passages: dense centripetal spline + open-air half-pipe attempt (L111, failed audits)

Route resampled to ~1 m (310 -> 2,790 segments); open air writes a 0.75 m floor slab plus 1.0 m
side walls, no roof. The 3D spline overshoots between planned route points, raising floor grades
above 15 deg; a grade-limited variant left 2 unsupported samples on passage 0-1, and the shell/
ripple audits still model the old chord route. Stopped after two designs. Not merged.

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

Standalone/Core/include/VoxelForgeCore/VoxelForgeCore.h

@@ -468,8 +468,9 @@ namespace VoxelForgeCore
     // 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.
     // Version 212 balances generated entry routes against existing walk lanes and preserves their shared treads.
-    // Version 217 replaces passage supports with flat-floor hollow-shell geometry.
-    inline constexpr std::uint32_t WorldAssemblyEvaluatorVersion = 217;
+    // Version 218 resamples passages on a smooth spline and uses open-air half-pipe shells.
+    // Version 218 sweeps passages around a dense smooth spline and limits exposed shells to a trough.
+    inline constexpr std::uint32_t WorldAssemblyEvaluatorVersion = 218;
 
     enum class FieldChannel : std::uint32_t
     {

Standalone/Core/src/ShapeWorldInternal.h

@@ -1196,6 +1196,7 @@ public:
         constexpr double Q=static_cast<double>(VoxelForgeCore::WorldAssemblySubvoxelsPerVoxel);
         constexpr double FloorShellThicknessMetres=0.75;
         constexpr double WallReliefMetres=0.21;
+        constexpr double OpenAirSideWallHeightMetres=1.0;
         constexpr double MouthShellBlendMetres=5.0;
         const double qPerMetre=Q*1000000.0/
             std::max<std::uint32_t>(1,ResolvedLayout->coreVoxelSizeMicrometres);
@@ -1264,7 +1265,7 @@ public:
                 }
 
                 const std::ptrdiff_t lastIndex=static_cast<std::ptrdiff_t>(
-                    passage.controlPoints.size())-1;
+                    PassageSegmentData[passageIndex].size())-1;
                 double bestDistance=std::numeric_limits<double>::infinity();
                 const auto visitSegment=[&](std::size_t segmentIndex,int)
                 {
@@ -1355,11 +1356,14 @@ public:
                     const double floorBlend=std::clamp(floorDistanceMetres/0.25,0.0,1.0);
                     const double smoothFloorBlend=floorBlend*floorBlend
                         *(3.0-2.0*floorBlend);
-                    const double mouthWallThickness=segmentIndex
-                            <constants.routeEndControlIndex
+                    const double wallElevationMetres=(qz-(floorCenterZ-floorDepth))
+                        /qPerMetre;
+                    const double mouthWallThickness=segment.routeSegment
+                            &&wallElevationMetres>=0.0
+                            &&wallElevationMetres<=OpenAirSideWallHeightMetres
                         ?smoothShellFade*shellThickness:0.0;
                     double floorExtensionFade=1.0;
-                    if(segmentIndex>=constants.routeEndControlIndex)
+                    if(!segment.routeSegment)
                     {
                         const double pastMouthMetres=std::max(0.0,alongMetres
                             -constants.totalPathLengthMetres);
@@ -1417,11 +1421,14 @@ public:
             const double floorBlend=std::clamp(floorDistanceMetres/0.25,0.0,1.0);
             const double smoothFloorBlend=floorBlend*floorBlend
                 *(3.0-2.0*floorBlend);
-            const double mouthWallThickness=nearest.segmentIndex
-                    <constants.routeEndControlIndex
+            const double wallElevationMetres=(qz-(nearest.floorCenterZ-nearest.floorDepth))
+                /qPerMetre;
+            const double mouthWallThickness=segment.routeSegment
+                    &&wallElevationMetres>=0.0
+                    &&wallElevationMetres<=OpenAirSideWallHeightMetres
                 ?smoothShellFade*shellThickness:0.0;
             double floorExtensionFade=1.0;
-            if(nearest.segmentIndex>=constants.routeEndControlIndex)
+            if(!segment.routeSegment)
             {
                 const double pastMouthMetres=std::max(0.0,alongMetres
                     -constants.totalPathLengthMetres);
@@ -1446,15 +1453,11 @@ public:
         // solid only in air, so it leaves host rock unchanged. Taking the union
         // before writing either polarity makes every tunnel interior beat every
         // overlapping tunnel shell.
-        // Positive native graph distance is authored tunnel interior. Blend it
-        // into the same air union before any passage shell can change its sign.
-        // This also preserves the cave interior across a shared-layer boundary
-        // blend, which may be solid on the passage's side of that interface.
-        if(nativeTunnelFieldDensity>=0.0f)
+        // Preserve native graph air inside the passage interior before any shell
+        // can change its sign. Outside that interior, the shell may cover host air.
+        if(nativeTunnelFieldDensity>=0.0f&&unionDistance<=0.0)
         {
-            const float passageAir=unionDistance<=0.0
-                ?static_cast<float>(-unionDistance/Q)
-                :std::numeric_limits<float>::lowest();
+            const float passageAir=static_cast<float>(-unionDistance/Q);
             return std::max(nativeTunnelFieldDensity,passageAir);
         }
         if(nativeFloorSupport!=std::numeric_limits<float>::lowest()
@@ -3377,7 +3380,38 @@ private:
         double radiusA=0.0,radiusB=0.0,radiusDelta=0.0;
         double lengthSq=0.0,horizontalLengthSq=0.0;
         double lengthSubvoxels=0.0,horizontalLength=0.0;
+        bool routeSegment=false;
     };
+    static double PassageCentripetalKnotSpan(
+        const std::array<double,4>& a,const std::array<double,4>& b)
+    {
+        const double dx=b[0]-a[0],dy=b[1]-a[1],dz=b[2]-a[2];
+        return std::max(1.0e-6,DeterministicSqrt(DeterministicSqrt(
+            dx*dx+dy*dy+dz*dz)));
+    }
+    static std::array<double,4> PassageCentripetalCatmullRom(
+        const std::array<double,4>& p0,const std::array<double,4>& p1,
+        const std::array<double,4>& p2,const std::array<double,4>& p3,
+        double t,double dt0,double dt1,double dt2)
+    {
+        std::array<double,4> result{};
+        const double t2=t*t,t3=t2*t;
+        for(std::size_t axis=0;axis<4;++axis)
+        {
+            const double m1=dt1*((p1[axis]-p0[axis])/dt0
+                -(p2[axis]-p0[axis])/(dt0+dt1)
+                +(p2[axis]-p1[axis])/dt1);
+            const double m2=dt1*((p2[axis]-p1[axis])/dt1
+                -(p3[axis]-p1[axis])/(dt1+dt2)
+                +(p3[axis]-p2[axis])/dt2);
+            result[axis]=(2.0*t3-3.0*t2+1.0)*p1[axis]
+                +(-2.0*t3+3.0*t2)*p2[axis]
+                +(t3-2.0*t2+t)*m1+(t3-t2)*m2;
+        }
+        result[3]=std::clamp(result[3],std::min(p1[3],p2[3]),
+            std::max(p1[3],p2[3]));
+        return result;
+    }
     static double PassageFlatFloorDepthSubvoxels(
         const FPassageComposerConstants& constants,std::size_t segmentIndex,double t,
         double radiusSubvoxels,double qPerMetre)
@@ -3411,7 +3445,7 @@ private:
         const FPassageComposerConstants& constants,std::size_t segmentIndex,double floorT,
         const FPassageSegmentData& segment,double floorDepthSubvoxels,double qPerMetre)
     {
-        if(segmentIndex>=constants.routeEndControlIndex||qPerMetre<=0.0)
+        if(!segment.routeSegment||qPerMetre<=0.0)
             return segment.a[2]+floorT*segment.delta[2];
         const double radiusMetres=(segment.radiusA+floorT*segment.radiusDelta)/qPerMetre;
         const double alongMetres=segment.authoredAlongMetres
@@ -4222,13 +4256,11 @@ private:
 
     int BuildPassageNearestNode(std::size_t passageIndex,std::vector<std::size_t> segments)
     {
-        const auto& points=ResolvedLayout->passages[passageIndex].controlPoints;
         FPassageNearestNode node;
         node.minimum.fill(std::numeric_limits<double>::infinity());
         node.maximum.fill(-std::numeric_limits<double>::infinity());
         for(const std::size_t segment:segments)
         {
-            const auto& a=points[segment];const auto& b=points[segment+1];
             const auto& prepared=PassageSegmentData[passageIndex][segment];
             for(std::size_t axis=0;axis<3;++axis)
             {
@@ -4238,7 +4270,7 @@ private:
                     prepared.a[axis],prepared.b[axis]});
             }
             node.maximumRadius=std::max({node.maximumRadius,
-                static_cast<double>(a.radiusSubvoxels),static_cast<double>(b.radiusSubvoxels)});
+                prepared.radiusA,prepared.radiusB});
         }
         node.minimumSegment=*std::min_element(segments.begin(),segments.end());
         node.maximumSegment=*std::max_element(segments.begin(),segments.end());
@@ -4258,8 +4290,8 @@ private:
                     -PassageNearestNodes[passageIndex][nodeIndex].minimum[splitAxis])splitAxis=axis;
             const std::size_t middle=segments.size()/2;
             const auto center=[&](std::size_t segment)
-            {return static_cast<double>(points[segment].positionSubvoxels[splitAxis])
-                +static_cast<double>(points[segment+1].positionSubvoxels[splitAxis]);};
+            {const auto& prepared=PassageSegmentData[passageIndex][segment];
+                return prepared.a[splitAxis]+prepared.b[splitAxis];};
             std::nth_element(segments.begin(),segments.begin()+middle,segments.end(),
                 [&](std::size_t a,std::size_t b)
                 {const double ca=center(a),cb=center(b);return ca==cb?a<b:ca<cb;});
@@ -4497,7 +4529,7 @@ private:
         if(!ResolvedLayout)
         {
             if(tracePreparation)
-                std::printf("[L98PassagePrepare] passages=0 segments=0 bytes=0 prepare_ms=%.3f\n",
+                std::printf("[L111PassagePrepare] passages=0 control_spans=0 segments=0 spacing_m=1.00 bytes=0 prepare_ms=%.3f\n",
                     std::chrono::duration<double,std::milli>(
                         std::chrono::steady_clock::now()-preparationStart).count());
             return;
@@ -4508,7 +4540,9 @@ private:
         constexpr double Q=static_cast<double>(VoxelForgeCore::WorldAssemblySubvoxelsPerVoxel);
         const double qPerMetre=Q*1000000.0/
             std::max<std::uint32_t>(1,ResolvedLayout->coreVoxelSizeMicrometres);
-        std::size_t preparedSegments=0;
+        constexpr double PassageSegmentSpacingMetres=1.0;
+        constexpr std::size_t ArcLengthTableSteps=32;
+        std::size_t preparedSegments=0,controlSpans=0;
         for(std::size_t passageIndex=0;passageIndex<ResolvedLayout->passages.size();
             ++passageIndex)
         {
@@ -4519,50 +4553,104 @@ private:
                 PassageSegmentOffsets[passageIndex+1]=preparedSegments;
                 continue;
             }
-            auto& segmentData=PassageSegmentData[passageIndex];
-            segmentData.resize(passage.controlPoints.size()-1);
             const std::size_t routeEnd=std::clamp<std::size_t>(
                 passage.lowerMouthControlIndex,1,passage.controlPoints.size()-1);
-            std::vector<double> radiiMetres;
-            radiiMetres.reserve(routeEnd+1);
-            for(std::size_t pointIndex=0;pointIndex<=routeEnd;++pointIndex)
-            {
-                radiiMetres.push_back(static_cast<double>(
-                    passage.controlPoints[pointIndex].radiusSubvoxels)/qPerMetre);
-            }
             auto& constants=PassageComposerConstants[passageIndex];
             constants.routeEndControlIndex=routeEnd;
-            std::vector<double> authoredPathDistanceMetres(
-                passage.controlPoints.size(),0.0);
-            for(std::size_t pointIndex=1;pointIndex<passage.controlPoints.size();
-                ++pointIndex)
+
+            struct FRawPassageSegment
             {
-                const auto& a=passage.controlPoints[pointIndex-1].positionSubvoxels;
-                const auto& b=passage.controlPoints[pointIndex].positionSubvoxels;
-                const double dx=static_cast<double>(b[0]-a[0])/qPerMetre;
-                const double dy=static_cast<double>(b[1]-a[1])/qPerMetre;
-                const double dz=static_cast<double>(b[2]-a[2])/qPerMetre;
-                authoredPathDistanceMetres[pointIndex]=
-                    authoredPathDistanceMetres[pointIndex-1]
-                    +DeterministicSqrt(dx*dx+dy*dy+dz*dz);
+                std::array<double,4> a{},b{};
+                double alongMetres=0.0,lengthMetres=0.0;
+                std::size_t span=0;
+                double tA=0.0,tB=1.0;
+                bool routeSegment=false;
+            };
+            std::vector<std::array<double,4>> controls;
+            controls.reserve(passage.controlPoints.size());
+            for(const auto& point:passage.controlPoints)
+                controls.push_back({static_cast<double>(point.positionSubvoxels[0]),
+                    static_cast<double>(point.positionSubvoxels[1]),
+                    static_cast<double>(point.positionSubvoxels[2]),
+                    static_cast<double>(point.radiusSubvoxels)});
+            std::vector<FRawPassageSegment> rawSegments;
+            rawSegments.reserve((passage.controlPoints.size()-1)*10);
+            std::vector<std::array<double,2>> routeRadiusSamples;
+            routeRadiusSamples.push_back({0.0,controls.front()[3]/qPerMetre});
+            double alongMetres=0.0,authoredTotalPathLengthMetres=0.0;
+            const auto curvePoint=[&](std::size_t span,double t)
+            {
+                const auto& p1=controls[span];
+                const auto& p2=controls[span+1];
+                const auto& p0=controls[span==0?0:span-1];
+                const auto& p3=controls[std::min(span+2,controls.size()-1)];
+                return PassageCentripetalCatmullRom(p0,p1,p2,p3,t,
+                    PassageCentripetalKnotSpan(p0,p1),
+                    PassageCentripetalKnotSpan(p1,p2),
+                    PassageCentripetalKnotSpan(p2,p3));
+            };
+            for(std::size_t span=0;span+1<controls.size();++span)
+            {
+                ++controlSpans;
+                std::array<double,ArcLengthTableSteps+1> arcLength{};
+                auto previous=curvePoint(span,0.0);
+                for(std::size_t step=1;step<=ArcLengthTableSteps;++step)
+                {
+                    const auto current=curvePoint(span,
+                        static_cast<double>(step)/ArcLengthTableSteps);
+                    const double dx=(current[0]-previous[0])/qPerMetre;
+                    const double dy=(current[1]-previous[1])/qPerMetre;
+                    const double dz=(current[2]-previous[2])/qPerMetre;
+                    arcLength[step]=arcLength[step-1]
+                        +DeterministicSqrt(dx*dx+dy*dy+dz*dz);
+                    previous=current;
+                }
+                const double spanLength=arcLength.back();
+                const std::size_t segmentCount=std::max<std::size_t>(1,
+                    static_cast<std::size_t>(std::ceil(
+                        spanLength/PassageSegmentSpacingMetres)));
+                auto a=curvePoint(span,0.0);
+                double aT=0.0;
+                for(std::size_t segment=1;segment<=segmentCount;++segment)
+                {
+                    const double targetArc=spanLength*static_cast<double>(segment)
+                        /segmentCount;
+                    const auto upper=std::lower_bound(arcLength.begin()+1,
+                        arcLength.end(),targetArc);
+                    const std::size_t upperIndex=static_cast<std::size_t>(
+                        upper-arcLength.begin());
+                    const std::size_t lowerIndex=upperIndex-1;
+                    const double arcSpan=arcLength[upperIndex]-arcLength[lowerIndex];
+                    const double arcT=arcSpan>1.0e-12
+                        ?std::clamp((targetArc-arcLength[lowerIndex])/arcSpan,0.0,1.0):0.0;
+                    const double t=(static_cast<double>(lowerIndex)+arcT)
+                        /ArcLengthTableSteps;
+                    const auto b=curvePoint(span,t);
+                    const double dx=(b[0]-a[0])/qPerMetre;
+                    const double dy=(b[1]-a[1])/qPerMetre;
+                    const double dz=(b[2]-a[2])/qPerMetre;
+                    const double length=DeterministicSqrt(dx*dx+dy*dy+dz*dz);
+                    rawSegments.push_back({a,b,alongMetres,length,span,aT,t,span<routeEnd});
+                    alongMetres+=length;
+                    if(span<routeEnd)
+                        routeRadiusSamples.push_back({alongMetres,b[3]/qPerMetre});
+                    a=b;
+                    aT=t;
+                }
+                if(span+1==routeEnd)
+                    authoredTotalPathLengthMetres=alongMetres;
             }
-            const double authoredTotalPathLengthMetres=
-                authoredPathDistanceMetres[routeEnd];
             constants.authoredTotalPathLengthMetres=authoredTotalPathLengthMetres;
             double minimumBodyRadius=std::numeric_limits<double>::infinity();
             double minimumRadius=std::numeric_limits<double>::infinity();
-            for(std::size_t pointIndex=0;pointIndex<=routeEnd;++pointIndex)
+            for(const auto& sample:routeRadiusSamples)
             {
-                const double radius=radiiMetres[pointIndex];
-                minimumRadius=std::min(minimumRadius,radius);
-                const double along=authoredPathDistanceMetres[pointIndex];
-                if(along>=10.0&&authoredTotalPathLengthMetres-along>=10.0)
-                    minimumBodyRadius=std::min(minimumBodyRadius,radius);
+                minimumRadius=std::min(minimumRadius,sample[1]);
+                if(sample[0]>=10.0&&authoredTotalPathLengthMetres-sample[0]>=10.0)
+                    minimumBodyRadius=std::min(minimumBodyRadius,sample[1]);
             }
             if(!std::isfinite(minimumBodyRadius))minimumBodyRadius=minimumRadius;
-            // One fixed flat-floor depth through the body. The authored grade
-            // constraint follows centreline-radius+0.23 m; shift the swept centreline
-            // where a taper changes radius so this floor keeps that same route.
+            // Keep one flat-floor depth through the body and ease it into both mouths.
             constants.floorDepthMetres=std::max(0.5,minimumBodyRadius-0.23);
             constants.upperMouthFloorDepthMetres=std::max(0.0,
                 static_cast<double>(passage.controlPoints.front().positionSubvoxels[2]
@@ -4586,76 +4674,135 @@ private:
                 constants.lowerMouthFloorDepthMetres=std::max(0.0,
                     routeFloorMetres-nativeFloorMetres);
             }
-            const auto routeFloorDepth=[&](std::size_t pointIndex,double radius)
+
+            struct FRouteFloorSample
             {
-                const double localRadiusDepth=std::max(0.0,radius-0.23);
-                const double along=authoredPathDistanceMetres[pointIndex];
-                const double mouthDistance=std::max(0.0,std::min(along,
-                    authoredTotalPathLengthMetres-along));
-                const double linear=std::clamp(mouthDistance/5.0,0.0,1.0);
-                const double ramp=linear*linear*(3.0-2.0*linear);
-                const double target=along<=authoredTotalPathLengthMetres*0.5
-                    ?constants.upperMouthFloorDepthMetres
-                    :constants.lowerMouthFloorDepthMetres;
-                const double mouthDepth=std::clamp(target,0.0,std::max(0.0,radius));
-                return std::lerp(mouthDepth,localRadiusDepth,ramp);
+                std::array<double,4> point{};
+                double alongMetres=0.0,desiredFloorZMetres=0.0;
             };
-            std::vector<double> effectiveCenterZSubvoxels(
-                passage.controlPoints.size(),0.0);
-            for(std::size_t pointIndex=0;pointIndex<passage.controlPoints.size();
-                ++pointIndex)
+            std::vector<FRouteFloorSample> routeFloorSamples;
+            routeFloorSamples.reserve(rawSegments.size()+1);
+            const auto appendRouteFloorSample=[&](const std::array<double,4>& point,
+                double along)
             {
-                const double radius=pointIndex<=routeEnd
-                    ?radiiMetres[pointIndex]
-                    :static_cast<double>(passage.controlPoints[pointIndex]
-                        .radiusSubvoxels)/qPerMetre;
-                const double localTubeDepth=std::min(constants.floorDepthMetres,
-                    std::max(0.0,radius-0.23));
-                const double routeDepth=pointIndex<=routeEnd
-                    ?routeFloorDepth(pointIndex,radius):std::max(0.0,radius-0.23);
-                effectiveCenterZSubvoxels[pointIndex]=
-                    static_cast<double>(passage.controlPoints[pointIndex].positionSubvoxels[2])
-                    +(-routeDepth+localTubeDepth)*qPerMetre;
+                const double radiusMetres=point[3]/qPerMetre;
+                const double routeDepth=PassageRouteFloorDepthMetres(constants,along,
+                    radiusMetres);
+                routeFloorSamples.push_back({point,along,point[2]/qPerMetre-routeDepth});
+            };
+            for(const auto& raw:rawSegments)
+            {
+                if(!raw.routeSegment)break;
+                if(routeFloorSamples.empty())appendRouteFloorSample(raw.a,raw.alongMetres);
+                appendRouteFloorSample(raw.b,raw.alongMetres+raw.lengthMetres);
             }
-            for(std::size_t segmentIndex=0;segmentIndex<segmentData.size();++segmentIndex)
+            if(routeFloorSamples.size()>1)
             {
-                const auto& a=passage.controlPoints[segmentIndex];
-                const auto& b=passage.controlPoints[segmentIndex+1];
-                FPassageSegmentData& data=segmentData[segmentIndex];
-                data.authoredCenterZA=static_cast<double>(a.positionSubvoxels[2]);
-                data.authoredCenterZDelta=static_cast<double>(
-                    b.positionSubvoxels[2]-a.positionSubvoxels[2]);
-                data.authoredAlongMetres=authoredPathDistanceMetres[segmentIndex];
-                data.authoredLengthMetres=authoredPathDistanceMetres[segmentIndex+1]
-                    -authoredPathDistanceMetres[segmentIndex];
+                constexpr double MaximumWalkGradeTangent=0.2586407821;
+                std::vector<double> horizontalGradeLimits(routeFloorSamples.size()-1);
+                std::vector<double> remainingGradeAllowance(routeFloorSamples.size(),0.0);
+                for(std::size_t i=0;i+1<routeFloorSamples.size();++i)
+                {
+                    const double dx=(routeFloorSamples[i+1].point[0]
+                        -routeFloorSamples[i].point[0])/qPerMetre;
+                    const double dy=(routeFloorSamples[i+1].point[1]
+                        -routeFloorSamples[i].point[1])/qPerMetre;
+                    horizontalGradeLimits[i]=MaximumWalkGradeTangent
+                        *DeterministicSqrt(dx*dx+dy*dy);
+                }
+                for(std::size_t i=horizontalGradeLimits.size();i>0;--i)
+                    remainingGradeAllowance[i-1]=remainingGradeAllowance[i]
+                        +horizontalGradeLimits[i-1];
+                std::vector<double> walkableFloor(routeFloorSamples.size());
+                walkableFloor.front()=routeFloorSamples.front().desiredFloorZMetres;
+                walkableFloor.back()=routeFloorSamples.back().desiredFloorZMetres;
+                for(std::size_t i=1;i+1<routeFloorSamples.size();++i)
+                {
+                    const double limit=horizontalGradeLimits[i-1];
+                    const double remaining=remainingGradeAllowance[i];
+                    const double low=std::max(walkableFloor[i-1]-limit,
+                        walkableFloor.back()-remaining);
+                    const double high=std::min(walkableFloor[i-1]+limit,
+                        walkableFloor.back()+remaining);
+                    walkableFloor[i]=std::clamp(
+                        routeFloorSamples[i].desiredFloorZMetres,low,high);
+                }
+                for(std::size_t i=0;i+1<rawSegments.size();++i)
+                {
+                    auto& raw=rawSegments[i];
+                    if(!raw.routeSegment)break;
+                    const auto& floorA=routeFloorSamples[i];
+                    const auto& floorB=routeFloorSamples[i+1];
+                    const double radiusA=floorA.point[3]/qPerMetre;
+                    const double radiusB=floorB.point[3]/qPerMetre;
+                    raw.a[2]=(walkableFloor[i]
+                        +PassageRouteFloorDepthMetres(constants,floorA.alongMetres,radiusA))
+                        *qPerMetre;
+                    raw.b[2]=(walkableFloor[i+1]
+                        +PassageRouteFloorDepthMetres(constants,floorB.alongMetres,radiusB))
+                        *qPerMetre;
+                }
+                const std::size_t routeSegmentCount=routeFloorSamples.size()-1;
+                if(routeSegmentCount<rawSegments.size())
+                {
+                    auto& firstCap=rawSegments[routeSegmentCount];
+                    const double localDepth=std::max(0.0,
+                        firstCap.a[3]/qPerMetre-0.23);
+                    firstCap.a[2]=(walkableFloor.back()+localDepth)*qPerMetre;
+                }
+            }
+
+            auto& segmentData=PassageSegmentData[passageIndex];
+            segmentData.clear();
+            segmentData.reserve(rawSegments.size());
+            for(const auto& raw:rawSegments)
+            {
+                FPassageSegmentData data;
+                data.authoredCenterZA=raw.a[2];
+                data.authoredCenterZDelta=raw.b[2]-raw.a[2];
+                data.authoredAlongMetres=raw.alongMetres;
+                data.authoredLengthMetres=raw.lengthMetres;
+                data.routeSegment=raw.routeSegment;
+                data.radiusA=raw.a[3];
+                data.radiusB=raw.b[3];
+                data.radiusDelta=raw.b[3]-raw.a[3];
+                const double alongB=raw.alongMetres+raw.lengthMetres;
+                const auto effectiveCenterZ=[&](double authoredZ,double radiusQ,double along)
+                {
+                    const double radiusMetres=radiusQ/qPerMetre;
+                    const double localTubeDepth=std::min(constants.floorDepthMetres,
+                        std::max(0.0,radiusMetres-0.23));
+                    const double routeDepth=raw.routeSegment
+                        ?PassageRouteFloorDepthMetres(constants,along,radiusMetres)
+                        :std::max(0.0,radiusMetres-0.23);
+                    return authoredZ+(-routeDepth+localTubeDepth)*qPerMetre;
+                };
                 for(std::size_t axis=0;axis<3;++axis)
                 {
-                    data.a[axis]=static_cast<double>(a.positionSubvoxels[axis]);
-                    data.b[axis]=static_cast<double>(b.positionSubvoxels[axis]);
+                    data.a[axis]=raw.a[axis];
+                    data.b[axis]=raw.b[axis];
                     if(axis==2)
                     {
-                        data.a[axis]=effectiveCenterZSubvoxels[segmentIndex];
-                        data.b[axis]=effectiveCenterZSubvoxels[segmentIndex+1];
+                        data.a[axis]=effectiveCenterZ(raw.a[2],raw.a[3],raw.alongMetres);
+                        data.b[axis]=effectiveCenterZ(raw.b[2],raw.b[3],alongB);
                     }
                     data.delta[axis]=data.b[axis]-data.a[axis];
                 }
-                data.radiusA=static_cast<double>(a.radiusSubvoxels);
-                data.radiusB=static_cast<double>(b.radiusSubvoxels);
-                data.radiusDelta=static_cast<double>(b.radiusSubvoxels)-a.radiusSubvoxels;
                 const double dx=data.delta[0],dy=data.delta[1],dz=data.delta[2];
                 data.lengthSq=dx*dx+dy*dy+dz*dz;
                 data.horizontalLengthSq=dx*dx+dy*dy;
                 data.lengthSubvoxels=DeterministicSqrt(data.lengthSq);
                 data.horizontalLength=DeterministicSqrt(data.horizontalLengthSq);
+                segmentData.push_back(data);
                 ++preparedSegments;
             }
             constants.totalPathLengthMetres=authoredTotalPathLengthMetres;
             PassageSegmentOffsets[passageIndex+1]=preparedSegments;
         }
         if(tracePreparation)
-            std::printf("[L109PassagePrepare] passages=%zu segments=%zu bytes=%zu prepare_ms=%.3f\n",
-                PassageSegmentData.size(),preparedSegments,
-                preparedSegments*sizeof(FPassageSegmentData),
+            std::printf("[L111PassagePrepare] passages=%zu control_spans=%zu segments=%zu spacing_m=%.2f bytes=%zu prepare_ms=%.3f\n",
+                PassageSegmentData.size(),controlSpans,preparedSegments,
+                PassageSegmentSpacingMetres,preparedSegments*sizeof(FPassageSegmentData),
                 std::chrono::duration<double,std::milli>(
                     std::chrono::steady_clock::now()-preparationStart).count());
     }
@@ -4681,20 +4828,16 @@ private:
         for(std::size_t passageIndex=0;passageIndex<ResolvedLayout->passages.size();
             ++passageIndex)
         {
-            const auto& passage=ResolvedLayout->passages[passageIndex];
-            const std::size_t segmentCount=passage.controlPoints.size()>1
-                ?passage.controlPoints.size()-1:0;
+            const std::size_t segmentCount=PassageSegmentData[passageIndex].size();
             if(segmentCount==0)continue;
             std::vector<std::size_t> segmentIds(segmentCount);
             for(std::size_t i=0;i<segmentCount;++i)segmentIds[i]=i;
             BuildPassageNearestNode(passageIndex,std::move(segmentIds));
             for(std::size_t segmentIndex=0;segmentIndex<segmentCount;++segmentIndex)
             {
-                const auto& a=passage.controlPoints[segmentIndex];
-                const auto& b=passage.controlPoints[segmentIndex+1];
                 auto& prepared=PassageSegmentData[passageIndex][segmentIndex];
-                double maximumRadius=std::max(static_cast<double>(a.radiusSubvoxels),
-                    static_cast<double>(b.radiusSubvoxels))/Q;
+                const double maximumRadius=std::max(prepared.radiusA,
+                    prepared.radiusB)/Q;
                 std::array<double,3> routeMinimum{},routeMaximum{};
                 for(std::size_t axis=0;axis<3;++axis)
                 {
@@ -11286,6 +11429,7 @@ inline void FStandaloneShapeWorld::FScopedPassageTileQueries::prepareSweptTubeBa
 {
     constexpr std::int64_t Q=VoxelForgeCore::WorldAssemblySubvoxelsPerVoxel;
     constexpr double InfluenceMetres=4.0;
+    constexpr double OpenAirSideWallHeightMetres=1.0;
     if(!shape_||step<=0||cells<=0||!std::isfinite(passageCarveReachMetres_)
         ||std::abs(passageCarveReachMetres_-InfluenceMetres)>1.0e-9)return;
 
@@ -11403,11 +11547,14 @@ inline void FStandaloneShapeWorld::FScopedPassageTileQueries::prepareSweptTubeBa
                 const double floorBlend=std::clamp(floorDistanceMetres/0.25,0.0,1.0);
                 const double smoothFloorBlend=floorBlend*floorBlend
                     *(3.0-2.0*floorBlend);
-                const double mouthWallThickness=candidate.segmentIndex
-                        <constants.routeEndControlIndex
+                const double wallElevationMetres=(qz-(floorCenterZ-floorDepth))
+                    /qPerMetre;
+                const double mouthWallThickness=segment.routeSegment
+                        &&wallElevationMetres>=0.0
+                        &&wallElevationMetres<=OpenAirSideWallHeightMetres
                     ?smoothShellFade*shellThickness:0.0;
                 double floorExtensionFade=1.0;
-                if(candidate.segmentIndex>=constants.routeEndControlIndex)
+                if(!segment.routeSegment)
                 {
                     const double pastMouthMetres=std::max(0.0,alongMetres
                         -constants.totalPathLengthMetres);

Standalone/Research/WorldAssemblerM3/Linux111/REPORT.md

@@ -0,0 +1,42 @@
+# Linux111 report
+
+## Design
+
+Version 218 resamples passage controls with a centripetal Catmull–Rom curve at about 1 m spacing (310 control spans became 2,790 prepared segments). Open-air shells use a 0.75 m floor slab and side walls up to 1.0 m above the floor; there is no roof. Passage interior remains higher priority than shell. The second design constrained the floor route to a 14.5° grade ceiling.
+
+The per-tile candidate lists were not measured. The 310→2,790 figures are prepared route segment counts, not tile candidate list sizes.
+
+## Speed
+
+L109 medians below are the candidate column from the saved five-pair timing matrix. L111 timing was not run after the audits failed.
+
+| Stratum | L109 W8 near-ready (s) | L109 W12 near-ready (s) | L111 W8/W12 |
+|---|---:|---:|---|
+| SurfaceWorld | 0.737 | 0.761 | Not run |
+| FloatingIslands | 0.911 | 0.863 | Not run |
+| TunnelNetwork | 0.956 | 0.895 | Not run |
+| VerticalShafts | 0.789 | 0.738 | Not run |
+
+## Audits
+
+- Clang standalone build completed. The second design removed all grade failures. Passage 0–1 still had 2 unsupported walk samples; passages 1–2 and 2–3 passed. The combined resolved-passage audit failed.
+- Mouth-profile audits passed 3/3. Naturalness and ripple audits passed 2/3.
+- The half-pipe shell audit passed 2/3; passage 0–1 reported 11,544 floor and 6,945 wall violations. A targeted trace showed at least one reported floor sample was 0.101 m inside the passage after relief, where interior correctly overrides the shell. The audit's smooth-route overlap model still disagreed at that point, so the remaining shell counts are not conclusive.
+- Fast tier, Clang/GCC W1/W8/W12 hash matrix, readiness timing, and Unreal Linux build were not run. Canonical v218 hashes were not generated.
+
+## Captures
+
+No Linux111 capture images were generated. Mouths, 25/50/75% stations, open-air sections, and programmatically verified 4 m outside/interior close-ups remain outstanding.
+
+The candidate audit found these open-air sections:
+
+- passage 0–1: 6.408–16.782 m; 19.500–24.439 m; 1,044.046–1,498.708 m
+- passage 1–2: 81.654–85.646 m; 104.092–104.829 m
+- passage 2–3: 7.701–26.008 m; 372.697–377.363 m
+
+## Failed attempts
+
+1. Dense spline plus half-pipe: walk grades exceeded 15° and passage 0–1 failed shell, naturalness, and ripple checks.
+2. Dense spline plus a grade-limited floor: grade failures cleared, but passage 0–1 retained 2 unsupported walk samples and its shell/naturalness/ripple audits still failed. Work stopped after this second design as requested.
+
+Logs: `Saved/Linux/l111/build-clang.log` and `Saved/Linux/l111/audit-owner.log`.

Standalone/Source/StreamBenchmarkPipeline.h

@@ -3,6 +3,7 @@
 #include "OwnerWorldLoader.h"
 #include "StreamingWorld.h"
 #include "LinuxScreenSpaceGate.h"
+#include "../Core/src/VoxelForgeFieldShared.h"
 
 #include <algorithm>
 #include <array>
@@ -2967,6 +2968,52 @@ namespace StandaloneStreamBenchmark
             const auto qToMetres=[&](std::int64_t q)
             {return static_cast<double>(q)*World.CoreVoxelSizeMicrons
                 /(VoxelForgeCore::WorldAssemblySubvoxelsPerVoxel*1000000.0);};
+            const auto passageSplineControl=[&](
+                const VoxelForgeCore::ResolvedLayoutPassageV1& passage,std::size_t index)
+            {
+                const auto& point=passage.controlPoints[index];
+                return std::array<double,4>{qToMetres(point.positionSubvoxels[0]),
+                    qToMetres(point.positionSubvoxels[1]),
+                    qToMetres(point.positionSubvoxels[2]),
+                    qToMetres(point.radiusSubvoxels)};
+            };
+            const auto passageSplineKnotSpan=[](const std::array<double,4>& a,
+                const std::array<double,4>& b)
+            {
+                const double dx=b[0]-a[0],dy=b[1]-a[1],dz=b[2]-a[2];
+                return std::max(1.0e-6,std::sqrt(std::sqrt(dx*dx+dy*dy+dz*dz)));
+            };
+            const auto passageSplinePoint=[&](
+                const VoxelForgeCore::ResolvedLayoutPassageV1& passage,
+                std::size_t span,double t)
+            {
+                const auto p0=passageSplineControl(passage,span==0?0:span-1);
+                const auto p1=passageSplineControl(passage,span);
+                const auto p2=passageSplineControl(passage,span+1);
+                const auto p3=passageSplineControl(passage,
+                    std::min(span+2,passage.controlPoints.size()-1));
+                const double dt0=passageSplineKnotSpan(p0,p1);
+                const double dt1=passageSplineKnotSpan(p1,p2);
+                const double dt2=passageSplineKnotSpan(p2,p3);
+                const double t2=t*t,t3=t2*t;
+                std::array<double,4> result{};
+                for(std::size_t axis=0;axis<4;++axis)
+                {
+                    const double m1=dt1*((p1[axis]-p0[axis])/dt0
+                        -(p2[axis]-p0[axis])/(dt0+dt1)
+                        +(p2[axis]-p1[axis])/dt1);
+                    const double m2=dt1*((p2[axis]-p1[axis])/dt1
+                        -(p3[axis]-p1[axis])/(dt1+dt2)
+                        +(p3[axis]-p2[axis])/dt2);
+                    result[axis]=(2.0*t3-3.0*t2+1.0)*p1[axis]
+                        +(-2.0*t3+3.0*t2)*p2[axis]
+                        +(t3-2.0*t2+t)*m1+(t3-t2)*m2;
+                }
+                result[3]=std::clamp(result[3],std::min(p1[3],p2[3]),
+                    std::max(p1[3],p2[3]));
+                return result;
+            };
+            constexpr std::size_t PassageSplineArcSteps=32;
             const auto passageBodyFloorDepth=[&](
                 const VoxelForgeCore::ResolvedLayoutPassageV1& passage)
             {
@@ -2976,12 +3023,19 @@ namespace StandaloneStreamBenchmark
                 std::vector<double> distances(routeEnd+1,0.0);
                 for(std::size_t i=1;i<=routeEnd;++i)
                 {
-                    const auto& a=passage.controlPoints[i-1].positionSubvoxels;
-                    const auto& b=passage.controlPoints[i].positionSubvoxels;
-                    const double dx=qToMetres(b[0]-a[0]);
-                    const double dy=qToMetres(b[1]-a[1]);
-                    const double dz=qToMetres(b[2]-a[2]);
-                    distances[i]=distances[i-1]+std::sqrt(dx*dx+dy*dy+dz*dz);
+                    auto previous=passageSplinePoint(passage,i-1,0.0);
+                    double spanLength=0.0;
+                    for(std::size_t step=1;step<=PassageSplineArcSteps;++step)
+                    {
+                        const auto current=passageSplinePoint(passage,i-1,
+                            static_cast<double>(step)/PassageSplineArcSteps);
+                        const double dx=current[0]-previous[0];
+                        const double dy=current[1]-previous[1];
+                        const double dz=current[2]-previous[2];
+                        spanLength+=std::sqrt(dx*dx+dy*dy+dz*dz);
+                        previous=current;
+                    }
+                    distances[i]=distances[i-1]+spanLength;
                 }
                 double minimumRadius=std::numeric_limits<double>::infinity();
                 double minimumBodyRadius=minimumRadius;
@@ -3007,8 +3061,23 @@ namespace StandaloneStreamBenchmark
                 const double lower=qToMetres(
                     passage.controlPoints[routeEnd].positionSubvoxels[2]
                         -passage.lowerMouthSubvoxels[2])+1.13;
-                return std::array<double,2>{{std::max(0.0,upper),
-                    std::max(0.0,lower)}};
+                double lowerDepth=std::max(0.0,lower);
+                const auto nativeCaveMouth=std::find_if(ResolvedLayout->cavernEdges.begin(),
+                    ResolvedLayout->cavernEdges.end(),[&](const auto& edge)
+                    {
+                        return edge.strateIndex==passage.lowerStrateIndex
+                            &&edge.startAnchorStableId==passage.stableId+"/lower-mouth"
+                            &&!edge.polylineMicrometres.empty();
+                    });
+                if(nativeCaveMouth!=ResolvedLayout->cavernEdges.end())
+                {
+                    const double routeFloor=qToMetres(
+                        passage.controlPoints[routeEnd].positionSubvoxels[2]);
+                    const double nativeFloor=static_cast<double>(
+                        nativeCaveMouth->polylineMicrometres.front()[2])/1000000.0;
+                    lowerDepth=std::max(0.0,routeFloor-nativeFloor);
+                }
+                return std::array<double,2>{{std::max(0.0,upper),lowerDepth}};
             };
             const auto passageFloorDepthAt=[](double alongMetres,double totalMetres,
                 double radiusMetres,double bodyDepthMetres,double upperMouthDepth,
@@ -3040,12 +3109,19 @@ namespace StandaloneStreamBenchmark
                 if(passage.controlPoints.size()<2)return distances;
                 for(std::size_t i=1;i<passage.controlPoints.size();++i)
                 {
-                    const auto& a=passage.controlPoints[i-1].positionSubvoxels;
-                    const auto& b=passage.controlPoints[i].positionSubvoxels;
-                    const double dx=qToMetres(b[0]-a[0]);
-                    const double dy=qToMetres(b[1]-a[1]);
-                    const double dz=qToMetres(b[2]-a[2]);
-                    distances[i]=distances[i-1]+std::sqrt(dx*dx+dy*dy+dz*dz);
+                    auto previous=passageSplinePoint(passage,i-1,0.0);
+                    double spanLength=0.0;
+                    for(std::size_t step=1;step<=PassageSplineArcSteps;++step)
+                    {
+                        const auto current=passageSplinePoint(passage,i-1,
+                            static_cast<double>(step)/PassageSplineArcSteps);
+                        const double dx=current[0]-previous[0];
+                        const double dy=current[1]-previous[1];
+                        const double dz=current[2]-previous[2];
+                        spanLength+=std::sqrt(dx*dx+dy*dy+dz*dz);
+                        previous=current;
+                    }
+                    distances[i]=distances[i-1]+spanLength;
                 }
                 return distances;
             };
@@ -3063,76 +3139,234 @@ namespace StandaloneStreamBenchmark
                 return qToMetres(point.positionSubvoxels[2])-routeFloorDepth
                     +passageTubeDepthAt(radius,bodyDepth);
             };
+            struct FPassageAuditRoutePoint
+            {
+                double x=0.0,y=0.0,z=0.0,radius=0.0,distance=0.0;
+                std::size_t segmentIndex=0;
+            };
+            const auto passageSmoothRoute=[&](
+                const VoxelForgeCore::ResolvedLayoutPassageV1& passage,
+                double bodyDepth,const std::array<double,2>& mouthFloorDepths)
+            {
+                std::vector<FPassageAuditRoutePoint> route;
+                if(passage.controlPoints.size()<2)return route;
+                const std::size_t routeEnd=std::clamp<std::size_t>(
+                    passage.lowerMouthControlIndex,1,passage.controlPoints.size()-1);
+                constexpr double AuditRouteSpacingMetres=1.0;
+                auto previous=passageSplinePoint(passage,0,0.0);
+                route.push_back({previous[0],previous[1],previous[2],previous[3],0.0,0});
+                double distance=0.0;
+                for(std::size_t span=0;span<routeEnd;++span)
+                {
+                    std::array<double,PassageSplineArcSteps+1> arcLength{};
+                    auto arcPrevious=passageSplinePoint(passage,span,0.0);
+                    for(std::size_t step=1;step<=PassageSplineArcSteps;++step)
+                    {
+                        const auto current=passageSplinePoint(passage,span,
+                            static_cast<double>(step)/PassageSplineArcSteps);
+                        const double dx=current[0]-arcPrevious[0];
+                        const double dy=current[1]-arcPrevious[1];
+                        const double dz=current[2]-arcPrevious[2];
+                        arcLength[step]=arcLength[step-1]
+                            +std::sqrt(dx*dx+dy*dy+dz*dz);
+                        arcPrevious=current;
+                    }
+                    const double spanLength=arcLength.back();
+                    const std::size_t steps=std::max<std::size_t>(1,
+                        static_cast<std::size_t>(std::ceil(
+                            spanLength/AuditRouteSpacingMetres)));
+                    for(std::size_t sample=1;sample<=steps;++sample)
+                    {
+                        const double targetArc=spanLength*static_cast<double>(sample)/steps;
+                        const auto upper=std::lower_bound(arcLength.begin()+1,
+                            arcLength.end(),targetArc);
+                        const std::size_t upperIndex=static_cast<std::size_t>(
+                            upper-arcLength.begin());
+                        const std::size_t lowerIndex=upperIndex-1;
+                        const double arcSpan=arcLength[upperIndex]-arcLength[lowerIndex];
+                        const double arcT=arcSpan>1.0e-12
+                            ?std::clamp((targetArc-arcLength[lowerIndex])/arcSpan,0.0,1.0):0.0;
+                        const double t=(static_cast<double>(lowerIndex)+arcT)
+                            /PassageSplineArcSteps;
+                        const auto current=passageSplinePoint(passage,span,t);
+                        const double dx=current[0]-previous[0];
+                        const double dy=current[1]-previous[1];
+                        const double dz=current[2]-previous[2];
+                        distance+=std::sqrt(dx*dx+dy*dy+dz*dz);
+                        route.push_back({current[0],current[1],current[2],current[3],
+                            distance,span+1});
+                        previous=current;
+                    }
+                }
+                const double totalLength=route.empty()?0.0:route.back().distance;
+                std::vector<double> desiredFloor(route.size());
+                std::vector<double> horizontalGradeLimits(route.size()>0?route.size()-1:0);
+                std::vector<double> remainingGradeAllowance(route.size(),0.0);
+                constexpr double MaximumWalkGradeTangent=0.2586407821;
+                for(std::size_t i=0;i<route.size();++i)
+                {
+                    const double routeDepth=passageFloorDepthAt(route[i].distance,totalLength,
+                        route[i].radius,bodyDepth,mouthFloorDepths[0],mouthFloorDepths[1]);
+                    desiredFloor[i]=route[i].z-routeDepth;
+                    if(i+1<route.size())
+                    {
+                        const double dx=route[i+1].x-route[i].x;
+                        const double dy=route[i+1].y-route[i].y;
+                        horizontalGradeLimits[i]=MaximumWalkGradeTangent
+                            *std::hypot(dx,dy);
+                    }
+                }
+                for(std::size_t i=horizontalGradeLimits.size();i>0;--i)
+                    remainingGradeAllowance[i-1]=remainingGradeAllowance[i]
+                        +horizontalGradeLimits[i-1];
+                if(route.size()>1)
+                {
+                    std::vector<double> walkableFloor(route.size());
+                    walkableFloor.front()=desiredFloor.front();
+                    walkableFloor.back()=desiredFloor.back();
+                    for(std::size_t i=1;i+1<route.size();++i)
+                    {
+                        const double limit=horizontalGradeLimits[i-1];
+                        const double remaining=remainingGradeAllowance[i];
+                        const double low=std::max(walkableFloor[i-1]-limit,
+                            walkableFloor.back()-remaining);
+                        const double high=std::min(walkableFloor[i-1]+limit,
+                            walkableFloor.back()+remaining);
+                        walkableFloor[i]=std::clamp(desiredFloor[i],low,high);
+                    }
+                    for(std::size_t i=0;i<route.size();++i)
+                        route[i].z=walkableFloor[i]
+                            +passageTubeDepthAt(route[i].radius,bodyDepth);
+                }
+                return route;
+            };
             std::vector<std::vector<double>> allPassageRouteDistances;
             std::vector<double> allPassageBodyFloorDepths;
+            std::vector<std::vector<FPassageAuditRoutePoint>> allPassageSmoothRoutes;
             allPassageRouteDistances.reserve(ResolvedLayout->passages.size());
             allPassageBodyFloorDepths.reserve(ResolvedLayout->passages.size());
+            allPassageSmoothRoutes.reserve(ResolvedLayout->passages.size());
             for(const auto& passage:ResolvedLayout->passages)
             {
                 allPassageRouteDistances.push_back(passageRouteDistances(passage));
-                allPassageBodyFloorDepths.push_back(passageBodyFloorDepth(passage));
+                const double bodyDepth=passageBodyFloorDepth(passage);
+                allPassageBodyFloorDepths.push_back(bodyDepth);
+                allPassageSmoothRoutes.push_back(passageSmoothRoute(passage,bodyDepth,
+                    passageMouthFloorDepths(passage)));
             }
+            const auto interpolatePassageRoute=[](
+                const std::vector<FPassageAuditRoutePoint>& route,double distance)
+            {
+                if(route.empty())return FPassageAuditRoutePoint{};
+                distance=std::clamp(distance,0.0,route.back().distance);
+                const auto upper=std::lower_bound(route.begin()+1,route.end(),distance,
+                    [](const FPassageAuditRoutePoint& point,double value)
+                    {return point.distance<value;});
+                const auto& b=*upper;
+                const auto& a=*(upper-1);
+                const double span=b.distance-a.distance;
+                const double t=span>1.0e-9?(distance-a.distance)/span:0.0;
+                return FPassageAuditRoutePoint{
+                    std::lerp(a.x,b.x,t),std::lerp(a.y,b.y,t),std::lerp(a.z,b.z,t),
+                    std::lerp(a.radius,b.radius,t),distance,b.segmentIndex};
+            };
             const auto passageInteriorWinsAt=[&](double xMetres,double yMetres,
                 double zMetres,std::size_t ignoredPassage=std::numeric_limits<std::size_t>::max(),
                 std::size_t ignoredSegment=std::numeric_limits<std::size_t>::max())
             {
                 constexpr double CornerBlendMetres=0.50;
-                // Relief moves the curved surface by up to 0.21 m. Samples in this
-                // band around another segment's boundary are ambiguous shell overlaps;
-                // the composed union resolves them locally, with interior air winning.
-                constexpr double OverlapBandMetres=0.21;
+                constexpr double WallReliefMetres=0.21;
                 for(std::size_t passageIndex=0;
                     passageIndex<ResolvedLayout->passages.size();++passageIndex)
                 {
                     const auto& passage=ResolvedLayout->passages[passageIndex];
                     if(passage.controlPoints.size()<2)continue;
-                    const std::size_t routeEnd=passage.controlPoints.size()-1;
-                    const auto& distances=allPassageRouteDistances[passageIndex];
-                    const double totalLength=distances[std::clamp<std::size_t>(
-                        passage.lowerMouthControlIndex,1,passage.controlPoints.size()-1)];
+                    const auto& route=allPassageSmoothRoutes[passageIndex];
+                    if(route.size()<2)continue;
                     const double bodyDepth=allPassageBodyFloorDepths[passageIndex];
-                    const auto mouthFloorDepths=passageMouthFloorDepths(passage);
-                    for(std::size_t segment=1;segment<=routeEnd;++segment)
+                    double bestDistance=std::numeric_limits<double>::infinity();
+                    double bestRoundDistance=0.0,bestCenterZ=0.0;
+                    std::size_t bestSegment=std::numeric_limits<std::size_t>::max();
+                    for(std::size_t segment=1;segment<route.size();++segment)
                     {
-                        if(passageIndex==ignoredPassage&&segment==ignoredSegment)continue;
-                        const auto& a=passage.controlPoints[segment-1];
-                        const auto& b=passage.controlPoints[segment];
-                        const double ax=qToMetres(a.positionSubvoxels[0]);
-                        const double ay=qToMetres(a.positionSubvoxels[1]);
-                        const double az=passageEffectiveCenterZ(passage,segment-1,
-                            distances,totalLength,bodyDepth,mouthFloorDepths);
-                        const double dx=qToMetres(b.positionSubvoxels[0]-a.positionSubvoxels[0]);
-                        const double dy=qToMetres(b.positionSubvoxels[1]-a.positionSubvoxels[1]);
-                        const double bz=passageEffectiveCenterZ(passage,segment,
-                            distances,totalLength,bodyDepth,mouthFloorDepths);
-                        const double dz=bz-az;
+                        const auto& a=route[segment-1];
+                        const auto& b=route[segment];
+                        if(passageIndex==ignoredPassage
+                            &&b.segmentIndex==ignoredSegment)continue;
+                        const double dx=b.x-a.x,dy=b.y-a.y,dz=b.z-a.z;
                         const double lengthSquared=dx*dx+dy*dy+dz*dz;
                         if(lengthSquared<=1.0e-12)continue;
-                        const double t=std::clamp(((xMetres-ax)*dx+(yMetres-ay)*dy
-                            +(zMetres-az)*dz)/lengthSquared,0.0,1.0);
-                        const double centerX=ax+t*dx,centerY=ay+t*dy,centerZ=az+t*dz;
-                        const double radius=std::lerp(qToMetres(a.radiusSubvoxels),
-                            qToMetres(b.radiusSubvoxels),t);
+                        const double t=std::clamp(((xMetres-a.x)*dx+(yMetres-a.y)*dy
+                            +(zMetres-a.z)*dz)/lengthSquared,0.0,1.0);
+                        const double centerX=a.x+t*dx,centerY=a.y+t*dy,centerZ=a.z+t*dz;
+                        const double radius=std::lerp(a.radius,b.radius,t);
                         const double horizontalLengthSquared=dx*dx+dy*dy;
                         const double floorT=horizontalLengthSquared>1.0e-12
-                            ?std::clamp(((xMetres-ax)*dx+(yMetres-ay)*dy)
+                            ?std::clamp(((xMetres-a.x)*dx+(yMetres-a.y)*dy)
                                 /horizontalLengthSquared,0.0,1.0):t;
-                        const double floorCenterZ=az+floorT*dz;
-                        const double floorRadius=std::lerp(qToMetres(a.radiusSubvoxels),
-                            qToMetres(b.radiusSubvoxels),floorT);
-                        const double along=distances[segment-1]
-                            +std::sqrt(lengthSquared)*floorT;
+                        const double floorCenterZ=a.z+floorT*dz;
+                        const double floorRadius=std::lerp(a.radius,b.radius,floorT);
                         const double floorDepth=passageTubeDepthAt(floorRadius,bodyDepth);
                         const double roundDistance=std::sqrt((xMetres-centerX)*(xMetres-centerX)
                             +(yMetres-centerY)*(yMetres-centerY)
                             +(zMetres-centerZ)*(zMetres-centerZ))-radius;
-                        const double floorDistance=floorCenterZ-floorDepth-zMetres;
+                        const double floorPlaneZ=floorCenterZ-floorDepth;
+                        const double floorDistance=floorPlaneZ-zMetres;
                         const double h=std::max(CornerBlendMetres-
                             std::abs(roundDistance-floorDistance),0.0)/CornerBlendMetres;
                         const double flatDistance=std::max(roundDistance,floorDistance)
                             +h*h*h*(CornerBlendMetres/6.0);
-                        if(flatDistance<OverlapBandMetres)return true;
+                        if(flatDistance<bestDistance)
+                        {
+                            bestDistance=flatDistance;
+                            bestRoundDistance=roundDistance;
+                            bestCenterZ=centerZ;
+                            bestSegment=segment;
+                        }
                     }
+                    if(bestSegment==std::numeric_limits<std::size_t>::max())continue;
+                    const auto& a=route[bestSegment-1];
+                    const auto& b=route[bestSegment];
+                    const double dx=b.x-a.x,dy=b.y-a.y,dz=b.z-a.z;
+                    const double lengthSquared=dx*dx+dy*dy+dz*dz;
+                    if(lengthSquared<=1.0e-12)continue;
+                    const double t=std::clamp(((xMetres-a.x)*dx+(yMetres-a.y)*dy
+                        +(zMetres-a.z)*dz)/lengthSquared,0.0,1.0);
+                    const double radius=std::lerp(a.radius,b.radius,t);
+                    const double centerX=a.x+t*dx,centerY=a.y+t*dy;
+                    const double centerZ=a.z+t*dz;
+                    const double distanceToCenter=std::max(1.0e-9,
+                        bestRoundDistance+radius);
+                    const double verticalWallAlignment=std::clamp(
+                        -(zMetres-centerZ)/distanceToCenter,0.0,1.0);
+                    const double wallReliefWeight=0.05+0.95
+                        *(1.0-verticalWallAlignment);
+                    const float relief=VF_FieldPassageWallRelief(
+                        static_cast<float>(xMetres/coreMetres),
+                        static_cast<float>(yMetres/coreMetres),
+                        static_cast<float>(zMetres/coreMetres),
+                        static_cast<std::uint32_t>(World.Seed));
+                    const double roughRoundDistance=bestRoundDistance
+                        +static_cast<double>(std::clamp(relief,-1.0f,1.0f))
+                            *WallReliefMetres*wallReliefWeight;
+                    const auto& aFloor=route[bestSegment-1];
+                    const auto& bFloor=route[bestSegment];
+                    const double floorDx=bFloor.x-aFloor.x;
+                    const double floorDy=bFloor.y-aFloor.y;
+                    const double floorDz=bFloor.z-aFloor.z;
+                    const double horizontalSquared=floorDx*floorDx+floorDy*floorDy;
+                    const double floorT=horizontalSquared>1.0e-12
+                        ?std::clamp(((xMetres-aFloor.x)*floorDx
+                            +(yMetres-aFloor.y)*floorDy)/horizontalSquared,0.0,1.0):t;
+                    const double floorRadius=std::lerp(aFloor.radius,bFloor.radius,floorT);
+                    const double floorDepth=passageTubeDepthAt(floorRadius,bodyDepth);
+                    const double floorCenterZ=aFloor.z+floorT*floorDz;
+                    const double floorDistance=floorCenterZ-floorDepth-zMetres;
+                    const double blend=std::max(CornerBlendMetres-
+                        std::abs(roughRoundDistance-floorDistance),0.0)/CornerBlendMetres;
+                    const double shapedDistance=std::max(roughRoundDistance,floorDistance)
+                        +blend*blend*blend*(CornerBlendMetres/6.0);
+                    if(shapedDistance<=0.0)return true;
                 }
                 return false;
             };
@@ -3438,31 +3672,20 @@ namespace StandaloneStreamBenchmark
                     >=PassageProfilePlateauMinimumMetres
                 &&l23TerraceControlResult.second>=PassageProfileStepThresholdMetres;
             const auto auditPassageNaturalness=[&](const VoxelForgeCore::World& Field,
-                const VoxelForgeCore::ResolvedLayoutPassageV1& passage)
+                std::size_t passageIndex)
             {
                 FPassageNaturalnessAudit audit;
-                const std::size_t end=std::min<std::size_t>(passage.lowerMouthControlIndex,
-                    passage.controlPoints.size()-1);
-                const auto routeDistances=passageRouteDistances(passage);
-                const double totalRouteLength=routeDistances.empty()?0.0:
-                    routeDistances[end];
-                const double bodyFloorDepth=passageBodyFloorDepth(passage);
-                const auto mouthFloorDepths=passageMouthFloorDepths(passage);
+                const auto& path=allPassageSmoothRoutes[passageIndex];
+                if(path.size()<3)return audit;
+                const double bodyFloorDepth=allPassageBodyFloorDepths[passageIndex];
                 double flatRun=0.0;
-                for(std::size_t i=1;i<=end;++i)
+                for(std::size_t i=1;i<path.size();++i)
                 {
-                    const auto& a=passage.controlPoints[i-1];
-                    const auto& b=passage.controlPoints[i];
-                    const double dx=qToMetres(b.positionSubvoxels[0]-a.positionSubvoxels[0]);
-                    const double dy=qToMetres(b.positionSubvoxels[1]-a.positionSubvoxels[1]);
-                    const double floorA=qToMetres(a.positionSubvoxels[2])
-                        -passageFloorDepthAt(routeDistances[i-1],totalRouteLength,
-                            qToMetres(a.radiusSubvoxels),bodyFloorDepth,
-                            mouthFloorDepths[0],mouthFloorDepths[1])+1.13;
-                    const double floorB=qToMetres(b.positionSubvoxels[2])
-                        -passageFloorDepthAt(routeDistances[i],totalRouteLength,
-                            qToMetres(b.radiusSubvoxels),bodyFloorDepth,
-                            mouthFloorDepths[0],mouthFloorDepths[1])+1.13;
+                    const auto& a=path[i-1];
+                    const auto& b=path[i];
+                    const double dx=b.x-a.x,dy=b.y-a.y;
+                    const double floorA=a.z-passageTubeDepthAt(a.radius,bodyFloorDepth)+1.13;
+                    const double floorB=b.z-passageTubeDepthAt(b.radius,bodyFloorDepth)+1.13;
                     const double dz=floorB-floorA;
                     const double horizontal=std::hypot(dx,dy);
                     if(horizontal>1.0e-6&&std::abs(dz)/horizontal
@@ -3471,28 +3694,31 @@ namespace StandaloneStreamBenchmark
                         audit.maximumFlatRunMetres,flatRun);}
                     else flatRun=0.0;
                 }
-                if(end>=6)
+                if(path.size()>=8)
                 {
-                    const std::size_t sampleCount=std::min<std::size_t>(64,end-4);
+                    const std::size_t sampleCount=std::min<std::size_t>(64,path.size()-4);
                     double minimumRadius=std::numeric_limits<double>::infinity();
                     double maximumRadius=-std::numeric_limits<double>::infinity();
                     for(std::size_t sample=0;sample<sampleCount;++sample)
                     {
-                        const std::size_t index=2+(sample*(end-4))
+                        const std::size_t index=2+(sample*(path.size()-5))
                             /std::max<std::size_t>(1,sampleCount-1);
-                        const auto& point=passage.controlPoints[index];
-                        const auto& before=passage.controlPoints[index-1];
-                        const auto& after=passage.controlPoints[index+1];
-                        const double tangentX=qToMetres(after.positionSubvoxels[0]-before.positionSubvoxels[0]);
-                        const double tangentY=qToMetres(after.positionSubvoxels[1]-before.positionSubvoxels[1]);
+                        const auto& point=path[index];
+                        const auto& before=path[index-1];
+                        const auto& after=path[index+1];
+                        const double tangentX=after.x-before.x;
+                        const double tangentY=after.y-before.y;
                         const double tangentLength=std::hypot(tangentX,tangentY);
                         if(tangentLength<=1.0e-6){++audit.missingWallSamples;continue;}
-                        const double radiusMetres=qToMetres(point.radiusSubvoxels);
-                        const double sampleRadius=std::max(0.20,radiusMetres-0.18);
-                        const double centerX=qToMetres(point.positionSubvoxels[0]);
-                        const double centerY=qToMetres(point.positionSubvoxels[1]);
-                        const double centerZ=passageEffectiveCenterZ(passage,index,
-                            routeDistances,totalRouteLength,bodyFloorDepth,mouthFloorDepths);
+                        constexpr double WallProbeHeightMetres=0.75;
+                        const double floorDepth=passageTubeDepthAt(point.radius,bodyFloorDepth);
+                        const double vertical=WallProbeHeightMetres-floorDepth;
+                        const double wallRadiusSquared=point.radius*point.radius-vertical*vertical;
+                        if(wallRadiusSquared<=0.0){audit.missingWallSamples+=2;continue;}
+                        const double sampleRadius=std::max(0.20,
+                            std::sqrt(wallRadiusSquared)-0.18);
+                        const double centerX=point.x,centerY=point.y;
+                        const double centerZ=point.z-floorDepth+WallProbeHeightMetres;
                         const double nx=-tangentY/tangentLength,ny=tangentX/tangentLength;
                         for(const double side:{-1.0,1.0})
                         {
@@ -3523,7 +3749,6 @@ namespace StandaloneStreamBenchmark
                 return audit;
             };
             const auto auditPassageRipples=[&](const VoxelForgeCore::World& Field,
-                const VoxelForgeCore::ResolvedLayoutPassageV1& passage,
                 std::size_t passageIndex)
             {
                 FPassageRippleAudit audit;
@@ -3539,33 +3764,16 @@ namespace StandaloneStreamBenchmark
                     double x=0.0,y=0.0,z=0.0,radius=0.0,distance=0.0;
                     std::size_t segmentIndex=0;
                 };
-                const std::size_t end=std::min<std::size_t>(passage.lowerMouthControlIndex,
-                    passage.controlPoints.size()-1);
-                if(end<2)return audit;
-                const auto routeDistances=passageRouteDistances(passage);
-                const double totalRouteLength=routeDistances.empty()?0.0:
-                    routeDistances[end];
-                const double bodyFloorDepth=passageBodyFloorDepth(passage);
-                const auto mouthFloorDepths=passageMouthFloorDepths(passage);
+                const auto& passage=ResolvedLayout->passages[passageIndex];
+                const auto& smoothRoute=allPassageSmoothRoutes[passageIndex];
+                if(smoothRoute.size()<2)return audit;
+                const double bodyFloorDepth=allPassageBodyFloorDepths[passageIndex];
                 std::vector<FPathPoint> path;
-                path.reserve(end+1);
-                for(std::size_t i=0;i<=end;++i)
+                path.reserve(smoothRoute.size());
+                for(const auto& point:smoothRoute)
                 {
-                    const auto& point=passage.controlPoints[i];
-                    FPathPoint value{qToMetres(point.positionSubvoxels[0]),
-                        qToMetres(point.positionSubvoxels[1]),
-                        passageEffectiveCenterZ(passage,i,routeDistances,
-                            totalRouteLength,bodyFloorDepth,mouthFloorDepths),
-                        qToMetres(point.radiusSubvoxels),0.0,i==0?1:i};
-                    if(!path.empty())
-                    {
-                        const auto& previous=path.back();
-                        value.distance=previous.distance+std::sqrt(
-                            (value.x-previous.x)*(value.x-previous.x)
-                            +(value.y-previous.y)*(value.y-previous.y)
-                            +(value.z-previous.z)*(value.z-previous.z));
-                    }
-                    path.push_back(value);
+                    path.push_back({point.x,point.y,point.z,point.radius,
+                        point.distance,point.segmentIndex});
                 }
                 const double total=path.back().distance;
                 if(total<WindowLengthMetres)return audit;
@@ -3973,51 +4181,31 @@ namespace StandaloneStreamBenchmark
                 {
                     const auto& passage=ResolvedLayout->passages[passageIndex];
                     if(passage.controlPoints.size()<2)continue;
-                    const std::size_t routeEnd=std::clamp<std::size_t>(
-                        passage.lowerMouthControlIndex,1,passage.controlPoints.size()-1);
-                    const auto& distances=allPassageRouteDistances[passageIndex];
-                    const double totalLength=distances[std::clamp<std::size_t>(
-                        passage.lowerMouthControlIndex,1,passage.controlPoints.size()-1)];
                     const double bodyDepth=allPassageBodyFloorDepths[passageIndex];
-                    const auto mouthFloorDepths=passageMouthFloorDepths(passage);
+                    const auto& path=allPassageSmoothRoutes[passageIndex];
+                    if(path.size()<2)continue;
+                    const double totalLength=path.back().distance;
                     double bestFlatDistance=std::numeric_limits<double>::infinity();
                     double bestFloorDistance=0.0,bestMouthDistance=0.0;
-                    for(std::size_t segment=0;segment<routeEnd;++segment)
+                    for(std::size_t segment=1;segment<path.size();++segment)
                     {
-                        const auto& a=passage.controlPoints[segment];
-                        const auto& b=passage.controlPoints[segment+1];
-                        const double ax=qToMetres(a.positionSubvoxels[0]);
-                        const double ay=qToMetres(a.positionSubvoxels[1]);
-                        const double az=passageEffectiveCenterZ(passage,segment,
-                            distances,totalLength,bodyDepth,mouthFloorDepths);
-                        const double dx=qToMetres(b.positionSubvoxels[0]-a.positionSubvoxels[0]);
-                        const double dy=qToMetres(b.positionSubvoxels[1]-a.positionSubvoxels[1]);
-                        const double bz=passageEffectiveCenterZ(passage,segment+1,
-                            distances,totalLength,bodyDepth,mouthFloorDepths);
-                        const double dz=bz-az;
+                        const auto& a=path[segment-1];
+                        const auto& b=path[segment];
+                        const double ax=a.x,ay=a.y,az=a.z;
+                        const double dx=b.x-a.x,dy=b.y-a.y,dz=b.z-a.z;
                         const double lengthSquared=dx*dx+dy*dy+dz*dz;
                         if(lengthSquared<=1.0e-12)continue;
                         const double t=std::clamp(((xMetres-ax)*dx+(yMetres-ay)*dy
                             +(zMetres-az)*dz)/lengthSquared,0.0,1.0);
                         const double centerX=ax+t*dx,centerY=ay+t*dy,centerZ=az+t*dz;
-                        const double radius=std::lerp(qToMetres(a.radiusSubvoxels),
-                            qToMetres(b.radiusSubvoxels),t);
+                        const double radius=std::lerp(a.radius,b.radius,t);
                         const double horizontalSquared=dx*dx+dy*dy;
                         const double floorT=horizontalSquared>1.0e-12
                             ?std::clamp(((xMetres-ax)*dx+(yMetres-ay)*dy)
                                 /horizontalSquared,0.0,1.0):t;
-                        const double floorRadius=std::lerp(qToMetres(a.radiusSubvoxels),
-                            qToMetres(b.radiusSubvoxels),floorT);
-                        const double floorAlong=distances[segment]
-                            +(distances[segment+1]-distances[segment])*floorT;
-                        const double floorCenterZ=std::lerp(
-                            qToMetres(a.positionSubvoxels[2]),
-                            qToMetres(b.positionSubvoxels[2]),floorT)
-                            -passageFloorDepthAt(floorAlong,totalLength,floorRadius,
-                                bodyDepth,mouthFloorDepths[0],mouthFloorDepths[1])
-                            +passageTubeDepthAt(floorRadius,bodyDepth);
-                        const double along=distances[segment]
-                            +(distances[segment+1]-distances[segment])*t;
+                        const double floorRadius=std::lerp(a.radius,b.radius,floorT);
+                        const double floorCenterZ=std::lerp(a.z,b.z,floorT);
+                        const double along=std::lerp(a.distance,b.distance,t);
                         const double floorDepth=passageTubeDepthAt(floorRadius,bodyDepth);
                         const double roundDistance=std::sqrt((xMetres-centerX)*(xMetres-centerX)
                             +(yMetres-centerY)*(yMetres-centerY)
@@ -4045,7 +4233,11 @@ namespace StandaloneStreamBenchmark
                     const double fade=std::clamp(bestMouthDistance/5.0,0.0,1.0);
                     const double smoothFade=fade*fade*(3.0-2.0*fade);
                     const double floorBlend=smoothstep(bestFloorDistance/0.25);
-                    const double thickness=0.75*std::max(smoothFade,floorBlend);
+                    const double wallElevation=-bestFloorDistance;
+                    const double wallThickness=wallElevation>=0.0&&wallElevation<=1.0
+                        ?smoothFade:0.0;
+                    const double floorThickness=smoothFade*floorBlend;
+                    const double thickness=0.75*std::max(wallThickness,floorThickness);
                     if(bestFlatDistance+ReliefBoundMetres<thickness)expectedSolid=true;
                     else if(bestFlatDistance-ReliefBoundMetres<thickness)ambiguous=true;
                     else if(bestMouthDistance<5.0)mouthBlend=true;
@@ -4056,19 +4248,18 @@ namespace StandaloneStreamBenchmark
             };
             const auto auditPassageShell=[&](const VoxelForgeCore::World& Field,
                 const VoxelForgeCore::World& Native,
-                const VoxelForgeCore::ResolvedLayoutPassageV1& passage)
+                const VoxelForgeCore::ResolvedLayoutPassageV1& passage,
+                std::size_t passageIndex)
             {
                 FPassageShellAudit audit;
-                if(passage.controlPoints.size()<2)return audit;
-                const std::size_t routeEnd=std::clamp<std::size_t>(
-                    passage.lowerMouthControlIndex,1,passage.controlPoints.size()-1);
-                const std::size_t geometryEnd=passage.controlPoints.size()-1;
-                const auto routeDistances=passageRouteDistances(passage);
-                const double totalRouteLength=routeDistances[std::clamp<std::size_t>(
-                    passage.lowerMouthControlIndex,1,passage.controlPoints.size()-1)];
-                const double bodyFloorDepth=passageBodyFloorDepth(passage);
-                const auto mouthFloorDepths=passageMouthFloorDepths(passage);
-                const auto expectedShellThickness=[&](double along,double floorDistance)
+                const auto& route=allPassageSmoothRoutes[passageIndex];
+                if(route.size()<2)return audit;
+                const double totalRouteLength=route.back().distance;
+                const double bodyFloorDepth=allPassageBodyFloorDepths[passageIndex];
+                constexpr std::array<std::array<double,2>,5> floorOffsets{{
+                    {{0.0,0.0}},{{0.30,0.0}},{{-0.30,0.0}},
+                    {{0.0,0.30}},{{0.0,-0.30}}}};
+                const auto expectedFloorThickness=[&](double along,double floorDistance)
                 {
                     const double mouthDistance=std::max(0.0,std::min(along,
                         totalRouteLength-along));
@@ -4077,43 +4268,27 @@ namespace StandaloneStreamBenchmark
                     const double floorBlend=std::clamp(floorDistance/0.25,0.0,1.0);
                     const double smoothFloorBlend=floorBlend*floorBlend
                         *(3.0-2.0*floorBlend);
-                    const double extensionFade=std::clamp(1.0
-                        -(along-totalRouteLength)/5.0,0.0,1.0);
-                    const double smoothExtensionFade=extensionFade*extensionFade
-                        *(3.0-2.0*extensionFade);
-                    return 0.75*std::max(smoothFade,
-                        smoothFloorBlend*smoothExtensionFade);
+                    return 0.75*smoothFade*smoothFloorBlend;
                 };
-                constexpr std::array<std::array<double,2>,5> floorOffsets{{
-                    {{0.0,0.0}},{{0.30,0.0}},{{-0.30,0.0}},{{0.0,0.30}},{{0.0,-0.30}}}};
-                for(std::size_t segment=1;segment<=geometryEnd;++segment)
+                for(std::size_t segment=1;segment<route.size();++segment)
                 {
-                    const auto& a=passage.controlPoints[segment-1];
-                    const auto& b=passage.controlPoints[segment];
-                    const double ax=qToMetres(a.positionSubvoxels[0]);
-                    const double ay=qToMetres(a.positionSubvoxels[1]);
-                    const double az=passageEffectiveCenterZ(passage,segment-1,
-                        routeDistances,totalRouteLength,bodyFloorDepth,mouthFloorDepths);
-                    const double bx=qToMetres(b.positionSubvoxels[0]);
-                    const double by=qToMetres(b.positionSubvoxels[1]);
-                    const double bz=passageEffectiveCenterZ(passage,segment,
-                        routeDistances,totalRouteLength,bodyFloorDepth,mouthFloorDepths);
-                    const double dx=bx-ax,dy=by-ay,dz=bz-az;
+                    const auto& a=route[segment-1];
+                    const auto& b=route[segment];
+                    const double dx=b.x-a.x,dy=b.y-a.y,dz=b.z-a.z;
                     const double length=std::sqrt(dx*dx+dy*dy+dz*dz);
-                    const double authoredSegmentLength=routeDistances[segment]
-                        -routeDistances[segment-1];
+                    const double alongLength=b.distance-a.distance;
                     const std::size_t intervals=std::max<std::size_t>(1,
-                        static_cast<std::size_t>(std::ceil(length/PassageShellAuditSpacingMetres)));
-                    for(std::size_t sampleIndex=0;sampleIndex<=intervals;++sampleIndex)
+                        static_cast<std::size_t>(std::ceil(
+                            length/PassageShellAuditSpacingMetres)));
+                    for(std::size_t sampleIndex=segment==1?0:1;
+                        sampleIndex<=intervals;++sampleIndex)
                     {
-                        if(segment>1&&sampleIndex==0)continue;
                         const double t=static_cast<double>(sampleIndex)/intervals;
-                        const double centerX=ax+dx*t,centerY=ay+dy*t,centerZ=az+dz*t;
-                        const double along=routeDistances[segment-1]
-                            +authoredSegmentLength*t;
-                        const double radius=std::lerp(qToMetres(a.radiusSubvoxels),
-                            qToMetres(b.radiusSubvoxels),t);
-                    if(std::min(along,totalRouteLength-along)>0.0)
+                        const double centerX=a.x+dx*t,centerY=a.y+dy*t,centerZ=a.z+dz*t;
+                        const double along=a.distance+alongLength*t;
+                        const double radius=std::lerp(a.radius,b.radius,t);
+                        if(std::min(along,totalRouteLength-along)>0.0)
+                        {
                             for(const auto& offset:floorOffsets)
                             for(const double depth:PassageShellAuditDepthsMetres)
                             {
@@ -4121,44 +4296,30 @@ namespace StandaloneStreamBenchmark
                                 const double sampleX=centerX+offset[0];
                                 const double sampleY=centerY+offset[1];
                                 const double floorT=horizontalLengthSquared>1.0e-12
-                                    ?std::clamp(((sampleX-ax)*dx+(sampleY-ay)*dy)
+                                    ?std::clamp(((sampleX-a.x)*dx+(sampleY-a.y)*dy)
                                         /horizontalLengthSquared,0.0,1.0):t;
-                                const double floorAlong=routeDistances[segment-1]
-                                    +authoredSegmentLength*floorT;
-                                const double floorRadius=std::lerp(
-                                    qToMetres(a.radiusSubvoxels),
-                                    qToMetres(b.radiusSubvoxels),floorT);
-                        const double floorCenterZ=segment<=routeEnd
-                            ?std::lerp(qToMetres(a.positionSubvoxels[2]),
-                                qToMetres(b.positionSubvoxels[2]),floorT)
-                                -passageFloorDepthAt(floorAlong,totalRouteLength,
-                                    floorRadius,bodyFloorDepth,mouthFloorDepths[0],
-                                    mouthFloorDepths[1])
-                                +passageTubeDepthAt(floorRadius,bodyFloorDepth)
-                            :az+floorT*dz;
+                                const double floorAlong=a.distance+alongLength*floorT;
+                                const double floorRadius=std::lerp(a.radius,b.radius,floorT);
+                                const double floorCenterZ=std::lerp(a.z,b.z,floorT);
                                 const double floorDepth=passageTubeDepthAt(floorRadius,
                                     bodyFloorDepth);
                                 const double floorZ=floorCenterZ-floorDepth;
                                 const VoxelForgeCore::Vec3d position{
-                                    sampleX/coreMetres,
-                                    sampleY/coreMetres,
+                                    sampleX/coreMetres,sampleY/coreMetres,
                                     (floorZ-depth)/coreMetres};
                                 const double sampleZ=floorZ-depth;
-                                if(passageInteriorWinsAt(sampleX,sampleY,sampleZ,
-                                    static_cast<std::size_t>(&passage-
-                                        ResolvedLayout->passages.data()),segment))
+                                if(passageInteriorWinsAt(sampleX,sampleY,sampleZ))
                                 {
                                     ++audit.floorInteriorWins;
                                     continue;
                                 }
                                 ++audit.floorSamples;
-                                const float nativeFloor=Native.densityAt(position);
-                                if(nativeFloor>=0.0f)
+                                if(Native.densityAt(position)>=0.0f)
                                 {
                                     ++audit.openAirSamples;
                                     audit.openAirDistancesMetres.push_back(along);
                                     const bool shellExpected=depth+0.011
-                                        <expectedShellThickness(along,depth);
+                                        <expectedFloorThickness(along,depth);
                                     const float density=Field.densityAt(position);
                                     if((shellExpected&&density>=0.0f)
                                         ||(!shellExpected&&density<0.0f))
@@ -4166,64 +4327,68 @@ namespace StandaloneStreamBenchmark
                                         ++audit.floorViolations;
                                         if(audit.firstViolationCount<audit.firstViolations.size())
                                             audit.firstViolations[audit.firstViolationCount++]={
-                                                centerX+offset[0],centerY+offset[1],floorZ-depth,density};
-                                    }
-                                }
-                            }
-                        const double tangentLength=std::hypot(dx,dy);
-                        if(tangentLength>1.0e-6)
-                        {
-                            if(std::min(along,totalRouteLength-along)<5.0)
-                            {
-                                audit.wallMouthBlendSkips+=5;
-                                continue;
-                            }
-                            const double nx=-dy/tangentLength,ny=dx/tangentLength;
-                            const std::array<std::array<double,3>,5> wallDirections{{
-                                {{0.0,0.0,1.0}},
-                                {{-0.7071067811865475*nx,-0.7071067811865475*ny,
-                                    0.7071067811865475}},
-                                {{0.7071067811865475*nx,0.7071067811865475*ny,
-                                    0.7071067811865475}},
-                                {{-nx,-ny,0.0}},{{nx,ny,0.0}}}};
-                            for(const auto& direction:wallDirections)
-                            {
-                                const double sampleX=centerX+direction[0]*(radius+0.375);
-                                const double sampleY=centerY+direction[1]*(radius+0.375);
-                                const double sampleZ=centerZ+direction[2]*(radius+0.375);
-                                const VoxelForgeCore::Vec3d wallPosition{sampleX/coreMetres,
-                                    sampleY/coreMetres,sampleZ/coreMetres};
-                                const bool wallInteriorWins=passageInteriorWinsAt(sampleX,
-                                    sampleY,sampleZ,static_cast<std::size_t>(&passage-
-                                        ResolvedLayout->passages.data()),segment);
-                                if(wallInteriorWins)++audit.wallInteriorWins;
-                                else if(Native.densityAt(wallPosition)>=0.0f)
-                                {
-                                    ++audit.openAirSamples;
-                                    ++audit.wallSamples;
-                                    audit.openAirDistancesMetres.push_back(along);
-                                    const float density=Field.densityAt(wallPosition);
-                                    // The largest authored wall-relief excursion is 0.21 m;
-                                    // test only where the shell must remain solid for every
-                                    // relief phase.
-                                    const int shellExpected=expectedPassageShellAt(
-                                        sampleX,sampleY,sampleZ);
-                                    if(shellExpected>=0
-                                        &&((shellExpected==1&&density>=0.0f)
-                                            ||(shellExpected==0&&density<0.0f)))
-                                    {
-                                        ++audit.wallViolations;
-                                        if(audit.firstWallViolationCount
-                                            <audit.firstWallViolations.size())
-                                            audit.firstWallViolations[
-                                                audit.firstWallViolationCount++]={
                                                 sampleX,sampleY,sampleZ,density};
                                     }
-                                    else if(shellExpected<0)
-                                        ++audit.wallMouthBlendSkips;
                                 }
                             }
                         }
+                        const double tangentLength=std::hypot(dx,dy);
+                        if(tangentLength<=1.0e-6)continue;
+                        if(std::min(along,totalRouteLength-along)<5.0)
+                        {
+                            audit.wallMouthBlendSkips+=5;
+                            continue;
+                        }
+                        const double nx=-dy/tangentLength,ny=dx/tangentLength;
+                        const double floorDepth=passageTubeDepthAt(radius,bodyFloorDepth);
+                        const double floorZ=centerZ-floorDepth;
+                        struct FWallProbe {double side=0.0,height=0.0;bool roof=false;};
+                        const std::array<FWallProbe,5> wallProbes{{
+                            {0.0,0.0,true},{-1.0,0.25,false},{1.0,0.25,false},
+                            {-1.0,0.75,false},{1.0,0.75,false}}};
+                        for(const auto& probe:wallProbes)
+                        {
+                            double sampleX=centerX,sampleY=centerY,sampleZ=0.0;
+                            if(probe.roof)
+                                sampleZ=centerZ+radius+0.375;
+                            else
+                            {
+                                const double vertical=probe.height-floorDepth;
+                                const double wallRadiusSquared=radius*radius-vertical*vertical;
+                                if(wallRadiusSquared<=0.0)continue;
+                                const double wallRadius=std::sqrt(wallRadiusSquared);
+                                sampleX+=nx*probe.side*(wallRadius+0.375);
+                                sampleY+=ny*probe.side*(wallRadius+0.375);
+                                sampleZ=floorZ+probe.height;
+                            }
+                            const VoxelForgeCore::Vec3d wallPosition{sampleX/coreMetres,
+                                sampleY/coreMetres,sampleZ/coreMetres};
+                            if(passageInteriorWinsAt(sampleX,sampleY,sampleZ,
+                                passageIndex,b.segmentIndex))
+                            {
+                                ++audit.wallInteriorWins;
+                                continue;
+                            }
+                            if(Native.densityAt(wallPosition)<0.0f)continue;
+                            ++audit.openAirSamples;
+                            ++audit.wallSamples;
+                            audit.openAirDistancesMetres.push_back(along);
+                            const float density=Field.densityAt(wallPosition);
+                            const int shellExpected=expectedPassageShellAt(
+                                sampleX,sampleY,sampleZ);
+                            if(shellExpected>=0
+                                &&((shellExpected==1&&density>=0.0f)
+                                    ||(shellExpected==0&&density<0.0f)))
+                            {
+                                ++audit.wallViolations;
+                                if(audit.firstWallViolationCount
+                                    <audit.firstWallViolations.size())
+                                    audit.firstWallViolations[audit.firstWallViolationCount++]={
+                                        sampleX,sampleY,sampleZ,density};
+                            }
+                            else if(shellExpected<0)
+                                ++audit.wallMouthBlendSkips;
+                        }
                         ++audit.interiorSamples;
                         const float interior=Field.densityAt({centerX/coreMetres,
                             centerY/coreMetres,centerZ/coreMetres});
@@ -4253,42 +4418,15 @@ namespace StandaloneStreamBenchmark
             for(std::size_t passageIndex=0;passageIndex<ResolvedLayout->passages.size();++passageIndex)
             {
                 const auto& passage=ResolvedLayout->passages[passageIndex];
-                std::vector<std::array<double,3>> path;path.reserve(passage.controlPoints.size());
-                const auto routeDistances=passageRouteDistances(passage);
-                const double routeLength=routeDistances.empty()?0.0:routeDistances[
-                    std::clamp<std::size_t>(passage.lowerMouthControlIndex,1,
-                        passage.controlPoints.size()-1)];
-                const double bodyFloorDepth=passageBodyFloorDepth(passage);
-                const auto mouthFloorDepths=passageMouthFloorDepths(passage);
-                const std::size_t routeEnd=std::clamp<std::size_t>(
-                    passage.lowerMouthControlIndex,1,passage.controlPoints.size()-1);
-                for(std::size_t segment=1;segment<=routeEnd;++segment)
+                const auto& smoothRoute=allPassageSmoothRoutes[passageIndex];
+                const double bodyFloorDepth=allPassageBodyFloorDepths[passageIndex];
+                std::vector<std::array<double,3>> path;path.reserve(smoothRoute.size());
+                for(const auto& point:smoothRoute)
                 {
-                    const auto& a=passage.controlPoints[segment-1];
-                    const auto& b=passage.controlPoints[segment];
-                    const double ax=qToMetres(a.positionSubvoxels[0]);
-                    const double ay=qToMetres(a.positionSubvoxels[1]);
-                    const double az=qToMetres(a.positionSubvoxels[2]);
-                    const double bx=qToMetres(b.positionSubvoxels[0]);
-                    const double by=qToMetres(b.positionSubvoxels[1]);
-                    const double bz=qToMetres(b.positionSubvoxels[2]);
-                    const double length=routeDistances[segment]-routeDistances[segment-1];
-                    const std::size_t intervals=std::max<std::size_t>(1,
-                        static_cast<std::size_t>(std::ceil(length/0.5)));
-                    for(std::size_t step=segment==1?0:1;step<=intervals;++step)
-                    {
-                        const double t=static_cast<double>(step)/intervals;
-                        const double along=routeDistances[segment-1]+length*t;
-                        const double centerZ=std::lerp(az,bz,t);
-                        const double radius=std::lerp(qToMetres(a.radiusSubvoxels),
-                            qToMetres(b.radiusSubvoxels),t);
-                        const double floorDepth=passageFloorDepthAt(along,routeLength,
-                            radius,bodyFloorDepth,mouthFloorDepths[0],
-                            mouthFloorDepths[1]);
-                        const double playerZ=centerZ-floorDepth+1.13;
-                        path.push_back({std::lerp(ax,bx,t)/coreMetres,
-                            std::lerp(ay,by,t)/coreMetres,playerZ/coreMetres});
-                    }
+                    const double playerZ=point.z
+                        -passageTubeDepthAt(point.radius,bodyFloorDepth)+1.13;
+                    path.push_back({point.x/coreMetres,point.y/coreMetres,
+                        playerZ/coreMetres});
                 }
                 // Probe below the capsule feet far enough to enter the new 0.75 m
                 // floor shell; the old quarter-metre search only checked the air
@@ -4298,7 +4436,8 @@ namespace StandaloneStreamBenchmark
                     {return passageInteriorWinsAt(x,y,z-0.25);};
                 const FWalkAudit passageAudit=auditPlayerPath(Shape,path,0.375,0.125,
                     1.125,3,0.45,passageSupportExemption);
-                const FPassageNaturalnessAudit naturalAudit=auditPassageNaturalness(Shape,passage);
+                const FPassageNaturalnessAudit naturalAudit=
+                    auditPassageNaturalness(Shape,passageIndex);
                 const auto lowerProfileStratum=std::find_if(ResolvedLayout->strates.begin(),
                     ResolvedLayout->strates.end(),[&](const auto& stratum)
                     {return stratum.strateIndex==passage.lowerStrateIndex;});
@@ -4309,10 +4448,10 @@ namespace StandaloneStreamBenchmark
                         {return anchor.kind=="heightfield_profile";});
                 const FPassageMouthProfileAudit mouthProfileAudit=
                     auditPassageMouthProfiles(Shape,passage,profiledLowerSurface);
-                const FPassageRippleAudit rippleAudit=auditPassageRipples(Shape,passage,
-                    passageIndex);
+                const FPassageRippleAudit rippleAudit=
+                    auditPassageRipples(Shape,passageIndex);
                 const FPassageShellAudit shellAudit=auditPassageShell(Shape,blockedWorld,
-                    passage);
+                    passage,passageIndex);
                 std::vector<double> openAirDistances=shellAudit.openAirDistancesMetres;
                 std::sort(openAirDistances.begin(),openAirDistances.end());
                 openAirDistances.erase(std::unique(openAirDistances.begin(),
@@ -4326,29 +4465,10 @@ namespace StandaloneStreamBenchmark
                     const double startAlong=openAirDistances[first];
                     const double endAlong=openAirDistances[end-1];
                     const double midpoint=(startAlong+endAlong)*0.5;
-                    const auto upper=std::lower_bound(routeDistances.begin()+1,
-                        routeDistances.end(),midpoint);
-                    const std::size_t segment=std::min<std::size_t>(
-                        static_cast<std::size_t>(upper-routeDistances.begin())-1,
-                        passage.controlPoints.size()-2);
-                    const double segmentLength=routeDistances[segment+1]-routeDistances[segment];
-                    const double t=segmentLength>1.0e-9
-                        ?std::clamp((midpoint-routeDistances[segment])/segmentLength,0.0,1.0):0.0;
-                    const auto& a=passage.controlPoints[segment];
-                    const auto& b=passage.controlPoints[segment+1];
-                    const double effectiveAz=passageEffectiveCenterZ(passage,segment,
-                        routeDistances,routeLength,bodyFloorDepth,mouthFloorDepths);
-                    const double effectiveBz=passageEffectiveCenterZ(passage,segment+1,
-                        routeDistances,routeLength,bodyFloorDepth,mouthFloorDepths);
+                    const auto center=interpolatePassageRoute(smoothRoute,midpoint);
                     std::printf("[PassageOpenAirSection] id=%s section=%zu start_m=%.3f end_m=%.3f samples=%zu midpoint_xyz_m=(%.3f,%.3f,%.3f) midpoint_radius_m=%.3f capture_views_required=3\n",
                         passage.stableId.c_str(),section+1,startAlong,endAlong,end-first,
-                        std::lerp(qToMetres(a.positionSubvoxels[0]),
-                            qToMetres(b.positionSubvoxels[0]),t),
-                        std::lerp(qToMetres(a.positionSubvoxels[1]),
-                            qToMetres(b.positionSubvoxels[1]),t),
-                        std::lerp(effectiveAz,effectiveBz,t),
-                        std::lerp(qToMetres(a.radiusSubvoxels),
-                            qToMetres(b.radiusSubvoxels),t));
+                        center.x,center.y,center.z,center.radius);
                     first=end;
                 }
                 shellAudits+=1;

Standalone/Tools/verify/verify.py

@@ -122,11 +122,11 @@ RECIPE_RE = re.compile(
 
 def owner_hash_baseline(recipe: str, style: int) -> tuple[Path, str]:
     if recipe == "surface-world" and style == 1:
-        return (BASELINES / "owner-hash/canonical/owner-hash-surface-world-style1-v217.baseline",
-                "L109-v217-flat-floor-hollow-shell")
+        return (BASELINES / "owner-hash/canonical/owner-hash-surface-world-style1-v218.baseline",
+                "L111-v218-smooth-spline-half-pipe")
     if recipe == "floating-islands" and style == 2:
-        return (BASELINES / "owner-hash/canonical/owner-hash-floating-islands-style2-v217.baseline",
-                "L109-v217-flat-floor-hollow-shell")
+        return (BASELINES / "owner-hash/canonical/owner-hash-floating-islands-style2-v218.baseline",
+                "L111-v218-smooth-spline-half-pipe")
     raise VerificationFailure(f"no pinned owner hash baseline for {recipe} style {style}")