passages: four-strate passage floors supported (L67, evaluator v212); 1-2 wall beat still red

- Shared composer: a passage's restored support is applied after a physically overlapping
  later bore, instead of being carved away by it (0-1: 59 -> 0 unsupported).
- Capsule clearance for support restoration is tested against nearby route segments only
  (1-2: 3 -> 0, 2-3: 2 -> 0 unsupported).
- L66 index switches replaced by a physical criterion (both mouths inside their strata bands,
  neither a SurfaceWorld landing).
- Audit: floor zero-crossing refined by bisection (the 0.2498 m "step" was the gauge);
  wall ripple keeps the authored radius, cubic detrend per 32 m window. Controls detected:
  L35 ribs, beads, synthetic 0.25 m step, L36 washboard, L23 terrace.
- Result: 0-1 and 2-3 pass all audits; 1-2 fails wall ripple 7.27 cm (limit 3.5) from an
  authored-radius beat at 7.06 m. Fast tier was green before the final gauge change and was
  not re-run after it.

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

Standalone/Core/include/VoxelForgeCore/VoxelForgeCore.h

@@ -402,7 +402,8 @@ namespace VoxelForgeCore
     // Version 208 keeps the crater tread scoped to style-zero FI mouths.
     // Version 210 keeps bulk native-cave sampling on the scalar field path at strata edges.
     // Version 211 makes coordinate biasing in the shared cell hash unsigned, removing signed-overflow UB.
-    inline constexpr std::uint32_t WorldAssemblyEvaluatorVersion = 211;
+    // Version 212 balances generated entry routes against existing walk lanes and preserves their shared treads.
+    inline constexpr std::uint32_t WorldAssemblyEvaluatorVersion = 212;
 
     enum class FieldChannel : std::uint32_t
     {

Standalone/Core/src/ResolvedLayoutInternal.h

@@ -5,6 +5,7 @@
 
 #include <algorithm>
 #include <cmath>
+#include <cstdio>
 #include <iomanip>
 #include <limits>
 #include <sstream>
@@ -2459,18 +2460,29 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
             }
             std::uint32_t phase=static_cast<std::uint32_t>(PassageSeed(seed,
                 upper.strateIndex,lower.strateIndex,connection,0x50484153u)%16);
-            if(hasUpperRoute)
+            // Authored tangents and island anchors already determine the phase.
+            // A generated mouth in a native cave uses its radial approach; an
+            // island landing uses the tangent fit below to ease off the crater rim.
+            const bool generatedIslandWormEntry=!hasUpperRoute&&!hasUpperTangent
+                &&!anchoredSpiral&&upper.generatorKind=="FloatingIslands";
+            if(hasUpperRoute||(anchoredIslandPassage&&!anchoredSpiral)
+                ||(!hasUpperRoute&&!anchoredIslandPassage&&!anchoredSpiral
+                    &&upper.generatorKind!="FloatingIslands"))
             {
                 std::int64_t bestAlignment=std::numeric_limits<std::int64_t>::min();
                 const std::uint32_t hashedPhase=phase;
                 const std::int64_t phaseX=style==0&&anchoredIslandPassage
                     &&!anchoredSpiral&&passageAnchor
                     ?upperMouth[0]-passageAnchor->values[0]
-                    :(hasUpperTangent?upperTangent[0]:upperMouth[0]);
+                    :(hasUpperTangent?upperTangent[0]:upperMouth[0]
+                        -(anchoredIslandPassage&&passageAnchor
+                            ?passageAnchor->values[0]:0));
                 const std::int64_t phaseY=style==0&&anchoredIslandPassage
                     &&!anchoredSpiral&&passageAnchor
                     ?upperMouth[1]-passageAnchor->values[1]
-                    :(hasUpperTangent?upperTangent[1]:upperMouth[1]);
+                    :(hasUpperTangent?upperTangent[1]:upperMouth[1]
+                        -(anchoredIslandPassage&&passageAnchor
+                            ?passageAnchor->values[1]:0));
                 for(std::uint32_t offset=0;offset<16;++offset)
                 {
                     const std::uint32_t candidate=static_cast<std::uint32_t>(
@@ -2528,7 +2540,7 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
                 clockwise=clockwiseTangentX*upperTangent[0]
                     +clockwiseTangentY*upperTangent[1]>=0.0;
             }
-            const int direction=clockwise?1:-1;
+            int direction=clockwise?1:-1;
             constexpr std::int64_t TargetGradeQ16=12500; // leave margin below the 15-degree helix contract.
             const std::int64_t wormRadialWobble=std::min<std::int64_t>(
                 std::max<std::int64_t>(0,wander/3),2*qPerMetre);
@@ -2597,6 +2609,267 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
                     static_cast<std::int64_t>(std::llround(centerX+radius*directions[directionIndex][0]/65536.0)),
                     static_cast<std::int64_t>(std::llround(centerY+radius*directions[directionIndex][1]/65536.0))};
             };
+            if(generatedIslandWormEntry)
+            {
+                struct FPhaseScore
+                {
+                    std::uint32_t phase=0;
+                    int direction=1;
+                    std::uint64_t routeLength=0;
+                    double clearance=0.0;
+                    double tangent=0.0;
+                };
+                std::array<FPhaseScore,32> phaseScores{};
+                std::size_t phaseScoreCount=0;
+                const std::uint32_t hashedPhase=phase;
+                const int hashedDirection=direction;
+                const std::int64_t entryVerticalDistance=std::abs(
+                    lowerMouth[2]-upperMouth[2]);
+                const std::int64_t entryRouteGradeQ16=profiledSurfaceJoin?8000
+                    :style==0&&anchoredIslandPassage&&!anchoredSpiral?15500
+                    :TargetGradeQ16;
+                const auto candidateRouteLength=[&](std::uint32_t candidate,int candidateDirection)
+                {
+                    std::vector<std::array<std::int64_t,2>> candidateXY;
+                    const auto append=[&](std::array<std::int64_t,2> point)
+                    {if(candidateXY.empty()||candidateXY.back()!=point)
+                        candidateXY.push_back(point);};
+                    append({upperMouth[0],upperMouth[1]});
+                    append(ringPoint(candidate));
+                    const auto measure=[&]()
+                    {
+                        std::uint64_t length=0;
+                        for(std::size_t i=1;i<candidateXY.size();++i)
+                            length+=distanceQ(candidateXY[i][0]-candidateXY[i-1][0],
+                                candidateXY[i][1]-candidateXY[i-1][1]);
+                        length+=distanceQ(lowerMouth[0]-candidateXY.back()[0],
+                            lowerMouth[1]-candidateXY.back()[1]);
+                        return length;
+                    };
+                    std::uint32_t loops=0;
+                    std::uint64_t length=0;
+                    while(loops<256)
+                    {
+                        length=measure();
+                        if(length*static_cast<std::uint64_t>(entryRouteGradeQ16)
+                            >=static_cast<std::uint64_t>(entryVerticalDistance)*65536ull)break;
+                        for(int step=1;step<=16;++step)
+                        {
+                            int directionIndex=static_cast<int>(candidate)
+                                +candidateDirection*step;
+                            directionIndex=(directionIndex%16+16)%16;
+                            append(ringPoint(static_cast<std::uint32_t>(directionIndex),
+                                loops+(step==16?1u:0u)));
+                        }
+                        ++loops;
+                    }
+                    if(loops>=256)return std::uint64_t{0};
+                    const std::int64_t mouthPlanSeparation=distanceQ(
+                        lowerMouth[0]-upperMouth[0],lowerMouth[1]-upperMouth[1]);
+                    if(!hasLowerTangent&&!anchoredSpiral&&pathStyle==1u&&loops<=1
+                        &&mouthPlanSeparation<=2*mouthRadius
+                        &&entryVerticalDistance<=2*mouthRadius+qPerMetre/2)
+                    {
+                        double bestExitScore=-std::numeric_limits<double>::infinity();
+                        std::uint32_t lowerPhase=candidate;
+                        const auto firstRing=ringPoint(candidate);
+                        for(std::uint32_t exitCandidate=0;exitCandidate<16;++exitCandidate)
+                        {
+                            if(exitCandidate==candidate)continue;
+                            const std::uint32_t previous=static_cast<std::uint32_t>(
+                                (static_cast<int>(exitCandidate)-candidateDirection+16)%16);
+                            const auto terminal=ringPoint(exitCandidate,loops);
+                            const auto beforeTerminal=ringPoint(previous,loops);
+                            const double incomingX=static_cast<double>(terminal[0]-beforeTerminal[0]);
+                            const double incomingY=static_cast<double>(terminal[1]-beforeTerminal[1]);
+                            const double outgoingX=static_cast<double>(lowerMouth[0]-terminal[0]);
+                            const double outgoingY=static_cast<double>(lowerMouth[1]-terminal[1]);
+                            const double incomingLength=std::hypot(incomingX,incomingY);
+                            const double outgoingLength=std::hypot(outgoingX,outgoingY);
+                            if(incomingLength<=1.0e-6||outgoingLength<=1.0e-6)continue;
+                            const double alignment=(incomingX*outgoingX+incomingY*outgoingY)
+                                /(incomingLength*outgoingLength);
+                            const double separation=std::hypot(
+                                static_cast<double>(terminal[0]-firstRing[0]),
+                                static_cast<double>(terminal[1]-firstRing[1]));
+                            const double score=alignment+0.20*std::clamp(
+                                separation/(2.0*qPerMetre),0.0,2.0);
+                            if(score>bestExitScore)
+                            {bestExitScore=score;lowerPhase=exitCandidate;}
+                        }
+                        for(int step=1;step<=16;++step)
+                        {
+                            int directionIndex=static_cast<int>(candidate)
+                                +candidateDirection*step;
+                            directionIndex=(directionIndex%16+16)%16;
+                            append(ringPoint(static_cast<std::uint32_t>(directionIndex),loops));
+                            if(static_cast<std::uint32_t>(directionIndex)==lowerPhase)break;
+                        }
+                    }
+                    return measure();
+                };
+                for(std::uint32_t offset=0;offset<16;++offset)
+                {
+                    const std::uint32_t candidate=static_cast<std::uint32_t>(
+                        (hashedPhase+16-offset)%16);
+                    const auto point=ringPoint(candidate);
+                    const double entryX=static_cast<double>(point[0]-upperMouth[0]);
+                    const double entryY=static_cast<double>(point[1]-upperMouth[1]);
+                    const double entryLength=std::hypot(entryX,entryY);
+                    if(entryLength<=1.0e-6)continue;
+                    const auto entryDistance=distanceQ(point[0]-upperMouth[0],
+                        point[1]-upperMouth[1]);
+                    for(const int candidateDirection:{hashedDirection,-hashedDirection})
+                    {
+                        const std::uint64_t routeLength=candidateRouteLength(candidate,
+                            candidateDirection);
+                        if(routeLength==0)continue;
+                        const std::uint32_t next=static_cast<std::uint32_t>(
+                            (static_cast<int>(candidate)+candidateDirection+16)%16);
+                        const auto nextPoint=ringPoint(next);
+                        const double tangentX=static_cast<double>(nextPoint[0]-point[0]);
+                        const double tangentY=static_cast<double>(nextPoint[1]-point[1]);
+                        const double tangentLength=std::hypot(tangentX,tangentY);
+                        if(tangentLength<=1.0e-6)continue;
+                        const double tangentAlignment=(entryX*tangentX+entryY*tangentY)
+                            /(entryLength*tangentLength);
+                        const std::int64_t firstAxisZ=upperMouth[2]+mouthRadius
+                            -playerCenterAboveFloorQ;
+                        const std::int64_t secondAxisZ=firstAxisZ+PassageRoundRatio(
+                            lowerMouth[2]-upperMouth[2],static_cast<std::int64_t>(entryDistance),
+                            static_cast<std::int64_t>(routeLength));
+                        double candidateTreadClearance=std::numeric_limits<double>::infinity();
+                        const int entrySamples=std::max(1,static_cast<int>(std::ceil(
+                            entryLength/(0.25*qPerMetre))));
+                        for(int sample=0;sample<=entrySamples;++sample)
+                        {
+                            const double t=static_cast<double>(sample)/entrySamples;
+                            const double qx=upperMouth[0]+t*entryX;
+                            const double qy=upperMouth[1]+t*entryY;
+                            const double qz=firstAxisZ+t*(secondAxisZ-firstAxisZ)
+                                -mouthRadius+0.20*qPerMetre;
+                            for(const auto& previousPassage:layout.passages)
+                            {
+                                if(previousPassage.stableId==passage.stableId
+                                    ||previousPassage.controlPoints.size()<2)continue;
+                                for(std::size_t previousSegment=0;
+                                    previousSegment+1<previousPassage.controlPoints.size();
+                                    ++previousSegment)
+                                {
+                                    const auto& previousA=previousPassage.controlPoints[previousSegment];
+                                    const auto& previousB=previousPassage.controlPoints[previousSegment+1];
+                                    const double ax=static_cast<double>(previousA.positionSubvoxels[0]);
+                                    const double ay=static_cast<double>(previousA.positionSubvoxels[1]);
+                                    const double az=static_cast<double>(previousA.positionSubvoxels[2]);
+                                    const double dx=static_cast<double>(previousB.positionSubvoxels[0])-ax;
+                                    const double dy=static_cast<double>(previousB.positionSubvoxels[1])-ay;
+                                    const double dz=static_cast<double>(previousB.positionSubvoxels[2])-az;
+                                    const double horizontalLengthSquared=dx*dx+dy*dy;
+                                    const double projection=horizontalLengthSquared>0.0
+                                        ?std::clamp(((qx-ax)*dx+(qy-ay)*dy)
+                                            /horizontalLengthSquared,0.0,1.0):0.0;
+                                    const double centerX=ax+projection*dx;
+                                    const double centerY=ay+projection*dy;
+                                    const double centerZ=az+projection*dz
+                                        -(previousA.radiusSubvoxels+projection*(
+                                            static_cast<double>(previousB.radiusSubvoxels)
+                                                -previousA.radiusSubvoxels))
+                                        +1.13*qPerMetre;
+                                    const double vertical=std::max(0.0,
+                                        std::abs(qz-centerZ)-0.54*qPerMetre);
+                                    const double clearance=std::sqrt(
+                                        (qx-centerX)*(qx-centerX)+(qy-centerY)*(qy-centerY)
+                                            +vertical*vertical)-0.34*qPerMetre;
+                                    candidateTreadClearance=std::min(candidateTreadClearance,
+                                        clearance);
+                                }
+                            }
+                        }
+                        double previousTreadClearance=std::numeric_limits<double>::infinity();
+                        const double entryXQ=entryX,entryYQ=entryY;
+                        const double entryZQ=static_cast<double>(secondAxisZ-firstAxisZ);
+                        const double entryLengthSquared=entryXQ*entryXQ+entryYQ*entryYQ
+                            +entryZQ*entryZQ;
+                        const double mouthStartT=std::clamp(
+                            mouthRadius/entryLength,0.0,1.0);
+                        for(const auto& previousPassage:layout.passages)
+                        {
+                            if(previousPassage.stableId==passage.stableId
+                                ||previousPassage.controlPoints.size()<2)continue;
+                            for(std::size_t previousSegment=0;
+                                previousSegment+1<previousPassage.controlPoints.size();
+                                ++previousSegment)
+                            {
+                                const auto& previousA=previousPassage.controlPoints[previousSegment];
+                                const auto& previousB=previousPassage.controlPoints[previousSegment+1];
+                                const double ax=static_cast<double>(previousA.positionSubvoxels[0]);
+                                const double ay=static_cast<double>(previousA.positionSubvoxels[1]);
+                                const double az=static_cast<double>(previousA.positionSubvoxels[2]);
+                                const double dx=static_cast<double>(previousB.positionSubvoxels[0])-ax;
+                                const double dy=static_cast<double>(previousB.positionSubvoxels[1])-ay;
+                                const double dz=static_cast<double>(previousB.positionSubvoxels[2])-az;
+                                for(int sample=0;sample<=8;++sample)
+                                {
+                                    const double t=static_cast<double>(sample)/8.0;
+                                    const double px=ax+t*dx;
+                                    const double py=ay+t*dy;
+                                    const double pz=az+t*dz
+                                        -(previousA.radiusSubvoxels+t*(
+                                            static_cast<double>(previousB.radiusSubvoxels)
+                                                -previousA.radiusSubvoxels))
+                                        +0.20*qPerMetre;
+                                    const double projection=entryLengthSquared>0.0
+                                        ?std::clamp(((px-upperMouth[0])*entryXQ
+                                            +(py-upperMouth[1])*entryYQ
+                                            +(pz-firstAxisZ)*entryZQ)/entryLengthSquared,
+                                            mouthStartT,1.0):mouthStartT;
+                                    const double ex=px-(upperMouth[0]+projection*entryXQ);
+                                    const double ey=py-(upperMouth[1]+projection*entryYQ);
+                                    const double ez=pz-(firstAxisZ+projection*entryZQ);
+                                    const double clearance=std::sqrt(ex*ex+ey*ey+ez*ez)
+                                        -mouthRadius;
+                                    previousTreadClearance=std::min(previousTreadClearance,
+                                        clearance);
+                                }
+                            }
+                        }
+                        const double clearanceScore=std::isfinite(candidateTreadClearance)
+                            &&std::isfinite(previousTreadClearance)
+                            ?std::min(candidateTreadClearance,previousTreadClearance)/qPerMetre
+                            :0.0;
+                        if(phaseScoreCount<phaseScores.size())
+                            phaseScores[phaseScoreCount++]={candidate,candidateDirection,
+                                routeLength,clearanceScore,tangentAlignment};
+                    }
+                }
+                if(phaseScoreCount>0)
+                {
+                    double bestClearance=-std::numeric_limits<double>::infinity();
+                    for(std::size_t index=0;index<phaseScoreCount;++index)
+                        bestClearance=std::max(bestClearance,phaseScores[index].clearance);
+                    constexpr double ClearanceToleranceMetres=0.10;
+                    const FPhaseScore* selected=nullptr;
+                    for(std::size_t index=0;index<phaseScoreCount;++index)
+                    {
+                        const auto& candidate=phaseScores[index];
+                        if(candidate.clearance+ClearanceToleranceMetres<bestClearance)continue;
+                        const bool shorter=!selected||candidate.routeLength<selected->routeLength;
+                        const bool stableLengthTie=selected
+                            &&candidate.routeLength==selected->routeLength
+                            &&(candidate.clearance>selected->clearance+1.0e-6
+                                ||(std::abs(candidate.clearance-selected->clearance)<=1.0e-6
+                                    &&candidate.tangent>selected->tangent));
+                        if(shorter||stableLengthTie)selected=&candidate;
+                    }
+                    if(selected)
+                    {
+                        phase=selected->phase;
+                        direction=selected->direction;
+                        clockwise=direction>0;
+                    }
+                }
+            }
+            direction=clockwise?1:-1;
             std::vector<std::array<std::int64_t,2>> xy;
             const auto pushXY=[&](std::array<std::int64_t,2> p)
             {if(xy.empty()||xy.back()!=p)xy.push_back(p);};
@@ -2731,6 +3004,12 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
                 }
                 ++loops;
             }
+            const std::int64_t mouthPlanSeparation=distanceQ(
+                lowerMouth[0]-upperMouth[0],lowerMouth[1]-upperMouth[1]);
+            const bool shortGeneratedClosure=!hasLowerTangent&&!hasAnchorHelix
+                &&pathStyle==1u&&loops<=1
+                &&mouthPlanSeparation<=2*mouthRadius
+                &&verticalDistance<=2*mouthRadius+qPerMetre/2;
             if(hasLowerTangent)
             {
                 std::uint32_t lowerPhase=static_cast<std::uint32_t>(PassageSeed(seed,
@@ -2789,6 +3068,48 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
                     }
                 pushXY(ringPoint(lowerPhase));
             }
+            else if(shortGeneratedClosure)
+            {
+                // A one-turn generated route whose mouths share a plan location
+                // must leave and rejoin from different ring tangents. Returning on
+                // the entry chord creates a hairpin that overlaps its own tread.
+                double bestExitScore=-std::numeric_limits<double>::infinity();
+                std::uint32_t lowerPhase=phase;
+                const auto firstRing=ringPoint(phase,loops);
+                for(std::uint32_t candidate=0;candidate<16;++candidate)
+                {
+                    if(candidate==phase)continue;
+                    const std::uint32_t previous=static_cast<std::uint32_t>(
+                        (static_cast<int>(candidate)-direction+16)%16);
+                    const auto terminal=ringPoint(candidate,loops);
+                    const auto beforeTerminal=ringPoint(previous,loops);
+                    const double incomingX=static_cast<double>(terminal[0]-beforeTerminal[0]);
+                    const double incomingY=static_cast<double>(terminal[1]-beforeTerminal[1]);
+                    const double outgoingX=static_cast<double>(lowerMouth[0]-terminal[0]);
+                    const double outgoingY=static_cast<double>(lowerMouth[1]-terminal[1]);
+                    const double incomingLength=std::hypot(incomingX,incomingY);
+                    const double outgoingLength=std::hypot(outgoingX,outgoingY);
+                    if(incomingLength<=1.0e-6||outgoingLength<=1.0e-6)continue;
+                    const double tangentAlignment=(incomingX*outgoingX+incomingY*outgoingY)
+                        /(incomingLength*outgoingLength);
+                    const double separation=std::hypot(
+                        static_cast<double>(terminal[0]-firstRing[0]),
+                        static_cast<double>(terminal[1]-firstRing[1]));
+                    const double score=tangentAlignment
+                        +0.20*std::clamp(separation/(2.0*qPerMetre),0.0,2.0);
+                    if(score>bestExitScore)
+                    {bestExitScore=score;lowerPhase=candidate;}
+                }
+                for(int step=1;step<=16;++step)
+                {
+                    int directionIndex=static_cast<int>(phase)+direction*step;
+                    directionIndex=(directionIndex%16+16)%16;
+                    pushXY(ringPoint(static_cast<std::uint32_t>(directionIndex),loops));
+                    if(static_cast<std::uint32_t>(directionIndex)==lowerPhase)break;
+                }
+                std::printf("[ResolvedPassageGeneratedExitApproach] id=%s turns=%u phase=%u exit_phase=%u tangent_score=%.3f status=PASS\n",
+                    passage.stableId.c_str(),loops,phase,lowerPhase,bestExitScore);
+            }
             pushXY({lowerMouth[0],lowerMouth[1]});totalHorizontal=measurePath();
             std::size_t lowerMouthIndex=xy.size()-1;
             std::vector<std::array<std::int64_t,3>> lowerLandingPoints;

Standalone/Core/src/ShapeWorldInternal.h

@@ -971,6 +971,7 @@ public:
         const double floorThicknessVoxels=qPerMetre/Q;
         const double playerCenterAboveFloorQ=1.13*qPerMetre;
         float composed=density;
+        float deferredSupportDensity=std::numeric_limits<float>::infinity();
         const auto composeRouteMouthSupport=[&](std::int32_t strateIndex,
             const std::array<std::int64_t,3>& mouth,bool departure)
         {
@@ -1045,7 +1046,6 @@ public:
         {
             const auto& passage=ResolvedLayout->passages[passageIndex];
             if(passage.controlPoints.size()<2)continue;
-            const bool internalChainPassage=passageIndex>0;
             const auto supportStratum=[&](std::int32_t strateIndex)
                 ->const VoxelForgeCore::ResolvedLayoutStratumV2*
             {
@@ -1056,6 +1056,31 @@ public:
             };
             const auto* supportUpper=supportStratum(passage.upperStrateIndex);
             const auto* supportLower=supportStratum(passage.lowerStrateIndex);
+            const auto mouthInsideContent=[&](
+                const VoxelForgeCore::ResolvedLayoutStratumV2* stratum,
+                const std::array<std::int64_t,3>& mouth)
+            {
+                if(!stratum||!stratum->content.presentInCurrentField)return false;
+                const auto zMicrometres=static_cast<std::int64_t>(std::llround(
+                    static_cast<double>(mouth[2])
+                        *ResolvedLayout->coreVoxelSizeMicrometres/Q));
+                return zMicrometres>=stratum->content.bottomMicrometres
+                    &&zMicrometres<stratum->content.topMicrometres;
+            };
+            // A passage is internal when both mouths are bounded by their strate
+            // content and neither endpoint is a SurfaceWorld landing. Route order
+            // and the total number of strata are irrelevant.
+            const bool internalChainPassage=supportUpper&&supportLower
+                &&!supportUpper->passageCapabilities.hasSurfaceLanding
+                &&!supportLower->passageCapabilities.hasSurfaceLanding
+                &&mouthInsideContent(supportUpper,passage.upperMouthSubvoxels)
+                &&mouthInsideContent(supportLower,passage.lowerMouthSubvoxels);
+            const auto laterPassageMayCarve=[&](std::ptrdiff_t supportSegment,
+                double sampleX,double sampleY,double sampleZ)
+            {
+                return PassageSupportMayBeCarvedByLaterBore(passageIndex,
+                    supportSegment,sampleX,sampleY,sampleZ,0.35*qPerMetre);
+            };
             const bool floatingIslandPassage=supportUpper
                 &&supportUpper->passageCapabilities.hasFloatingIslandLanding;
             const bool surfaceToTunnelSupport=supportUpper&&supportLower
@@ -1223,7 +1248,8 @@ public:
                             +playerVertical*playerVertical)-0.34*qPerMetre);
                 }
                 double cx=ax+t*dx,cy=ay+t*dy,cz=az+t*dz;
-                const bool smoothCarveJoin=index>2&&index+12<lastIndex
+                const bool smoothCarveJoin=index>2
+                    &&index+(internalChainPassage?2:12)<lowerMouthIndex
                     &&DeterministicSqrt(lengthSq)<=8.0*qPerMetre
                     &&!IsPassageShortSpanSegment(passageIndex,segmentIndex-1)
                     &&!IsPassageShortSpanSegment(passageIndex,segmentIndex)
@@ -1301,8 +1327,9 @@ public:
                 ?std::clamp(-(qz-(nearestA.positionSubvoxels[2]+bestT*(
                     static_cast<double>(nearestB.positionSubvoxels[2])-nearestA.positionSubvoxels[2])))
                     /distanceToCenter,0.0,1.0):0.0;
-            const float relief=VF_FieldPassageWallRelief(static_cast<float>(X),static_cast<float>(Y),
+            const float relief=VF_FieldPassageWallRelief(static_cast<float>(X),
-                static_cast<float>(Z),static_cast<std::uint32_t>(Owner?Owner->Seed:0));
+                static_cast<float>(Y),static_cast<float>(Z),
+                static_cast<std::uint32_t>(Owner?Owner->Seed:0));
             const float mouthSurfaceRelief=VF_FieldSurfaceRelief(static_cast<float>(X)*1.5f,
                 static_cast<float>(Y)*1.5f,static_cast<float>(Z)*1.5f,
                 static_cast<std::uint32_t>(Owner?Owner->Seed:0)^0x4D4F5554u);
@@ -1427,7 +1454,8 @@ public:
                 static_cast<double>(mouthTerrainRelief),-1.0,1.0)
                 *0.20*qPerMetre*mouthFloorBlend*floorReliefWeight
                 *(upperMouthFloorFade?1.0:0.0);
-            const double wallReliefWeight=0.05+0.95*(1.0-verticalWallAlignment);
+            const double wallOpening=1.0-verticalWallAlignment;
+            const double wallReliefWeight=0.05+0.95*wallOpening;
             const double roughSignedDistance=bestSignedDistance
                 +static_cast<double>(std::clamp(relief,-1.0f,1.0f))*0.21*qPerMetre*wallReliefWeight
                 +floorReliefOffset;
@@ -1472,6 +1500,7 @@ public:
                 static_cast<float>(-roughSignedDistance/Q));
             composed=std::lerp(composed,fullyCarvedDensity,
                 static_cast<float>(floorCarveWeight));
+            const float composedAfterCarve=composed;
             const auto considerSupportSegment=[&](std::ptrdiff_t index)
             {
                 const auto& segmentA=passage.controlPoints[static_cast<std::size_t>(index)];
@@ -1570,15 +1599,25 @@ public:
                 const double minimumSupportQueryDepth=index==selectedSupportSegmentIndex
                     &&sparseRouteSupport?0.65:0.93;
                 if(supportQueryDepth<minimumSupportQueryDepth*qPerMetre
-                    ||supportQueryDepth>1.30*qPerMetre)return;
+                    ||supportQueryDepth>1.30*qPerMetre)
+                    return;
                 const bool fallbackSupport=qz>=supportPlayerCenterZ-1.50*qPerMetre;
                 const double supportThicknessVoxels=fallbackSupport
                     ?qPerMetre/Q:0.5*qPerMetre/Q;
                 // Keep the supported ramp to a comfortable walking width. Extending a
                 // full bore-radius shelf across overlapping helix coils can block the
                 // capsule on the neighbouring turn.
-                const bool lowerMouthBodyOverlap=ResolvedLayout->strates.size()>2
+                const double lowerMouthDx=centerX
-                    &&index>=lowerMouthIndex-2
+                    -static_cast<double>(passage.lowerMouthSubvoxels[0]);
+                const double lowerMouthDy=centerY
+                    -static_cast<double>(passage.lowerMouthSubvoxels[1]);
+                const double lowerMouthDz=centerZ-radius
+                    -static_cast<double>(passage.lowerMouthSubvoxels[2]);
+                const double lowerMouthBodyDistance=DeterministicSqrt(
+                    lowerMouthDx*lowerMouthDx+lowerMouthDy*lowerMouthDy
+                        +lowerMouthDz*lowerMouthDz);
+                const bool lowerMouthBodyOverlap=internalChainPassage
+                    &&lowerMouthBodyDistance<=2.0*qPerMetre
                     &&supportQueryDepth<0.98*qPerMetre;
                 // Keep a narrow walk core, but place its top on the native surface
                 // so the support remains a worn ramp instead of a route-height slab.
@@ -1731,7 +1770,8 @@ public:
                 bestSupportUsesSignedDistance=signedDistanceSupport;
                 bestSupportMouthBlend=mouthSupportBlend;
                 bestSupportNativeBlend=mouthTread
-                    ?0.85*mouthSupportBlend*(1.0-supportEdgeSmooth):0.0;
+                    ?(internalChainPassage?1.0:0.85)
+                        *mouthSupportBlend*(1.0-supportEdgeSmooth):0.0;
             };
             std::ptrdiff_t supportCenterIndex=bestIndex;
             if(bestIndex<lowerMouthIndex)
@@ -1775,6 +1815,8 @@ public:
                     lowerMouthIndex,mouthSearchBegin,mouthSearchEnd,lastIndex,qx,qy,
                     capsuleQueryZ,qPerMetre,capsuleClearanceMetres)
                 :bestPlayerCapsuleSignedDistance>=capsuleClearanceMetres*qPerMetre;
+            bool supportApplied=false;
+            bool supportNeedsDeferral=false;
             // Outside bridge and short-span segments, add the tread only where the
             // native field already provides a solid envelope; the capsule check keeps
             // that support below the player's walk space.
@@ -1782,6 +1824,8 @@ public:
                 ||shortSpanFloorSupport)
                 &&(capsuleAllowsSupport||bestSupportDensity>=0.0))
             {
+                supportNeedsDeferral=laterPassageMayCarve(bestSupportSegmentIndex,
+                    qx,qy,qz);
                 if(bestSupportIsMouthTread)
                 {
                     // Preserve the owner's native ground through the shallow mouth
@@ -1797,13 +1841,36 @@ public:
                         const double nativeSurfaceDetail=std::clamp(
                             static_cast<double>(mouthTerrainRelief),-1.0,1.0)
                             *0.18*qPerMetre/Q;
-                        const float nativeGroundWithRelief=static_cast<float>(density
+                        const float nativeGroundWithRelief=static_cast<float>(
+                            (supportNeedsDeferral?std::max(-1.0f,density):density)
                                 -nativeSurfaceDetail);
                         composed=std::lerp(composed,nativeGroundWithRelief,
                             static_cast<float>(bestSupportNativeBlend));
+                        supportApplied=composed<composedAfterCarve;
                     }
                 }
-                else composed=std::min(composed,static_cast<float>(bestSupportDensity));
+                else
+                {
+                    const float densityBeforeSupport=composed;
+                    composed=std::min(composed,static_cast<float>(bestSupportDensity));
+                    supportApplied=composed<densityBeforeSupport;
+                }
+            }
+            if(supportApplied)
+            {
+                if(PassageOtherCapsuleBlocksSupport(passageIndex,
+                    bestSupportSegmentIndex,qx,qy,qz,qPerMetre,capsuleClearanceMetres))
+                {
+                    composed=composedAfterCarve;
+                    supportApplied=false;
+                }
+            }
+            if(supportApplied&&supportNeedsDeferral)
+            {
+                deferredSupportDensity=std::min(deferredSupportDensity,composed);
+                // Preserve a tread only when a later passage bore reaches this
+                // sample; otherwise retain the ordinary composition order.
+                composed=composedAfterCarve;
             }
         }
         // Restore the surface route where the passage cut crossed otherwise solid
@@ -1818,6 +1885,7 @@ public:
                 composeRouteMouthSupport(passage.upperStrateIndex,
                     passage.upperMouthSubvoxels,true);
         }
+        composed=std::min(composed,deferredSupportDensity);
         return composed;
     }
 
@@ -3282,6 +3350,17 @@ private:
     {
         std::array<double,3> minimum{},maximum{};
     };
+    struct FPassageLaterBoreCandidate
+    {
+        std::array<double,3> minimum{},maximum{};
+        double reach=0.0;
+    };
+    struct FPassageLaterBoreSource
+    {
+        std::array<double,3> minimum{},maximum{};
+        std::vector<FPassageLaterBoreCandidate> candidates;
+        std::vector<std::size_t> capsuleCandidatePassages;
+    };
     struct FPassageProofNode
     {
         std::array<double,3> minimum{},maximum{};
@@ -4237,6 +4316,7 @@ private:
         PassageNearestNodes.clear();
         PassageProofBounds.clear();PassageProofNodes.clear();
         PassageNearestNodes.resize(ResolvedLayout?ResolvedLayout->passages.size():0);
+        PassageLaterBoreSources.clear();
         PassageColumnSegmentFlags.clear();PassageShortSpanSegmentFlags.clear();
         PassageHasShortSpanFlags.clear();
         if(!ResolvedLayout||ResolvedLayout->passages.empty())return;
@@ -4336,6 +4416,75 @@ private:
                 }
             }
         }
+        // Precompute the later-bore leaves that can intersect each tread segment.
+        // Passage support samples normally stay within this source envelope, so the
+        // hot query can test a short list of physical bounds instead of walking a
+        // full spatial tree for every density sample.
+        PassageLaterBoreSources.resize(ResolvedLayout->passages.size());
+        const double qPerMetre=Q*voxelsPerMetre;
+        for(std::size_t sourcePassageIndex=0;
+            sourcePassageIndex<ResolvedLayout->passages.size();++sourcePassageIndex)
+        {
+            const auto& sourcePassage=ResolvedLayout->passages[sourcePassageIndex];
+            const std::size_t sourceSegmentCount=sourcePassage.controlPoints.size()>1
+                ?sourcePassage.controlPoints.size()-1:0;
+            auto& sourceSegments=PassageLaterBoreSources[sourcePassageIndex];
+            sourceSegments.resize(sourceSegmentCount);
+            for(std::size_t sourceSegment=0;sourceSegment<sourceSegmentCount;++sourceSegment)
+            {
+                const auto& sourceA=sourcePassage.controlPoints[sourceSegment];
+                const auto& sourceB=sourcePassage.controlPoints[sourceSegment+1];
+                const double sourceRadius=std::max(sourceA.radiusSubvoxels,
+                    sourceB.radiusSubvoxels);
+                auto& source=sourceSegments[sourceSegment];
+                for(std::size_t axis=0;axis<3;++axis)
+                {
+                    source.minimum[axis]=std::min(sourceA.positionSubvoxels[axis],
+                        sourceB.positionSubvoxels[axis])-sourceRadius-3.0*qPerMetre;
+                    source.maximum[axis]=std::max(sourceA.positionSubvoxels[axis],
+                        sourceB.positionSubvoxels[axis])+sourceRadius+3.0*qPerMetre;
+                }
+                for(std::size_t laterPassageIndex=sourcePassageIndex+1;
+                    laterPassageIndex<ResolvedLayout->passages.size();++laterPassageIndex)
+                {
+                    for(const auto& node:PassageNearestNodes[laterPassageIndex])
+                    {
+                        if(node.left>=0)continue;
+                        const double reach=node.maximumRadius+0.35*qPerMetre+1.0e-6;
+                        bool intersectsSource=true;
+                        for(std::size_t axis=0;axis<3;++axis)
+                            intersectsSource=intersectsSource
+                                &&node.minimum[axis]-reach<=source.maximum[axis]
+                                &&node.maximum[axis]+reach>=source.minimum[axis];
+                        if(!intersectsSource)continue;
+                        source.candidates.push_back({node.minimum,node.maximum,reach});
+                    }
+                }
+                const double capsuleXYReach=0.39*qPerMetre;
+                for(std::size_t otherPassageIndex=0;
+                    otherPassageIndex<ResolvedLayout->passages.size();++otherPassageIndex)
+                {
+                    if(otherPassageIndex==sourcePassageIndex
+                        ||PassageNearestNodes[otherPassageIndex].empty())continue;
+                    const auto& otherRoot=PassageNearestNodes[otherPassageIndex].front();
+                    const std::array<double,3> blockerMinimum={
+                        otherRoot.minimum[0]-capsuleXYReach,
+                        otherRoot.minimum[1]-capsuleXYReach,
+                        otherRoot.minimum[2]-otherRoot.maximumRadius+0.20*qPerMetre};
+                    const std::array<double,3> blockerMaximum={
+                        otherRoot.maximum[0]+capsuleXYReach,
+                        otherRoot.maximum[1]+capsuleXYReach,
+                        otherRoot.maximum[2]+2.06*qPerMetre};
+                    bool intersectsSource=true;
+                    for(std::size_t axis=0;axis<3;++axis)
+                        intersectsSource=intersectsSource
+                            &&blockerMinimum[axis]<=source.maximum[axis]
+                            &&blockerMaximum[axis]>=source.minimum[axis];
+                    if(intersectsSource)
+                        source.capsuleCandidatePassages.push_back(otherPassageIndex);
+                }
+            }
+        }
         for(const auto& crossing:PassageVoidCrossings)
         {
             if(crossing.passageIndex<PassageColumnSegmentFlags.size())
@@ -4473,6 +4622,88 @@ private:
                 signedDistanceLimit);
     }
 
+    bool PassageSupportMayBeCarvedByLaterBore(std::size_t passageIndex,
+        std::ptrdiff_t supportSegment,double qx,double qy,double qz,
+        double signedDistanceLimit) const
+    {
+        if(!ResolvedLayout||passageIndex+1>=ResolvedLayout->passages.size())return false;
+        if(passageIndex<PassageLaterBoreSources.size()&&supportSegment>=0
+            &&static_cast<std::size_t>(supportSegment)
+                <PassageLaterBoreSources[passageIndex].size())
+        {
+            const auto& source=PassageLaterBoreSources[passageIndex][
+                static_cast<std::size_t>(supportSegment)];
+            const bool insideSourceEnvelope=qx>=source.minimum[0]&&qx<=source.maximum[0]
+                &&qy>=source.minimum[1]&&qy<=source.maximum[1]
+                &&qz>=source.minimum[2]&&qz<=source.maximum[2];
+            if(insideSourceEnvelope)
+            {
+                for(const auto& candidate:source.candidates)
+                {
+                    double distanceSquared=0.0;
+                    for(std::size_t axis=0;axis<3;++axis)
+                    {
+                        const double q=axis==0?qx:axis==1?qy:qz;
+                        const double distance=q<candidate.minimum[axis]
+                            ?candidate.minimum[axis]-q
+                            :q>candidate.maximum[axis]?q-candidate.maximum[axis]:0.0;
+                        distanceSquared+=distance*distance;
+                    }
+                    const double reach=candidate.reach;
+                    if(distanceSquared<=reach*reach)return true;
+                }
+                return false;
+            }
+        }
+        for(std::size_t otherPassageIndex=passageIndex+1;
+            otherPassageIndex<ResolvedLayout->passages.size();++otherPassageIndex)
+        {
+            const auto& otherPassage=ResolvedLayout->passages[otherPassageIndex];
+            if(otherPassage.controlPoints.size()<2)continue;
+            if(PassagePotentialWithinNode(otherPassageIndex,0,0,
+                otherPassage.controlPoints.size()-1,qx,qy,qz,signedDistanceLimit))return true;
+        }
+        return false;
+    }
+
+    bool PassageOtherCapsuleBlocksSupport(std::size_t passageIndex,
+        std::ptrdiff_t supportSegment,double qx,double qy,double qz,
+        double qPerMetre,double minimumClearanceMetres) const
+    {
+        if(passageIndex<PassageLaterBoreSources.size()&&supportSegment>=0
+            &&static_cast<std::size_t>(supportSegment)
+                <PassageLaterBoreSources[passageIndex].size())
+        {
+            const auto& source=PassageLaterBoreSources[passageIndex][
+                static_cast<std::size_t>(supportSegment)];
+            const bool insideSourceEnvelope=qx>=source.minimum[0]&&qx<=source.maximum[0]
+                &&qy>=source.minimum[1]&&qy<=source.maximum[1]
+                &&qz>=source.minimum[2]&&qz<=source.maximum[2];
+            if(insideSourceEnvelope)
+            {
+                for(const std::size_t otherPassageIndex:source.capsuleCandidatePassages)
+                {
+                    const auto& otherPassage=ResolvedLayout->passages[otherPassageIndex];
+                    if(PassagePlayerCapsuleBlocksSupportNode(otherPassageIndex,0,0,
+                        otherPassage.controlPoints.size()-1,qx,qy,qz,qPerMetre,
+                        minimumClearanceMetres))return true;
+                }
+                return false;
+            }
+        }
+        for(std::size_t otherPassageIndex=0;
+            otherPassageIndex<ResolvedLayout->passages.size();++otherPassageIndex)
+        {
+            if(otherPassageIndex==passageIndex)continue;
+            const auto& otherPassage=ResolvedLayout->passages[otherPassageIndex];
+            if(otherPassage.controlPoints.size()<2)continue;
+            if(PassagePlayerCapsuleBlocksSupportNode(otherPassageIndex,0,0,
+                otherPassage.controlPoints.size()-1,qx,qy,qz,qPerMetre,
+                minimumClearanceMetres))return true;
+        }
+        return false;
+    }
+
     bool PassageMayAffectDensity(std::size_t passageIndex,std::ptrdiff_t carveBegin,
         std::ptrdiff_t carveEnd,std::ptrdiff_t lowerMouthIndex,
         std::ptrdiff_t mouthSearchBegin,std::ptrdiff_t mouthSearchEnd,std::ptrdiff_t lastIndex,
@@ -4529,7 +4760,10 @@ private:
                 const double vertical=std::max(0.0,std::abs(qz-centerZ)-0.54*qPerMetre);
                 const double distance=DeterministicSqrt(horizontalX*horizontalX+horizontalY*horizontalY
                     +vertical*vertical)-0.34*qPerMetre;
-                if(distance<minimumClearanceMetres*qPerMetre)return true;
+                if(distance<minimumClearanceMetres*qPerMetre)
+                {
+                    return true;
+                }
             }
             return false;
         }
@@ -4749,8 +4983,12 @@ private:
         const double irregularity=1.25*qPerMetre
             +std::clamp(static_cast<double>(broadRelief),-1.0,1.0)*1.10*qPerMetre
             +std::clamp(static_cast<double>(surfaceRelief),-1.0,1.0)*0.35*qPerMetre;
+        // Add a subtle host-rock root only when the unmodified column lacks the
+        // vertical relief required for walkable passage support.
+        const double rootTaper=crossing.needsRootTaper
+            ?0.08*qPerMetre*smoothStep((t-0.35)/0.50):0.0;
         const double radius=static_cast<double>(crossing.minimumRadiusSubvoxels)
-            +std::max(0.15*qPerMetre,irregularity)+baseFlare+ceilingFlare;
+            +std::max(0.15*qPerMetre,irregularity)+rootTaper+baseFlare+ceilingFlare;
         const double radialDistanceField=radialDistance-radius;
         const double topDistance=qz-crossing.topZSubvoxels;
         const double bottomDistance=crossing.bottomZSubvoxels-qz;
@@ -4780,6 +5018,67 @@ private:
         return ApplyResolvedStrateBoundaryBand(density,X,Y,Z);
     }
 
+    double PassageColumnNaturalReliefMetres(
+        const FStandalonePassageVoidCrossing& crossing,double qPerMetre) const
+    {
+        constexpr double Q=static_cast<double>(VoxelForgeCore::WorldAssemblySubvoxelsPerVoxel);
+        constexpr std::array<double,6> HeightFractions{{0.25,0.35,0.45,0.55,0.65,0.75}};
+        constexpr std::size_t DirectionCount=16;
+        const auto smoothStep=[](double value)
+        {
+            value=std::clamp(value,0.0,1.0);
+            return value*value*(3.0-2.0*value);
+        };
+        std::array<double,HeightFractions.size()> meanRadii{};
+        std::size_t heightCount=0;
+        const auto seed=static_cast<std::uint32_t>(Owner?Owner->Seed:0);
+        const double height=static_cast<double>(crossing.topZSubvoxels
+            -crossing.bottomZSubvoxels);
+        if(height<=0.0)return 0.0;
+        for(const double fraction:HeightFractions)
+        {
+            const double qz=crossing.topZSubvoxels-height*fraction;
+            const float z=static_cast<float>(qz/Q);
+            const float scaledZ=z*0.12f;
+            const float driftX=VF_FieldSurfaceRelief(0.0f,0.0f,scaledZ,seed^0x434f4c58u);
+            const float driftY=VF_FieldSurfaceRelief(0.0f,0.0f,scaledZ,seed^0x434f4c59u);
+            const double axisX=crossing.centerXSubvoxels
+                +std::clamp(static_cast<double>(driftX),-1.0,1.0)*0.35*qPerMetre;
+            const double axisY=crossing.centerYSubvoxels
+                +std::clamp(static_cast<double>(driftY),-1.0,1.0)*0.35*qPerMetre;
+            const double t=(crossing.topZSubvoxels-qz)/height;
+            const double baseFlare=6.0*qPerMetre*smoothStep((t-0.82)/0.18);
+            const double ceilingFlare=2.0*qPerMetre*(1.0-smoothStep(t/0.075));
+            double meanRadius=0.0;
+            for(std::size_t direction=0;direction<DirectionCount;++direction)
+            {
+                const double angle=2.0*3.14159265358979323846*direction/DirectionCount;
+                double radius=crossing.minimumRadiusSubvoxels+1.25*qPerMetre
+                    +baseFlare+ceilingFlare;
+                for(int iteration=0;iteration<8;++iteration)
+                {
+                    const float sampleX=static_cast<float>((axisX+radius*std::cos(angle))/Q);
+                    const float sampleY=static_cast<float>((axisY+radius*std::sin(angle))/Q);
+                    const float broadRelief=VF_FieldSurfaceRelief(sampleX*0.12f,
+                        sampleY*0.12f,scaledZ,seed^0x434f4c52u);
+                    const float surfaceRelief=VF_FieldSurfaceRelief(sampleX,sampleY,z,
+                        seed^0x434f4c53u);
+                    const double irregularity=1.25*qPerMetre
+                        +std::clamp(static_cast<double>(broadRelief),-1.0,1.0)*1.10*qPerMetre
+                        +std::clamp(static_cast<double>(surfaceRelief),-1.0,1.0)*0.35*qPerMetre;
+                    radius=crossing.minimumRadiusSubvoxels
+                        +std::max(0.15*qPerMetre,irregularity)+baseFlare+ceilingFlare;
+                }
+                meanRadius+=radius;
+            }
+            meanRadii[heightCount++]=meanRadius/DirectionCount/qPerMetre;
+        }
+        if(heightCount<2)return 0.0;
+        const auto begin=meanRadii.begin();
+        const auto end=begin+static_cast<std::ptrdiff_t>(heightCount);
+        return *std::max_element(begin,end)-*std::min_element(begin,end);
+    }
+
     void BuildPassageVoidCrossingPlan()
     {
         BuildResolvedBoundaryZIntervals();
@@ -4789,7 +5088,8 @@ private:
         {BuildPassageSpatialIndices();return;}
         auto& cache=*Owner->PassageVoidCrossingCache;
         std::lock_guard<std::mutex> lock(cache.mutex);
-        const std::string cacheKey=ResolvedLayout->stableIdentity+"/passage-void-columns-v1";
+        const std::string cacheKey=ResolvedLayout->stableIdentity+"/passage-void-columns-v2-seed-"
+            +std::to_string(Owner->Seed);
         const auto cached=cache.byLayout.find(cacheKey);
         if(cached!=cache.byLayout.end())
         {PassageVoidCrossings=cached->second;BuildPassageSpatialIndices();return;}
@@ -4968,6 +5268,12 @@ private:
                         maximumCrossingZ+5.0*qPerMetre));
                     crossing.bottomZSubvoxels=static_cast<std::int64_t>(std::llround(
                         minimumCrossingZ-6.0*qPerMetre));
+                    crossing.naturalSurfaceReliefMetres=PassageColumnNaturalReliefMetres(
+                        crossing,qPerMetre);
+                    // The support-column audit requires 20 cm of vertical relief.
+                    // Add a shallow root flare only when the existing field profile
+                    // falls short, so naturally varied legacy columns remain intact.
+                    crossing.needsRootTaper=crossing.naturalSurfaceReliefMetres<0.20;
                 }
                 PassageVoidCrossings.push_back(crossing);
                 if(crossing.needsColumn)
@@ -4975,7 +5281,7 @@ private:
                     const double coreRadius=crossing.nominalRadiusSubvoxels/qPerMetre;
                     const double minimumWall=coreRadius-crossing.maximumRouteOffsetMetres
                         -crossing.maximumBoreRadiusMetres;
-                    std::printf("[PassageVoidColumnPlan] id=%s segments=%zu..%zu unsupported_samples=%llu span_m=%.3f threshold_m=%.3f connected=%d/%d axis_m=(%.3f,%.3f) z_m=%.3f..%.3f route_radius_m=%.3f bore_radius_m=%.3f min_radius_m=%.3f nominal_radius_m=%.3f max_radius_m=%.3f nominal_wall_m=%.3f flare_m=6.000 status=%s\n",
+                    std::printf("[PassageVoidColumnPlan] id=%s segments=%zu..%zu unsupported_samples=%llu span_m=%.3f threshold_m=%.3f connected=%d/%d axis_m=(%.3f,%.3f) z_m=%.3f..%.3f route_radius_m=%.3f bore_radius_m=%.3f min_radius_m=%.3f nominal_radius_m=%.3f max_radius_m=%.3f nominal_wall_m=%.3f natural_relief_m=%.3f root_taper=%d flare_m=6.000 status=%s\n",
                         passage.stableId.c_str(),crossing.firstSegment,crossing.lastSegment,
                         static_cast<unsigned long long>(crossing.unsupportedSamples),gapLength,
                         shortSpanMaximumMetres,static_cast<int>(crossing.connectedAtStart),
@@ -4985,6 +5291,7 @@ private:
                         crossing.maximumRouteOffsetMetres,crossing.maximumBoreRadiusMetres,
                         crossing.minimumRadiusSubvoxels/qPerMetre,coreRadius,
                         crossing.maximumRadiusSubvoxels/qPerMetre,minimumWall,
+                        crossing.naturalSurfaceReliefMetres,static_cast<int>(crossing.needsRootTaper),
                         crossing.connectedAtStart&&crossing.connectedAtEnd?"PLANNED":"UNATTACHED");
                 }
                 else
@@ -10801,6 +11108,7 @@ private:
     std::vector<FPassageFeatureNode> PassageFeatureNodes;
     bool PassageFeatureBoundsFailOpen=false;
     std::vector<std::vector<FPassageNearestNode>> PassageNearestNodes;
+    std::vector<std::vector<FPassageLaterBoreSource>> PassageLaterBoreSources;
     std::vector<FPassageProofBound> PassageProofBounds;
     std::vector<FPassageProofNode> PassageProofNodes;
     std::vector<std::vector<std::uint8_t>> PassageColumnSegmentFlags,PassageShortSpanSegmentFlags;

Standalone/Research/WorldAssemblerM3/Linux67/CaptureOwnerPassagesL67.py

@@ -0,0 +1,364 @@
+#!/usr/bin/env python3
+"""Render arrival, departure, and mid-tunnel views for the four-strate owner plan."""
+import json
+import importlib.util
+import argparse
+import math
+import os
+import re
+import subprocess
+import time
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT = ROOT / "Saved/Linux/l67/captures-run"
+BIN = ROOT / "Saved/Linux/l67/bin-final"
+CAPTURES = Path(__file__).resolve().parent / "captures"
+HEADLESS = BIN / "VoxelForgeCoreHeadless-l67-final-clang"
+RENDERER = BIN / "VoxelForgeOffscreenCapture-l67-final-clang"
+PNG_DIR = OUT / "capture-png"
+RECIPE_INPUTS = (
+    ("passage-0-1", ROOT / "Standalone/data/owner_world.json",
+     "surface-world", "SurfaceWorld", "upper"),
+    ("passage-1-2", ROOT / "Standalone/data/owner_world.json",
+     "surface-world", "FloatingIslands", "upper"),
+    ("passage-2-3", ROOT / "Standalone/data/owner_world.json",
+     "surface-world", "TunnelNetwork", "upper"),
+)
+SUBVOXELS_PER_VOXEL = 256.0
+RING_AUDIT = ROOT / "Standalone/Research/WorldAssemblerM3/Linux32/AuditRingTerraceL32.py"
+spec = importlib.util.spec_from_file_location("ring_profile_l32", RING_AUDIT)
+ring_profile = importlib.util.module_from_spec(spec)
+spec.loader.exec_module(ring_profile)
+
+for directory in (OUT, BIN, PNG_DIR, CAPTURES):
+    directory.mkdir(parents=True, exist_ok=True)
+ENV = os.environ.copy()
+ENV["LP_NUM_THREADS"] = "12"
+ENV["XDG_CACHE_HOME"] = str(OUT / "xdg-cache")
+PARSER = argparse.ArgumentParser(description=__doc__)
+PARSER.add_argument("--scene", choices=[value[0] for value in RECIPE_INPUTS])
+PARSER.add_argument("--view", choices=("arrival-mouth", "departure-mouth", "mid-tunnel"))
+OPTIONS = PARSER.parse_args()
+
+
+def run(name, command):
+    log = OUT / f"capture-{name}.log"
+    wrapped = ["taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--",
+               "timeout", "1800s", *map(str, command)]
+    started = time.monotonic()
+    with log.open("w", encoding="utf-8") as stream:
+        result = subprocess.run(wrapped, cwd=ROOT, env=ENV, stdout=stream,
+                                stderr=subprocess.STDOUT, timeout=1800, check=False)
+    elapsed = time.monotonic() - started
+    print(f"[L35CaptureRun] step={name} elapsed={elapsed:.1f}s exit={result.returncode} log={log}",
+          flush=True)
+    if result.returncode != 0:
+        raise SystemExit(f"{name} failed; see {log}")
+    return log
+
+
+def add(a, b):
+    return tuple(x + y for x, y in zip(a, b))
+
+
+def sub(a, b):
+    return tuple(x - y for x, y in zip(a, b))
+
+
+def mul(a, scale):
+    return tuple(x * scale for x in a)
+
+
+def norm(a):
+    length = math.sqrt(sum(x * x for x in a))
+    if length <= 1.0e-9:
+        raise ValueError("passage has a degenerate camera tangent")
+    return tuple(x / length for x in a)
+
+
+def interpolate_route(points, distance):
+    remaining = max(0.0, distance)
+    for a, b in zip(points, points[1:]):
+        delta = sub(b[0], a[0])
+        length = math.sqrt(sum(x * x for x in delta))
+        if length <= 1.0e-9:
+            continue
+        if remaining <= length:
+            t = remaining / length
+            pos = tuple(a[0][axis] + delta[axis] * t for axis in range(3))
+            radius = a[1] + (b[1] - a[1]) * t
+            return pos, radius
+        remaining -= length
+    return points[-1]
+
+
+def route_frame(points, distance):
+    center, radius = interpolate_route(points, distance)
+    before, _ = interpolate_route(points, max(0.0, distance - 0.25))
+    after, _ = interpolate_route(points, distance + 0.25)
+    tangent = norm(sub(after, before))
+    horizontal = norm((tangent[0], tangent[1], 0.0))
+    side = (-horizontal[1], horizontal[0], 0.0)
+    return center, radius, tangent, side
+
+
+def camera_angles(camera, target):
+    delta = sub(target, camera)
+    horizontal = math.hypot(delta[0], delta[1])
+    yaw = math.degrees(math.atan2(delta[0], delta[1]))
+    pitch = math.degrees(math.atan2(delta[2], horizontal))
+    return yaw, pitch
+
+
+def fmt(values):
+    return ",".join(f"{value:.6f}" for value in values)
+
+
+def load_reference_cameras():
+    log = ROOT / "Saved/Linux/l34/run-capture-standard-set-final-radius3.log"
+    pattern = re.compile(
+        r"^\[L34CaptureCamera\] view=(\S+).*?camera_m=\(([^)]*)\) "
+        r"target_m=\(([^)]*)\) clip=(\S+)", re.M)
+    values = {}
+    for name, camera, target, clip in pattern.findall(
+            log.read_text(encoding="utf-8", errors="replace")):
+        parse = lambda value: tuple(float(part) for part in value.split(","))
+        values[name] = (parse(camera), parse(target), None if clip == "none" else parse(clip))
+    return values
+
+
+REFERENCE_CAMERAS = {}
+
+
+def terrain_surface_near(mesh, x, y, expected_height):
+    bounds = (x - 2.0, x + 2.0, y - 2.0, y + 2.0)
+    _, triangles, _ = ring_profile.read_scene(
+        str(mesh), None, -1.0e9, 1.0e9, bounds)
+    buckets = ring_profile.build_buckets(triangles, True, bounds, cell_size=1.0)
+    hits = []
+    for dy in range(-4, 5):
+        for dx in range(-4, 5):
+            sample_x, sample_y = x + dx * 0.5, y + dy * 0.5
+            hit = ring_profile.sample_surface(buckets, sample_x, sample_y, True, 1.0,
+                                              preferred_height=expected_height)
+            if hit is not None:
+                hits.append((math.hypot(dx * 0.5, dy * 0.5),
+                             abs(hit[0] - expected_height), sample_x, sample_y, hit[0]))
+    if not hits:
+        return None
+    distance, _, sample_x, sample_y, height = min(hits)
+    if distance > 2.0 or abs(height - expected_height) > 8.0:
+        return None
+    return sample_x, sample_y, height
+
+
+def load_layout(name, source, recipe):
+    path = OUT / f"layout-{name}.json"
+    run(f"layout-{name}", [HEADLESS, source, "--workers=12", "--world-assembler-prototype",
+        "--stream-benchmark", "--stream-pipeline", "--force-generate", "--clip-radius=2",
+        "--max-clip-level=0", "--max-level=0", f"--recipe={recipe}",
+        f"--resolved-layout-output={path}", "--resolved-layout-only"])
+    return json.loads(path.read_text(encoding="utf-8"))
+
+
+def select_passage(layout, mouth_generator, preferred_side):
+    strata = {int(value["strate_index"]): value for value in layout["strates"]}
+    preferred_candidates = []
+    fallback_candidates = []
+    for passage in layout["passages"]:
+        upper = strata[int(passage["upper_strate_index"])]
+        lower = strata[int(passage["lower_strate_index"])]
+        sides = []
+        if upper["generator_kind"] == mouth_generator:
+            sides.append("upper")
+        if lower["generator_kind"] == mouth_generator:
+            sides.append("lower")
+        if preferred_side in sides:
+            preferred_candidates.append((passage, preferred_side == "lower"))
+        elif sides:
+            fallback_candidates.append((passage, sides[0] == "lower"))
+    candidates = preferred_candidates or fallback_candidates
+    if not candidates:
+        raise RuntimeError(f"no passage mouth in generator {mouth_generator}")
+    return sorted(candidates, key=lambda item: item[0]["stable_id"])[0]
+
+
+def make_views(layout, passage, reverse):
+    q_to_m = layout["core_voxel_size_um"] / (SUBVOXELS_PER_VOXEL * 1_000_000.0)
+    controls = [
+        (tuple(value * q_to_m for value in point["position_q"]),
+         point["radius_q"] * q_to_m)
+        for point in passage["control_points"]
+    ]
+    lower_mouth = tuple(value * q_to_m for value in passage["lower_mouth_q"])
+    lower_index = min(range(len(controls)), key=lambda i: sum(
+        (controls[i][0][axis] - lower_mouth[axis]) ** 2 for axis in range(3)))
+    path = controls[:lower_index + 1]
+    if len(path) < 2:
+        raise RuntimeError(f"{passage['stable_id']} has no mouth-to-mouth route")
+    if reverse:
+        path.reverse()
+    lengths = [math.sqrt(sum((b[0][axis] - a[0][axis]) ** 2 for axis in range(3)))
+               for a, b in zip(path, path[1:])]
+    total = sum(lengths)
+    upper, upper_radius, upper_tangent, upper_side = route_frame(path, 0.0)
+    lower, lower_radius, lower_tangent, lower_side = route_frame(path, total)
+    middle_distance = max(12.0, min(total - 12.0, total * 0.4)) if total > 24.0 else total * 0.4
+    entry_distance = min(6.0, total * 0.25)
+    entry, entry_radius, entry_tangent, entry_side = route_frame(path, entry_distance)
+    middle, middle_radius, middle_tangent, middle_side = route_frame(path, middle_distance)
+
+    def exterior_view(prefix, center, radius, outward, target):
+        horizontal_outward = norm((outward[0], outward[1], 0.0))
+        eye_height = center[2] - radius + 1.6
+        eye = (center[0] + horizontal_outward[0] * 5.5,
+               center[1] + horizontal_outward[1] * 5.5,
+               eye_height)
+        yaw, pitch = camera_angles(eye, target)
+        return {"name": prefix, "camera": eye, "yaw": yaw, "pitch": pitch,
+                "target": target, "clip": None, "camera_xy": eye[:2],
+                "focus": center, "mouth": center, "eye_height_z": eye_height}
+
+    entrance, entrance_radius, entrance_tangent = upper, upper_radius, upper_tangent
+    exit_point, exit_radius, exit_tangent = lower, lower_radius, lower_tangent
+    ground_target_pos, ground_target_radius = interpolate_route(path, min(total, 1.0))
+    ground = exterior_view("ground-mouth", entrance, entrance_radius,
+        mul(entrance_tangent, -1.0), (ground_target_pos[0], ground_target_pos[1],
+            ground_target_pos[2] - ground_target_radius + 1.0))
+    ground["focus"] = entrance
+    ground["outside_camera"] = True
+
+    def cutaway_view(prefix, center, radius, tangent, side, distance, target_distance):
+        camera = (center[0] - side[0] * 7.0, center[1] - side[1] * 7.0,
+                  center[2] - radius + 1.6)
+        target_pos, target_radius = interpolate_route(path, target_distance)
+        target = (target_pos[0], target_pos[1],
+                  target_pos[2] - target_radius + 1.6)
+        yaw, pitch = camera_angles(camera, target)
+        plane = (side[0], side[1], 0.0,
+                 -(side[0] * center[0] + side[1] * center[1]))
+        return {"name": prefix, "camera": camera, "yaw": yaw, "pitch": pitch,
+                "target": target, "clip": plane, "camera_xy": camera[:2],
+                "focus": center, "mouth": center}
+
+    # Place each interface view at its true route endpoint. The endpoint camera
+    # is a side cutaway so the solid terrain in front of an underground mouth
+    # cannot hide the floor-to-tunnel connection.
+    arrival_distance = 0.0
+    arrival_center, arrival_radius, arrival_tangent, arrival_side = route_frame(
+        path, arrival_distance)
+    arrival = cutaway_view("arrival", arrival_center, arrival_radius,
+        arrival_tangent, arrival_side, arrival_distance,
+        min(total, arrival_distance + 12.0))
+    arrival["camera_location"] = "passage-air"
+    arrival["focus_radius"] = 20.0
+    arrival["yaw"], arrival["pitch"] = camera_angles(
+        arrival["camera"], arrival["target"])
+
+    entry_camera_distance = min(8.0, total * 0.1)
+    entry_center, entry_radius, entry_tangent, entry_side = route_frame(
+        path, entry_camera_distance)
+    # Player-height view from just inside the passage, aimed through its actual
+    # interface mouth so the floor, bore, and opening share one frame.
+    entry_camera = (entry_center[0], entry_center[1],
+        entry_center[2] - entry_radius + 1.6)
+    entry_target_pos, entry_target_radius = interpolate_route(
+        path, min(total, entry_distance + 14.0))
+    entry_target = (entry_target_pos[0], entry_target_pos[1],
+        entry_camera[2] - 2.5)
+    entry_yaw, entry_pitch = camera_angles(entry_camera, entry_target)
+    entry_view = {"name": "rock-entry", "camera": entry_camera,
+        "yaw": entry_yaw, "pitch": entry_pitch, "target": entry_target,
+        "clip": None, "camera_xy": entry_camera[:2],
+        "focus": entry_center, "mouth": entrance, "outside_camera": False,
+        "camera_location": "passage-air", "focus_radius": 20.0,
+        "eye_height_z": entry_camera[2]}
+    middle_view = cutaway_view("mid-tunnel", middle, middle_radius, middle_tangent,
+        middle_side, middle_distance, min(total, middle_distance + 2.0))
+    ground["focus_radius"] = 20.0
+    middle_view["focus_radius"] = 20.0
+    middle_camera, _ = interpolate_route(path, max(0.0, middle_distance - 6.0))
+    middle_view["camera"] = middle_camera
+    middle_target_pos, _ = interpolate_route(path, min(total, middle_distance + 9.0))
+    middle_view["target"] = (middle_target_pos[0], middle_target_pos[1], middle[2])
+    # The camera sits in the passage air. Remove the near wall to open a
+    # longitudinal section and cap the remaining rock at that cut.
+    middle_cut_point = (middle[0] - middle_side[0] * 2.5,
+        middle[1] - middle_side[1] * 2.5, middle[2])
+    middle_view["clip"] = (*middle_side,
+        -sum(middle_side[axis] * middle_cut_point[axis] for axis in range(3)))
+    middle_view["camera_location"] = "passage-air"
+    middle_view["yaw"], middle_view["pitch"] = camera_angles(
+        middle_view["camera"], middle_view["target"])
+    return (ground, entry_view, middle_view, arrival), total, lower_index
+
+
+def export_capture(scene_name, source, recipe, passage, endpoint, view):
+    stem = f"{passage['stable_id'].replace('/', '-')}-{endpoint}"
+    view["name"] = stem
+    mesh = OUT / f"{stem}.vfmesh"
+    png = PNG_DIR / f"{stem}.png"
+    jpg = CAPTURES / f"{stem}.jpg"
+    yaw, pitch = view["yaw"], view["pitch"]
+    camera = view["camera"]
+    export_camera = view.get("focus", camera)
+    run(f"{stem}-export", [HEADLESS, source, "--workers=12",
+        "--world-assembler-prototype", "--stream-benchmark", "--stream-pipeline",
+        "--force-generate", "--clip-radius=3", "--max-clip-level=0", "--max-level=0",
+        "--render-distance-chunks=0", f"--recipe={recipe}",
+        f"--camera={fmt((*export_camera, yaw, pitch))}", f"--mesh-export={mesh}"])
+    render_clip = view["clip"]
+    surface = None
+    if view.get("outside_camera", False):
+        surface = terrain_surface_near(mesh, *view["camera_xy"], view["target"][2])
+        if surface is None:
+            camera = (view["camera_xy"][0], view["camera_xy"][1], view["eye_height_z"])
+        else:
+            camera = (surface[0], surface[1], surface[2] + 1.6)
+    elif render_clip is not None:
+        camera = view["camera"]
+    yaw, pitch = camera_angles(camera, view["target"])
+    print(f"[L67CaptureCamera] view={stem} camera_m=({fmt(camera)}) "
+        f"target_m=({fmt(view['target'])}) "
+        f"clip={fmt(render_clip) if render_clip is not None else 'none'} fov_deg=80",
+        flush=True)
+    render = [RENDERER, mesh, png, "--size=1600x900", "--fov-deg=80",
+        f"--camera-m={fmt(camera)}", f"--yaw-deg={yaw:.6f}", f"--pitch-deg={pitch:.6f}",
+        "--tile-skirts=off", "--shade=readable", "--headlamp=on", "--height-tint=on",
+        f"--height-center-m={view['target'][2]:.6f}", "--height-range-m=8", "--tile-edges=off"]
+    if view.get("focus_radius", 24.0) is not None:
+        render.append(f"--focus-region={fmt((*view['focus'], view.get('focus_radius', 24.0)))}")
+    if render_clip is not None:
+        render.append(f"--clip-plane={fmt(render_clip)}")
+    run(f"{stem}-render", render)
+    run(f"{stem}-jpeg", ["ffmpeg", "-nostdin", "-hide_banner", "-loglevel", "error",
+        "-y", "-i", png, "-frames:v", "1", "-q:v", "4", jpg])
+    size = jpg.stat().st_size if jpg.exists() else 0
+    print(f"[L67CaptureJPEG] file={jpg.relative_to(ROOT)} bytes={size} "
+        f"status={'PASS' if 0 < size <= 300_000 else 'FAIL'}", flush=True)
+    if not 0 < size <= 300_000:
+        raise SystemExit(f"{jpg.name} is missing or exceeds 300 KB")
+
+
+for scene_name, source, recipe, mouth_generator, preferred_side in RECIPE_INPUTS:
+    if OPTIONS.scene and scene_name != OPTIONS.scene:
+        continue
+    layout = load_layout(scene_name, source, recipe)
+    passage, _ = select_passage(layout, mouth_generator, preferred_side)
+    forward_views, route_length, lower_index = make_views(layout, passage, False)
+    reverse_views, _, _ = make_views(layout, passage, True)
+    print(f"[L67CapturePassage] interface={scene_name.removeprefix('passage-')} "
+        f"id={passage['stable_id']} route_m={route_length:.3f} "
+        f"control_points={lower_index + 1}", flush=True)
+    endpoint_views = (
+        ("arrival-mouth", forward_views[0] if scene_name == "passage-0-1" else forward_views[1]),
+        ("departure-mouth", reverse_views[3]),
+    )
+    for endpoint, view in endpoint_views:
+        if OPTIONS.view and endpoint != OPTIONS.view:
+            continue
+        export_capture(scene_name, source, recipe, passage, endpoint, view)
+    if scene_name == "passage-1-2" and (OPTIONS.view is None or OPTIONS.view == "mid-tunnel"):
+        export_capture(scene_name, source, recipe, passage, "mid-tunnel", forward_views[2])

Standalone/Research/WorldAssemblerM3/Linux67/REPORT.md

@@ -0,0 +1,81 @@
+# L67 — four-strate passage walkability
+
+## Cause and fix
+
+The FI, TN, and VS paths use the compiled analytic base evaluator and then the shared strate composer. The “native” 5/5 result was the same composed field with resolved passages removed; it was not a raw-generator probe. The band stage is therefore not the difference. The passage carve and the support/capsule gates are.
+
+- **0–1 SW→FI:** at the failed probe `(21.366, -11.480, -726.367)`, passage 0 first restored support, then passage 1’s bore changed density to `+1.613` (`carve_sdf=-0.292`), removing it. The shared composer now defers that support only when a physically overlapping later bore can reach it, then applies it after the later carve. The column’s natural relief is predictor-driven and tapers at the root; relief rose from `0.172 m` to `0.219 m`.
+- **1–2 FI→TN:** at `(2.419, -13.433, -735.870)`, support restoration was rejected by an adjacent route segment’s player-capsule test (`clearance=-0.245 m`, required `0.045 m`). The segment-specific overlap candidates now keep that test local to physically relevant route geometry. The reported `0.2498 m` step came from the audit switching to a neighboring zero crossing on its `0.25 m` scan. Refining and following the same root shows a continuous floor; the step audit now reports `0.000 m`.
+- **2–3 TN→VS:** at `(-1.365, -15.673, -897.088)`, the same capsule gate rejected support next to route segment 81 (`clearance=-0.329 m`). The shared segment-overlap handling fixes this link too.
+
+The L66 `passageIndex>0` / `strates.size()>2` switches are gone. “Internal chain” now means both mouths lie inside their endpoint strata content bands and neither endpoint is a SurfaceWorld landing. Lower-mouth body overlap uses actual 3D distance to the mouth and tread, independent of plan length or passage index.
+
+## Audit
+
+All existing thresholds are unchanged. The L66 baseline binary reproduced the original failures.
+
+| Passage | L66 negative control | L67 result |
+|---|---|---|
+| 0–1 SW→FI | 59 unsupported; column relief `0.172 m < 0.20 m` | 0 unsupported / 0 blocked / 0 grade failures; wall/floor ripple `1.49 / 0.06 cm`; column relief `0.219 m`; wall relief `0.267 m` |
+| 1–2 FI→TN | 3 unsupported; wall/floor ripple `6.78 / 2.90 cm`; apparent `0.2498 m` step | 0 / 0 / 0; wall/floor ripple `2.29 / 1.23 cm`; refined step `0.000 m`; wall relief `0.257 m` |
+| 2–3 TN→VS | 2 unsupported | 0 / 0 / 0; wall/floor ripple `1.48 / 0.47 cm`; wall relief `0.248 m` |
+
+All three now pass support, blocked, grade, mouth-binding, ripple, and naturalness gates. The detailed final audit is in [`owner-four-strata-route4.log`](../../../../Saved/Linux/l67/logs/owner-four-strata-route4.log); the measured composition trace is in [`l66-root-refined-audit.log`](../../../../Saved/Linux/l67/logs/l66-root-refined-audit.log).
+
+## Controls, hashes, and builds
+
+- The L66 build remains a negative control: it reproduces `59 / 3 / 2` unsupported and the `0.172 m` column relief failure. The expected audit exit is 10.
+- The pinned fast tier passes: **269 PASS, 5 diagnostic, overall PASS**. The prior L52 surface-world hash comparison is diagnostic because the route output changed; the changed style-1 baseline is [pinned at v212](hash-baselines/owner-hash-surface-world-style1-v212.log). See the [fast summary](../../../../Saved/Linux/l67/verify/fast-summary.json).
+- Evaluator version is **212** (from 211), required because shared tread composition and route selection changed generated output. Source stamp: `d49aa8d941fb390818569243d7783f3e2799795244a8d7ca48e3e640d4a2876f`.
+- All four strata produced 12 equal hash rows at each of W1/W8/W12 ([determinism summary](../../../../Saved/Linux/l67/verify/owner-w1-w8-w12-determinism.json)). Clang and GCC builds both pass.
+- Changed implementation files are `Standalone/Core/include/VoxelForgeCore/VoxelForgeCore.h`, `Standalone/Core/src/ResolvedLayoutInternal.h`, `Standalone/Core/src/ShapeWorldInternal.h`, `Standalone/Source/OwnerWorldLoader.h`, `Standalone/Source/StreamBenchmarkPipeline.h`, and `Standalone/Tools/verify/verify.py`. No Unreal `Source/` files changed.
+
+## Cost
+
+Three interleaved whole-view pairs per strate, L66→L67 median seconds ([summary](../../../../Saved/Linux/l67/cost/cost-summary.json)):
+
+| Strate | L66 | L67 | Change |
+|---:|---:|---:|---:|
+| 0 | 1.101 | 1.121 | +1.8% |
+| 1 | 1.575 | 1.552 | −1.5% |
+| 2 | 0.581 | 0.602 | +3.6% |
+| 3 | 0.216 | 0.212 | −1.9% |
+
+Strate 2’s samples overlap (`0.582–0.600 s`) and paired results are within observed run variation. The route chooser now selects the shortest candidate within `0.10 m` of maximum sampled tread clearance, with tangent alignment as a tie-breaker. It also skips an extra closure turn when mouth separation exceeds the tread envelope; the FI→TN route is `114.231 m` rather than the earlier `165.799 m` candidate.
+
+## Captures
+
+Seven JPEGs are in `captures/`; each is under 300 KB. The TN→VS endpoint meshes are sparse in these offscreen views, so those two frames show the nearby cave/strate surface more clearly than the tread.
+
+- 0–1 arrival [26,342 B](captures/passage-0-1-0-arrival-mouth.jpg), departure [40,012 B](captures/passage-0-1-0-departure-mouth.jpg)
+- 1–2 arrival [34,298 B](captures/passage-1-2-0-arrival-mouth.jpg), departure [42,450 B](captures/passage-1-2-0-departure-mouth.jpg)
+- 2–3 arrival [23,937 B](captures/passage-2-3-0-arrival-mouth.jpg), departure [23,380 B](captures/passage-2-3-0-departure-mouth.jpg)
+- Mid-tunnel, 1–2 [22,392 B](captures/passage-1-2-0-mid-tunnel.jpg)
+
+## Failed runs
+
+- The expected L66 negative-control audit exited 10 after reproducing the failures.
+- One p0 clipped arrival-camera trial exited 3 because the clip plane left two open contours. It was replaced by the successful uncut SurfaceWorld entrance view.
+- A p2 clipped arrival-camera trial also exited 3 on open contours. The final endpoint image uses the no-clip interior view. Both cap failures are recorded in [`failed-capture-trials.log`](../../../../Saved/Linux/l67/logs/failed-capture-trials.log).
+- No final capture, Clang/GCC build, determinism run, fast-tier gate, or cost run failed. No run exceeded 30 minutes.
+
+## Audit controls (follow-up)
+
+This section supersedes the earlier wall-ripple values; the support, blocked, grade, mouth, and column results remain as reported. The residual-only gauge omitted `pose.radius` and hid an authored-radius beat:
+
+| Field / gauge | Old gauge (authored radius, linear detrend) | Residual-only gauge |
+|---|---:|---:|
+| L66 four-strata field | 6.78 cm | 2.21 cm |
+| L67 four-strata field | 14.52 cm | 2.29 cm |
+
+On the old gauge, the geometry change raised 1–2 by 7.74 cm. On L67 geometry, the residual-only gauge then removed 12.23 cm; the reported 6.78→2.29 cm drop therefore masked the radius beat. The final gauge keeps `sampleRadius + 0.5*(left+right)` and cubic-detrends each 32 m window. The 0.18 m is the probe depth inside the authored radius; its former standalone subtraction is removed. The cubic baseline leaves the 0–1 and 2–3 taper profiles below 0.01 cm, while 1–2 retains a 4.77 cm authored-radius beat at 7.06 m. Final ripple results are 1.45 / 7.27 / 0.92 cm: 1–2 fails the unchanged 3.5 cm wall limit. Support, blocked, grade, and mouth-binding checks still pass for all three; overall passage audit is 2/3. See [`audit-control-l67-final-owner.log`](../../../../Saved/Linux/l67/logs/audit-control-l67-final-owner.log) and [`audit-control-authored-radius-all.log`](../../../../Saved/Linux/l67/logs/audit-control-authored-radius-all.log).
+
+| Negative control under the updated gauge | Measured | Result |
+|---|---:|---|
+| L35 wall ribs | 9.75 cm at 6.50 m; limit 3.50 cm | Detected |
+| Synthetic wall spheres / floor beads | 5.98 / 5.98 cm; limits 3.50 / 2.50 cm | Detected |
+| Synthetic signed-distance floor step | 0.25 m step; 2.97 cm ripple vs 2.50 cm limit | Detected |
+| L36 washboard field, five-step root refinement | 6.46 cm; limit 2.50 cm | Detected |
+| L23 terrace profile | 2.00 m flat then 0.25 m step | Detected |
+
+No control passed, so no old audit behavior was restored. Logs: [L35 ribs](../../../../Saved/Linux/l67/logs/audit-control-l35-wall-ribs-cubic-audit.log), [L36 washboard](../../../../Saved/Linux/l67/logs/audit-control-l36-washboard-l35field-bisection.log). The L67 synthetic controls are in the final owner log above. One direct link of the current headless code against archived Core libraries failed route setup and was discarded; the control runs used source/Core-matched L35 builds. The follow-up changed only `Standalone/Source/StreamBenchmarkPipeline.h`; Clang Linux build succeeded. No timing run, commit, push, or stash was made.

Standalone/Research/WorldAssemblerM3/Linux67/RunInterleavedWholeViewCostL67.py

@@ -0,0 +1,110 @@
+#!/usr/bin/env python3
+"""Measure three interleaved L66/L67 whole-view pairs for each owner strate."""
+import json
+import os
+import re
+import subprocess
+import time
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT = ROOT / "Saved/Linux/l67/cost"
+DATA = ROOT / "Standalone/data/owner_world.json"
+BASELINE = ROOT / "Saved/Linux/l67/bin-l66-baseline/VoxelForgeCoreHeadless-l67-l66-baseline-clang"
+CANDIDATE = ROOT / "Saved/Linux/l67/bin-final/VoxelForgeCoreHeadless-l67-final-clang"
+CAMERAS = {
+    0: "0.000000,0.000000,-374.939453,0.000000,0.000000",
+    1: "25.836914,3.199219,-737.000000,0.000000,0.000000",
+    2: "19.166016,-14.200195,-753.374023,0.000000,0.000000",
+    3: "-20.062500,-5.068359,-900.353516,0.000000,0.000000",
+}
+ORDER = ("l66", "l67", "l67", "l66", "l66", "l67")
+PREFIXES = (
+    "[PipelineFullDetailHash]", "[PipelineWholeViewHash]",
+    "[PipelineLODHash]", "[PipelineExactQueryHash]",
+)
+ELAPSED_RE = re.compile(r"\belapsed_ms=([0-9.]+)")
+WHOLE_VIEW_RE = re.compile(r"^\[StreamPipeline\].*?whole_view_ready=([0-9.]+)s", re.M)
+ENV = os.environ.copy()
+
+
+def run(strate, repetition, variant):
+    binary = BASELINE if variant == "l66" else CANDIDATE
+    name = f"strate{strate}-pair{repetition // 2 + 1}-{variant}"
+    log_path = OUT / f"{name}.log"
+    layout_path = OUT / f"{name}.json"
+    command = [
+        str(binary), str(DATA), "--workers=1", "--world-assembler-prototype",
+        "--stream-benchmark", "--stream-pipeline", "--force-generate",
+        "--clip-radius=1", "--max-clip-level=8", "--max-level=0",
+        "--recipe=surface-world", "--stream-hash", "--max-clip-level=0",
+        "--render-distance-chunks=0", f"--camera={CAMERAS[strate]}",
+        f"--resolved-layout-output={layout_path}",
+    ]
+    wrapped = [
+        "taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--",
+        "timeout", "1800s", *command,
+    ]
+    start = time.monotonic()
+    with log_path.open("w", encoding="utf-8") as stream:
+        result = subprocess.run(wrapped, cwd=ROOT, env=ENV, stdout=stream,
+                                stderr=subprocess.STDOUT, timeout=1800, check=False)
+    elapsed = time.monotonic() - start
+    lines = log_path.read_text(encoding="utf-8", errors="replace").splitlines()
+    hashes = [line for line in lines if line.startswith(PREFIXES)]
+    pipeline_elapsed = [float(value) for line in lines
+        if line.startswith("[PipelineWholeViewHash]")
+        for value in ELAPSED_RE.findall(line)]
+    whole_view_match = WHOLE_VIEW_RE.search("\n".join(lines))
+    record = {
+        "strate": strate, "pair_order": repetition, "variant": variant,
+        "elapsed_seconds": elapsed, "pipeline_elapsed_ms": pipeline_elapsed,
+        "whole_view_seconds": float(whole_view_match.group(1))
+            if whole_view_match else None,
+        "exit_code": result.returncode, "hash_rows": len(hashes),
+        "log": str(log_path.relative_to(ROOT)),
+    }
+    print(json.dumps(record, sort_keys=True), flush=True)
+    return record
+
+
+def main():
+    OUT.mkdir(parents=True, exist_ok=True)
+    results = []
+    for strate in range(4):
+        for repetition, variant in enumerate(ORDER):
+            record = run(strate, repetition, variant)
+            results.append(record)
+            if record["exit_code"] != 0 or record["hash_rows"] != 12:
+                break
+        else:
+            continue
+        break
+    strata = {}
+    for strate in range(4):
+        values = {variant: [row["whole_view_seconds"] for row in results
+            if row["strate"] == strate and row["variant"] == variant
+            and row["whole_view_seconds"] is not None]
+            for variant in ("l66", "l67")}
+        if all(len(values[variant]) == 3 for variant in ("l66", "l67")):
+            l66 = sorted(values["l66"])[1]
+            l67 = sorted(values["l67"])[1]
+            strata[str(strate)] = {"l66_seconds": values["l66"],
+                "l67_seconds": values["l67"], "l66_median_seconds": l66,
+                "l67_median_seconds": l67,
+                "change_percent": (l67 / l66 - 1.0) * 100.0}
+    summary = {"pairs_per_strate": 3, "order": ORDER, "strata": strata,
+               "runs": results,
+               "complete": len(results) == 24
+                   and all(x["exit_code"] == 0 and x["hash_rows"] == 12
+                           for x in results)}
+    (OUT / "cost-summary.json").write_text(json.dumps(summary, indent=2) + "\n",
+        encoding="utf-8")
+    print(f"[L67CostSummary] complete={summary['complete']} runs={len(results)}",
+          flush=True)
+    return 0 if summary["complete"] else 1
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

Standalone/Research/WorldAssemblerM3/Linux67/RunOwnerW12DeterminismL67.py

@@ -0,0 +1,68 @@
+#!/usr/bin/env python3
+"""Compare owner four-strata W12 hashes with the pinned W1/W8 cameras."""
+import json
+import re
+import subprocess
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT = ROOT / "Saved/Linux/l67"
+DATA = ROOT / "Standalone/data/owner_world.json"
+BINARY = OUT / "bin-final/VoxelForgeCoreHeadless-l67-final-clang"
+HASH_RE = re.compile(r"^\[Pipeline(?:FullDetailHash|WholeViewHash|LODHash|ExactQueryHash)\].*$", re.M)
+CAMERA_RE = re.compile(r"camera_m=\(([-0-9.]+),([-0-9.]+),([-0-9.]+)\)")
+RESULTS = []
+
+
+def hashes(path):
+    return HASH_RE.findall(path.read_text(encoding="utf-8", errors="replace"))
+
+
+def main():
+    logs = OUT / "logs"
+    layouts = OUT / "layouts"
+    logs.mkdir(parents=True, exist_ok=True)
+    layouts.mkdir(parents=True, exist_ok=True)
+    for strate in range(4):
+        w1_path = OUT / "verify" / f"owner-new-plan-clang-strate{strate}-w1.log"
+        w8_path = OUT / "verify" / f"owner-new-plan-clang-strate{strate}-w8.log"
+        match = CAMERA_RE.search(w1_path.read_text(encoding="utf-8", errors="replace"))
+        if not match:
+            raise RuntimeError(f"camera not found in {w1_path}")
+        camera = ",".join(match.groups()) + ",0.000000,0.000000"
+        log_path = logs / f"owner-new-plan-clang-strate{strate}-w12-final.log"
+        layout_path = layouts / f"owner-new-plan-clang-strate{strate}-w12-final.json"
+        command = [
+            "taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--",
+            "timeout", "1800s", str(BINARY), str(DATA), "--workers=12",
+            "--world-assembler-prototype", "--stream-benchmark", "--stream-pipeline",
+            "--force-generate", "--clip-radius=1", "--max-clip-level=8",
+            "--max-level=0", "--recipe=surface-world", "--stream-hash",
+            "--max-clip-level=0", "--render-distance-chunks=0", f"--camera={camera}",
+            f"--resolved-layout-output={layout_path}",
+        ]
+        with log_path.open("w", encoding="utf-8") as stream:
+            result = subprocess.run(command, cwd=ROOT, stdout=stream,
+                stderr=subprocess.STDOUT, timeout=1800, check=False)
+        current = hashes(log_path)
+        w1 = hashes(w1_path)
+        w8 = hashes(w8_path)
+        passed = result.returncode == 0 and len(current) == 12 \
+            and current == w1 == w8
+        row = {"strate": strate, "exit_code": result.returncode,
+            "w1_hashes": len(w1), "w8_hashes": len(w8),
+            "w12_hashes": len(current), "w1_w8_w12_equal": passed,
+            "log": str(log_path.relative_to(ROOT))}
+        RESULTS.append(row)
+        print(json.dumps(row, sort_keys=True), flush=True)
+    summary = {"status": "PASS" if all(row["w1_w8_w12_equal"] for row in RESULTS)
+        else "FAIL", "strata": RESULTS}
+    (OUT / "verify" / "owner-w1-w8-w12-determinism.json").write_text(
+        json.dumps(summary, indent=2) + "\n", encoding="utf-8")
+    print(f"[L67OwnerW1W8W12] status={summary['status']}", flush=True)
+    return 0 if summary["status"] == "PASS" else 1
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

Standalone/Source/OwnerWorldLoader.h

@@ -43,8 +43,10 @@ struct FStandalonePassageVoidCrossing
     std::int64_t minimumRadiusSubvoxels=0;
     std::int64_t nominalRadiusSubvoxels=0;
     std::int64_t maximumRadiusSubvoxels=0;
+    double naturalSurfaceReliefMetres=0.0;
     double maximumRouteOffsetMetres=0.0;
     double maximumBoreRadiusMetres=0.0;
+    bool needsRootTaper=false;
 };
 
 struct FStandalonePassageVoidCrossingCache

Standalone/Source/StreamBenchmarkPipeline.h

@@ -2357,19 +2357,22 @@ namespace StandaloneStreamBenchmark
                             {{0.0,-supportProbeRadiusMetres}}}};
                         std::uint32_t supportedProbes=0;
                         std::uint32_t nativeSupportedProbes=0;
-                        double firstUnsupportedX=x,firstUnsupportedY=y,lastUnsupportedDensity=0.0;
+                        double firstUnsupportedX=x,firstUnsupportedY=y,
+                            firstUnsupportedZ=footZ,lastUnsupportedDensity=0.0;
                         std::array<bool,5> supportMask{};
                         for(std::size_t offsetIndex=0;offsetIndex<supportOffsets.size();++offsetIndex)
                         {
                             const auto& offset=supportOffsets[offsetIndex];
                             const double supportX=x+offset[0],supportY=y+offset[1];
                             bool supported=false;
+                            double offsetSampleZ=footZ;
                             for(double depth=supportStartMetres;
                                 depth<=supportMaximumMetres+1.0e-6;depth+=supportStepMetres)
                             {
                                 ++audit.supportSamples;
+                                offsetSampleZ=(footZ-depth)/coreMetres;
                                 lastUnsupportedDensity=Field.densityAt({supportX/coreMetres,
-                                    supportY/coreMetres,(footZ-depth)/coreMetres});
+                                    supportY/coreMetres,offsetSampleZ});
                                 if(lastUnsupportedDensity<0.0)
                                 {
                                     supported=true;break;
@@ -2384,7 +2387,11 @@ namespace StandaloneStreamBenchmark
                                     {++nativeSupportedProbes;break;}
                             }
                             if(supported){++supportedProbes;supportMask[offsetIndex]=true;}
-                            else{firstUnsupportedX=supportX;firstUnsupportedY=supportY;}
+                            else
+                            {
+                                firstUnsupportedX=supportX;firstUnsupportedY=supportY;
+                                firstUnsupportedZ=offsetSampleZ*coreMetres;
+                            }
                         }
                         if(nativeField&&segmentAudit
                             &&nativeSupportedProbes<minimumSupportProbes)
@@ -2414,17 +2421,18 @@ namespace StandaloneStreamBenchmark
                             {
                                 audit.hasDeepUnsupported=true;
                                 audit.firstDeepUnsupported={firstUnsupportedX,firstUnsupportedY,
-                                    footZ,lastUnsupportedDensity};
+                                    firstUnsupportedZ,lastUnsupportedDensity};
                                 audit.firstDeepSupportMask=supportMask;
                             }
                             if(audit.firstUnsupportedCount<audit.firstUnsupported.size())
                             {
                                 const std::size_t sample=audit.firstUnsupportedCount++;
                                 audit.firstUnsupported[sample]={
-                                    firstUnsupportedX,firstUnsupportedY,footZ,lastUnsupportedDensity};
+                                    firstUnsupportedX,firstUnsupportedY,firstUnsupportedZ,
+                                    lastUnsupportedDensity};
                                 audit.firstSupportMasks[sample]=supportMask;
                                 std::printf("[ResolvedWalkDispatch] kind=unsupported xyz_m=(%.3f,%.3f,%.3f) support_probes=%u/5 mask=%d%d%d%d%d path=%s\n",
-                                    firstUnsupportedX,firstUnsupportedY,footZ,supportedProbes,
+                                    firstUnsupportedX,firstUnsupportedY,firstUnsupportedZ,supportedProbes,
                                     supportMask[0],supportMask[1],supportMask[2],supportMask[3],supportMask[4],
                                     Field.densityDispatchPathAt({firstUnsupportedX/coreMetres,
                                         firstUnsupportedY/coreMetres,footZ/coreMetres}).c_str());
@@ -2467,6 +2475,8 @@ namespace StandaloneStreamBenchmark
                 std::uint64_t floorSamples=0,floorExpectedSamples=0;
                 bool controlDetected=false,passed=false;
                 bool floorControlDetected=false;
+                double floorStepControlAmplitudeMetres=0.0;
+                bool floorStepControlDetected=false;
             };
             constexpr double MaximumFlatRunMetres=8.0;
             constexpr double MinimumWallReliefMetres=0.20;
@@ -2859,21 +2869,55 @@ namespace StandaloneStreamBenchmark
                     double startDistance,std::vector<std::array<double,2>>& output)
                 {
                     if(values.size()<64)return;
+                    // Remove a smooth mouth taper across each 32 m window while
+                    // preserving the authored radius, where regular wall ribs can live.
+                    // A cubic baseline tracks the broad flare without fitting the
+                    // 0.5–8 m periods that this audit is meant to detect.
+                    constexpr std::size_t Degree=3;
+                    std::array<std::array<double,Degree+2>,Degree+1> normal{};
                     const double meanIndex=0.5*static_cast<double>(values.size()-1);
-                    double mean=0.0,xy=0.0,xx=0.0;
+                    const double halfSpan=std::max(1.0,meanIndex);
-                    for(double value:values)mean+=value;
-                    mean/=static_cast<double>(values.size());
                     for(std::size_t i=0;i<values.size();++i)
                     {
-                        const double x=(static_cast<double>(i)-meanIndex)*SampleSpacingMetres;
+                        const double x=(static_cast<double>(i)-meanIndex)/halfSpan;
-                        xy+=x*(values[i]-mean);xx+=x*x;
+                        std::array<double,2*Degree+1> powers{};
+                        powers[0]=1.0;
+                        for(std::size_t power=1;power<powers.size();++power)
+                            powers[power]=powers[power-1]*x;
+                        for(std::size_t row=0;row<=Degree;++row)
+                        {
+                            for(std::size_t column=0;column<=Degree;++column)
+                                normal[row][column]+=powers[row+column];
+                            normal[row][Degree+1]+=values[i]*powers[row];
+                        }
+                    }
+                    for(std::size_t column=0;column<=Degree;++column)
+                    {
+                        std::size_t pivot=column;
+                        for(std::size_t row=column+1;row<=Degree;++row)
+                            if(std::abs(normal[row][column])>
+                                std::abs(normal[pivot][column]))pivot=row;
+                        if(std::abs(normal[pivot][column])<=1.0e-12)return;
+                        if(pivot!=column)std::swap(normal[pivot],normal[column]);
+                        const double divisor=normal[column][column];
+                        for(std::size_t value=column;value<=Degree+1;++value)
+                            normal[column][value]/=divisor;
+                        for(std::size_t row=0;row<=Degree;++row)
+                        {
+                            if(row==column)continue;
+                            const double scale=normal[row][column];
+                            for(std::size_t value=column;value<=Degree+1;++value)
+                                normal[row][value]-=scale*normal[column][value];
+                        }
                     }
-                    const double slope=xx>0.0?xy/xx:0.0;
                     for(std::size_t i=0;i<values.size();++i)
                     {
-                        const double x=(static_cast<double>(i)-meanIndex)*SampleSpacingMetres;
+                        const double x=(static_cast<double>(i)-meanIndex)/halfSpan;
+                        double trend=normal[Degree][Degree+1];
+                        for(std::size_t coefficient=Degree;coefficient-->0;)
+                            trend=trend*x+normal[coefficient][Degree+1];
                         output.push_back({startDistance+static_cast<double>(i)*SampleSpacingMetres,
-                            values[i]-mean-slope*x});
+                            values[i]-trend});
                     }
                 };
                 const auto appendDetrendedPairs=[](
@@ -2915,6 +2959,50 @@ namespace StandaloneStreamBenchmark
                 audit.floorControlAmplitudeMetres=audit.controlAmplitudeMetres;
                 audit.floorControlDetected=audit.floorControlAmplitudeMetres
                     >=FloorRippleAmplitudeLimitMetres;
+                // A signed-distance floor with a real 0.25 m ledge must still trip
+                // the same floor-ripple gauge after the crossing-refinement change.
+                std::vector<std::array<double,2>> floorStepResiduals;
+                floorStepResiduals.reserve(static_cast<std::size_t>(WindowLengthMetres/
+                    SampleSpacingMetres)+1);
+                constexpr double FloorStepControlProbeSpacingMetres=0.25;
+                for(std::size_t sample=0;
+                    sample<=static_cast<std::size_t>(WindowLengthMetres/SampleSpacingMetres);
+                    ++sample)
+                {
+                    const double distance=static_cast<double>(sample)*SampleSpacingMetres;
+                    const double stepHeight=distance>=16.0?0.25:0.0;
+                    double previousDensity=0.0,previousZ=0.0;
+                    bool havePrevious=false,haveFloor=false;
+                    double bestFloor=0.0,bestDistance=std::numeric_limits<double>::infinity();
+                    for(int vertical=0;vertical<7;++vertical)
+                    {
+                        const double z=-1.0+vertical*FloorStepControlProbeSpacingMetres;
+                        const double density=z-stepHeight;
+                        if(havePrevious&&previousDensity<0.0&&density>=0.0)
+                        {
+                            double lowZ=previousZ,highZ=z;
+                            for(int refine=0;refine<5;++refine)
+                            {
+                                const double middleZ=(lowZ+highZ)*0.5;
+                                if(middleZ-stepHeight<0.0)lowZ=middleZ;
+                                else highZ=middleZ;
+                            }
+                            const double crossing=(lowZ+highZ)*0.5;
+                            const double candidateDistance=std::abs(crossing);
+                            if(candidateDistance<bestDistance)
+                            {bestDistance=candidateDistance;bestFloor=crossing;haveFloor=true;}
+                        }
+                        previousDensity=density;previousZ=z;havePrevious=true;
+                    }
+                    if(haveFloor)floorStepResiduals.push_back({distance,bestFloor});
+                }
+                std::vector<std::array<double,2>> floorStepSamples;
+                appendDetrendedPairs(floorStepResiduals,floorStepSamples);
+                double floorStepPeriod=0.0;
+                audit.floorStepControlAmplitudeMetres=sinusoidAmplitude(
+                    floorStepSamples,floorStepPeriod);
+                audit.floorStepControlDetected=audit.floorStepControlAmplitudeMetres
+                    >=FloorRippleAmplitudeLimitMetres;
                 const std::array<double,5> windowStarts{{0.03,0.31,0.457,0.61,0.91}};
                 std::vector<std::array<double,2>> coherentSamples;
                 std::vector<std::array<double,2>> coherentFloorSamples;
@@ -2955,8 +3043,27 @@ namespace StandaloneStreamBenchmark
                             if(havePrevious&&previousDensity<0.0&&density>=0.0)
                             {
                                 const double denominator=density-previousDensity;
-                                const double crossing=denominator>1.0e-12
+                                double crossing=denominator>1.0e-12
                                     ?previousZ+(z-previousZ)*(-previousDensity)/denominator:z;
+                                // Density can change sharply at a composed floor. Refine
+                                // the sign bracket instead of assuming it is linear over
+                                // an entire Core voxel; linear interpolation can report a
+                                // one-voxel step even when the zero crossing is nearby.
+                                double lowZ=previousZ,highZ=z;
+                                double lowDensity=previousDensity,highDensity=density;
+                                for(int refine=0;refine<5;++refine)
+                                {
+                                    const double middleZ=(lowZ+highZ)*0.5;
+                                    const double middleDensity=static_cast<double>(Field.densityAt({
+                                        pose.x/coreMetres,pose.y/coreMetres,middleZ/coreMetres}))
+                                        *coreMetres;
+                                    if(middleDensity<0.0)
+                                    {lowZ=middleZ;lowDensity=middleDensity;}
+                                    else
+                                    {highZ=middleZ;highDensity=middleDensity;}
+                                }
+                                (void)lowDensity;(void)highDensity;
+                                crossing=(lowZ+highZ)*0.5;
                                 const double candidateDistance=std::abs(crossing-expectedFloor);
                                 if(candidateDistance<bestDistance)
                                 {bestDistance=candidateDistance;bestFloor=crossing;haveFloor=true;}
@@ -2985,6 +3092,9 @@ namespace StandaloneStreamBenchmark
                             {x0-nx*offset,y0-ny*offset,z0}))*coreMetres;
                         if(!std::isfinite(left)||!std::isfinite(right)
                             ||left< -0.75||left>0.75||right< -0.75||right>0.75)continue;
+                        // The probes sit 0.18 m inside the authored radius. Add that
+                        // radius back to the signed wall distance so radius-carried ribs
+                        // remain visible; the cubic detrend removes the smooth mouth flare.
                         radii.push_back(sampleRadius+0.5*(left+right));
                         ++audit.samples;
                     }
@@ -3052,7 +3162,8 @@ namespace StandaloneStreamBenchmark
                     ?static_cast<double>(audit.floorSamples)/audit.floorExpectedSamples:0.0;
                 audit.passed=audit.controlDetected&&coverage>=0.75
                     &&audit.localPeakAmplitudeMetres<RippleAmplitudeLimitMetres
-                    &&audit.floorControlDetected&&floorCoverage>=0.75
+                    &&audit.floorControlDetected&&audit.floorStepControlDetected
+                    &&floorCoverage>=0.75
                     &&audit.floorAmplitudeMetres<FloorRippleAmplitudeLimitMetres;
                 return audit;
             };
@@ -3546,6 +3657,12 @@ namespace StandaloneStreamBenchmark
                             meanRadiusByHeight.begin()+heightSamples)
                             -*std::min_element(meanRadiusByHeight.begin(),
                                 meanRadiusByHeight.begin()+heightSamples):0.0;
+                    std::printf("[PassageColumnReliefProfile] id=%s heights=%zu radii_m=",
+                        passage.stableId.c_str(),heightSamples);
+                    for(std::size_t height=0;height<heightSamples;++height)
+                        std::printf("%s%.3f",height?",":"",
+                            meanRadiusByHeight[height]);
+                    std::printf("\n");
                     audit.minimumSurfaceRadiusMetres=std::min(audit.minimumSurfaceRadiusMetres,
                         crossingMinimumSurfaceRadius);
                     audit.maximumSurfaceRadiusMetres=std::max(audit.maximumSurfaceRadiusMetres,
@@ -3675,7 +3792,7 @@ namespace StandaloneStreamBenchmark
             };
             std::uint64_t passageCount=0,passagePasses=0,blockedControls=0,naturalPasses=0;
                 std::uint64_t mouthProfilePasses=0,ripplePasses=0,rippleControlsDetected=0;
-            std::uint64_t floorRippleControlsDetected=0;
+            std::uint64_t floorRippleControlsDetected=0,floorStepRippleControlsDetected=0;
             std::uint64_t openAirViolations=0,openAirLegacyViolations=0,openAirSamples=0;
             std::uint64_t openAirAudits=0,openAirColumnSamples=0,openAirShortSpanSamples=0;
             std::uint64_t columnCrossings=0,shortGroundedSpans=0,columnConnectedEnds=0;
@@ -3767,6 +3884,7 @@ namespace StandaloneStreamBenchmark
                 ripplePasses+=rippleAudit.passed;
                 rippleControlsDetected+=rippleAudit.controlDetected;
                 floorRippleControlsDetected+=rippleAudit.floorControlDetected;
+                floorStepRippleControlsDetected+=rippleAudit.floorStepControlDetected;
                 passagePasses+=passageAudit.passed&&mouthsInRadius&&mouthsInContent
                     &&naturalAudit.passed&&mouthProfileAudit.passed&&rippleAudit.passed;
                 std::printf("[ResolvedPassageAudit] id=%s interface=%d-%d control_points=%zu center_samples=%llu capsule_samples=%llu blocked=%llu support_samples=%llu unsupported=%llu grade_failures=%llu mouth_content=%d/2 mouth_radius=%d/2 walkability=%s\n",
@@ -3794,7 +3912,7 @@ namespace StandaloneStreamBenchmark
                     mouthProfileAudit.wallFlatStepRunMetres,mouthProfileAudit.wallStepMetres,
                     PassageProfileSpacingMetres,PassageProfilePlateauMinimumMetres,
                     PassageProfileStepThresholdMetres,mouthProfileAudit.passed?"PASS":"FAIL");
-                std::printf("[PassageRippleAudit] id=%s window_m=32.000 spacing_m=0.125 period_m=%.3f amplitude_m=%.4f amplitude_cm=%.2f coherent_period_m=%.3f coherent_amplitude_m=%.4f coherent_amplitude_cm=%.2f local_peak_amplitude_m=%.4f coverage=%llu/%llu threshold_m=0.035 synthetic_spheres_period_m=1.500 synthetic_spheres_amplitude_m=%.4f synthetic_spheres_detected=%s floor_period_m=%.3f floor_amplitude_m=%.4f floor_amplitude_cm=%.2f floor_coherent_period_m=%.3f floor_coherent_amplitude_m=%.4f floor_coverage=%llu/%llu floor_threshold_m=0.025 floor_beaded_control_amplitude_m=%.4f floor_beaded_control_detected=%s status=%s\n",
+                std::printf("[PassageRippleAudit] id=%s window_m=32.000 spacing_m=0.125 period_m=%.3f amplitude_m=%.4f amplitude_cm=%.2f coherent_period_m=%.3f coherent_amplitude_m=%.4f coherent_amplitude_cm=%.2f local_peak_amplitude_m=%.4f coverage=%llu/%llu threshold_m=0.035 synthetic_spheres_period_m=1.500 synthetic_spheres_amplitude_m=%.4f synthetic_spheres_detected=%s floor_period_m=%.3f floor_amplitude_m=%.4f floor_amplitude_cm=%.2f floor_coherent_period_m=%.3f floor_coherent_amplitude_m=%.4f floor_coverage=%llu/%llu floor_threshold_m=0.025 floor_beaded_control_amplitude_m=%.4f floor_beaded_control_detected=%s floor_step_control_amplitude_m=%.4f floor_step_control_detected=%s status=%s\n",
                     passage.stableId.c_str(),rippleAudit.periodMetres,
                     rippleAudit.amplitudeMetres,rippleAudit.amplitudeMetres*100.0,
                     rippleAudit.coherentPeriodMetres,rippleAudit.coherentAmplitudeMetres,
@@ -3810,7 +3928,12 @@ namespace StandaloneStreamBenchmark
                     static_cast<unsigned long long>(rippleAudit.floorExpectedSamples),
                     rippleAudit.floorControlAmplitudeMetres,
                     rippleAudit.floorControlDetected?"true":"false",
+                    rippleAudit.floorStepControlAmplitudeMetres,
+                    rippleAudit.floorStepControlDetected?"true":"false",
                     rippleAudit.passed?"PASS":"FAIL");
+                std::printf("[PassageFloorStepNegativeControl] id=%s source=synthetic_signed_distance_step height_m=0.250 threshold_m=0.025 amplitude_m=%.4f detected=%s\n",
+                    passage.stableId.c_str(),rippleAudit.floorStepControlAmplitudeMetres,
+                    rippleAudit.floorStepControlDetected?"true":"false");
                 for(std::size_t sample=0;sample<rippleAudit.floorPeakProfile.size();sample+=4)
                 {
                     const auto& value=rippleAudit.floorPeakProfile[sample];
@@ -4134,11 +4257,12 @@ namespace StandaloneStreamBenchmark
                 PassageProfilePlateauMinimumMetres,PassageProfileStepThresholdMetres,
                 l23TerraceControlDetected?"DETECTED":"MISSED",
                 mouthProfilePasses==passageCount&&l23TerraceControlDetected?"PASS":"FAIL");
-            std::printf("[PassageRippleAuditSummary] passed=%llu/%llu synthetic_spheres_negative_control=%s max_amplitude_m=0.035 floor_beaded_negative_control=%s max_floor_amplitude_m=0.015 status=%s\n",
+            std::printf("[PassageRippleAuditSummary] passed=%llu/%llu synthetic_spheres_negative_control=%s max_amplitude_m=0.035 floor_beaded_negative_control=%s max_floor_amplitude_m=0.025 floor_step_negative_control=%s status=%s\n",
                 static_cast<unsigned long long>(ripplePasses),
                 static_cast<unsigned long long>(passageCount),
                 rippleControlsDetected==passageCount?"DETECTED":"MISSED",
                 floorRippleControlsDetected==passageCount?"DETECTED":"MISSED",
+                floorStepRippleControlsDetected==passageCount?"DETECTED":"MISSED",
                 ripplePasses==passageCount?"PASS":"FAIL");
             const bool auditPassed=passageCount>0&&passagePasses==passageCount
                 &&naturalPasses==passageCount&&l23SmoothWallDetected

Standalone/Tools/verify/verify.py

@@ -29,6 +29,7 @@ LINUX54 = ROOT / "Standalone/Research/WorldAssemblerM3/Linux54"
 LINUX56 = ROOT / "Standalone/Research/WorldAssemblerM3/Linux56"
 LINUX58 = ROOT / "Standalone/Research/WorldAssemblerM3/Linux58"
 LINUX60 = ROOT / "Standalone/Research/WorldAssemblerM3/Linux60"
+LINUX67 = ROOT / "Standalone/Research/WorldAssemblerM3/Linux67"
 OWNER = ROOT / "Standalone/data/regression/owner_world_2strate_l61.json"
 OWNER_NEW = ROOT / "Standalone/data/owner_world.json"
 OWNER_2STRATE_SHA256 = "7b095f9bcc6b90133d5a463f99f0b571133b2c549ce1ecf2d64fe9175e41e183"
@@ -623,9 +624,25 @@ def run_hash_pairs(runner: VerificationRunner,
         l52_baseline = ROOT / "Saved/Linux/l52" / f"owner-hash-{recipe}-style{style}-w12.log"
         l52_hashes = tuple(HASH_RE.findall(l52_baseline.read_text(
             encoding="utf-8", errors="replace")))
-        same_l52 = hashes[12] == l52_hashes and len(l52_hashes) == 12
+        if recipe == "surface-world":
-        runner.require(f"owner-hash-{recipe}-w12-matches-L52", same_l52,
+            expected_baseline = LINUX67 / "hash-baselines" / (
-            f"current={len(hashes[12])} L52={len(l52_hashes)} exact canonical hash rows")
+                "owner-hash-surface-world-style1-v212.log")
+            expected_label = "L67-v212"
+        else:
+            expected_baseline = l52_baseline
+            expected_label = "L52"
+        expected_hashes = tuple(HASH_RE.findall(expected_baseline.read_text(
+            encoding="utf-8", errors="replace")))
+        same_expected = hashes[12] == expected_hashes and len(expected_hashes) == 12
+        runner.require(f"owner-hash-{recipe}-w12-matches-{expected_label}", same_expected,
+            f"current={len(hashes[12])} {expected_label}={len(expected_hashes)} exact canonical hash rows")
+        if recipe == "surface-world":
+            diagnostic = {"name": "owner-hash-surface-world-matches-L52-diagnostic",
+                "status": "DIAGNOSTIC",
+                "detail": f"matches={hashes[12] == l52_hashes} L52 rows={len(l52_hashes)}; "
+                    "the v212 generated-route change has its own pinned baseline"}
+            runner.steps.append(diagnostic)
+            print(f"[{runner.tier}] {diagnostic['name']} {diagnostic['detail']}", flush=True)
         baseline = ROOT / "Saved/Linux/l46" / f"owner-hash-{recipe}-style{style}-w12.log"
         old_hashes = tuple(HASH_RE.findall(baseline.read_text(encoding="utf-8", errors="replace")))
         same_l46 = hashes[12] == old_hashes and len(old_hashes) == 12