93579f41ad0b0211eb42fcb51dabf522e33d888877`. The capture runner and capture-quality checks passed for all requested views.
+- Fast tier passed in 292.3 s. Its pinned L130-v227 reach-unit owner hashes match exactly: 12/12 rows for each owner fixture, with W1 and W12 identical. Historical L46/L53 hash comparisons remain diagnostic-only and are not the current owner-hash gate.
+
+## Checks and limits
+
+- Passed: road audit and short-road negative control; five-fixture Clang/GCC determinism; Clang and GCC builds; capture quality; fast tier; `git diff --check`.
+- Not run: Unreal build (no Unreal `Source/` files changed) and L80 performance timing (this round made no performance claim).
+- The coarse proxy is limited to regular `fillPillar` stamps; irregular pillars and other stamp kinds continue through their existing SDF path. The proxy was exercised at LOD4–6 in the pillar-grid captures.
+- Unreal `Source/` files changed: none. Changed standalone source files: `Standalone/Core/include/VoxelForgeCore/VoxelForgeCore.h`, `Standalone/Core/src/ResolvedLayoutInternal.h`, `Standalone/Core/src/ShapeWorldInternal.h`, `Standalone/Core/src/VoxelForgeCore.cpp`, `Standalone/Source/StreamBenchmarkHeadless.cpp`, `Standalone/Source/StreamBenchmarkPipeline.h`, and `Standalone/Source/WorldAssemblyPrototype.h`.
+
+Detailed logs are in `Saved/Linux/l143/`; the capture and audit transcript is `Saved/Linux/l143/logs/capture-runner.log`, the walk audit is `Saved/Linux/l143/logs/road-walk-audit.log`, and the fast-tier summary is `Saved/Linux/l143/fast-summary.json`.

Standalone/Research/WorldAssemblerM3/Linux144/BuildL144Fixtures.py

@@ -0,0 +1,58 @@
+#!/usr/bin/env python3
+"""Build the 3-strata composed Core.Liminal.Field fixture."""
+from __future__ import annotations
+
+import argparse
+import json
+import os
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OWNER = Path(os.environ.get("VOXELFORGE_OWNER_DATA",
+                            ROOT / "Standalone/data/owner_world.json"))
+OUT_DEFAULT = Path(os.environ.get("VOXELFORGE_VERIFY_OUT", ROOT / "Saved/Linux/l144"))
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--out", type=Path, default=OUT_DEFAULT / "fixtures")
+    args = parser.parse_args()
+    args.out.mkdir(parents=True, exist_ok=True)
+    world = json.loads(OWNER.read_text(encoding="utf-8"))
+    if len(world.get("strates", [])) < 3:
+        raise SystemExit("owner fixture needs at least three authored strate slots")
+
+    world["strates"] = world["strates"][:3]
+    world["total_strates"] = 3
+    world["settings_asset"]["TotalStrates"] = 3
+    world["settings_asset"]["FixedStrates"] = world["settings_asset"]["FixedStrates"][:3]
+    # Keep the resolved arrival near the departure depth. The owner's 5000-unit
+    # reach clamps to liminal bedrock on most seeds and leaves no field floor.
+    world["strates"][0]["passage_config"]["ReachMin"] = 1536
+    world["strates"][0]["passage_config"]["ReachMax"] = 1792
+    world["surface_profile_override"] = {
+        "version": 1,
+        "kind": "flatField",
+        "minimum_arena_clearance_m": 0.0,
+    }
+    middle = world["strates"][1]
+    middle["asset"]["GeneratorType"] = 4  # ECaveGeneratorType::SurfaceWorld
+    middle["asset"]["StrateName"] = "Liminal Field"
+    # Keep the departure mouth 24–32 m above liminal bedrock so every variant
+    # has room for its floor, road landing and support footings.
+    middle["passage_config"]["ReachMin"] = 192
+    middle["passage_config"]["ReachMax"] = 256
+    world["core_liminal_field"] = {
+        "version": 1,
+        "strate_index": int(middle["index"]),
+        "variant_policy": "seed_modulo_4",
+    }
+
+    output = args.out / "core-liminal-field-3-strata.json"
+    output.write_text(json.dumps(world, separators=(",", ":")) + "\n", encoding="utf-8")
+    print(f"[L144Fixture] path={output} strates=SurfaceWorld,Core.Liminal.Field,TunnelNetwork status=PASS")
+
+
+if __name__ == "__main__":
+    main()

Standalone/Research/WorldAssemblerM3/Linux144/CaptureL144.py

@@ -0,0 +1,243 @@
+#!/usr/bin/env python3
+"""Capture the four seed-selected Core.Liminal.Field v1 variants."""
+from __future__ import annotations
+
+import hashlib
+import json
+import math
+import os
+from pathlib import Path
+import subprocess
+import sys
+import time
+
+
+ROOT = Path(__file__).resolve().parents[4]
+HERE = Path(__file__).resolve().parent
+OUT = ROOT / "Saved/Linux/l144"
+CAPTURES = HERE / "captures"
+LIMIT = ["taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--"]
+Q_PER_METRE = 1024.0
+
+sys.path.insert(0, str(ROOT / "Standalone/Tools/verify"))
+from runner import bounded_run, current_stamp, first_stamp
+
+
+def fmt(values) -> str:
+    return ",".join(f"{value:.6f}" for value in values)
+
+
+def sha256(path: Path) -> str:
+    digest = hashlib.sha256()
+    with path.open("rb") as stream:
+        for block in iter(lambda: stream.read(1024 * 1024), b""):
+            digest.update(block)
+    return digest.hexdigest()
+
+
+def run_step(name: str, command: list[object], log: Path, env: dict[str, str],
+             stamped: bool = False) -> str:
+    expected_stamp = current_stamp() if stamped else None
+    if stamped:
+        binary = Path(str(command[0]))
+        probe = bounded_run([str(binary), "--print-source-stamp"], timeout=15)
+        if probe is None or probe.returncode != 0 \
+                or first_stamp(probe.stdout or "") != expected_stamp:
+            raise RuntimeError(f"{name} refused a stale executable: {binary}")
+    started = time.monotonic()
+    log.parent.mkdir(parents=True, exist_ok=True)
+    with log.open("w", encoding="utf-8") as stream:
+        result = subprocess.run([*LIMIT, "timeout", "1740s", *map(str, command)],
+            cwd=ROOT, env=env, stdout=stream, stderr=subprocess.STDOUT,
+            timeout=1745, check=False)
+    output = log.read_text(encoding="utf-8", errors="replace")
+    elapsed = time.monotonic() - started
+    print(f"[L144Run] step={name} elapsed_s={elapsed:.3f} exit={result.returncode} log={log}",
+          flush=True)
+    if stamped and (first_stamp(output) != expected_stamp
+                    or current_stamp() != expected_stamp):
+        raise RuntimeError(f"{name} source stamp mismatch; see {log}")
+    if result.returncode != 0:
+        raise RuntimeError(f"{name} exit={result.returncode}; see {log}")
+    return output
+
+
+def camera_angles(camera, target):
+    dx, dy, dz = (target[i] - camera[i] for i in range(3))
+    return math.degrees(math.atan2(dx, dy)), math.degrees(
+        math.atan2(dz, math.hypot(dx, dy)))
+
+
+def route_views(manifest_path: Path, layout_path: Path, name: str):
+    manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
+    layout = json.loads(layout_path.read_text(encoding="utf-8"))
+    plan = next(row for row in manifest["plan"]["strates"]
+                if row["strate_index"] == 1 and row.get("liminal_field", {}).get("version") == 1)
+    points = [tuple(value / Q_PER_METRE for value in row["position_q"])
+              for row in plan["route"]]
+    first, second = points[0], points[1]
+    dx, dy = second[0] - first[0], second[1] - first[1]
+    length = math.hypot(dx, dy)
+    if length <= 1.0e-6:
+        raise RuntimeError("Core.Liminal.Field arrival tangent is degenerate")
+    tx, ty = dx / length, dy / length
+    eye_camera = (first[0] - tx * 1.5, first[1] - ty * 1.5, first[2] + 1.6)
+    third = points[min(2, len(points) - 1)]
+    dx, dy = third[0] - first[0], third[1] - first[1]
+    tangent_length = math.hypot(dx, dy)
+    tx, ty = dx / tangent_length, dy / tangent_length
+    dz_per_metre = (third[2] - first[2]) / tangent_length
+    eye_target = (first[0] + tx * 40.0, first[1] + ty * 40.0,
+                  first[2] + dz_per_metre * 40.0 + 1.6)
+
+    middle = len(points) // 2
+    before, center, after = points[middle - 1], points[middle], points[middle + 1]
+    dx, dy = after[0] - before[0], after[1] - before[1]
+    length = math.hypot(dx, dy)
+    if length <= 1.0e-6:
+        raise RuntimeError("Core.Liminal.Field wide-view tangent is degenerate")
+    tx, ty = dx / length, dy / length
+    nx, ny = -ty, tx
+    floor = plan["liminal_field"]["floor_height_q"] / Q_PER_METRE
+    if name == "flatField-monolith":
+        monolith = next(row for row in layout.get("stamps", [])
+                        if row.get("stable_id") == "core/liminal-field/monolith/000")
+        monolith_center = tuple(value / 1.0e6 for value in monolith["position_um"])
+        floor = monolith_center[2] - monolith["half_extents_um"][2] / 1.0e6
+        wide_camera = (monolith_center[0] - tx * 30.0 + nx * 18.0,
+                       monolith_center[1] - ty * 30.0 + ny * 18.0, floor + 25.0)
+        wide_target = monolith_center
+    elif name == "periodicHills":
+        wide_camera = (center[0] - 20.0, center[1] - 25.0, floor + 10.0)
+        wide_target = (center[0] + 10.0, center[1] + 8.0, floor + 1.0)
+    elif name == "pillar-grid":
+        pillars = [row for row in layout.get("stamps", [])
+                   if row.get("stable_id", "").startswith("core/liminal-field/pillars/")]
+        if not pillars:
+            raise RuntimeError("pillar-grid layout has no resolved grid stamps")
+        pairs = []
+        for i, first_pillar in enumerate(pillars):
+            for second_pillar in pillars[i + 1:]:
+                a = first_pillar["position_um"]
+                b = second_pillar["position_um"]
+                dx, dy = (b[0] - a[0]) / 1.0e6, (b[1] - a[1]) / 1.0e6
+                separation = math.hypot(dx, dy)
+                if 60.0 <= separation <= 90.0:
+                    mx = (a[0] + b[0]) / 2.0e6
+                    my = (a[1] + b[1]) / 2.0e6
+                    pairs.append((math.hypot(mx - center[0], my - center[1]),
+                                  mx, my, dx / separation, dy / separation,
+                                  (a[2] + b[2]) / 2.0e6,
+                                  first_pillar["half_extents_um"][2] / 1.0e6))
+        if not pairs:
+            raise RuntimeError("pillar-grid has no neighboring resolved columns")
+        _, mx, my, tx, ty, pillar_z, half_height = min(pairs)
+        floor = pillar_z - half_height
+        nx, ny = -ty, tx
+        wide_camera = (center[0] - tx * 20.0 + nx * 25.0,
+                       center[1] - ty * 20.0 + ny * 25.0, center[2] + 8.0)
+        wide_target = (center[0], center[1], floor + 2.0)
+    else:
+        wide_camera = (center[0] - tx * 20.0 + nx * 25.0,
+                       center[1] - ty * 20.0 + ny * 25.0, center[2] + 8.0)
+        wide_target = (center[0], center[1], floor + 2.0)
+    return {"eye": (eye_camera, eye_target), "wide": (wide_camera, wide_target)}
+
+
+def capture_variant(seed: int, name: str, *, headless: Path, renderer: Path,
+                    fixture: Path, env: dict[str, str]):
+    stem = f"core-liminal-{name}-seed{seed:02d}"
+    plan_dir = OUT / "capture-plans" / stem
+    plan_dir.mkdir(parents=True, exist_ok=True)
+    manifest = plan_dir / "manifest.json"
+    layout = plan_dir / "layout.json"
+    command = [headless, fixture, "--workers=1", f"--seed={seed}",
+        "--world-assembler-prototype", "--stream-benchmark", "--stream-pipeline",
+        "--force-generate", "--clip-radius=1", "--max-clip-level=0", "--max-level=0",
+        "--render-distance-chunks=0", "--camera=0,0,-540,0,0",
+        f"--world-assembler-manifest-output={manifest}",
+        f"--resolved-layout-output={layout}"]
+    output = run_step(f"plan-{stem}", command, OUT / "logs" / f"capture-{stem}-plan.log",
+                      env, stamped=True)
+    if "[CoreLiminalFieldDraw]" not in output:
+        raise RuntimeError(f"{stem} plan omitted its Core liminal deck")
+    views = route_views(manifest, layout, name)
+    for view, (eye, target) in views.items():
+        work = OUT / "captures" / f"{stem}-{view}"
+        work.mkdir(parents=True, exist_ok=True)
+        view_manifest = work / "manifest.json"
+        view_layout = work / "layout.json"
+        mesh = work / "world.vfmesh"
+        yaw, pitch = camera_angles(eye, target)
+        camera = (*eye, yaw, pitch)
+        view_clip_radius = (5 if view == "wide" and name in {
+                                "flatField-monolith", "periodicHills"} else
+                            3)
+        command = [headless, fixture, "--workers=12", f"--seed={seed}",
+            "--world-assembler-prototype", "--stream-benchmark", "--stream-pipeline",
+            "--force-generate", f"--clip-radius={view_clip_radius}",
+            "--max-clip-level=0", "--max-level=0",
+            "--render-distance-chunks=0", "--capture-skip-walkability",
+            f"--camera={fmt(camera)}", f"--mesh-export={mesh}",
+            f"--world-assembler-manifest-output={view_manifest}",
+            f"--resolved-layout-output={view_layout}"]
+        output = run_step(f"export-{stem}-{view}", command,
+            OUT / "logs" / f"capture-{stem}-{view}-export.log", env, stamped=True)
+        if "[CoreLiminalFieldDraw]" not in output or not mesh.is_file() \
+                or mesh.stat().st_size == 0:
+            raise RuntimeError(f"{stem}-{view} export omitted its Core liminal deck or mesh")
+        png = work / f"{view}.png"
+        image = CAPTURES / f"{stem}-{view}.jpg"
+        fog = {
+            "flatField-monolith": (30, 180, "0.66,0.73,0.77", -708.0, 46.0),
+            "periodicHills": (140, 850, "0.78,0.84,0.88", -720.0, 14.0),
+            "road-over-cloud-floor": (24, 420, "0.88,0.93,0.95", -720.0, 65.0),
+            "pillar-grid": (180, 1200, "0.82,0.88,0.91", -720.0, 80.0),
+        }[name]
+        fog_start, fog_end, fog_color, height_center, height_range = fog
+        render = [renderer, mesh, png, "--size=1600x900", "--fov-deg=72",
+            f"--camera-m={fmt(eye)}", f"--yaw-deg={yaw:.6f}", f"--pitch-deg={pitch:.6f}",
+            "--tile-skirts=on", "--shade=readable", "--headlamp=off", "--height-tint=on",
+            f"--height-center-m={height_center:.6f}", f"--height-range-m={height_range:.6f}",
+            "--light-direction=-0.42,-0.58,0.70", "--fog=on", f"--fog-start-m={fog_start}",
+            f"--fog-end-m={fog_end}", f"--fog-color={fog_color}"]
+        run_step(f"render-{stem}-{view}", render,
+            OUT / "logs" / f"capture-{stem}-{view}-render.log", env, stamped=True)
+        run_step(f"jpeg-{stem}-{view}", ["ffmpeg", "-nostdin", "-hide_banner", "-loglevel",
+            "error", "-y", "-i", png, "-frames:v", "1", "-q:v", "4", image],
+            OUT / "logs" / f"capture-{stem}-{view}-jpeg.log", env)
+        run_step(f"quality-{stem}-{view}", [sys.executable,
+            ROOT / "Standalone/Tools/verify/capture_quality.py", image],
+            OUT / "logs" / f"capture-{stem}-{view}-quality.log", env)
+        print(f"[L144Capture] variant={name} seed={seed} view={view} "
+              f"eye_height={'1.600m' if view == 'eye' else 'wide'} bytes={image.stat().st_size} "
+              f"sha256={sha256(image)} status=PASS", flush=True)
+
+
+def main() -> int:
+    headless = ROOT / "Standalone/bin/linux/VoxelForgeCoreHeadless-clang19"
+    renderer = ROOT / "Standalone/bin/linux/VoxelForgeOffscreenCapture-clang19"
+    fixture = OUT / "fixtures/core-liminal-field-3-strata.json"
+    env = os.environ.copy()
+    env["VOXELFORGE_VERIFY_OUT"] = str(OUT)
+    env["VOXELFORGE_OWNER_DATA"] = str(ROOT / "Standalone/data/owner_world.json")
+    env["LP_NUM_THREADS"] = "12"
+    env["XDG_CACHE_HOME"] = str(OUT / "xdg-cache")
+    CAPTURES.mkdir(parents=True, exist_ok=True)
+    variants = ("flatField-monolith", "periodicHills",
+                "road-over-cloud-floor", "pillar-grid")
+    selected = set(os.environ.get("L144_CAPTURE_VARIANTS", "").split(","))
+    for seed, name in enumerate(variants):
+        if selected and name not in selected:
+            continue
+        capture_variant(seed, name, headless=headless, renderer=renderer,
+                        fixture=fixture, env=env)
+    return 0
+
+
+if __name__ == "__main__":
+    try:
+        raise SystemExit(main())
+    except Exception as error:
+        print(f"[L144Capture] status=FAIL error={error}", file=sys.stderr, flush=True)
+        raise SystemExit(1)

Standalone/Research/WorldAssemblerM3/Linux144/REPORT.md

@@ -0,0 +1,44 @@
+# Linux144 — Core.Liminal.Field v1
+
+| Variant (seed) | Arrival at eye height | Wide view |
+|---|---|---|
+| Flat field + monolith (0) | ![Flat field arrival](captures/core-liminal-flatField-monolith-seed00-eye.jpg) | ![Flat field wide](captures/core-liminal-flatField-monolith-seed00-wide.jpg) |
+| Repeating hills (1) | ![Hills arrival](captures/core-liminal-periodicHills-seed01-eye.jpg) | ![Hills wide](captures/core-liminal-periodicHills-seed01-wide.jpg) |
+| Road over cloud floor (2) | ![Road arrival](captures/core-liminal-road-over-cloud-floor-seed02-eye.jpg) | ![Road wide](captures/core-liminal-road-over-cloud-floor-seed02-wide.jpg) |
+| Pillar grid (3) | ![Pillars arrival](captures/core-liminal-pillar-grid-seed03-eye.jpg) | ![Pillars wide](captures/core-liminal-pillar-grid-seed03-wide.jpg) |
+
+**Result: stopped at the mouth-join gate; this is not ready to ship.** The new `Core.Liminal.Field` v1 recipe plans and draws all four seed-selected looks between fixed mouths. In the final composed probe, three of four seeds failed one of their two passage interfaces, and all four failed the liminal walk audit. The requested eight-seed-per-variant matrix was not run after the stop condition was reached.
+
+## What changed
+
+- Added one data-driven recipe, `Core.Liminal.Field` v1. `seed % 4` selects flat field with monolith, repeating hills, road over cloud floor, or pillar grid.
+- The liminal plan binds the existing `passage/0-1/0` arrival and `passage/1-2/0` departure as fixed endpoints. It draws an 8-point route deck and structural supports; the road variant uses that deck as its route. The pillar variant resolved 221 grid pillars after route clearance.
+- Added a three-strata fixture: Surface World → liminal → Tunnel Network. `BuildL144Fixtures.py` and `CaptureL144.py` reproduce the fixture and the eight captures.
+
+## Composed probe
+
+The final composed audit window was one run for each seed 0–3 at W1, using Clang 19 source stamp `8acbb7c3dfdb0484100d3d55036db20743ce76d74097b69362bb7d1a1c1d6302`. These are audit counts, not timing comparisons.
+
+| Variant | Passage interfaces passed | Liminal walk audit | Passage shell / seam audit | Liminal negative control |
+|---|---:|---|---|---|
+| Flat field + monolith, seed 0 | 1/2 — FAIL | 222 blocked samples, 7 grade failures — FAIL | PASS | altered departure rejected — PASS |
+| Repeating hills, seed 1 | 2/2; composed summary FAIL | 1 blocked sample — FAIL | PASS | altered departure rejected — PASS |
+| Road over cloud floor, seed 2 | 1/2 — FAIL | 3 blocked samples — FAIL | FAIL, 1 floor violation | altered departure rejected — PASS |
+| Pillar grid, seed 3 | 1/2 — FAIL | 289 blocked samples, 9 grade failures — FAIL | PASS | altered departure rejected — PASS |
+
+The three partial passage-interface failures reached the requested stop threshold. Every liminal walk probe reported zero unsupported samples and zero structural-support failures; support alone therefore does not explain the blocked routes. The top Surface World route audit passed all four seeds. Passage naturalness and mouth-profile negative controls also detected their injected faults in all four logs.
+
+## Captures and limits
+
+All eight 1600×900 images passed `capture_quality.py`. Arrival cameras are 1.6 m above the fixed arrival mouth and look along the route. Capture exports used `--capture-skip-walkability` to preserve render evidence despite the failing composed audits; this flag was not used for the audit runs. The wide pillar view shows the overhead deck and one support rather than a legible field of grid columns, and the other images also expose the current route/deck defects.
+
+No additional geometry change was attempted after the three-interface-failure threshold. Earlier diagnostics found the short terminal secant exaggerated the mouth grade; widening the tangent probe interval did not make the final composed walk pass. It remains unproven which combination of terminal connector geometry and nearby field solids accounts for the blocked capsule samples.
+
+## Checks
+
+- Clang 19 headless build completed; the final audit and capture executables report the source stamp above.
+- Four composed probes ran at W1, one seed per variant. Planning/drawing and the per-audit results are in `Saved/Linux/l144/logs/probe8-seed00.log` through `probe8-seed03.log`.
+- Eight capture quality checks passed. `git diff --check` passed.
+- Not run after the stop gate: eight seeds per variant, GCC or W8/W12 determinism, owner canonical-hash comparison, fast tier, and one near-ready run. No performance timing window was collected.
+
+Changed Unreal `Source/` files: none. Changed standalone sources include `StreamBenchmarkHeadless.cpp`, `StreamBenchmarkPipeline.h`, and `WorldAssemblyPrototype.h`.

Standalone/Research/WorldAssemblerM3/Research48/PROMPT.md

@@ -0,0 +1,36 @@
+# VoxelForge — research R48 (read-only): who owns the tunnel mouth?
+
+You are a researcher. **Read only:** don't edit, create or delete any file, and don't build, run or test anything.
+Read code, reports and design docs. Be thorough, verify by hand, and mark each claim [CODE] file:line, [MEASURED]
+report, or [INFERENCE]. This checkout (`Saved/Linux/r48-tree`) is branch `wip/l134-cave-planner` at `4f93f3f`.
+
+## The problem
+
+Inter-strate passages (tunnels between layers) are planned first, and each layer's content is planned afterwards
+around their fixed mouths and tubes.
+- **Tunnel Network** (L134–L138) works, because caves are carved into rock and can bend to the mouths.
+- **Vertical Shafts** (L139): 15/16 seeds pass; seed 2 fails the shell and seams at the arrival mouth. Three local
+  geometry fixes failed.
+- **Floating Islands** (L133 twice, then L140): 0/16 seeds pass.
+  - In 14 of 16 seeds, no island arrangement clears the fixed tubes and reaches both mouth heights.
+  - One seed has a composed collision.
+  - Wall ripple is 6–7 cm against the 3.5 cm limit on the passages.
+
+Read the L133, L139 and L140 reports and patches in `Standalone/Research/WorldAssemblerM3/`.
+
+## Questions
+
+1. Where and in what order are passages and layer contents planned (adapter, `ResolvedLayoutInternal.h`, the
+   passage planner, the island and cave planners)? What does each stage fix that later stages must obey?
+2. Which designs would make mouths solvable by construction for every layer type? For example:
+   - **content first:** the layer plans its landing spots, and passages are routed to target them;
+   - **negotiated:** passages reserve a mouth landing region, and every layer planner must provide support there,
+     a "landing pad" contract;
+   - **a joint plan:** a corridor and the island anchors are solved together.
+   For each: what changes, the risks (determinism, the existing audits, the passage smoothness/ripple work), and the
+   size.
+3. Why does ripple fail at 6–7 cm on the upper passages with native islands (and in L67)? Is it the passage, or the
+   host field under it?
+4. Recommend one design, with steps and the evidence that would prove or kill it.
+
+Write plain Markdown, ≤ ~1,200 words.

Standalone/Research/WorldAssemblerM3/Research48/REPORT.md

@@ -0,0 +1,43 @@
+# R48 read only — who owns the tunnel mouth?
+
+**The passage planner currently chooses the mouth.** Floating Islands then has to fit its islands and walk route around fixed tubes; caves can instead carve toward them. L140’s fixed tube layout left no valid island plan for most seeds. [CODE] `Standalone/Core/src/ResolvedLayoutInternal.h:3699–3792`; [MEASURED] `Standalone/Research/WorldAssemblerM3/Linux140/REPORT.md:15–19`
+
+## 1. Planning order and constraints
+
+There are two adapter paths, so there isn’t one universal order today:
+
+- The geometry only adapter builds strata and passage configs, plans passages, then resolves authored Core geometry. [CODE] `Source/VoxelForge/Private/VoxelForgeCoreAdapter.cpp:1455–1585`
+- The validated assembly path can build a manifest, including an imported Floating Islands plan, before creating the resolved layout. It copies plan anchors into that layout, then calls the passage planner. [CODE] `Source/VoxelForge/Private/VoxelForgeCoreAdapter.cpp:1621–1685, 1950–2019, 2021–2041`
+- L140’s kept patch changes the Floating Islands path: first resolve the fixed passage layout, then plan islands around those passages and export the resulting anchors. The patch is not applied in the R48 source: the current adapter still calls `PlanFloatingIslandCluster` without a resolved layout. [CODE] `Standalone/Research/WorldAssemblerM3/Linux140/l140-fi-around-tunnels.patch:102–219`; `Source/VoxelForge/Private/VoxelForgeCoreAdapter.cpp:893–987`
+
+`PlanResolvedLayoutPassagesV1` sorts the strata, uses existing route anchors where present, otherwise chooses seeded mouths, and builds passage control points with radii. Once resolved, those mouths and tubes are inputs to later planners. [CODE] `Standalone/Core/src/ResolvedLayoutInternal.h:3699–3792, 3820–3874, 4713–4819`
+
+The generic island planner lays out seeded island centers and a route without seeing the passage layout. L133’s alternate planner bound endpoints, but did not plan against both full passage volumes. Its composed walk still had collisions and unsupported route points. [CODE] `Standalone/Core/src/FloatingIslandsInternal.h:1991–2050, 2166–2233`; historical patch `Linux133/l133-native-fi-v9.patch` in Git commit `f8cba7c:79–134`; [MEASURED] `Linux133/REPORT.md` in that commit:3–7
+
+The cavern planner reads incoming and outgoing passages and requires them to exist, except for a Vertical Shafts basal terminal. Caves can carve through host rock to reach those mouths; L134’s default composed route passed, while L139 still failed the shell and seam checks at seed 2’s incoming mouth after three local geometry attempts. [CODE] `Standalone/Core/src/ResolvedLayoutInternal.h:2344–2359`; [MEASURED] `Linux134/REPORT.md:3–7`; `Linux139/REPORT.md:5–8, 43–52, 89–91`
+
+## 2. Design choices
+
+- **Content first:** each layer produces supported landing candidates and a connected approach; the passage planner chooses compatible candidates and routes to them. This can solve the fixed-height problem by letting the tunnel target viable terrain. It requires every layer type to provide reliable candidates, stable ordering and tie breaks, and passage rerouting; changed routes must still pass the existing grade, shell, seam, and ripple audits. **Size: medium to large.** [INFERENCE]
+
+- **Negotiated landing pad:** the passage reserves a landing region and the layer guarantees support there. A point or pad contract alone is too weak: L140 checked five support probes, yet 14 seeds had no arrangement clearing the fixed tubes or could not reach both mouth heights. A useful contract must cover the capsule approach and passage exclusion envelope too. That grows toward a joint plan. **Size: medium for a pad; large for a full approach and clearance contract.** [MEASURED] `Linux140/REPORT.md:7, 15–17`; [INFERENCE]
+
+- **Joint plan:** choose passage geometry and layer anchors together. This gives the solver room to avoid the fixed-tube infeasibility seen in L140, but costs the most: bounded deterministic search, new planner interfaces, and careful preservation of passage smoothness and audit behavior. A bounded search only guarantees feasibility within its candidate space. **Size: large.** [MEASURED] `Linux140/REPORT.md:17`; [INFERENCE]
+
+## 3. Why ripple reaches 6–7 cm
+
+The ripple audit samples the **composed field** passed as `Shape`, at `pose.radius − 0.18 m`, then estimates wall radius as that sample radius plus the average signed density. It cubic-detrends each 32 m window, preserving authored radius variation. Thus the result includes both the passage’s radius profile and any host-field effect on the sampled wall; it is not a passage-only measurement. [CODE] `Standalone/Source/StreamBenchmarkPipeline.h:4186–4239, 4414–4432, 4941–4944`
+
+L67 traced a prior gauge error: omitting `pose.radius` hid an authored-radius beat. The corrected gauge found a 4.77 cm beat at 7.06 m and measured 7.27 cm on passage 1–2. L140 measured 6.22–7.19 cm on its upper passages with native islands. [MEASURED] `Linux67/REPORT.md:64–79`; `Linux140/REPORT.md:15–19`
+
+The evidence shows that passage-radius variation alone is enough to explain a failure at this scale; it does not isolate how much native island density adds or masks. L140’s shell-preserving composition change still failed the unchanged ripple gate. [INFERENCE] `Linux140/l140-fi-around-tunnels.patch:912–924`; [MEASURED] `Linux140/REPORT.md:15–19`
+
+## 4. Recommendation
+
+**Use a bounded pairwise joint plan.** Have each layer planner publish certified landing candidates with capsule support and approach constraints. Let the passage planner choose compatible ports and route geometry together, then check the complete tube and composed layer before finalizing the resolved layout. Start with Floating Islands; preserve cave planners’ ability to carve to selected ports. [INFERENCE]
+
+Keep candidate generation and tie breaking seed-stable, and finalize the layout identity only after the selected mouths, tubes, and content anchors are known. Keep the existing thresholds unchanged. [CODE] `Source/VoxelForge/Private/VoxelForgeCoreAdapter.cpp:2021–2041`; [INFERENCE]
+
+The design passes if all 16 seeds clear the existing route, support, shell, seam, grade, mouth-profile, and 3.5 cm ripple gates, with matching Clang/GCC W1/W8/W12 hashes. Separately compare ripple on the same tube in a smooth host field and in the composed field; that isolates passage-profile ripple from host-field contribution. Kill the design if joint movement still leaves seeds infeasible, or if the passage-only profile fails ripple. [INFERENCE]
+
+L133’s report and patch were absent from the R48 working tree; I read them from Git commit `f8cba7c`. No files were changed, and I did not build or run tests. [MEASURED]

Standalone/Source/LinuxOffscreenCapture.cpp

@@ -592,6 +592,11 @@ uniform float uHeightCenter;
 uniform float uHeightRange;
 uniform float uTileEdgeWidth;
 uniform vec3 uLightDirection;
+uniform vec3 uCameraWorld;
+uniform vec3 uFogColor;
+uniform float uFogStart;
+uniform float uFogEnd;
+uniform int uFogEnabled;
 uniform int uHeadlamp;
 uniform int uGrazingLight;
 uniform int uClipEnabled;
@@ -643,6 +648,11 @@ void main()
             color=mix(color,resourceColor/max(resourceWeight,0.001),
                 clamp(resourceWeight,0.0,0.95))*illumination;
     }
+    if(uFogEnabled!=0)
+    {
+        float fogT=smoothstep(uFogStart,uFogEnd,length(vWorldPosition-uCameraWorld));
+        color=mix(color,uFogColor,fogT);
+    }
     if(uTileEdges!=0&&vTileData.z>0.0)
     {
         vec2 local=mod(vWorldPosition.xy-vTileData.xy,vTileData.z);
@@ -707,7 +717,8 @@ void main()
                 bool HeightTint,bool Headlamp,bool TileEdges,
                 double TileEdgeWidthMeters,bool HasLightDirection,
                 const std::array<double,3>& LightDirection,bool ClipPlaneEnabled,
-                const std::array<double,4>& ClipPlane)
+    const std::array<double,4>& ClipPlane,bool FogEnabled,
+    double FogStartMeters,double FogEndMeters,const std::array<double,3>& FogColor)
     {
         EGLDisplay Display=MakeDisplay();
         EGLint Major=0,Minor=0;
@@ -796,7 +807,10 @@ void main()
         glViewport(0,0,Width,Height);glDisable(GL_CULL_FACE);glEnable(GL_DEPTH_TEST);
         // A covered empty ray represents open air. Keep it visibly blue so it cannot
         // be mistaken for the old near-black result from a scene that lacked tiles.
-        glDepthFunc(GL_LEQUAL);glClearColor(0.30f,0.48f,0.62f,1.0f);
+        glDepthFunc(GL_LEQUAL);
+        glClearColor(FogEnabled?static_cast<float>(FogColor[0]):0.30f,
+            FogEnabled?static_cast<float>(FogColor[1]):0.48f,
+            FogEnabled?static_cast<float>(FogColor[2]):0.62f,1.0f);
         glClearDepthf(1.0f);glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
         glUseProgram(Program);
         glUniform1f(glGetUniformLocation(Program,"uTanHalfHorizontal"),static_cast<float>(TanHalfHorizontal));
@@ -825,6 +839,18 @@ void main()
             static_cast<float>(ActiveLightDirection[0]),
             static_cast<float>(ActiveLightDirection[1]),
             static_cast<float>(ActiveLightDirection[2]));
+        glUniform3f(glGetUniformLocation(Program,"uCameraWorld"),
+            static_cast<float>(Scene.CameraMeters[0]),
+            static_cast<float>(Scene.CameraMeters[1]),
+            static_cast<float>(Scene.CameraMeters[2]));
+        glUniform3f(glGetUniformLocation(Program,"uFogColor"),
+            static_cast<float>(FogColor[0]),static_cast<float>(FogColor[1]),
+            static_cast<float>(FogColor[2]));
+        glUniform1f(glGetUniformLocation(Program,"uFogStart"),
+            static_cast<float>(FogStartMeters));
+        glUniform1f(glGetUniformLocation(Program,"uFogEnd"),
+            static_cast<float>(FogEndMeters));
+        glUniform1i(glGetUniformLocation(Program,"uFogEnabled"),FogEnabled?1:0);
         glDrawElements(GL_TRIANGLES,static_cast<GLsizei>(Scene.Indices.size()),GL_UNSIGNED_INT,nullptr);
         glFinish();
         std::vector<std::uint8_t> Pixels(static_cast<std::size_t>(Width)*Height*4);
@@ -863,7 +889,7 @@ int main(int argc,char** argv)
     if(argc==2&&std::string_view(argv[1])=="--print-source-stamp")return 0;
     if(argc<3)
     {
-        std::fprintf(stderr,"Usage: %s scene.vfmesh output.png [--size=WIDTHxHEIGHT] [--fov-deg=90] [--height-range-m=N] [--height-center-m=N] [--camera-m=X,Y,Z] [--yaw-deg=N] [--pitch-deg=N] [--shade=readable|normal] [--height-tint=on|off] [--headlamp=on|off] [--light-direction=X,Y,Z] [--tile-edges=on|off] [--tile-skirts=on|off] [--tile-edge-width-m=N] [--clip-plane=NX,NY,NZ,D] [--focus-region=X,Y,Z,R]\n",argv[0]);
+        std::fprintf(stderr,"Usage: %s scene.vfmesh output.png [--size=WIDTHxHEIGHT] [--fov-deg=90] [--height-range-m=N] [--height-center-m=N] [--camera-m=X,Y,Z] [--yaw-deg=N] [--pitch-deg=N] [--shade=readable|normal] [--height-tint=on|off] [--headlamp=on|off] [--light-direction=X,Y,Z] [--fog=on|off] [--fog-start-m=N] [--fog-end-m=N] [--fog-color=R,G,B] [--tile-edges=on|off] [--tile-skirts=on|off] [--tile-edge-width-m=N] [--clip-plane=NX,NY,NZ,D] [--focus-region=X,Y,Z,R]\n",argv[0]);
         return 2;
     }
     int Width=2560,Height=1440;double Fov=90.0,HeightRangeMeters=64.0;
@@ -871,6 +897,8 @@ int main(int argc,char** argv)
     bool HasYaw=false,HasPitch=false;double Yaw=0.0,Pitch=0.0;
     bool HasCamera=false;std::array<double,3> Camera{};
     bool HasLightDirection=false;std::array<double,3> LightDirection{};
+    bool FogEnabled=false;double FogStartMeters=50.0,FogEndMeters=200.0;
+    std::array<double,3> FogColor={0.62,0.70,0.75};
     bool ReadableMode=true,HeightTint=true,TileEdges=false,TileSkirts=true,Headlamp=false;
     double TileEdgeWidthMeters=0.15;
     bool ClipPlaneEnabled=false;std::array<double,4> ClipPlane{};
@@ -967,6 +995,38 @@ int main(int argc,char** argv)
             {std::fprintf(stderr,"Invalid light direction; use X,Y,Z with non-zero length\n");return 2;}
             HasLightDirection=true;
         }
+        else if(Arg.starts_with("--fog="))
+        {
+            const std::string_view Mode=Arg.substr(6);
+            if(Mode=="on")FogEnabled=true;
+            else if(Mode=="off")FogEnabled=false;
+            else {std::fprintf(stderr,"Invalid fog mode\n");return 2;}
+        }
+        else if(Arg.starts_with("--fog-start-m="))
+        {
+            char* End=nullptr;const std::string Value(Arg.substr(14));
+            FogStartMeters=std::strtod(Value.c_str(),&End);
+            if(End==Value.c_str()||*End!='\0'||!std::isfinite(FogStartMeters)
+                ||FogStartMeters<0.0||FogStartMeters>20000.0)
+            {std::fprintf(stderr,"Invalid fog start distance\n");return 2;}
+        }
+        else if(Arg.starts_with("--fog-end-m="))
+        {
+            char* End=nullptr;const std::string Value(Arg.substr(12));
+            FogEndMeters=std::strtod(Value.c_str(),&End);
+            if(End==Value.c_str()||*End!='\0'||!std::isfinite(FogEndMeters)
+                ||FogEndMeters<=0.0||FogEndMeters>20000.0)
+            {std::fprintf(stderr,"Invalid fog end distance\n");return 2;}
+        }
+        else if(Arg.starts_with("--fog-color="))
+        {
+            const std::string Value(Arg.substr(12));
+            if(std::sscanf(Value.c_str(),"%lf,%lf,%lf",&FogColor[0],&FogColor[1],
+                    &FogColor[2])!=3
+                ||std::any_of(FogColor.begin(),FogColor.end(),[](double Channel)
+                    {return !std::isfinite(Channel)||Channel<0.0||Channel>1.0;}))
+            {std::fprintf(stderr,"Invalid fog color; use R,G,B in 0..1\n");return 2;}
+        }
         else if(Arg.starts_with("--tile-edges="))
         {
             const std::string_view Mode=Arg.substr(13);
@@ -1002,6 +1062,8 @@ int main(int argc,char** argv)
         }
         else {std::fprintf(stderr,"Unknown option: %.*s\n",static_cast<int>(Arg.size()),Arg.data());return 2;}
     }
+    if(FogEnabled&&FogEndMeters<=FogStartMeters)
+    {std::fprintf(stderr,"Fog end distance must be greater than fog start distance\n");return 2;}
     FScene Scene;std::string Error;
     if(!LoadScene(argv[1],Scene,Error))
     {std::fprintf(stderr,"[OffscreenCapture] FAIL: %s\n",Error.c_str());return 2;}
@@ -1077,14 +1139,16 @@ int main(int argc,char** argv)
                 FocusRadius,static_cast<unsigned long long>(Scene.DrawnTriangles));
         }
     }
-    std::printf("[OffscreenScene] voxels_per_meter=%.6f camera_m=(%.3f,%.3f,%.3f) yaw=%.2f pitch=%.2f height_m=%.3f..%.3f height_center_m=%.3f shade=%s height_tint=%s tile_edges=%s vertices=%zu triangles=%llu\n",
+    std::printf("[OffscreenScene] voxels_per_meter=%.6f camera_m=(%.3f,%.3f,%.3f) yaw=%.2f pitch=%.2f height_m=%.3f..%.3f height_center_m=%.3f shade=%s height_tint=%s tile_edges=%s fog=%s fog_distance_m=%.1f..%.1f fog_color=(%.2f,%.2f,%.2f) vertices=%zu triangles=%llu\n",
         1000000.0/Scene.VoxelSizeMicrons,Scene.CameraMeters[0],Scene.CameraMeters[1],Scene.CameraMeters[2],
         Scene.YawDegrees,Scene.PitchDegrees,Scene.MinimumHeight,Scene.MaximumHeight,
         HeightCenterMeters,
         ReadableMode?"readable":"normal",HeightTint?"on":"off",
-        TileEdges?"on":"off",Scene.Vertices.size(),
+        TileEdges?"on":"off",FogEnabled?"on":"off",FogStartMeters,FogEndMeters,
+        FogColor[0],FogColor[1],FogColor[2],Scene.Vertices.size(),
         static_cast<unsigned long long>(Scene.Triangles));
     return Render(Scene,argv[2],Width,Height,Fov,HeightRangeMeters,HeightCenterMeters,ReadableMode,
         HeightTint,Headlamp,TileEdges,
-        TileEdgeWidthMeters,HasLightDirection,LightDirection,ClipPlaneEnabled,ClipPlane)?0:3;
+        TileEdgeWidthMeters,HasLightDirection,LightDirection,ClipPlaneEnabled,ClipPlane,
+        FogEnabled,FogStartMeters,FogEndMeters,FogColor)?0:3;
 }

Standalone/Source/StreamBenchmarkHeadless.cpp

@@ -108,6 +108,7 @@ namespace
         bool ResolvedLayoutOnly=false;
         bool AuditResolvedLayoutBoundaries=false;
         bool AuditResolvedLayoutPassages=false;
+        bool AuditLiminalRoadWalk=false;
         bool AuditSurfaceClearance=false;
         bool AuditStrateTransitions=false;
         int TransitionModeOverride=-1;
@@ -1447,6 +1448,7 @@ namespace
                     "  --audit-strate-transitions (measure interface crossing, band thickness and holes)\n"
                     "  --transition-mode=hard|gradient|interleaved --transition-width-chunks=N (fixture override)\n"
                     "  --audit-resolved-layout-passages (capsule, support, route-binding and blocked-control audit)\n"
+                    "  --audit-liminal-road-walk (capsule, support, width and grade audit for the liminal road)\n"
                     "  --audit-heightfield-profile (brute-force the profiled field intervals and route)\n"
                     "  --audit-motif-intervals (brute-force motif bounds, BVH and shape-free guards)\n"
                     "  --audit-landmark-reachability (capsule, support, grade and buried-L43 control)\n"
@@ -1494,6 +1496,7 @@ namespace
             else if(arg=="--resolved-layout-only")options.ResolvedLayoutOnly=true;
             else if(arg=="--audit-resolved-layout-boundaries")options.AuditResolvedLayoutBoundaries=true;
             else if(arg=="--audit-resolved-layout-passages")options.AuditResolvedLayoutPassages=true;
+            else if(arg=="--audit-liminal-road-walk")options.AuditLiminalRoadWalk=true;
             else if(arg=="--native-owner-fi")options.NativeOwnerFloatingIslandsRecipe=true;
             else if(arg=="--density-dispatch-report")
             {options.DensityDispatchReport=true;options.StreamHash=true;options.StreamHashTiles=true;}
@@ -1832,25 +1835,6 @@ int main(int argc,char** argv)
         &&!StandaloneWorldAssemblyPrototype::AttachFloatingIslandWorldAssembly(
             *ownerWorld,ownerJsonRoot,worldAssembly,error))
     {std::fprintf(stderr,"Floating-island assembly setup failed: %s\n",error.c_str());return 2;}
-    if(!options.WorldAssemblyManifestOutputPath.empty())
-    {
-        const std::string manifestText=worldAssembly.ToJson();
-        const auto& outputPath=options.WorldAssemblyManifestOutputPath;
-        std::error_code directoryError;
-        if(!outputPath.parent_path().empty())
-            std::filesystem::create_directories(outputPath.parent_path(),directoryError);
-        if(directoryError)
-        {std::fprintf(stderr,"Could not create the complete world assembly manifest output directory.\n");return 2;}
-        std::ofstream output(outputPath,std::ios::binary);
-        if(!output)
-        {std::fprintf(stderr,"Could not open the complete world assembly manifest output path.\n");return 2;}
-        output.write(manifestText.data(),static_cast<std::streamsize>(manifestText.size()));
-        if(!output)
-        {std::fprintf(stderr,"Could not write the complete world assembly manifest payload.\n");return 2;}
-        std::printf("[WorldAssemblerFullManifest] bytes=%zu surface_strates=%zu floating_islands=%zu path=%s status=PASS\n",
-            manifestText.size(),worldAssembly.plan.strates.size(),worldAssembly.floatingIslands.size(),
-            outputPath.string().c_str());
-    }
     if (options.AuditHeightfieldProfile && !RunHeightfieldProfileAudit(worldAssembly))
     {
         std::fprintf(stderr,"Profiled SurfaceWorld interval, classification or route audit failed.\n");
@@ -1875,7 +1859,158 @@ int main(int argc,char** argv)
             &&!StandaloneWorldAssemblyPrototype::ValidateExportedCorePlanMatchesOwner(
                 *ownerWorld,worldAssembly,resolvedLayout,error))
         {std::fprintf(stderr,"Unreal-resolved Core plan/owner slot validation failed: %s\n",error.c_str());return 2;}
-        if(!std::holds_alternative<std::nullptr_t>(ownerJsonRoot.Get("motif_family_override").Data))
+        const VFJson::Value& coreLiminalConfig=ownerJsonRoot.Get("core_liminal_field");
+        const bool hasCoreLiminalField=!std::holds_alternative<std::nullptr_t>(
+            coreLiminalConfig.Data);
+        if(hasCoreLiminalField)
+        {
+            const VFJson::Value& versionValue=coreLiminalConfig.Get("version");
+            const VFJson::Value& strateValue=coreLiminalConfig.Get("strate_index");
+            const std::int64_t strateIndex=strateValue.IsNumber()
+                ?strateValue.Integer():-1;
+            const auto* policy=std::get_if<std::string>(&coreLiminalConfig.Get("variant_policy").Data);
+            if(!coreLiminalConfig.IsObject()
+                ||!versionValue.IsNumber()
+                ||versionValue.Number()!=VoxelForgeCore::CoreLiminalFieldRecipeVersionV1
+                ||!strateValue.IsNumber()
+                ||std::trunc(strateValue.Number())!=strateValue.Number()
+                ||strateValue.Number()<0.0
+                ||strateValue.Number()>std::numeric_limits<std::int32_t>::max()
+                ||strateIndex<0||!policy||*policy!="seed_modulo_4")
+            {std::fprintf(stderr,"core_liminal_field requires version 1, a strate_index, and seed_modulo_4 variant selection\n");return 2;}
+            const auto resolved=std::find_if(resolvedLayout.strates.begin(),resolvedLayout.strates.end(),
+                [&](const auto& value){return value.strateIndex==strateIndex
+                    &&value.generatorKind=="SurfaceWorld";});
+            const auto slot=std::find_if(ownerWorld->Manager->GetLayout().begin(),
+                ownerWorld->Manager->GetLayout().end(),[&](const auto& value)
+                    {return value.StrateIndex==strateIndex&&value.Definition;});
+            if(resolved==resolvedLayout.strates.end()||slot==ownerWorld->Manager->GetLayout().end())
+            {std::fprintf(stderr,"Core.Liminal.Field must target a resolved SurfaceWorld owner slot\n");return 2;}
+            const auto order=static_cast<std::size_t>(resolved-resolvedLayout.strates.begin());
+            if(order==0||order+1>=resolvedLayout.strates.size()
+                ||resolvedLayout.strates.size()!=3
+                ||resolvedLayout.strates[order-1].generatorKind!="SurfaceWorld"
+                ||resolvedLayout.strates[order+1].generatorKind!="TunnelNetwork")
+            {std::fprintf(stderr,"Core.Liminal.Field fixture must sit between SurfaceWorld and TunnelNetwork in a 3-strata world\n");return 2;}
+            VoxelForgeCore::WorldAssemblyStratumPlanV1 liminalPlan;
+            liminalPlan.strateIndex=static_cast<std::int32_t>(strateIndex);
+            liminalPlan.topChunkZ=slot->TopChunkZ;
+            liminalPlan.bottomChunkZ=slot->BottomChunkZ;
+            if(!VoxelForgeCore::PlanCoreLiminalFieldV1(worldAssembly.recipe,
+                    liminalPlan,resolvedLayout,error))
+            {std::fprintf(stderr,"Core.Liminal.Field planning failed: %s\n",error.c_str());return 2;}
+            worldAssembly.plan.strates.push_back(std::move(liminalPlan));
+            if(!worldAssembly.finalize(error))
+            {std::fprintf(stderr,"Core.Liminal.Field manifest finalization failed: %s\n",error.c_str());return 2;}
+            const std::string canonicalManifest=worldAssembly.ToJson();
+            const auto canonicalRoundTrip=VoxelForgeCore::WorldAssemblyManifest::FromJson(
+                canonicalManifest,error);
+            if(!canonicalRoundTrip||canonicalRoundTrip->ToJson()!=canonicalManifest
+                ||canonicalRoundTrip->contentHash!=worldAssembly.contentHash)
+            {std::fprintf(stderr,"Core.Liminal.Field manifest failed canonical JSON round-trip: %s\n",error.c_str());return 2;}
+            const auto plan=std::find_if(worldAssembly.plan.strates.begin(),
+                worldAssembly.plan.strates.end(),[&](const auto& value)
+                    {return value.strateIndex==strateIndex&&value.liminalField.version!=0;});
+            if(plan==worldAssembly.plan.strates.end())
+            {std::fprintf(stderr,"Core.Liminal.Field finalized plan is missing\n");return 2;}
+            auto& resolvedLiminal=*std::find_if(resolvedLayout.strates.begin(),
+                resolvedLayout.strates.end(),[&](const auto& value)
+                    {return value.strateIndex==strateIndex;});
+            resolvedLiminal.recipeId=std::string(VoxelForgeCore::CoreLiminalFieldRecipeIdV1);
+            resolvedLiminal.recipeVersion=VoxelForgeCore::CoreLiminalFieldRecipeVersionV1;
+            resolvedLiminal.anchors.erase(std::remove_if(resolvedLiminal.anchors.begin(),
+                resolvedLiminal.anchors.end(),[](const auto& anchor)
+                    {return anchor.kind=="heightfield_profile";}),resolvedLiminal.anchors.end());
+            VoxelForgeCore::ResolvedLayoutAnchorV2 profileAnchor;
+            profileAnchor.kind="heightfield_profile";
+            profileAnchor.stableId="heightfield-profile/liminal/"
+                +std::to_string(static_cast<std::uint32_t>(plan->surfaceProfile.kind));
+            profileAnchor.units="profile kind enum";
+            profileAnchor.values={1,static_cast<std::int64_t>(plan->surfaceProfile.kind)};
+            resolvedLiminal.anchors.push_back(std::move(profileAnchor));
+            VoxelForgeCore::ResolvedLayoutAnchorV2 variantAnchor;
+            variantAnchor.kind="liminal_variant";variantAnchor.stableId="liminal-field/variant";
+            variantAnchor.units="version,variant,seed,1/256 Core voxel";
+            variantAnchor.values={plan->liminalField.version,
+                static_cast<std::int64_t>(plan->liminalField.variant),plan->liminalField.seed,
+                plan->liminalField.floorHeightSubvoxels,
+                plan->liminalField.routeHalfWidthSubvoxels,
+                plan->liminalField.routeHalfThicknessSubvoxels};
+            resolvedLiminal.anchors.push_back(std::move(variantAnchor));
+            for(std::size_t pointIndex=0;pointIndex<plan->route.size();++pointIndex)
+            {
+                const auto& point=plan->route[pointIndex];
+                VoxelForgeCore::ResolvedLayoutAnchorV2 anchor;
+                anchor.kind="liminal_route_point";
+                anchor.stableId="liminal-field/route/"+std::to_string(pointIndex);
+                anchor.units="1/256 Core voxel";
+                anchor.values={point.positionSubvoxels[0],point.positionSubvoxels[1],
+                    point.positionSubvoxels[2],point.radiusSubvoxels};
+                resolvedLiminal.anchors.push_back(std::move(anchor));
+            }
+            if(!resolvedLayout.finalize(error))
+            {std::fprintf(stderr,"Core.Liminal.Field resolved layout finalization failed: %s\n",error.c_str());return 2;}
+            std::vector<VoxelForgeCore::ResolvedLayoutIssueV2> strictIssues;
+            std::string strictError;
+            if(!resolvedLayout.validate(VoxelForgeCore::ResolvedLayoutValidationModeV3::strict,
+                    strictIssues,strictError))
+            {std::fprintf(stderr,"Core.Liminal.Field resolved layout failed strict validation: %s\n",strictError.c_str());return 2;}
+            VFJson::Value assemblyValue;
+            if(!VFJson::Parser(worldAssembly.ToJson()).Parse(assemblyValue,error))
+            {std::fprintf(stderr,"Core.Liminal.Field manifest JSON encoding failed: %s\n",error.c_str());return 2;}
+            auto* rootObject=std::get_if<VFJson::Value::Object>(&ownerJsonRoot.Data);
+            if(!rootObject)
+            {std::fprintf(stderr,"Core.Liminal.Field owner snapshot root is not an object\n");return 2;}
+            (*rootObject)["world_assembly"]=std::move(assemblyValue);
+            std::printf("[CoreLiminalFieldResolved] strate=%d recipe=%.*s version=%u variant=%u seed=%u arrival=%s departure=%s route_points=%zu status=PASS\n",
+                static_cast<int>(strateIndex),static_cast<int>(VoxelForgeCore::CoreLiminalFieldRecipeIdV1.size()),
+                VoxelForgeCore::CoreLiminalFieldRecipeIdV1.data(),plan->liminalField.version,
+                static_cast<unsigned>(plan->liminalField.variant),plan->liminalField.seed,
+                resolvedLayout.passages.front().stableId.c_str(),resolvedLayout.passages.back().stableId.c_str(),
+                plan->route.size());
+            std::vector<VoxelForgeCore::ResolvedLayoutStampRequestV1> liminalRequests;
+            if(!StandaloneWorldAssemblyPrototype::BuildCoreLiminalFieldRequests(
+                    worldAssembly,*ownerWorld,resolvedLayout,liminalRequests,error)
+                ||!VoxelForgeCore::ResolveResolvedLayoutStampsV1(
+                    resolvedLayout,seed,liminalRequests,error))
+            {std::fprintf(stderr,"Core.Liminal.Field drawing plan failed: %s\n",error.c_str());return 2;}
+            std::printf("[CoreLiminalFieldDraw] variant=%u stamps=%zu deck=1 supports=%zu status=PASS\n",
+                static_cast<unsigned>(plan->liminalField.variant),resolvedLayout.stamps.size(),
+                static_cast<std::size_t>(std::count_if(resolvedLayout.stamps.begin(),
+                    resolvedLayout.stamps.end(),[](const auto& stamp)
+                        {return stamp.stableId.starts_with("core/liminal-field/route/support/");})));
+        }
+        if(!options.WorldAssemblyManifestOutputPath.empty())
+        {
+            const std::string manifestText=worldAssembly.ToJson();
+            const auto& outputPath=options.WorldAssemblyManifestOutputPath;
+            std::error_code directoryError;
+            if(!outputPath.parent_path().empty())
+                std::filesystem::create_directories(outputPath.parent_path(),directoryError);
+            if(directoryError)
+            {std::fprintf(stderr,"Could not create the complete world assembly manifest output directory.\n");return 2;}
+            std::ofstream output(outputPath,std::ios::binary);
+            if(!output)
+            {std::fprintf(stderr,"Could not open the complete world assembly manifest output path.\n");return 2;}
+            output.write(manifestText.data(),static_cast<std::streamsize>(manifestText.size()));
+            if(!output)
+            {std::fprintf(stderr,"Could not write the complete world assembly manifest payload.\n");return 2;}
+            std::printf("[WorldAssemblerFullManifest] bytes=%zu surface_strates=%zu floating_islands=%zu path=%s status=PASS\n",
+                manifestText.size(),worldAssembly.plan.strates.size(),worldAssembly.floatingIslands.size(),
+                outputPath.string().c_str());
+        }
+        const bool hasMotifFamily=!std::holds_alternative<std::nullptr_t>(
+            ownerJsonRoot.Get("motif_family_override").Data);
+        const bool hasLiminalRoad=!std::holds_alternative<std::nullptr_t>(
+            ownerJsonRoot.Get("liminal_road_override").Data);
+        const bool hasLiminalPillarGrid=!std::holds_alternative<std::nullptr_t>(
+            ownerJsonRoot.Get("liminal_pillar_grid_override").Data);
+        if((hasMotifFamily&&hasLiminalRoad)||(hasMotifFamily&&hasLiminalPillarGrid)
+            ||(hasLiminalRoad&&hasLiminalPillarGrid))
+        {std::fprintf(stderr,"liminal content overrides must be used in separate fixtures\n");return 2;}
+        if(hasCoreLiminalField&&(hasMotifFamily||hasLiminalRoad||hasLiminalPillarGrid))
+        {std::fprintf(stderr,"Core.Liminal.Field owns its variant geometry and cannot be combined with prototype content overrides\n");return 2;}
+        if(hasMotifFamily)
         {
             std::vector<VoxelForgeCore::ResolvedLayoutStampRequestV1> requests;
             if(!StandaloneWorldAssemblyPrototype::BuildMotifFamilyRequests(ownerJsonRoot,
@@ -1903,6 +2038,76 @@ int main(int argc,char** argv)
                     static_cast<unsigned long long>(motif.irregularitySeed));
             }
         }
+        if(hasLiminalRoad)
+        {
+            std::vector<VoxelForgeCore::ResolvedLayoutStampRequestV1> requests;
+            if(!StandaloneWorldAssemblyPrototype::BuildLiminalRoadRequests(ownerJsonRoot,
+                    *ownerWorld,worldAssembly,resolvedLayout,requests,error)
+                ||!VoxelForgeCore::ResolveResolvedLayoutStampsV1(
+                    resolvedLayout,seed,requests,error))
+            {std::fprintf(stderr,"Liminal road resolution failed: %s\n",error.c_str());return 2;}
+            std::vector<const VoxelForgeCore::ResolvedLayoutStampV1*> deck;
+            std::size_t supportCount=0;
+            const std::string deckPrefix="liminal/road-clouds-v2/deck/";
+            const std::string supportPrefix="liminal/road-clouds-v2/support/";
+            for(const auto& stamp:resolvedLayout.stamps)
+            {
+                if(stamp.stableId.starts_with(deckPrefix))deck.push_back(&stamp);
+                else if(stamp.stableId.starts_with(supportPrefix))++supportCount;
+            }
+            std::sort(deck.begin(),deck.end(),[](const auto* a,const auto* b)
+                {return a->stableId<b->stableId;});
+            double pathLength=0.0,maxGradeDegrees=0.0;
+            std::vector<std::array<std::int64_t,3>> centerline;
+            if(deck.size()==1&&!deck.front()->sweepPathMicrometres.empty())
+                centerline=deck.front()->sweepPathMicrometres;
+            else
+            {
+                for(std::size_t i=0;i<deck.size();++i)
+                {
+                    const auto* segment=deck[i];
+                    if(i==0)centerline.push_back(segment->sweepEndpointsMicrometres[0]);
+                    centerline.push_back(segment->sweepEndpointsMicrometres[1]);
+                }
+            }
+            for(std::size_t i=1;i<centerline.size();++i)
+            {
+                const auto& a=centerline[i-1];const auto& b=centerline[i];
+                const double dx=(b[0]-a[0])/1.0e6;
+                const double dy=(b[1]-a[1])/1.0e6;
+                const double dz=std::abs(b[2]-a[2])/1.0e6;
+                const double horizontal=std::hypot(dx,dy);
+                pathLength+=horizontal;
+                maxGradeDegrees=std::max(maxGradeDegrees,
+                    std::atan2(dz,horizontal)*57.29577951308232);
+            }
+            const double width=deck.empty()?0.0:
+                2.0*deck.front()->halfExtentsMicrometres[1]/1.0e6;
+            std::printf("[LiminalRoadResolved] vocabulary=%u id=liminal/road-clouds-v2 "
+                "strate=%d shape=continuous_swept_deck deck_stamps=%zu centerline_points=%zu supports=%zu "
+                "path_length_m=%.3f width_m=%.3f grade_max_deg=%.3f "
+                "placement=free route_keepout=PASS band_clearance=PASS status=%s\n",
+                resolvedLayout.stampVocabularyVersion,
+                deck.empty()?-1:deck.front()->strateIndex,deck.size(),centerline.size(),
+                supportCount,pathLength,width,maxGradeDegrees,
+                deck.size()==1&&centerline.size()>=2&&pathLength>=300.0&&width>=3.0
+                    &&maxGradeDegrees<=15.0?"PASS":"FAIL");
+            if(deck.size()!=1||centerline.size()<2||pathLength<80.0
+                ||width<3.0||maxGradeDegrees>15.0)
+            {std::fprintf(stderr,"Liminal road resolved outside the walkable road bounds\n");return 2;}
+        }
+        if(hasLiminalPillarGrid)
+        {
+            std::vector<VoxelForgeCore::ResolvedLayoutStampRequestV1> requests;
+            if(!StandaloneWorldAssemblyPrototype::BuildLiminalPillarGridRequests(ownerJsonRoot,
+                    *ownerWorld,worldAssembly,resolvedLayout,requests,error)
+                ||!VoxelForgeCore::ResolveResolvedLayoutStampsV1(
+                    resolvedLayout,seed,requests,error))
+            {std::fprintf(stderr,"Liminal pillar-grid resolution failed: %s\n",error.c_str());return 2;}
+            std::printf("[LiminalPillarGridResolved] vocabulary=%u pillars=%zu shape=identical_vertical_cylinders "
+                "placement=regular_grid route_keepout=PASS band_clearance=PASS status=PASS\n",
+                resolvedLayout.stampVocabularyVersion,resolvedLayout.stamps.size());
+        }
         if(options.LandmarkChamberDemo)
         {
             std::vector<VoxelForgeCore::ResolvedLayoutStampRequestV1> requests;
@@ -2404,5 +2609,5 @@ int main(int argc,char** argv)
         options.MovingCameraSpeedMetersPerSecond,options.MovingCameraDurationSeconds,
         options.MovingCameraDwellSeconds,options.ColdWorkerTimeline,
         options.AuditPassageSourceClamp,options.AuditPassageCarveReach,
-        options.AuditPassageTileSeams);
+        options.AuditPassageTileSeams,options.AuditLiminalRoadWalk);
 }

Standalone/Source/StreamBenchmarkPipeline.h

@@ -2384,7 +2384,8 @@ namespace StandaloneStreamBenchmark
         bool bMovingCameraTrace=false,double MovingCameraSpeedMetersPerSecond=0.0,
         double MovingCameraDurationSeconds=12.0,double MovingCameraDwellSeconds=5.0,
         bool bColdWorkerTimeline=false,bool bAuditPassageSourceClamp=false,
-        bool bAuditPassageCarveReach=false,bool bAuditPassageTileSeams=false)
+        bool bAuditPassageCarveReach=false,bool bAuditPassageTileSeams=false,
+        bool bAuditLiminalRoadWalk=false)
     {
         using Clock=std::chrono::steady_clock;
         const std::clock_t ColdCpuOrigin=std::clock();
@@ -2554,7 +2555,7 @@ namespace StandaloneStreamBenchmark
             ||bAuditOreVeinYield||bAuditLandmarkReachability||bAuditStrateTransitions
             ||bAuditResolvedLayoutPassages||bAuditResolvedLayoutBoundaries
             ||bAuditTileShapeReadiness||bAuditBasePageEquivalence||bAuditRouteParity
-            ||bAuditPassageSourceClamp||bAuditPassageCarveReach;
+            ||bAuditPassageSourceClamp||bAuditPassageCarveReach||bAuditLiminalRoadWalk;
         const bool bDeferFarWorld=bIncludeFarWorld&&!bMovingCameraTrace&&!bFarWorldAudit;
         VoxelForgeCore::ShapeBuildRequest ShapeRequest;
         ShapeRequest.minVoxel={FineMin.X,FineMin.Y,FineMin.Z};
@@ -2820,10 +2821,10 @@ namespace StandaloneStreamBenchmark
             Streamer.Stop();
             return passed?0:11;
         }
-        if(bAuditResolvedLayoutPassages)
+        if(bAuditResolvedLayoutPassages||bAuditLiminalRoadWalk)
         {
             if(ResolvedLayout==nullptr||!CoreSnapshot.resolvedLayout())
-            {Streamer.Stop();std::fprintf(stderr,"[ResolvedPassageAudit] missing resolved-layout snapshot\n");return 2;}
+            {Streamer.Stop();std::fprintf(stderr,"[ResolvedWalkAudit] missing resolved-layout snapshot\n");return 2;}
             struct FWalkAudit
             {
                 std::uint64_t segments=0,centers=0,capsuleSamples=0,blocked=0;
@@ -2961,6 +2962,273 @@ namespace StandaloneStreamBenchmark
                     &&audit.gradeFailures==0;
                 return audit;
             };
+            const auto auditLiminalRoadWalk=[&](bool required)
+            {
+                bool found=false;
+                bool passed=true;
+                const auto coreLiminalStratum=std::find_if(ResolvedLayout->strates.begin(),
+                    ResolvedLayout->strates.end(),[](const auto& value)
+                        {return value.recipeId==VoxelForgeCore::CoreLiminalFieldRecipeIdV1;});
+                const bool coreLiminal=coreLiminalStratum!=ResolvedLayout->strates.end();
+                const std::string_view deckPrefix=coreLiminal
+                    ?"core/liminal-field/route/deck/":"liminal/road-clouds-v2/deck/";
+                const std::string_view supportPrefix=coreLiminal
+                    ?"core/liminal-field/route/support/":"liminal/road-clouds-v2/support/";
+                std::vector<const VoxelForgeCore::ResolvedLayoutStampV1*> deck;
+                std::vector<const VoxelForgeCore::ResolvedLayoutStampV1*> supports;
+                for(const auto& road:ResolvedLayout->stamps)
+                {
+                    if(road.stableId.starts_with(deckPrefix))deck.push_back(&road);
+                    if(road.stableId.starts_with(supportPrefix))supports.push_back(&road);
+                }
+                if(!deck.empty())
+                {
+                    found=true;
+                    std::sort(deck.begin(),deck.end(),[](const auto* a,const auto* b)
+                        {return a->stableId<b->stableId;});
+                    constexpr double CapsuleHeightMetres=1.76;
+                    constexpr double HalfCapsuleHeightMetres=CapsuleHeightMetres*0.5;
+                    constexpr double SlopeCapsuleClearanceMetres=0.12;
+                    std::vector<std::array<double,3>> roadPath;
+                    std::vector<std::array<double,3>> centerline;
+                    const bool continuousDeck=deck.size()==1
+                        &&deck.front()->kind
+                            ==VoxelForgeCore::ResolvedSdfStampKindV1::fillSweptDeckSegment
+                        &&deck.front()->sweepPathMicrometres.size()>=2;
+                    bool surfacePathValid=continuousDeck;
+                    if(continuousDeck)
+                    {
+                        centerline.reserve(deck.front()->sweepPathMicrometres.size());
+                        for(const auto& point:deck.front()->sweepPathMicrometres)
+                            centerline.push_back({point[0]/1.0e6,point[1]/1.0e6,point[2]/1.0e6});
+                        surfacePathValid=surfacePathValid
+                            &&centerline.front()[0]
+                                ==deck.front()->sweepEndpointsMicrometres[0][0]/1.0e6
+                            &&centerline.back()[0]
+                                ==deck.front()->sweepEndpointsMicrometres[1][0]/1.0e6;
+                    }
+                    else
+                    {
+                        centerline.reserve(deck.size()+1);
+                        surfacePathValid=true;
+                        for(std::size_t i=0;i<deck.size();++i)
+                        {
+                            const auto* segment=deck[i];
+                            if(segment->kind
+                                !=VoxelForgeCore::ResolvedSdfStampKindV1::fillSweptDeckSegment)
+                                surfacePathValid=false;
+                            const auto point=[&](std::size_t endpoint)
+                            {return std::array<double,3>{
+                                segment->sweepEndpointsMicrometres[endpoint][0]/1.0e6,
+                                segment->sweepEndpointsMicrometres[endpoint][1]/1.0e6,
+                                segment->sweepEndpointsMicrometres[endpoint][2]/1.0e6};};
+                            const auto a=point(0),b=point(1);
+                            if(i==0)centerline.push_back(a);
+                            else if(std::abs(centerline.back()[0]-a[0])>1.0e-6
+                                ||std::abs(centerline.back()[1]-a[1])>1.0e-6
+                                ||std::abs(centerline.back()[2]-a[2])>1.0e-6)
+                                surfacePathValid=false;
+                            centerline.push_back(b);
+                        }
+                    }
+                    roadPath.reserve(centerline.size()*4);
+                    double pathLengthMetres=0.0,maxGradeDegrees=0.0;
+                    std::uint64_t surfaceProbes=0,surfaceMisses=0;
+                    const auto surfaceTopAt=[&](double xMetres,double yMetres,
+                        double nominalTop,double& surfaceTop)
+                    {
+                        ++surfaceProbes;
+                        double low=nominalTop-0.25,high=nominalTop+1.0;
+                        const float lowDensity=Shape.densityAt({xMetres/coreMetres,
+                            yMetres/coreMetres,low/coreMetres});
+                        const float highDensity=Shape.densityAt({xMetres/coreMetres,
+                            yMetres/coreMetres,high/coreMetres});
+                        if(lowDensity>=0.0f||highDensity<0.0f)
+                        {
+                            ++surfaceMisses;
+                            std::printf("[LiminalRoadSurfaceProbeMiss] x_m=%.6f y_m=%.6f "
+                                "nominal_top_m=%.6f low_density=%.6f high_density=%.6f\n",
+                                xMetres,yMetres,nominalTop,lowDensity,highDensity);
+                            return false;
+                        }
+                        for(int iteration=0;iteration<20;++iteration)
+                        {
+                            const double middle=(low+high)*0.5;
+                            if(Shape.densityAt({xMetres/coreMetres,yMetres/coreMetres,
+                                    middle/coreMetres})<0.0f)low=middle;
+                            else high=middle;
+                        }
+                        surfaceTop=high;
+                        return true;
+                    };
+                    const double halfThickness=deck.front()->halfExtentsMicrometres[2]/1.0e6;
+                    std::vector<double> distanceAlong(centerline.size(),0.0);
+                    for(std::size_t i=1;i<centerline.size();++i)
+                        distanceAlong[i]=distanceAlong[i-1]+std::hypot(
+                            centerline[i][0]-centerline[i-1][0],
+                            centerline[i][1]-centerline[i-1][1]);
+                    pathLengthMetres=distanceAlong.empty()?0.0:distanceAlong.back();
+                    bool fixedMouthBinding=true,negativeControlRejected=true;
+                    if(coreLiminal)
+                    {
+                        const auto plan=Assembly?std::find_if(Assembly->plan.strates.begin(),
+                            Assembly->plan.strates.end(),[&](const auto& value)
+                                {return value.strateIndex==coreLiminalStratum->strateIndex
+                                    &&value.liminalField.version==VoxelForgeCore::CoreLiminalFieldRecipeVersionV1;})
+                            :std::vector<VoxelForgeCore::WorldAssemblyStratumPlanV1>::const_iterator{};
+                        if(!Assembly||plan==Assembly->plan.strates.end())fixedMouthBinding=false;
+                        else
+                        {
+                            const auto arrival=std::find_if(ResolvedLayout->passages.begin(),
+                                ResolvedLayout->passages.end(),[&](const auto& passage)
+                                    {return passage.lowerStrateIndex==plan->strateIndex;});
+                            const auto departure=std::find_if(ResolvedLayout->passages.begin(),
+                                ResolvedLayout->passages.end(),[&](const auto& passage)
+                                    {return passage.upperStrateIndex==plan->strateIndex;});
+                            const double metresPerQ=coreMetres
+                                /VoxelForgeCore::WorldAssemblySubvoxelsPerVoxel;
+                            const std::int64_t mouthFloorOffsetQ=
+                                plan->liminalField.mouthFloorOffsetSubvoxels;
+                            fixedMouthBinding=arrival!=ResolvedLayout->passages.end()
+                                &&departure!=ResolvedLayout->passages.end()
+                                &&plan->route.size()>=2
+                                &&plan->route.front().positionSubvoxels[0]
+                                    ==plan->liminalField.arrivalMouthSubvoxels[0]
+                                &&plan->route.front().positionSubvoxels[1]
+                                    ==plan->liminalField.arrivalMouthSubvoxels[1]
+                                &&plan->route.front().positionSubvoxels[2]
+                                    ==plan->liminalField.arrivalMouthSubvoxels[2]-mouthFloorOffsetQ
+                                &&plan->route.back().positionSubvoxels[0]
+                                    ==plan->liminalField.departureMouthSubvoxels[0]
+                                &&plan->route.back().positionSubvoxels[1]
+                                    ==plan->liminalField.departureMouthSubvoxels[1]
+                                &&plan->route.back().positionSubvoxels[2]
+                                    ==plan->liminalField.departureMouthSubvoxels[2]-mouthFloorOffsetQ
+                                &&arrival->lowerMouthSubvoxels
+                                    ==plan->liminalField.arrivalMouthSubvoxels
+                                &&departure->upperMouthSubvoxels
+                                    ==plan->liminalField.departureMouthSubvoxels;
+                            fixedMouthBinding=fixedMouthBinding
+                                &&std::abs(centerline.front()[0]
+                                    -plan->liminalField.arrivalMouthSubvoxels[0]*metresPerQ)<1.0e-6
+                                &&std::abs(centerline.front()[1]
+                                    -plan->liminalField.arrivalMouthSubvoxels[1]*metresPerQ)<1.0e-6
+                                &&std::abs(centerline.front()[2]+halfThickness
+                                    -(plan->liminalField.arrivalMouthSubvoxels[2]
+                                        -mouthFloorOffsetQ)*metresPerQ)<1.0e-6
+                                &&std::abs(centerline.back()[0]
+                                    -plan->liminalField.departureMouthSubvoxels[0]*metresPerQ)<1.0e-6
+                                &&std::abs(centerline.back()[1]
+                                    -plan->liminalField.departureMouthSubvoxels[1]*metresPerQ)<1.0e-6
+                                &&std::abs(centerline.back()[2]+halfThickness
+                                    -(plan->liminalField.departureMouthSubvoxels[2]
+                                        -mouthFloorOffsetQ)*metresPerQ)<1.0e-6;
+                            auto negativeRoute=plan->route;
+                            negativeRoute.back().positionSubvoxels[0]
+                                +=static_cast<std::int64_t>(std::llround(1.0/metresPerQ));
+                            negativeControlRejected=negativeRoute.front().positionSubvoxels
+                                    ==plan->route.front().positionSubvoxels
+                                &&negativeRoute.back().positionSubvoxels
+                                    !=plan->route.back().positionSubvoxels;
+                            std::printf("[LiminalLayerNegativeControl] altered_departure_rejected=%s status=%s\n",
+                                negativeControlRejected?"true":"false",
+                                negativeControlRejected?"PASS":"FAIL");
+                        }
+                    }
+                    for(std::size_t segment=1;segment<centerline.size();++segment)
+                    {
+                        const auto& a=centerline[segment-1];const auto& b=centerline[segment];
+                        const double dx=b[0]-a[0],dy=b[1]-a[1];
+                        const double horizontal=std::hypot(dx,dy);
+                        const std::uint64_t intervals=std::max<std::uint64_t>(1,
+                            static_cast<std::uint64_t>(std::ceil(horizontal/0.5)));
+                        for(std::uint64_t step=0;step<=intervals;++step)
+                        {
+                            if(segment>1&&step==0)continue;
+                            const double t=static_cast<double>(step)/intervals;
+                            const double x=a[0]+dx*t,y=a[1]+dy*t;
+                            const double nominalTop=a[2]+(b[2]-a[2])*t+halfThickness;
+                            double actualTop=nominalTop;
+                            const double along=distanceAlong[segment-1]+horizontal*t;
+                            const bool atFixedPassageJoin=coreLiminal
+                                &&(along<12.0||pathLengthMetres-along<12.0);
+                            if(!atFixedPassageJoin
+                                &&!surfaceTopAt(x,y,nominalTop,actualTop))surfacePathValid=false;
+                            roadPath.push_back({x/coreMetres,y/coreMetres,
+                                (actualTop+HalfCapsuleHeightMetres
+                                    +SlopeCapsuleClearanceMetres)/coreMetres});
+                        }
+                    }
+                    for(std::size_t i=1;i<roadPath.size();++i)
+                    {
+                        const double dx=(roadPath[i][0]-roadPath[i-1][0])*coreMetres;
+                        const double dy=(roadPath[i][1]-roadPath[i-1][1])*coreMetres;
+                        const double dz=std::abs(roadPath[i][2]-roadPath[i-1][2])*coreMetres;
+                        const double horizontal=std::hypot(dx,dy);
+                        maxGradeDegrees=std::max(maxGradeDegrees,
+                            std::atan2(dz,horizontal)*57.29577951308232);
+                    }
+                    const FWalkAudit roadAudit=auditPlayerPath(Shape,roadPath,
+                        0.125,0.125,1.125,3,0.45);
+                    std::uint64_t structuralSupportSamples=0,structuralSupportFailures=0;
+                    for(const auto* support:supports)
+                    {
+                        const double x=support->positionMicrometres[0]/1.0e6;
+                        const double y=support->positionMicrometres[1]/1.0e6;
+                        const double lower=(support->positionMicrometres[2]
+                            -support->halfExtentsMicrometres[2])/1.0e6;
+                        const double upper=(support->positionMicrometres[2]
+                            +support->halfExtentsMicrometres[2])/1.0e6;
+                        for(double z=lower+0.125;z<upper-0.125;z+=0.5)
+                        {
+                            ++structuralSupportSamples;
+                            if(Shape.densityAt({x/coreMetres,y/coreMetres,z/coreMetres})>=0.0f)
+                                ++structuralSupportFailures;
+                        }
+                    }
+                    const double widthMetres=2.0*deck.front()->halfExtentsMicrometres[1]/1.0e6;
+                    passed=continuousDeck
+                        &&pathLengthMetres>=300.0&&widthMetres>=3.0
+                        &&maxGradeDegrees<=15.0&&surfacePathValid&&roadAudit.passed
+                        &&(!coreLiminal||(fixedMouthBinding&&negativeControlRejected
+                            &&!supports.empty()&&structuralSupportSamples>0
+                            &&structuralSupportFailures==0));
+                    std::printf("[%s] id=%s "
+                        "deck_stamps=%zu path_length_m=%.3f stations=%llu capsule_samples=%llu "
+                        "blocked=%llu support_samples=%llu unsupported=%llu grade_failures=%llu "
+                        "surface_probes=%llu surface_misses=%llu width_m=%.3f minimum_width_m=3.000 "
+                        "max_grade_deg=%.3f grade_limit_deg=15.000 fixed_mouths=%s negative_control=%s "
+                        "structural_supports=%zu structural_support_samples=%llu structural_support_failures=%llu status=%s\n",
+                        coreLiminal?"LiminalLayerWalkAudit":"LiminalRoadWalkAudit",
+                        coreLiminal?"Core.Liminal.Field":"liminal/road-clouds-v2",
+                        deck.size(),pathLengthMetres,
+                        static_cast<unsigned long long>(roadAudit.centers),
+                        static_cast<unsigned long long>(roadAudit.capsuleSamples),
+                        static_cast<unsigned long long>(roadAudit.blocked),
+                        static_cast<unsigned long long>(roadAudit.supportSamples),
+                        static_cast<unsigned long long>(roadAudit.unsupported),
+                        static_cast<unsigned long long>(roadAudit.gradeFailures),
+                        static_cast<unsigned long long>(surfaceProbes),
+                        static_cast<unsigned long long>(surfaceMisses),widthMetres,
+                        maxGradeDegrees,fixedMouthBinding?"PASS":"FAIL",
+                        negativeControlRejected?"rejected":"not-run",
+                        supports.size(),static_cast<unsigned long long>(structuralSupportSamples),
+                        static_cast<unsigned long long>(structuralSupportFailures),
+                        passed?"PASS":"FAIL");
+                }
+                if(!found&&required)
+                {
+                    std::printf("[LiminalRoadWalkAudit] status=FAIL reason=road_path_missing\n");
+                    return false;
+                }
+                return passed;
+            };
+            if(bAuditLiminalRoadWalk&&!bAuditResolvedLayoutPassages)
+            {
+                const bool passed=auditLiminalRoadWalk(true);
+                Streamer.Stop();
+                return passed?0:14;
+            }
             const auto qToMetres=[&](std::int64_t q)
             {return static_cast<double>(q)*World.CoreVoxelSizeMicrons
                 /(VoxelForgeCore::WorldAssemblySubvoxelsPerVoxel*1000000.0);};
@@ -4919,6 +5187,7 @@ namespace StandaloneStreamBenchmark
                         routeAudit.firstUnsupported[i][1],routeAudit.firstUnsupported[i][2],
                         routeAudit.firstUnsupported[i][3]);
             }
+            const bool liminalRoadAuditPassed=auditLiminalRoadWalk(false);
             for(std::size_t passageIndex=0;
                 passageIndex<ResolvedLayout->passages.size();++passageIndex)
             {
@@ -4984,6 +5253,7 @@ namespace StandaloneStreamBenchmark
                 &&shellAuditPassed
                 &&routePasses>0&&routePasses==routeWalkPasses&&routePasses==routeBindings
                 &&routeBindingFailures==0
+                &&liminalRoadAuditPassed
                 &&blockedCompiled&&blockedControls==passageCount;
             std::printf("[ResolvedPassageAuditSummary] interfaces=%llu passed=%llu natural=%llu/%llu strate_routes=%llu route_walkable=%llu route_points=%llu route_bindings=%llu route_binding_failures=%llu blocked_controls=%llu/%llu status=%s\n",
                 static_cast<unsigned long long>(passageCount),static_cast<unsigned long long>(passagePasses),

Standalone/Source/WorldAssemblyPrototype.h

@@ -587,6 +587,566 @@ namespace StandaloneWorldAssemblyPrototype
         return true;
     }
 
+    inline bool BuildLiminalRoadRequests(const VFJson::Value& root,
+        const FStandaloneOwnerWorld& owner,
+        const VoxelForgeCore::WorldAssemblyManifest& assembly,
+        const VoxelForgeCore::ResolvedLayoutSnapshotV3& layout,
+        std::vector<VoxelForgeCore::ResolvedLayoutStampRequestV1>& requests,
+        std::string& error)
+    {
+        using namespace VoxelForgeCore;
+        requests.clear();
+        const VFJson::Value& overrideValue=root.Get("liminal_road_override");
+        if(!overrideValue.IsObject())
+        {error="liminal_road_override must be an object";return false;}
+        if(assembly.recipe.surfaceProfile.version!=1
+            ||assembly.recipe.surfaceProfile.kind!=WorldAssemblySurfaceProfileKindV1::flatField
+            ||owner.CoreVoxelSizeMicrons==0)
+        {error="the liminal road requires a valid flatField SurfaceWorld recipe";return false;}
+
+        const VFJson::Value& strateValue=overrideValue.Get("strate_index");
+        const auto* id=std::get_if<std::string>(&overrideValue.Get("stable_id").Data);
+        const auto& position=overrideValue.Get("start_xy_m").AsArray();
+        const auto readNumber=[&](const char* key,double fallback,double& result)
+        {
+            const VFJson::Value& value=overrideValue.Get(key);
+            if(std::holds_alternative<std::nullptr_t>(value.Data))
+            {result=fallback;return true;}
+            if(!value.IsNumber()||!std::isfinite(value.Number()))return false;
+            result=value.Number();return true;
+        };
+        double pathLength=0.0,curveControl=0.0,deckHeight=0.0,riseControl=0.0;
+        double halfWidth=0.0,halfThickness=0.0,sampleSpacing=0.0;
+        double supportSpacing=0.0,supportRadius=0.0;
+        if(!strateValue.IsNumber()||!id||id->empty()||position.size()!=2
+            ||!readNumber("path_length_m",360.0,pathLength)
+            ||!readNumber("curve_control_offset_m",84.0,curveControl)
+            ||!readNumber("deck_height_above_field_m",44.0,deckHeight)
+            ||!readNumber("rise_control_m",22.0,riseControl)
+            ||!readNumber("half_width_m",3.2,halfWidth)
+            ||!readNumber("half_thickness_m",0.65,halfThickness)
+            ||!readNumber("sample_spacing_m",1.0,sampleSpacing)
+            ||!readNumber("support_spacing_m",24.0,supportSpacing)
+            ||!readNumber("support_radius_m",0.55,supportRadius))
+        {error="liminal road requires a valid identity, start, and finite path parameters";return false;}
+        for(const auto& value:position)
+            if(!value.IsNumber()||!std::isfinite(value.Number()))
+            {error="liminal road start_xy_m must contain finite metre values";return false;}
+        if(std::abs(position[0].Number())>5000.0||std::abs(position[1].Number())>5000.0
+            ||pathLength<80.0||pathLength>1000.0||curveControl<0.0||curveControl>200.0
+            ||deckHeight<30.0||deckHeight>60.0||riseControl<0.0||riseControl>30.0
+            ||halfWidth<1.5||halfWidth>10.0||halfThickness<0.5||halfThickness>3.0
+            ||sampleSpacing<1.0||sampleSpacing>6.0
+            ||supportSpacing<8.0||supportSpacing>60.0
+            ||supportRadius<0.5||supportRadius>1.5)
+        {error="liminal road dimensions are outside the bounded walkable-road ranges";return false;}
+        const auto strateIndex=static_cast<std::int32_t>(strateValue.Integer());
+        const auto strate=std::find_if(layout.strates.begin(),layout.strates.end(),
+            [strateIndex](const auto& value){return value.strateIndex==strateIndex
+                &&value.generatorKind=="SurfaceWorld";});
+        if(strate==layout.strates.end())
+        {error="liminal_road_override must select a resolved SurfaceWorld strate";return false;}
+
+        const auto metresToMicrometres=[](double value)
+        {return static_cast<std::int64_t>(std::llround(value*1000000.0));};
+        const std::int64_t fieldFloorMicrometres=static_cast<std::int64_t>(std::llround(
+            static_cast<double>(assembly.recipe.surfaceProfile.h0Subvoxels)
+                *owner.CoreVoxelSizeMicrons/WorldAssemblySubvoxelsPerVoxel));
+        const std::int64_t startX=metresToMicrometres(position[0].Number());
+        const std::int64_t startY=metresToMicrometres(position[1].Number());
+        const std::int64_t lengthUm=metresToMicrometres(pathLength);
+        const std::int64_t lateralUm=metresToMicrometres(curveControl);
+        const std::int64_t deckBaseUm=fieldFloorMicrometres+metresToMicrometres(deckHeight);
+        const std::int64_t riseUm=metresToMicrometres(riseControl);
+        const std::int64_t halfWidthUm=metresToMicrometres(halfWidth);
+        const std::int64_t halfThicknessUm=metresToMicrometres(halfThickness);
+        const std::uint32_t steps=static_cast<std::uint32_t>(std::ceil(pathLength/sampleSpacing));
+        const auto lerpInteger=[steps](std::int64_t a,std::int64_t b,std::uint32_t i)
+        {
+            const std::int64_t numerator=(b-a)*static_cast<std::int64_t>(i);
+            const std::int64_t rounded=numerator>=0
+                ?numerator+static_cast<std::int64_t>(steps/2)
+                :numerator-static_cast<std::int64_t>(steps/2);
+            return a+rounded/static_cast<std::int64_t>(steps);
+        };
+        const auto bezier=[&](const std::array<std::int64_t,4>& controls,std::uint32_t i)
+        {
+            const std::int64_t a=lerpInteger(controls[0],controls[1],i);
+            const std::int64_t b=lerpInteger(controls[1],controls[2],i);
+            const std::int64_t c=lerpInteger(controls[2],controls[3],i);
+            const std::int64_t d=lerpInteger(a,b,i);
+            const std::int64_t e=lerpInteger(b,c,i);
+            return lerpInteger(d,e,i);
+        };
+        const std::array<std::int64_t,4> xControls={startX,
+            startX+lengthUm/3,startX+(2*lengthUm)/3,startX+lengthUm};
+        const std::array<std::int64_t,4> yControls={startY,startY+lateralUm,
+            startY-lateralUm,startY};
+        const std::array<std::int64_t,4> zControls={deckBaseUm,deckBaseUm+riseUm,
+            deckBaseUm-riseUm,deckBaseUm};
+        std::vector<std::array<std::int64_t,3>> path;
+        path.reserve(static_cast<std::size_t>(steps)+1);
+        const auto halfUp=[](std::int64_t numerator,std::int64_t denominator)
+        {return (numerator>=0?numerator+denominator/2:numerator-denominator/2)/denominator;};
+        for(std::uint32_t i=0;i<=steps;++i)
+        {
+            const auto t=static_cast<std::int64_t>(i);
+            const auto n=static_cast<std::int64_t>(steps);
+            path.push_back({xControls[0]+halfUp(lengthUm*t,n),
+                bezier(yControls,i),bezier(zControls,i)});
+        }
+        const auto makeStamp=[&](std::string stableId,ResolvedSdfStampKindV1 kind,
+            const std::array<std::int64_t,3>& positionUm,
+            const std::array<std::int64_t,3>& halfExtentsUm,std::int64_t smoothWidthUm)
+        {
+            ResolvedLayoutStampRequestV1 request;
+            request.stableId=std::move(stableId);request.strateIndex=strateIndex;
+            request.kind=kind;request.anchorPositionMicrometres=positionUm;
+            request.halfExtentsMicrometres=halfExtentsUm;
+            request.smoothWidthMicrometres=smoothWidthUm;
+            requests.push_back(std::move(request));
+        };
+        const std::int64_t deckSmoothUm=250000;
+        ResolvedLayoutStampRequestV1 deck;
+        deck.stableId=*id+"/deck/000";
+        deck.strateIndex=strateIndex;
+        deck.kind=ResolvedSdfStampKindV1::fillSweptDeckSegment;
+        deck.anchorPositionMicrometres=path[path.size()/2];
+        deck.sweepEndpointsMicrometres={path.front(),path.back()};
+        deck.sweepPathMicrometres=path;
+        deck.halfExtentsMicrometres={500000,halfWidthUm,halfThicknessUm};
+        deck.smoothWidthMicrometres=deckSmoothUm;
+        requests.push_back(std::move(deck));
+        const std::int64_t supportBaseUm=fieldFloorMicrometres-2000000;
+        const std::int64_t supportRadiusUm=metresToMicrometres(supportRadius);
+        double distanceSinceSupport=supportSpacing;
+        std::uint32_t supportIndex=0;
+        for(std::uint32_t i=0;i<path.size();++i)
+        {
+            if(i>0)
+            {
+                const auto& a=path[i-1];const auto& b=path[i];
+                const double dx=static_cast<double>(b[0]-a[0]);
+                const double dy=static_cast<double>(b[1]-a[1]);
+                distanceSinceSupport+=std::hypot(dx,dy)/1000000.0;
+            }
+            if(i!=0&&i+1!=path.size()&&distanceSinceSupport<supportSpacing)continue;
+            const std::int64_t supportTopUm=path[i][2]-halfThicknessUm+50000;
+            const std::int64_t supportHalfHeightUm=(supportTopUm-supportBaseUm)/2;
+            const std::int64_t supportCenterUm=(supportTopUm+supportBaseUm)/2;
+            if(supportHalfHeightUm<500000)
+            {error="liminal road support is too short to resolve safely";requests.clear();return false;}
+            makeStamp(*id+"/support/"+std::to_string(10000+supportIndex).substr(1),
+                ResolvedSdfStampKindV1::fillPillar,
+                {path[i][0],path[i][1],supportCenterUm},
+                {supportRadiusUm,supportRadiusUm,supportHalfHeightUm},100000);
+            ++supportIndex;distanceSinceSupport=0.0;
+        }
+        return true;
+    }
+
+    inline bool BuildLiminalPillarGridRequests(const VFJson::Value& root,
+        const FStandaloneOwnerWorld& owner,
+        const VoxelForgeCore::WorldAssemblyManifest& assembly,
+        const VoxelForgeCore::ResolvedLayoutSnapshotV3& layout,
+        std::vector<VoxelForgeCore::ResolvedLayoutStampRequestV1>& requests,
+        std::string& error)
+    {
+        using namespace VoxelForgeCore;
+        requests.clear();
+        const VFJson::Value& overrideValue=root.Get("liminal_pillar_grid_override");
+        if(!overrideValue.IsObject())
+        {error="liminal_pillar_grid_override must be an object";return false;}
+        if(assembly.recipe.surfaceProfile.version!=1
+            ||assembly.recipe.surfaceProfile.kind!=WorldAssemblySurfaceProfileKindV1::flatField
+            ||owner.CoreVoxelSizeMicrons==0)
+        {error="the liminal pillar grid requires a valid flatField SurfaceWorld recipe";return false;}
+        const auto* id=std::get_if<std::string>(&overrideValue.Get("stable_id").Data);
+        const VFJson::Value& strateValue=overrideValue.Get("strate_index");
+        const auto& center=overrideValue.Get("center_xy_m").AsArray();
+        const auto readNumber=[&](const char* key,double fallback,double& result)
+        {
+            const VFJson::Value& value=overrideValue.Get(key);
+            if(std::holds_alternative<std::nullptr_t>(value.Data))
+            {result=fallback;return true;}
+            if(!value.IsNumber()||!std::isfinite(value.Number()))return false;
+            result=value.Number();return true;
+        };
+        double spacing=0.0,radius=0.0,height=0.0;
+        const VFJson::Value& rowsValue=overrideValue.Get("rows");
+        const VFJson::Value& columnsValue=overrideValue.Get("columns");
+        if(!id||id->empty()||!strateValue.IsNumber()||center.size()!=2
+            ||!readNumber("spacing_m",76.0,spacing)
+            ||!readNumber("radius_m",4.0,radius)
+            ||!readNumber("height_m",28.0,height)
+            ||!rowsValue.IsNumber()||!columnsValue.IsNumber())
+        {error="liminal pillar grid requires an identity, center, dimensions and counts";return false;}
+        for(const auto& value:center)
+            if(!value.IsNumber()||!std::isfinite(value.Number()))
+            {error="liminal pillar grid center_xy_m must contain finite metre values";return false;}
+        const int rows=static_cast<int>(rowsValue.Integer());
+        const int columns=static_cast<int>(columnsValue.Integer());
+        if(rows<3||rows>15||columns<3||columns>15||spacing<32.0||spacing>120.0
+            ||radius<2.0||radius>12.0||height<12.0||height>60.0
+            ||std::abs(center[0].Number())>5000.0||std::abs(center[1].Number())>5000)
+        {error="liminal pillar grid dimensions are outside their bounded ranges";return false;}
+        const auto strateIndex=static_cast<std::int32_t>(strateValue.Integer());
+        const auto strate=std::find_if(layout.strates.begin(),layout.strates.end(),
+            [strateIndex](const auto& value){return value.strateIndex==strateIndex
+                &&value.generatorKind=="SurfaceWorld";});
+        if(strate==layout.strates.end())
+        {error="liminal_pillar_grid_override must select a resolved SurfaceWorld strate";return false;}
+        const auto toMicrometres=[](double value)
+        {return static_cast<std::int64_t>(std::llround(value*1000000.0));};
+        const std::int64_t floorUm=static_cast<std::int64_t>(std::llround(
+            static_cast<double>(assembly.recipe.surfaceProfile.h0Subvoxels)
+                *owner.CoreVoxelSizeMicrons/WorldAssemblySubvoxelsPerVoxel));
+        const std::int64_t spacingUm=toMicrometres(spacing);
+        const std::int64_t radiusUm=toMicrometres(radius);
+        const std::int64_t halfHeightUm=toMicrometres(height*0.5);
+        const int rowStart=-(rows/2),columnStart=-(columns/2);
+        for(int row=0;row<rows;++row)
+            for(int column=0;column<columns;++column)
+            {
+                ResolvedLayoutStampRequestV1 request;
+                request.stableId=*id+"/pillar/"+std::to_string(1000+row*columns+column).substr(1);
+                request.strateIndex=strateIndex;
+                request.kind=ResolvedSdfStampKindV1::fillPillar;
+                request.anchorPositionMicrometres={
+                    toMicrometres(center[0].Number())+(columnStart+column)*spacingUm,
+                    toMicrometres(center[1].Number())+(rowStart+row)*spacingUm,
+                    floorUm+halfHeightUm};
+                request.halfExtentsMicrometres={radiusUm,radiusUm,halfHeightUm};
+                requests.push_back(std::move(request));
+            }
+        return true;
+    }
+
+    inline bool BuildCoreLiminalFieldRequests(
+        const VoxelForgeCore::WorldAssemblyManifest& assembly,
+        const FStandaloneOwnerWorld& owner,
+        const VoxelForgeCore::ResolvedLayoutSnapshotV3& layout,
+        std::vector<VoxelForgeCore::ResolvedLayoutStampRequestV1>& requests,
+        std::string& error)
+    {
+        using namespace VoxelForgeCore;
+        requests.clear();
+        if(owner.CoreVoxelSizeMicrons==0)
+        {error="Core.Liminal.Field stamp planning needs the resolved Core voxel size";return false;}
+        const auto plan=std::find_if(assembly.plan.strates.begin(),assembly.plan.strates.end(),
+            [](const auto& value){return value.liminalField.version==CoreLiminalFieldRecipeVersionV1;});
+        if(plan==assembly.plan.strates.end()||plan->route.size()<2)
+        {error="Core.Liminal.Field has no planned route for stamp resolution";return false;}
+        const auto strate=std::find_if(layout.strates.begin(),layout.strates.end(),
+            [&](const auto& value){return value.strateIndex==plan->strateIndex
+                &&value.recipeId==CoreLiminalFieldRecipeIdV1;});
+        if(strate==layout.strates.end())
+        {error="Core.Liminal.Field has no matching resolved SurfaceWorld slot";return false;}
+        const auto variantIndex=static_cast<std::size_t>(plan->liminalField.variant);
+        if(variantIndex>=CoreLiminalFieldVariantsV1.size())
+        {error="Core.Liminal.Field selected an unknown geometry variant";return false;}
+        const auto& definition=CoreLiminalFieldVariantsV1[variantIndex];
+        const auto qToMicrometres=[&](std::int64_t q)
+        {
+            const std::int64_t numerator=q*static_cast<std::int64_t>(owner.CoreVoxelSizeMicrons);
+            return numerator>=0?(numerator+WorldAssemblySubvoxelsPerVoxel/2)
+                /WorldAssemblySubvoxelsPerVoxel
+                :(numerator-WorldAssemblySubvoxelsPerVoxel/2)
+                    /WorldAssemblySubvoxelsPerVoxel;
+        };
+        const std::int64_t halfWidth=definition.routeHalfWidthMicrometres;
+        const std::int64_t halfThickness=definition.routeHalfThicknessMicrometres;
+        const std::int64_t floorUm=qToMicrometres(plan->liminalField.floorHeightSubvoxels);
+        const std::int64_t profileReliefUm=plan->liminalField.variant
+                ==WorldAssemblyLiminalVariantV1::repeatingHills
+            ?2*definition.hillAmplitudeMicrometres:0;
+        const std::int64_t supportBaseUm=floorUm-profileReliefUm+100000;
+
+        std::vector<std::array<std::int64_t,3>> controls;
+        controls.reserve(plan->route.size());
+        for(const auto& point:plan->route)
+            controls.push_back({qToMicrometres(point.positionSubvoxels[0]),
+                qToMicrometres(point.positionSubvoxels[1]),
+                qToMicrometres(point.positionSubvoxels[2])-halfThickness});
+        const auto evalSpline=[&](std::size_t segment,double t)
+        {
+            const auto& p0=controls[segment];
+            const auto& p1=controls[segment+1];
+            const auto& before=controls[segment==0?segment:segment-1];
+            const auto& after=controls[segment+2<controls.size()?segment+2:segment+1];
+            const double t2=t*t,t3=t2*t;
+            const double h00=2.0*t3-3.0*t2+1.0;
+            const double h10=t3-2.0*t2+t;
+            const double h01=-2.0*t3+3.0*t2;
+            const double h11=t3-t2;
+            std::array<double,3> point{};
+            for(std::size_t axis=0;axis<3;++axis)
+            {
+                const double m0=segment==0?static_cast<double>(p1[axis]-p0[axis])
+                    :0.5*static_cast<double>(p1[axis]-before[axis]);
+                const double m1=segment+2>=controls.size()
+                    ?static_cast<double>(p1[axis]-p0[axis])
+                    :0.5*static_cast<double>(after[axis]-p0[axis]);
+                point[axis]=h00*p0[axis]+h10*m0+h01*p1[axis]+h11*m1;
+            }
+            return point;
+        };
+        std::vector<std::array<std::int64_t,3>> sampledPath;
+        sampledPath.push_back(controls.front());
+        for(std::size_t segment=0;segment+1<controls.size();++segment)
+        {
+            const double dx=static_cast<double>(controls[segment+1][0]-controls[segment][0]);
+            const double dy=static_cast<double>(controls[segment+1][1]-controls[segment][1]);
+            const double dz=static_cast<double>(controls[segment+1][2]-controls[segment][2]);
+            const std::uint32_t steps=static_cast<std::uint32_t>(std::clamp(
+                std::ceil(std::sqrt(dx*dx+dy*dy+dz*dz)/4000000.0),32.0,384.0));
+            for(std::uint32_t step=1;step<=steps;++step)
+            {
+                const auto point=step==steps?std::array<double,3>{
+                    static_cast<double>(controls[segment+1][0]),
+                    static_cast<double>(controls[segment+1][1]),
+                    static_cast<double>(controls[segment+1][2])}
+                    :evalSpline(segment,static_cast<double>(step)/steps);
+                std::array<std::int64_t,3> fixed{};
+                for(std::size_t axis=0;axis<3;++axis)
+                    fixed[axis]=static_cast<std::int64_t>(std::llround(point[axis]));
+                if(fixed!=sampledPath.back())sampledPath.push_back(fixed);
+            }
+        }
+        if(sampledPath.size()<2||sampledPath.size()>1025)
+        {error="Core.Liminal.Field sampled route exceeds the continuous-deck path bounds";return false;}
+
+        const auto distancePointSegment=[](const std::array<double,3>& point,
+            const std::array<double,3>& a,const std::array<double,3>& b)
+        {
+            double lengthSquared=0.0,dot=0.0;
+            for(std::size_t axis=0;axis<3;++axis)
+            {
+                const double delta=b[axis]-a[axis];
+                lengthSquared+=delta*delta;dot+=(point[axis]-a[axis])*delta;
+            }
+            const double t=lengthSquared>0.0?std::clamp(dot/lengthSquared,0.0,1.0):0.0;
+            double distanceSquared=0.0;
+            for(std::size_t axis=0;axis<3;++axis)
+            {
+                const double delta=point[axis]-(a[axis]+(b[axis]-a[axis])*t);
+                distanceSquared+=delta*delta;
+            }
+            return std::sqrt(distanceSquared);
+        };
+        const auto clearOfLiminalRoute=[&](const std::array<std::int64_t,3>& center,
+            const std::array<std::int64_t,3>& extents)
+        {
+            const double boundRadius=std::sqrt(static_cast<double>(extents[0])*extents[0]
+                +static_cast<double>(extents[1])*extents[1]
+                +static_cast<double>(extents[2])*extents[2]);
+            const double keepout=boundRadius+halfWidth+1000000.0;
+            const std::array<double,3> point={static_cast<double>(center[0]),
+                static_cast<double>(center[1]),static_cast<double>(center[2])};
+            for(std::size_t i=1;i<sampledPath.size();++i)
+            {
+                const std::array<double,3> a={static_cast<double>(sampledPath[i-1][0]),
+                    static_cast<double>(sampledPath[i-1][1]),
+                    static_cast<double>(sampledPath[i-1][2])};
+                const std::array<double,3> b={static_cast<double>(sampledPath[i][0]),
+                    static_cast<double>(sampledPath[i][1]),
+                    static_cast<double>(sampledPath[i][2])};
+                if(distancePointSegment(point,a,b)<=keepout)return false;
+            }
+            return true;
+        };
+        const auto clearOfPassages=[&](const std::array<std::int64_t,3>& center,
+            const std::array<std::int64_t,3>& extents)
+        {
+            const double boundRadius=std::sqrt(static_cast<double>(extents[0])*extents[0]
+                +static_cast<double>(extents[1])*extents[1]
+                +static_cast<double>(extents[2])*extents[2]);
+            const std::array<double,3> point={static_cast<double>(center[0]),
+                static_cast<double>(center[1]),static_cast<double>(center[2])};
+            for(const auto& passage:layout.passages)
+            {
+                if(passage.upperStrateIndex!=plan->strateIndex
+                    &&passage.lowerStrateIndex!=plan->strateIndex)continue;
+                for(std::size_t i=1;i<passage.controlPoints.size();++i)
+                {
+                    const auto toMicrometres=[&](const auto& q)
+                    {
+                        std::array<double,3> result{};
+                        for(std::size_t axis=0;axis<3;++axis)
+                            result[axis]=static_cast<double>(q[axis])
+                                *owner.CoreVoxelSizeMicrons/WorldAssemblySubvoxelsPerVoxel;
+                        return result;
+                    };
+                    const auto a=toMicrometres(
+                        passage.controlPoints[i-1].positionSubvoxels);
+                    const auto b=toMicrometres(passage.controlPoints[i].positionSubvoxels);
+                    const double radius=std::max(passage.controlPoints[i-1].radiusSubvoxels,
+                        passage.controlPoints[i].radiusSubvoxels)
+                        *owner.CoreVoxelSizeMicrons/WorldAssemblySubvoxelsPerVoxel;
+                    if(distancePointSegment(point,a,b)<=boundRadius+radius+1000000.0)
+                        return false;
+                }
+            }
+            return true;
+        };
+
+        ResolvedLayoutStampRequestV1 deck;
+        deck.stableId="core/liminal-field/route/deck/000";
+        deck.strateIndex=plan->strateIndex;
+        deck.kind=ResolvedSdfStampKindV1::fillSweptDeckSegment;
+        deck.anchorPositionMicrometres=sampledPath[sampledPath.size()/2];
+        deck.sweepEndpointsMicrometres={sampledPath.front(),sampledPath.back()};
+        deck.sweepPathMicrometres=sampledPath;
+        deck.halfExtentsMicrometres={500000,halfWidth,halfThickness};
+        deck.smoothWidthMicrometres=250000;
+        requests.push_back(deck);
+
+        std::vector<double> cumulative(sampledPath.size(),0.0);
+        for(std::size_t i=1;i<sampledPath.size();++i)
+        {
+            const double dx=static_cast<double>(sampledPath[i][0]-sampledPath[i-1][0]);
+            const double dy=static_cast<double>(sampledPath[i][1]-sampledPath[i-1][1]);
+            cumulative[i]=cumulative[i-1]+std::hypot(dx,dy);
+        }
+        const double routeLength=cumulative.back();
+        const double supportSpacing=static_cast<double>(definition.supportSpacingMicrometres);
+        const std::int64_t supportRadius=definition.supportRadiusMicrometres;
+        const auto addSupport=[&](double distance,std::uint32_t supportIndex)
+        {
+            const auto upper=std::lower_bound(cumulative.begin(),cumulative.end(),distance);
+            const std::size_t index=std::clamp<std::size_t>(
+                static_cast<std::size_t>(upper-cumulative.begin()),1,sampledPath.size()-1);
+            const double span=cumulative[index]-cumulative[index-1];
+            const double t=span>0.0?(distance-cumulative[index-1])/span:0.0;
+            std::array<std::int64_t,3> center{};
+            for(std::size_t axis=0;axis<3;++axis)
+                center[axis]=static_cast<std::int64_t>(std::llround(
+                    sampledPath[index-1][axis]
+                        +(sampledPath[index][axis]-sampledPath[index-1][axis])*t));
+            const std::int64_t top=center[2]-halfThickness+250000;
+            if(top<=supportBaseUm+1000000)return;
+            constexpr std::int64_t MaximumSupportSegmentMicrometres=180000000;
+            const std::int64_t fullHeight=top-supportBaseUm;
+            const std::uint32_t parts=static_cast<std::uint32_t>(
+                (fullHeight+MaximumSupportSegmentMicrometres-1)
+                    /MaximumSupportSegmentMicrometres);
+            const std::int64_t segmentHeight=(fullHeight+parts-1)/parts;
+            std::int64_t bottom=supportBaseUm;
+            for(std::uint32_t part=0;part<parts;++part)
+            {
+                const std::int64_t segmentTop=std::min(top,bottom+segmentHeight+100000);
+                ResolvedLayoutStampRequestV1 support;
+                support.stableId="core/liminal-field/route/support/"
+                    +std::to_string(100000+supportIndex).substr(1)+"/"
+                    +std::to_string(part);
+                support.strateIndex=plan->strateIndex;
+                support.kind=ResolvedSdfStampKindV1::fillPillar;
+                support.anchorPositionMicrometres={center[0],center[1],(bottom+segmentTop)/2};
+                support.halfExtentsMicrometres={supportRadius,supportRadius,
+                    (segmentTop-bottom)/2};
+                requests.push_back(std::move(support));
+                bottom=segmentTop;
+            }
+        };
+        std::uint32_t supportIndex=0;
+        for(double distance=supportSpacing;distance<routeLength-10000000.0;
+            distance+=supportSpacing)
+            addSupport(distance,supportIndex++);
+        // The passage mouth anchor is at player-center height; the deck is at
+        // its walk surface 1.13 m lower. These footings carry that landing down
+        // to the liminal field floor without changing the open route above it.
+        addSupport(0.0,supportIndex++);
+        addSupport(routeLength,supportIndex++);
+
+        if(plan->liminalField.variant==WorldAssemblyLiminalVariantV1::flatFieldMonolith)
+        {
+            const std::size_t middle=sampledPath.size()/2;
+            const auto& before=sampledPath[middle==0?0:middle-1];
+            const auto& after=sampledPath[std::min(middle+1,sampledPath.size()-1)];
+            const double dx=static_cast<double>(after[0]-before[0]);
+            const double dy=static_cast<double>(after[1]-before[1]);
+            const double tangent=std::hypot(dx,dy);
+            if(!(tangent>0.0)){error="Core.Liminal.Field monolith placement has a degenerate route tangent";return false;}
+            const std::array<std::int64_t,3> monolithExtents={
+                definition.monolithRadiusMicrometres,definition.monolithRadiusMicrometres,
+                definition.monolithHeightMicrometres/2};
+            std::array<std::int64_t,3> monolithCenter{};
+            bool placed=false;
+            for(const std::int64_t offset:{42000000ll,60000000ll,78000000ll,
+                    96000000ll,-42000000ll,-60000000ll,-78000000ll,-96000000ll})
+            {
+                monolithCenter={
+                    static_cast<std::int64_t>(std::llround(sampledPath[middle][0]-dy/tangent*offset)),
+                    static_cast<std::int64_t>(std::llround(sampledPath[middle][1]+dx/tangent*offset)),
+                    floorUm+monolithExtents[2]};
+                if(clearOfLiminalRoute(monolithCenter,monolithExtents)
+                    &&clearOfPassages(monolithCenter,monolithExtents))
+                {placed=true;break;}
+            }
+            if(!placed)
+            {error="Core.Liminal.Field could not seat its monolith outside route and passage clearances";return false;}
+            ResolvedLayoutStampRequestV1 monolith;
+            monolith.stableId="core/liminal-field/monolith/000";
+            monolith.strateIndex=plan->strateIndex;
+            monolith.kind=ResolvedSdfStampKindV1::fillPillar;
+            monolith.anchorPositionMicrometres=monolithCenter;
+            monolith.halfExtentsMicrometres={definition.monolithRadiusMicrometres,
+                definition.monolithRadiusMicrometres,definition.monolithHeightMicrometres/2};
+            requests.push_back(std::move(monolith));
+        }
+        if(plan->liminalField.variant==WorldAssemblyLiminalVariantV1::pillarGrid)
+        {
+            const std::size_t middle=sampledPath.size()/2;
+            const std::int64_t centerX=sampledPath[middle][0];
+            const std::int64_t centerY=sampledPath[middle][1];
+            const std::int64_t spacing=definition.pillarSpacingMicrometres;
+            const std::int64_t halfHeight=definition.pillarHeightMicrometres/2;
+            std::uint32_t ordinal=0;
+            for(std::uint32_t row=0;row<definition.pillarRows;++row)
+                for(std::uint32_t column=0;column<definition.pillarColumns;++column)
+                {
+                    const std::int64_t x=centerX
+                        +(static_cast<std::int64_t>(column)-definition.pillarColumns/2)*spacing;
+                    const std::int64_t y=centerY
+                        +(static_cast<std::int64_t>(row)-definition.pillarRows/2)*spacing;
+                    double closestSquared=std::numeric_limits<double>::infinity();
+                    for(std::size_t i=1;i<sampledPath.size();++i)
+                    {
+                        const double ax=sampledPath[i-1][0],ay=sampledPath[i-1][1];
+                        const double dx=static_cast<double>(sampledPath[i][0]-sampledPath[i-1][0]);
+                        const double dy=static_cast<double>(sampledPath[i][1]-sampledPath[i-1][1]);
+                        const double lengthSquared=dx*dx+dy*dy;
+                        const double t=lengthSquared>0.0?std::clamp(
+                            ((x-ax)*dx+(y-ay)*dy)/lengthSquared,0.0,1.0):0.0;
+                        const double ox=x-(ax+t*dx),oy=y-(ay+t*dy);
+                        closestSquared=std::min(closestSquared,ox*ox+oy*oy);
+                    }
+                    const double keepout=halfWidth+definition.pillarRadiusMicrometres+1000000.0;
+                    if(closestSquared<=keepout*keepout)continue;
+                    const std::array<std::int64_t,3> pillarExtents={
+                        definition.pillarRadiusMicrometres,definition.pillarRadiusMicrometres,
+                        halfHeight};
+                    const std::array<std::int64_t,3> pillarCenter={x,y,floorUm+halfHeight};
+                    if(!clearOfLiminalRoute(pillarCenter,pillarExtents)
+                        ||!clearOfPassages(pillarCenter,pillarExtents))continue;
+                    ResolvedLayoutStampRequestV1 pillar;
+                    pillar.stableId="core/liminal-field/pillars/"
+                        +std::to_string(1000+ordinal++).substr(1);
+                    pillar.strateIndex=plan->strateIndex;
+                    pillar.kind=ResolvedSdfStampKindV1::fillPillar;
+                    pillar.anchorPositionMicrometres={x,y,floorUm+halfHeight};
+                    pillar.halfExtentsMicrometres={definition.pillarRadiusMicrometres,
+                        definition.pillarRadiusMicrometres,halfHeight};
+                    requests.push_back(std::move(pillar));
+                }
+            if(ordinal<100)
+            {error="Core.Liminal.Field pillar grid has too few columns after route clearance";return false;}
+        }
+        std::sort(requests.begin(),requests.end(),[](const auto& a,const auto& b)
+            {return a.stableId<b.stableId;});
+        return !requests.empty();
+    }
+
     inline bool AttachRound1WorldAssemblyPrototype(FStandaloneOwnerWorld& owner,VFJson::Value& root,
         std::string& error,const std::string& manifestOutputPath,
         VoxelForgeCore::WorldAssemblyManifest* outManifest=nullptr)