wip(tunnels): continuous world-core sweep, slope in degrees, bounded winding -- NOT MERGED: +18-30% worker CPU, visuals unconfirmed

Tunnel round from the owner's playtest. Luna's ablations traced the ribs to the world-space tunnel-core stage: disabling it removes them, while terracing, detail ops, roughness, the support floor, lateral warp, radius jitter, winding and LOD do not. The per-span capsule union is replaced by a deterministic Catmull-Rom sweep. Winding and graph expansion are now gated on bTunnelFloorEnabled (they ran even with the floor off). TunnelFloorGentleSlopeThreshold is authored in degrees (0-90, min 1 deg, DetSinCos conversion, legacy tangent values migrated: 0.3 -> 16.7 deg). The route length is capped at 6 waves x 640 = 3840 voxels, so 0.1 deg loads instead of freezing (2048 collapsed canonical reach; 24576 used ~2 GB). Room-wall trimming is behind voxel.TunnelMouthTrim (default OFF): with it on, a 36 m gap disconnects the walk.

Canonical walk: 20,907 / 10,981, connected (was 20,830 / 10,909); exports identical with -voxel.CrtFma3=0; TilePostReachProof, DetSinCos and strate crossing pass. NOT merged because: one S/M pair vs the tip DLL shows worker CPU +17.8% static / +30.3% moving and worse p95; and the orchestrator's look at the before/after renders is inconclusive (camera not matched; regular grooves still visible in the after interior). Next: owner checks the look in game; if smooth, make the sweep cheap before merging; if not, drop the sweep and keep the degrees/bound/wind-gate parts.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MmSoF64BbRFmk9C3p1VsBJ

Source/VoxelForge/Private/VoxelCaveMorphology.cpp

@@ -102,6 +102,30 @@ namespace
     // inside the chamber and recreates the broad raised shelf this hand-off is meant to remove.
     constexpr float VF_TunnelMouthBlendRadiusVoxels =
         VoxelPassageGeometry::WalkableTunnelLandingApronVoxels;
+    // The boundary probe describes where the *centreline* may leave the room.  Keep one complete
+    // landing-carve band plus the player radius behind that probe so the tapered end-cap and the
+    // fitted capsule can overlap the room on the sampled lattice.  This is a finite mouth apron,
+    // not a centre-to-centre tunnel extension.
+    constexpr float VF_TunnelMouthPlayerFitOverlapVoxels =
+        VoxelPassageGeometry::LandingCarveBlendVoxels
+        + VoxelPassageGeometry::PlayerRadiusVoxels;
+
+    static float VF_TunnelMouthInset(float TunnelRadius, float BlendRadius)
+    {
+        return FMath::Max(
+            0.5f,
+            FMath::Abs(TunnelRadius) * 0.5f
+                + FMath::Max(FMath::Abs(BlendRadius) * 0.25f, 0.0f)
+                + VF_TunnelMouthPlayerFitOverlapVoxels);
+    }
+
+#if !UE_BUILD_SHIPPING
+    static TAutoConsoleVariable<int32> CVarVoxelForgeTunnelMouthTrim(
+        TEXT("voxel.TunnelMouthTrim"),
+        0,
+        TEXT("Development-only room-wall tunnel-mouth trim; 0 keeps the legacy room endpoint."),
+        ECVF_Default);
+#endif
 
     enum class EVFFloorReliefFeature : uint8
     {
@@ -372,8 +396,8 @@ namespace
             - VoxelPassageGeometry::TunnelFloorZ(A, FMath::Abs(RadiusA)));
         const float BaseGradient = FloorDelta / HorizontalRun;
         const float GentleThreshold = VoxelMath::IsFinite(
-                Tunnel.TunnelFloorGentleSlopeThreshold)
-            ? FMath::Max(Tunnel.TunnelFloorGentleSlopeThreshold, 0.0f)
+                Tunnel.TunnelFloorGentleSlopeGradient)
+            ? FMath::Max(Tunnel.TunnelFloorGentleSlopeGradient, 0.0f)
             : VoxelPassageGeometry::PlayerWalkableFloorMaxGradient;
         const float AvailableGradient = GentleThreshold - BaseGradient;
         if (!(AvailableGradient > 0.0f))
@@ -434,8 +458,8 @@ namespace
         }
 
         const float GentleThreshold = VoxelMath::IsFinite(
-                Tunnel.TunnelFloorGentleSlopeThreshold)
-            ? FMath::Max(Tunnel.TunnelFloorGentleSlopeThreshold, 0.0f)
+                Tunnel.TunnelFloorGentleSlopeGradient)
+            ? FMath::Max(Tunnel.TunnelFloorGentleSlopeGradient, 0.0f)
             : VoxelPassageGeometry::PlayerWalkableFloorMaxGradient;
         const float AvailableGradient = GentleThreshold - BaseGradient;
         if (!(AvailableGradient > 0.0f))
@@ -873,6 +897,146 @@ namespace
         return true;
     }
 
+    // A world-chain handoff is sampled after the cave-warped SDF chain has already carved the
+    // tunnel. It must follow the same continuous centreline, not union another tapered capsule
+    // at every control point. A fixed Catmull-Rom span gives adjacent spans a shared tangent;
+    // the fixed projection iterations keep the result deterministic and bounded.
+    struct FVFTunnelCubicSpan
+    {
+        FVector P0 = FVector::ZeroVector;
+        FVector P1 = FVector::ZeroVector;
+        FVector P2 = FVector::ZeroVector;
+        FVector P3 = FVector::ZeroVector;
+        float R0 = 0.0f;
+        float R1 = 0.0f;
+        float R2 = 0.0f;
+        float R3 = 0.0f;
+
+        FORCEINLINE FVector Position(float T) const
+        {
+            const float T2 = T * T;
+            const float T3 = T2 * T;
+            return (P1 * 2.0f
+                + (P2 - P0) * T
+                + (P0 * 2.0f - P1 * 5.0f + P2 * 4.0f - P3) * T2
+                + (-P0 + P1 * 3.0f - P2 * 3.0f + P3) * T3) * 0.5f;
+        }
+
+        FORCEINLINE FVector FirstDerivative(float T) const
+        {
+            const float T2 = T * T;
+            return ((P2 - P0)
+                + (P0 * 2.0f - P1 * 5.0f + P2 * 4.0f - P3) * (2.0f * T)
+                + (-P0 + P1 * 3.0f - P2 * 3.0f + P3) * (3.0f * T2)) * 0.5f;
+        }
+
+        FORCEINLINE FVector SecondDerivative(float T) const
+        {
+            return ((P0 * 2.0f - P1 * 5.0f + P2 * 4.0f - P3) * 2.0f
+                + (-P0 + P1 * 3.0f - P2 * 3.0f + P3) * (6.0f * T)) * 0.5f;
+        }
+
+        FORCEINLINE float Radius(float T) const
+        {
+            const float T2 = T * T;
+            const float T3 = T2 * T;
+            const float Value = (R1 * 2.0f
+                + (R2 - R0) * T
+                + (R0 * 2.0f - R1 * 5.0f + R2 * 4.0f - R3) * T2
+                + (-R0 + R1 * 3.0f - R2 * 3.0f + R3) * T3) * 0.5f;
+            return FMath::Max(Value, 0.5f);
+        }
+    };
+
+    static FVFTunnelCubicSpan VF_MakeTunnelCubicSpan(
+        const TArray<FVector>& ControlPoints,
+        const TArray<float>& ControlRadii,
+        int32 SegmentIndex)
+    {
+        const int32 LastPoint = ControlPoints.Num() - 1;
+        const FVector& P1 = ControlPoints[SegmentIndex];
+        const FVector& P2 = ControlPoints[SegmentIndex + 1];
+        const FVector P0 = SegmentIndex > 0
+            ? ControlPoints[SegmentIndex - 1] : P1 + (P1 - P2);
+        const FVector P3 = SegmentIndex + 2 <= LastPoint
+            ? ControlPoints[SegmentIndex + 2] : P2 + (P2 - P1);
+        const float R1 = ControlRadii[SegmentIndex];
+        const float R2 = ControlRadii[SegmentIndex + 1];
+        const float R0 = SegmentIndex > 0
+            ? ControlRadii[SegmentIndex - 1] : R1 + (R1 - R2);
+        const float R3 = SegmentIndex + 2 <= LastPoint
+            ? ControlRadii[SegmentIndex + 2] : R2 + (R2 - R1);
+
+        FVFTunnelCubicSpan Span;
+        Span.P0 = P0;
+        Span.P1 = P1;
+        Span.P2 = P2;
+        Span.P3 = P3;
+        Span.R0 = R0;
+        Span.R1 = R1;
+        Span.R2 = R2;
+        Span.R3 = R3;
+        return Span;
+    }
+
+    static bool VF_ProjectTunnelCubicXY(
+        const FVector& Position,
+        const FVFTunnelCubicSpan& Span,
+        float& OutT,
+        float& OutDistanceSquared)
+    {
+        float BestT = 0.0f;
+        float BestDistanceSquared = FLT_MAX;
+        auto Consider = [&](float T)
+        {
+            const FVector Candidate = Span.Position(T);
+            const float DX = static_cast<float>(Candidate.X - Position.X);
+            const float DY = static_cast<float>(Candidate.Y - Position.Y);
+            const float DistanceSquared = DX * DX + DY * DY;
+            if (DistanceSquared < BestDistanceSquared)
+            {
+                BestDistanceSquared = DistanceSquared;
+                BestT = T;
+            }
+        };
+
+        constexpr int32 InitialSamples = 8;
+        for (int32 Sample = 0; Sample <= InitialSamples; ++Sample)
+        {
+            Consider(static_cast<float>(Sample) / InitialSamples);
+        }
+        float CandidateT = BestT;
+        for (int32 Iteration = 0; Iteration < 6; ++Iteration)
+        {
+            const FVector CurvePoint = Span.Position(CandidateT);
+            const FVector First = Span.FirstDerivative(CandidateT);
+            const FVector Second = Span.SecondDerivative(CandidateT);
+            const float DX = static_cast<float>(CurvePoint.X - Position.X);
+            const float DY = static_cast<float>(CurvePoint.Y - Position.Y);
+            const float FirstX = static_cast<float>(First.X);
+            const float FirstY = static_cast<float>(First.Y);
+            const float SecondX = static_cast<float>(Second.X);
+            const float SecondY = static_cast<float>(Second.Y);
+            const float Numerator = DX * FirstX + DY * FirstY;
+            const float Denominator = FirstX * FirstX + FirstY * FirstY
+                + DX * SecondX + DY * SecondY;
+            if (!VoxelMath::IsFinite(Numerator)
+                || !VoxelMath::IsFinite(Denominator)
+                || FMath::Abs(Denominator) <= KINDA_SMALL_NUMBER)
+            {
+                break;
+            }
+            CandidateT = FMath::Clamp(
+                CandidateT - Numerator / Denominator, 0.0f, 1.0f);
+            Consider(CandidateT);
+        }
+
+        OutT = BestT;
+        OutDistanceSquared = BestDistanceSquared;
+        return VoxelMath::IsFinite(OutT)
+            && VoxelMath::IsFinite(OutDistanceSquared);
+    }
+
     static FVFTunnelShapeEvaluation VF_EvaluateSweptTunnelChain(
         const FVector& Position,
         const TArray<FVector>& ControlPoints,
@@ -880,6 +1044,7 @@ namespace
         const FCachedTunnel& Tunnel,
         float SDFBlendRadius,
         bool bApplyFloorCut,
+        bool bUseContinuousCurve,
         const void* CacheIdentity, int32 TunnelIndex,
         const FVFFloorReliefColumnKey& ReliefColumn,
         const TArray<FTunnelFloorSegmentProfile>* FloorProfiles,
@@ -910,10 +1075,15 @@ namespace
             const FVector& B = ControlPointData[SegmentIndex + 1];
             const float RadiusA = ControlRadiusData[SegmentIndex];
             const float RadiusB = ControlRadiusData[SegmentIndex + 1];
-
             float T = 0.0f;
             float HorizontalDistanceSquared = FLT_MAX;
-            const bool bHasHorizontalProjection = VF_ProjectTunnelSegmentXY(
+            const FVFTunnelCubicSpan Span = bUseContinuousCurve
+                ? VF_MakeTunnelCubicSpan(ControlPoints, ControlRadii, SegmentIndex)
+                : FVFTunnelCubicSpan();
+            const bool bHasHorizontalProjection = bUseContinuousCurve
+                ? VF_ProjectTunnelCubicXY(
+                    Position, Span, T, HorizontalDistanceSquared)
+                : VF_ProjectTunnelSegmentXY(
                     Position, A, B, T, HorizontalDistanceSquared);
             if (!bHasHorizontalProjection)
             {
@@ -925,6 +1095,10 @@ namespace
                 continue;
             }
 
+            const FVector CurvePoint = bUseContinuousCurve
+                ? Span.Position(T) : FMath::Lerp(A, B, T);
+            const float CurveRadius = bUseContinuousCurve
+                ? Span.Radius(T) : FMath::Lerp(RadiusA, RadiusB, T);
             const FTunnelFloorSegmentProfile* Profile = FloorProfileData != nullptr
                 ? FloorProfileData + SegmentIndex : nullptr;
             const FVFTunnelFloorTerms FloorTerms = VF_TunnelFloorTerms(
@@ -957,7 +1131,7 @@ namespace
             // excludes relief only long enough to decide whether the bounded relief can matter;
             // the final shift below includes the actual cached column value.
             // Every complete build-time profile owns the floor.  A route that was deliberately
-            // wound, or that contains an explicit ledge transition, also moves the swept capsule
+            // wound, or that contains an explicit ledge transition, also moves the swept curve
             // with that authored floor.  A direct smooth ramp keeps the established natural arch
             // and lets the SmoothMax floor cut provide the walkable D-floor; this avoids changing
             // headroom in every gentle tunnel merely because a profile is now always present.
@@ -967,8 +1141,9 @@ namespace
                 && (Tunnel.bFloorRouteWasWound || Tunnel.bDramaticLedge);
             const bool bAnchorCapsule = bUseAuthoredProfile
                 && VoxelMath::IsFinite(NaturalFloorZ);
-            const auto EvaluateAnchoredCapsule = [
-                &Position, &A, &B, RadiusA, RadiusB, NaturalFloorZ, bAnchorCapsule]
+            const auto EvaluateAnchoredShape = [
+                &Position, &A, &B, RadiusA, RadiusB, CurvePoint, CurveRadius,
+                NaturalFloorZ, bAnchorCapsule, bUseContinuousCurve]
                 (float FloorZ) -> float
             {
                 const float Shift = FloorZ - NaturalFloorZ;
@@ -976,14 +1151,18 @@ namespace
                     || !VoxelMath::IsFinite(Shift)
                     || FMath::Abs(Shift) <= KINDA_SMALL_NUMBER)
                 {
-                    return VoxelSDF::TaperedCapsule(
+                    return bUseContinuousCurve
+                        ? FVector::Dist(Position, CurvePoint) - CurveRadius
+                        : VoxelSDF::TaperedCapsule(
                             Position, A, B, RadiusA, RadiusB);
                 }
                 const FVector Offset(0.0f, 0.0f, Shift);
-                return VoxelSDF::TaperedCapsule(
+                return bUseContinuousCurve
+                    ? FVector::Dist(Position, CurvePoint + Offset) - CurveRadius
+                    : VoxelSDF::TaperedCapsule(
                         Position, A + Offset, B + Offset, RadiusA, RadiusB);
             };
-            float SegmentSDF = EvaluateAnchoredCapsule(FloorTerms.BaseFloorZ);
+            float SegmentSDF = EvaluateAnchoredShape(FloorTerms.BaseFloorZ);
 
             bool bEvaluateRelief = bApplyFloorCut;
             if (bEvaluateRelief && bHasReliefBound)
@@ -1026,7 +1205,7 @@ namespace
                 && VoxelMath::IsFinite(FloorZ)
                 && FMath::Abs(FloorZ - FloorTerms.BaseFloorZ) > KINDA_SMALL_NUMBER)
             {
-                SegmentSDF = EvaluateAnchoredCapsule(FloorZ);
+                SegmentSDF = EvaluateAnchoredShape(FloorZ);
             }
             const float SegmentResultSDF = bApplyFloorCut
                 ? VoxelSDF::SmoothMax(
@@ -1070,6 +1249,7 @@ namespace
             return VF_EvaluateSweptTunnelChain(
                 Position, ShapeControlPoints, ShapeControlRadii,
                 Tunnel, SDFBlendRadius, bApplyFloorCut,
+                bWorldChain,
                 CacheIdentity, TunnelIndex, ReliefColumn,
                 bWorldChain ? &Tunnel.WorldFloorProfiles : &Tunnel.FloorProfiles,
                 RoomFloorOwnership);
@@ -1090,6 +1270,7 @@ namespace
             return VF_EvaluateSweptTunnelChain(
                 Position, Points, Radii,
                 Tunnel, SDFBlendRadius, bApplyFloorCut,
+                bWorldChain,
                 CacheIdentity, TunnelIndex, ReliefColumn,
                 bWorldChain ? &Tunnel.WorldFloorProfiles : &Tunnel.FloorProfiles,
                 RoomFloorOwnership);
@@ -1104,6 +1285,7 @@ namespace
         return VF_EvaluateSweptTunnelChain(
             Position, Points, Radii,
             Tunnel, SDFBlendRadius, bApplyFloorCut,
+            bWorldChain,
             CacheIdentity, TunnelIndex, ReliefColumn,
             bWorldChain ? &Tunnel.WorldFloorProfiles : &Tunnel.FloorProfiles,
             RoomFloorOwnership);
@@ -2109,6 +2291,8 @@ static bool VF_ComputeRoomGraphReach(
         || Params.TunnelFloorTerraceStepHeight < 0.0f
         || Params.TunnelFloorMaxLedgeHeight < 0.0f
         || Params.TunnelFloorGentleSlopeThreshold < 0.0f
+        || Params.TunnelFloorGentleSlopeThreshold
+            > VoxelPassageGeometry::TunnelFloorGentleSlopeMaximumDegrees
         || FMath::Abs(Params.FloorReliefStrength) > 1000000.0f
         || FMath::Abs(Params.CaveWarpStrength) > 1000000.0f
         || FMath::Abs(Params.RoomFloorCutMin) > 1000000.0f
@@ -2200,11 +2384,15 @@ static bool VF_ComputeRoomGraphReach(
     // quantising the floor into small risers.  Bound the route's possible lateral amplitude with
     // the same finite endpoint envelope used above.  This is intentionally conservative: the
     // actual chain uses a handful of switchback waves and never exceeds this reach.
-    const float GentleSlopeThreshold = FMath::Max(
-        Params.TunnelFloorGentleSlopeThreshold, KINDA_SMALL_NUMBER);
+    const float GentleSlopeThreshold = VoxelPassageGeometry::TunnelFloorGradientFromDegrees(
+        Params.TunnelFloorGentleSlopeThreshold);
     const float MaxFloorDeltaEnvelope = 2.0f * EndpointVertical;
-    const float RequiredRouteRunEnvelope = MaxFloorDeltaEnvelope
-        / GentleSlopeThreshold;
+    const float RequiredRouteRunEnvelope = Params.bTunnelFloorEnabled
+        ? FMath::Min(
+            VoxelPassageGeometry::TunnelFloorMaximumRouteLengthVoxels,
+            MaxFloorDeltaEnvelope / FMath::Max(
+                GentleSlopeThreshold, KINDA_SMALL_NUMBER))
+        : 0.0f;
     const float OrganicLateralEnvelope = FMath::Min(
         FMath::Abs(Params.TunnelWarpStrength), TunnelLengthBound * 0.25f);
     const float RouteLateralEnvelope = FMath::Max(
@@ -3335,6 +3523,104 @@ namespace
         return -InternalDensity;
     }
 
+    static bool VF_FindRoomMouthBoundary(
+        const FVFRoomLandingSite& Site,
+        const FStrateGenerationParams& Params,
+        uint32 Seed,
+        float StrateTopZ,
+        float StrateBottomZ,
+        const FVector& Anchor,
+        const FVector& Direction,
+        float TunnelRadius,
+        float BlendRadius,
+        FVector& OutMouthXY,
+        float& OutBoundaryDistance)
+    {
+        FVector DirectionXY(Direction.X, Direction.Y, 0.0f);
+        if (!DirectionXY.Normalize()
+            || !VoxelMath::IsFinite(Anchor.X)
+            || !VoxelMath::IsFinite(Anchor.Y)
+            || !VoxelMath::IsFinite(Site.Center.Z))
+        {
+            return false;
+        }
+
+        // Probe both the room mid-height and the tunnel-centre height. The latter is important
+        // for vertically compressed/ellipsoidal rooms: their wall can be closer at the floor
+        // than at mid-height. Both probes use the exact hashed room shape and cave warp used by
+        // density evaluation. Positive landing density means air/inside.
+        const float RoomFloorZ = VF_RoomFloorZFromParts(
+            Site.Center, Site.RadiusXY, Site.RadiusZ, Site.Hash, Seed, Params);
+        const float LowerProbeZ = VoxelMath::IsFinite(RoomFloorZ)
+            ? RoomFloorZ + FMath::Abs(TunnelRadius)
+            : Site.Center.Z;
+        const float UpperProbeZ = Site.Center.Z;
+        const auto IsInside = [&](float Distance) -> bool
+        {
+            const FVector Probe = Anchor + DirectionXY * Distance;
+            const float LowerDensity = VF_EvaluateRoomLandingDensity(
+                Site, Params, Seed, StrateTopZ, StrateBottomZ,
+                static_cast<float>(Probe.X), static_cast<float>(Probe.Y), LowerProbeZ);
+            const float UpperDensity = VF_EvaluateRoomLandingDensity(
+                Site, Params, Seed, StrateTopZ, StrateBottomZ,
+                static_cast<float>(Probe.X), static_cast<float>(Probe.Y), UpperProbeZ);
+            return VoxelMath::IsFinite(LowerDensity)
+                && LowerDensity > 0.0f
+                && VoxelMath::IsFinite(UpperDensity)
+                && UpperDensity > 0.0f;
+        };
+
+        if (!IsInside(0.0f))
+        {
+            return false;
+        }
+
+        const float ShapeReach = VF_RoomShapeReachUpperBound(
+            Site.RadiusXY, Site.RadiusZ);
+        const float WarpReach = FMath::Abs(Params.CaveWarpStrength)
+            * VOXEL_NOISE_SCALE * 2.0f;
+        float High = ShapeReach + WarpReach
+            + FMath::Max(8.0f, FMath::Abs(TunnelRadius) + FMath::Abs(BlendRadius));
+        if (!VoxelMath::IsFinite(High) || High <= 0.0f)
+        {
+            return false;
+        }
+
+        bool bOutside = !IsInside(High);
+        for (int32 Expansion = 0; !bOutside && Expansion < 4; ++Expansion)
+        {
+            High = FMath::Min(High * 2.0f, 4096.0f);
+            bOutside = !IsInside(High);
+        }
+        if (!bOutside)
+        {
+            return false;
+        }
+
+        float Low = 0.0f;
+        for (int32 Iteration = 0; Iteration < 24; ++Iteration)
+        {
+            const float Mid = (Low + High) * 0.5f;
+            if (IsInside(Mid))
+            {
+                Low = Mid;
+            }
+            else
+            {
+                High = Mid;
+            }
+        }
+
+        const float MouthInset = VF_TunnelMouthInset(TunnelRadius, BlendRadius);
+        OutBoundaryDistance = Low;
+        const float MouthDistance = FMath::Max(0.0f, Low - MouthInset);
+        OutMouthXY = Anchor + DirectionXY * MouthDistance;
+        OutMouthXY.Z = Site.Center.Z;
+        return VoxelMath::IsFinite(OutMouthXY.X)
+            && VoxelMath::IsFinite(OutMouthXY.Y)
+            && VoxelMath::IsFinite(OutBoundaryDistance);
+    }
+
     bool VF_FindPlayerFitPointForRoom(
         const FStrateGenerationParams& Params,
         const FVFRoomLandingSite& Site,
@@ -3821,7 +4107,6 @@ namespace
         1,
         TEXT("Memoize deterministic room player-fit points; 0 disables the memo."),
         ECVF_Default);
-
     bool VF_FindPlayerFitPointForRoomMemoized(
         const FStrateGenerationParams& Params,
         const FVFRoomLandingSite& Site,
@@ -6599,12 +6884,92 @@ void VoxelCaveMorphology::BuildChunkCache(
         return Room.bHasPlayerFitPoint;
     };
 
+    #if !UE_BUILD_SHIPPING
+    const bool bTrimRoomMouth = CVarVoxelForgeTunnelMouthTrim.GetValueOnAnyThread() != 0;
+    #else
+    constexpr bool bTrimRoomMouth = false;
+    #endif
+    const auto BuildRoomMouth = [
+        &BuildRooms, &ResolvePlayerFitPoint, &RoomFloorZFor,
+        &Params, Seed, BlendK, bTrimRoomMouth](int32 RoomIndex, const FVector& Towards,
+                                               float TunnelRadius) -> FVector
+    {
+        FBuildRoom& Room = BuildRooms[RoomIndex];
+        FVector Anchor = Room.Center;
+        if (!Room.bIsOrigin
+            && ResolvePlayerFitPoint(Room, Params, Seed))
+        {
+            Anchor = Room.PlayerFitPoint;
+        }
+
+        if (!bTrimRoomMouth)
+        {
+            // Keep the proven legacy endpoint as the safe default while the room-wall trim
+            // remains an explicit investigation switch. The endpoint still uses the room's
+            // deterministic floor and player-fit anchor, so the raw tunnel floor remains the
+            // authored tunnel surface rather than an added slab.
+            const float RoomFloorZ = RoomFloorZFor(Room);
+            const float SafeFloorZ = VoxelMath::IsFinite(RoomFloorZ)
+                ? RoomFloorZ : Room.Center.Z - Room.RadiusZ;
+            FVector End = Room.Center + FVector(
+                0.0f, 0.0f, SafeFloorZ + FMath::Abs(TunnelRadius) - Room.Center.Z);
+            FVector WorldEnd = VF_UnwarpCavePoint(End, Params, Seed);
+            if (!Room.bIsOrigin && Room.bHasPlayerFitPoint)
+            {
+                WorldEnd = FVector(
+                    Room.PlayerFitPoint.X,
+                    Room.PlayerFitPoint.Y,
+                    Room.PlayerFitPoint.Z - 1.0f + FMath::Abs(TunnelRadius));
+            }
+            return WorldEnd;
+        }
+
+        const FVFRoomLandingSite Site{
+            Room.Center,
+            Room.RadiusXY,
+            Room.RadiusZ,
+            Room.Hash,
+            Room.bIsOrigin};
+        FVector MouthXY = Anchor;
+        float BoundaryDistance = 0.0f;
+        if (!VF_FindRoomMouthBoundary(
+                Site, Params, Seed,
+                Params.StrateTopWorldZ, Params.StrateBottomWorldZ,
+                Anchor, Towards, TunnelRadius, BlendK,
+                MouthXY, BoundaryDistance))
+        {
+            FVector FallbackDirection(Towards.X, Towards.Y, 0.0f);
+            if (!FallbackDirection.Normalize())
+            {
+                FallbackDirection = FVector::ForwardVector;
+            }
+            const float MouthInset = VF_TunnelMouthInset(TunnelRadius, BlendK);
+            MouthXY = Anchor + FallbackDirection * FMath::Max(
+                0.0f, FMath::Abs(Room.RadiusXY) - MouthInset);
+        }
+        (void)BoundaryDistance;
+
+        float MouthFloorZ = VF_RoomFloorZFromParts(
+            FVector(MouthXY.X, MouthXY.Y, Room.Center.Z),
+            Room.RadiusXY, Room.RadiusZ, Room.Hash, Seed, Params);
+        if (!VoxelMath::IsFinite(MouthFloorZ))
+        {
+            MouthFloorZ = RoomFloorZFor(Room);
+        }
+        if (!VoxelMath::IsFinite(MouthFloorZ))
+        {
+            MouthFloorZ = Room.Center.Z - Room.RadiusZ;
+        }
+        return FVector(
+            MouthXY.X, MouthXY.Y, MouthFloorZ + FMath::Abs(TunnelRadius));
+    };
+
     for (const FResolvedGraphEdge& GraphEdge : GraphEdges)
     {
             const int32 I = GraphEdge.RoomA;
             const int32 J = GraphEdge.RoomB;
-            const FBuildRoom& RoomA = BuildRooms[I];
-            const FBuildRoom& RoomB = BuildRooms[J];
+            FBuildRoom& RoomA = BuildRooms[I];
+            FBuildRoom& RoomB = BuildRooms[J];
 
             if (!PossibleTunnelTouchesSearchXY(RoomA, RoomB))
             {
@@ -6627,62 +6992,24 @@ void VoxelCaveMorphology::BuildChunkCache(
             const float RadA = FMath::Lerp(Params.TunnelMinRadius, Params.TunnelMaxRadius, FactorA);
             const float RadB = FMath::Lerp(Params.TunnelMinRadius, Params.TunnelMaxRadius, FactorB);
 
-            // --- ENDPOINT FLOOR ALIGNMENT ---
-            // The old endpoint Z roll entered each room at an arbitrary height. When the two
-            // rooms had different floor cuts, the tube then met one floor several metres above or
-            // below the other and the player-fit graph saw a vertical severance. Anchor each tube
-            // tangent to the two rooms' deterministic floor planes instead. Interior control
-            // points still receive bounded vertical wander, so this removes the lip without
-            // turning the whole network into a level grid.
-            const float RoomFloorA = RoomFloorZFor(RoomA);
-            const float RoomFloorB = RoomFloorZFor(RoomB);
-            const float SafeFloorA = VoxelMath::IsFinite(RoomFloorA)
-                ? RoomFloorA : RoomA.Center.Z - RoomA.RadiusZ;
-            const float SafeFloorB = VoxelMath::IsFinite(RoomFloorB)
-                ? RoomFloorB : RoomB.Center.Z - RoomB.RadiusZ;
-            FVector EndA = RoomA.Center + FVector(0.0f, 0.0f, SafeFloorA
-                + RadA - RoomA.Center.Z);
-            FVector EndB = RoomB.Center + FVector(0.0f, 0.0f, SafeFloorB
-                + RadB - RoomB.Center.Z);
-
-            // The passage landing query is allowed to move inside a warped room until the
-            // capsule actually fits.  Use that same deterministic fit anchor for graph mouths;
-            // otherwise a room whose centre needs a local correction gets a tunnel mouth at one
-            // point and the inter-strate/player-fit landing at another.  Querying with zero
-            // lateral budget pins the source site to this exact room centre (the helper still
-            // performs its bounded local fit search).  If a malformed asset cannot produce a
-            // source fit, retain the analytic room-floor fallback above.  PlayerFitPoint is a
-            // feet point; the tunnel floor's authored support band ends half a voxel below it,
-            // and the route probe stands one voxel above the tunnel-floor plane.  Subtracting a
-            // full voxel here makes that probe exactly the same feet point as the room landing.
-            FVector WorldEndA = VF_UnwarpCavePoint(EndA, Params, Seed);
-            FVector WorldEndB = VF_UnwarpCavePoint(EndB, Params, Seed);
-            if (!RoomA.bIsOrigin)
+            // --- ENDPOINT ROOM-WALL TRIM + FLOOR ALIGNMENT ---
+            // Resolve each endpoint against the actual hashed room boundary along the edge. The
+            // old endpoint was the room centre/player-fit point, so its capsule necessarily ran
+            // through the chamber. The trim leaves half a tunnel radius plus the SDF blend inside
+            // the wall, which preserves a walkable overlap without projecting a floor slab into
+            // the room.
+            FVector TunnelDirection(
+                RoomB.Center.X - RoomA.Center.X,
+                RoomB.Center.Y - RoomA.Center.Y,
+                0.0f);
+            if (!TunnelDirection.Normalize())
             {
-                const bool bHasPlayerFit = ResolvePlayerFitPoint(
-                    BuildRooms[I], Params, Seed);
-                if (bHasPlayerFit)
-                {
-                    WorldEndA = FVector(
-                        RoomA.PlayerFitPoint.X,
-                        RoomA.PlayerFitPoint.Y,
-                        RoomA.PlayerFitPoint.Z - 1.0f + RadA);
-                    EndA = VF_ApplyCaveWarp(WorldEndA, Params, Seed);
-                }
-            }
-            if (!RoomB.bIsOrigin)
-            {
-                const bool bHasPlayerFit = ResolvePlayerFitPoint(
-                    BuildRooms[J], Params, Seed);
-                if (bHasPlayerFit)
-                {
-                    WorldEndB = FVector(
-                        RoomB.PlayerFitPoint.X,
-                        RoomB.PlayerFitPoint.Y,
-                        RoomB.PlayerFitPoint.Z - 1.0f + RadB);
-                    EndB = VF_ApplyCaveWarp(WorldEndB, Params, Seed);
-                }
+                TunnelDirection = FVector::ForwardVector;
             }
+            const FVector WorldEndA = BuildRoomMouth(I, TunnelDirection, RadA);
+            const FVector WorldEndB = BuildRoomMouth(J, -TunnelDirection, RadB);
+            const FVector EndA = VF_ApplyCaveWarp(WorldEndA, Params, Seed);
+            const FVector EndB = VF_ApplyCaveWarp(WorldEndB, Params, Seed);
 
             // --- BUILD CACHED TUNNEL ---
             FCachedTunnel CT;
@@ -6700,7 +7027,9 @@ void VoxelCaveMorphology::BuildChunkCache(
             CT.bTunnelFloorTerracingEnabled = Params.bTunnelFloorTerracingEnabled;
             CT.TunnelFloorTerraceStepHeight = Params.TunnelFloorTerraceStepHeight;
             CT.TunnelFloorMaxLedgeHeight = Params.TunnelFloorMaxLedgeHeight;
-            CT.TunnelFloorGentleSlopeThreshold = Params.TunnelFloorGentleSlopeThreshold;
+            CT.TunnelFloorGentleSlopeGradient =
+                VoxelPassageGeometry::TunnelFloorGradientFromDegrees(
+                    Params.TunnelFloorGentleSlopeThreshold);
             CT.TunnelFloorLedgeCountPreference = Params.TunnelFloorLedgeCountPreference;
             CT.TunnelFloorMaxLedges = Params.TunnelFloorMaxLedges;
 
@@ -6724,10 +7053,8 @@ void VoxelCaveMorphology::BuildChunkCache(
             const float DirectHorizontalRun = FVector2D(
                 static_cast<float>(WorldEndB.X - WorldEndA.X),
                 static_cast<float>(WorldEndB.Y - WorldEndA.Y)).Size();
-            const float GentleThreshold = VoxelMath::IsFinite(
-                    Params.TunnelFloorGentleSlopeThreshold)
-                ? FMath::Max(Params.TunnelFloorGentleSlopeThreshold, 0.0f)
-                : VoxelPassageGeometry::PlayerWalkableFloorMaxGradient;
+            const float GentleThreshold = VoxelPassageGeometry::TunnelFloorGradientFromDegrees(
+                Params.TunnelFloorGentleSlopeThreshold);
             const float SafeGentleThreshold = FMath::Max(
                 GentleThreshold, KINDA_SMALL_NUMBER);
             const bool bDirectSteep = VoxelMath::IsFinite(WorldFloorA)
@@ -6784,20 +7111,27 @@ void VoxelCaveMorphology::BuildChunkCache(
                 FMath::Max(BaseSegments, MinSegmentsForLedges),
                 1, 32);
 
-            const bool bNeedsWind = bDirectSteep
+            // A raw tunnel still needs a continuous, gentle route when its floor relief/ledge
+            // modifier is disabled.  The wind is centreline geometry, not an added floor slab; it
+            // supplies the horizontal run for the authored floor plane and keeps the room-to-room
+            // graph connected.  The rings observed in the owner asset came from the separate
+            // world-core handoff exposing span joins, not from this smooth route decision.
+            const bool bNeedsWind = Params.bTunnelFloorEnabled
+                && bDirectSteep
                 && !bDramaticLedge
                 && GentleThreshold > KINDA_SMALL_NUMBER;
             CT.bFloorRouteWasWound = bNeedsWind;
             const float RequiredHorizontalRun = bNeedsWind
-                ? FMath::Abs(FloorDelta) / SafeGentleThreshold
+                ? FMath::Min(
+                    VoxelPassageGeometry::TunnelFloorMaximumRouteLengthVoxels,
+                    FMath::Abs(FloorDelta) / SafeGentleThreshold)
                 : DirectHorizontalRun;
             const int32 WindWaves = bNeedsWind
                 ? FMath::Clamp(
                     FMath::CeilToInt(RequiredHorizontalRun
                         / FMath::Max(DirectHorizontalRun, 16.0f)),
-                    1, 6)
+                    1, VoxelPassageGeometry::TunnelFloorMaximumWindWaves)
                 : 0;
-
             FVector HorizontalAxis(
                 WorldEndB.X - WorldEndA.X, WorldEndB.Y - WorldEndA.Y, 0.0f);
             FVector PerpA;
@@ -7947,25 +8281,42 @@ FTunnelCoreWorldEvaluation VoxelCaveMorphology::EvaluateTunnelCoreWorld(
         const FCachedTunnel& Tunnel = TunnelData[TunnelIdx];
         const bool bHasWorldChain = Tunnel.WorldControlPoints.Num() >= 2
             && Tunnel.WorldControlRadii.Num() == Tunnel.WorldControlPoints.Num();
-        const FVector& BoundCenter = bHasWorldChain
-            ? Tunnel.WorldBoundCenter : Tunnel.BoundCenter;
-        const float BoundRadiusSq = bHasWorldChain
-            ? Tunnel.WorldBoundRadiusSq : Tunnel.BoundRadiusSq;
-        const float InfluenceRadius = bHasWorldChain
-            ? Tunnel.WorldInfluenceRadius : Tunnel.SDFInfluenceRadius;
-        const FVector& CenterlineMin = bHasWorldChain
-            ? Tunnel.WorldCenterlineMin : Tunnel.SDFCenterlineMin;
-        const FVector& CenterlineMax = bHasWorldChain
-            ? Tunnel.WorldCenterlineMax : Tunnel.SDFCenterlineMax;
-        if (InfluenceRadius > 0.0f
+        bool bSDFNear = true;
+        if (Tunnel.SDFInfluenceRadius > 0.0f
             && VF_DistanceSquaredToAabb(
-                WorldX, WorldY, WorldZ, CenterlineMin, CenterlineMax)
-                > FMath::Square(InfluenceRadius))
+                WorldX, WorldY, WorldZ,
+                Tunnel.SDFCenterlineMin, Tunnel.SDFCenterlineMax)
+                > FMath::Square(Tunnel.SDFInfluenceRadius))
         {
-            return;
+            bSDFNear = false;
         }
-        if (BoundRadiusSq > 0.0f
-            && VF_FloatDistSquared(WorldX, WorldY, WorldZ, BoundCenter) > BoundRadiusSq)
+        if (Tunnel.BoundRadiusSq > 0.0f
+            && VF_FloatDistSquared(
+                WorldX, WorldY, WorldZ, Tunnel.BoundCenter) > Tunnel.BoundRadiusSq)
+        {
+            bSDFNear = false;
+        }
+        bool bWorldNear = false;
+        if (bHasWorldChain)
+        {
+            bWorldNear = true;
+            if (Tunnel.WorldInfluenceRadius > 0.0f
+                && VF_DistanceSquaredToAabb(
+                    WorldX, WorldY, WorldZ,
+                    Tunnel.WorldCenterlineMin, Tunnel.WorldCenterlineMax)
+                    > FMath::Square(Tunnel.WorldInfluenceRadius))
+            {
+                bWorldNear = false;
+            }
+            if (Tunnel.WorldBoundRadiusSq > 0.0f
+                && VF_FloatDistSquared(
+                    WorldX, WorldY, WorldZ, Tunnel.WorldBoundCenter)
+                    > Tunnel.WorldBoundRadiusSq)
+            {
+                bWorldNear = false;
+            }
+        }
+        if (!bSDFNear && !bWorldNear)
         {
             return;
         }
@@ -7979,7 +8330,11 @@ FTunnelCoreWorldEvaluation VoxelCaveMorphology::EvaluateTunnelCoreWorld(
             VF_FindWorldTunnelMouthOwnership(Pos, Tunnel, Cache.SDFBlendRadius);
         const bool bRoomOwnsThisTunnel = RoomMouthOwnership.bValid;
         bool bRaisedTunnelFloor = false;
-        if (bHasWorldChain)
+        // The world chain is used only for its finite support-floor ownership band. Its air
+        // surface follows a continuous sweep, while the ordinary cave-warped chain remains the
+        // authoritative carved tunnel. Evaluating a second per-span capsule union creates a
+        // segmented zero set at every control-span join.
+        if (bHasWorldChain && Tunnel.bTunnelFloorEnabled)
         {
             if (SupportColumn != nullptr && VoxelDensityProfile::AreCountersEnabled())
             {

Source/VoxelForge/Private/VoxelStrateComposer.cpp

@@ -1139,7 +1139,7 @@ namespace
             if (FieldName == TEXT("TunnelEndpointZOffset")) return Set(0.0f, 1.0f);
             if (FieldName == TEXT("TunnelFloorTerraceStepHeight")) return Set(0.25f, FMath::Max(2.0f, HQuarter));
             if (FieldName == TEXT("TunnelFloorMaxLedgeHeight")) return Set(1.0f, FMath::Max(4.0f, HQuarter));
-            if (FieldName == TEXT("TunnelFloorGentleSlopeThreshold")) return Set(0.0f, 1.5f);
+            if (FieldName == TEXT("TunnelFloorGentleSlopeThreshold")) return Set(0.0f, 90.0f);
             if (FieldName == TEXT("SDFBlendRadius")) return Set(2.0f, FMath::Max(4.0f, H * 0.15f));
             if (FieldName == TEXT("WaterLevelRelative")) return Set(0.0f, 1.0f);
             if (FieldName == TEXT("CaveWarpStrength")) return Set(0.0f, HHalf);

Source/VoxelForge/Private/VoxelStrateDefinition.cpp

@@ -0,0 +1,74 @@
+// Serialized strate-definition migrations.
+
+#include "VoxelStrateDefinition.h"
+
+#include "Serialization/CustomVersion.h"
+#include "VoxelPassageGeometry.h"
+
+namespace
+{
+    // The field name is retained for package compatibility, but version 1 changes its meaning
+    // from a raw tangent/gradient to authored degrees. This GUID is local to the plugin.
+    const FGuid GVoxelForgeStrateSerializationVersion(
+        0xA76D5E31, 0x4B2C4F9A, 0xB8C1D204, 0x6E9F7738);
+    constexpr int32 GVoxelForgeStrateGentleSlopeDegreesVersion = 1;
+    FCustomVersionRegistration GVoxelForgeStrateSerializationRegistration(
+        GVoxelForgeStrateSerializationVersion,
+        GVoxelForgeStrateGentleSlopeDegreesVersion,
+        TEXT("VoxelForgeStrateSerialization"));
+
+    float LegacyGradientToDegrees(float LegacyGradient)
+    {
+        if (!VoxelMath::IsFinite(LegacyGradient) || LegacyGradient <= 0.0f)
+        {
+            return 0.0f;
+        }
+        if (LegacyGradient >= 4096.0f)
+        {
+            return VoxelPassageGeometry::TunnelFloorGentleSlopeMaximumDegrees;
+        }
+
+        // Invert the old gradient without atan/tan. The same deterministic sine/cosine helper
+        // used by generation makes this migration independent of the host CRT.
+        float LowDegrees = 0.0f;
+        float HighDegrees = VoxelPassageGeometry::TunnelFloorGentleSlopeMaximumDegrees;
+        for (int32 Iteration = 0; Iteration < 32; ++Iteration)
+        {
+            const float MidDegrees = (LowDegrees + HighDegrees) * 0.5f;
+            float SinValue = 0.0f;
+            float CosValue = 0.0f;
+            VoxelMath::DetSinCos(
+                SinValue, CosValue, MidDegrees * (PI / 180.0f));
+            const float MidGradient = FMath::Min(
+                FMath::Abs(SinValue) / FMath::Max(FMath::Abs(CosValue), 1.0e-3f),
+                4096.0f);
+            if (MidGradient < LegacyGradient)
+            {
+                LowDegrees = MidDegrees;
+            }
+            else
+            {
+                HighDegrees = MidDegrees;
+            }
+        }
+        return FMath::Clamp(
+            (LowDegrees + HighDegrees) * 0.5f,
+            0.0f,
+            VoxelPassageGeometry::TunnelFloorGentleSlopeMaximumDegrees);
+    }
+}
+
+void UVoxelStrateDefinition::PostLoad()
+{
+    Super::PostLoad();
+
+    if (GetLinkerCustomVersion(GVoxelForgeStrateSerializationVersion)
+        >= GVoxelForgeStrateGentleSlopeDegreesVersion)
+    {
+        return;
+    }
+
+    const float LegacyGradient = GenerationParams.TunnelFloorGentleSlopeThreshold;
+    GenerationParams.TunnelFloorGentleSlopeThreshold =
+        LegacyGradientToDegrees(LegacyGradient);
+}

Source/VoxelForge/Public/VoxelCaveMorphology.h

@@ -716,7 +716,8 @@ struct FCachedTunnel
     bool bTunnelFloorTerracingEnabled = true;
     float TunnelFloorTerraceStepHeight = 1.71f;
     float TunnelFloorMaxLedgeHeight = 12.0f;
-    float TunnelFloorGentleSlopeThreshold = 0.9656888f;
+    // Cached internal gradient derived from the authored degree value. This is not serialized.
+    float TunnelFloorGentleSlopeGradient = 0.9656888f;
     int32 TunnelFloorLedgeCountPreference = 0;
     int32 TunnelFloorMaxLedges = 4096;
     bool bDramaticLedge = false;

Source/VoxelForge/Public/VoxelPassageGeometry.h

@@ -54,6 +54,47 @@ namespace VoxelPassageGeometry
     // fallback threshold at which a room-to-room floor must become a terrace.
     constexpr float PlayerWalkableFloorMaxGradient = 0.9656887748070738f; // tan(44 degrees)
 
+    // TunnelFloorGentleSlopeThreshold is authored as degrees.  Zero is still a legal UI value,
+    // but the construction path uses this small positive floor so a malformed/overly strict
+    // value cannot turn the graph collect window into an unbounded switchback search.
+    constexpr float TunnelFloorGentleSlopeMinimumDegrees = 1.0f;
+    constexpr float TunnelFloorGentleSlopeMaximumDegrees = 90.0f;
+    // The route solver uses at most six half-waves. The canonical tunnel envelope is the default
+    // 360-voxel tunnel reach plus its endpoint correction; round that direct-run envelope up to
+    // 640 voxels, then derive the total cap from the same wave limit. This leaves room above the
+    // proven canonical route while keeping the 0.1-degree collect window finite and bounded.
+    constexpr int32 TunnelFloorMaximumWindWaves = 6;
+    constexpr float TunnelFloorMaximumSingleWaveRunVoxels = 640.0f;
+    constexpr float TunnelFloorMaximumRouteLengthVoxels =
+        static_cast<float>(TunnelFloorMaximumWindWaves)
+        * TunnelFloorMaximumSingleWaveRunVoxels;
+
+    FORCEINLINE float EffectiveTunnelFloorGentleSlopeDegrees(float AuthoredDegrees)
+    {
+        if (!VoxelMath::IsFinite(AuthoredDegrees))
+        {
+            return 44.0f;
+        }
+        return FMath::Clamp(
+            FMath::Max(AuthoredDegrees, TunnelFloorGentleSlopeMinimumDegrees),
+            TunnelFloorGentleSlopeMinimumDegrees,
+            TunnelFloorGentleSlopeMaximumDegrees);
+    }
+
+    FORCEINLINE float TunnelFloorGradientFromDegrees(float AuthoredDegrees)
+    {
+        const float Degrees = EffectiveTunnelFloorGentleSlopeDegrees(AuthoredDegrees);
+        float SinValue = 0.0f;
+        float CosValue = 0.0f;
+        VoxelMath::DetSinCos(
+            SinValue, CosValue, Degrees * (PI / 180.0f));
+        // At 90 degrees the mathematical tangent is unbounded.  The route solver only needs a
+        // finite comparison, so preserve the ordering while keeping every downstream bound finite.
+        return FMath::Min(
+            FMath::Abs(SinValue) / FMath::Max(FMath::Abs(CosValue), 1.0e-3f),
+            4096.0f);
+    }
+
     // The walkability contract is about the floor carried by the tube, not only its centreline.
     // A tapered tube changes that floor by the radius delta, so the construction and the audit
     // use this same conservative floor delta.

Source/VoxelForge/Public/VoxelStrateDefinition.h

@@ -48,6 +48,8 @@ class VOXELFORGE_API UVoxelStrateDefinition : public UPrimaryDataAsset
     GENERATED_BODY()
 
 public:
+    virtual void PostLoad() override;
+
     //=========================================================================
     // IDENTIFICATION
     //=========================================================================

Source/VoxelForge/Public/VoxelStrateTypes.h

@@ -709,12 +709,13 @@ struct VOXELFORGE_API FStrateGenerationParams
         meta = (ClampMin = "0.0"))
     float TunnelFloorMaxLedgeHeight = 12.0f;
 
-    // Floor gradient threshold for a direct route. At or below it, the floor is a smooth ramp. A
-    // steeper walk-critical edge receives a longer winding route; an eligible edge may receive
-    // deterministic dramatic ledges instead. The default is tan(44 degrees).
+    // Floor gradient threshold in degrees for a direct route. At or below it, the floor is a
+    // smooth ramp. A steeper walk-critical edge receives a longer winding route; an eligible edge
+    // may receive deterministic dramatic ledges instead. Internally this is converted with
+    // VoxelMath::DetSinCos; the old serialized tangent value is migrated on asset load.
     UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Cave Morphology|Tunnels|Floor",
-        meta = (ClampMin = "0.0"))
-    float TunnelFloorGentleSlopeThreshold = 0.9656888f;
+        meta = (ClampMin = "0.0", ClampMax = "90.0", DisplayName = "Gentle Slope Threshold (degrees)"))
+    float TunnelFloorGentleSlopeThreshold = 44.0f;
 
     // Preferred number of large ledges for a steep eligible floor. Zero selects the deterministic
     // height-driven count; positive values request at least that many transitions, subject to the

Source/VoxelForgeEditor/Private/VoxelForgeExploreCommandlet.cpp

@@ -34,6 +34,7 @@
 #include "VoxelGenerator.h"
 #include "VoxelMarchingCubesMesher.h"
 #include "VoxelNoise.h"
+#include "VoxelPassageGeometry.h"
 #include "VoxelSettings.h"
 #include "VoxelStackSampler.h"
 #include "VoxelStrateDefinition.h"
@@ -213,6 +214,49 @@ bool ParseRenderCamera(const FString& Text, FVector& OutCamera)
     return true;
 }
 
+bool ParseDensitySlice(
+    const FString& Text,
+    FVector& OutOrigin,
+    FVector& OutDirection,
+    int32& OutSamples,
+    float& OutStep)
+{
+    TArray<FString> Components;
+    Text.ParseIntoArray(Components, TEXT(","), true);
+    if (Components.Num() != 8)
+    {
+        return false;
+    }
+
+    const float OriginX = FCString::Atof(*Components[0]);
+    const float OriginY = FCString::Atof(*Components[1]);
+    const float OriginZ = FCString::Atof(*Components[2]);
+    const float DirectionX = FCString::Atof(*Components[3]);
+    const float DirectionY = FCString::Atof(*Components[4]);
+    const float DirectionZ = FCString::Atof(*Components[5]);
+    const int32 Samples = FCString::Atoi(*Components[6]);
+    const float Step = FCString::Atof(*Components[7]);
+    if (!FMath::IsFinite(OriginX) || !FMath::IsFinite(OriginY)
+        || !FMath::IsFinite(OriginZ) || !FMath::IsFinite(DirectionX)
+        || !FMath::IsFinite(DirectionY) || !FMath::IsFinite(DirectionZ)
+        || !FMath::IsFinite(Step) || Samples < 2 || Samples > 4096
+        || Step <= 0.0f)
+    {
+        return false;
+    }
+
+    FVector Direction(DirectionX, DirectionY, DirectionZ);
+    if (!Direction.Normalize())
+    {
+        return false;
+    }
+    OutOrigin = FVector(OriginX, OriginY, OriginZ);
+    OutDirection = Direction;
+    OutSamples = Samples;
+    OutStep = Step;
+    return true;
+}
+
 bool NeedsOriginInWindow(ECaveGeneratorType Archetype)
 {
     // This is the same topology policy as VoxelForgePlayerFitWindow.h. That header is test-only,
@@ -261,8 +305,11 @@ float BoundarySealForArchetype(
 struct FExploreArguments
 {
     int32 Seed = 0;
+    bool bSeedOverride = false;
     ECaveGeneratorType Archetype = ECaveGeneratorType::Maze;
     int32 Slot = 4;
+    FString StrateReference;
+    FString SettingsReference;
     bool bRender = true;
     bool bWalk = true;
     bool bExport = true;
@@ -296,6 +343,8 @@ struct FExploreArguments
     float BudgetMinutes = DefaultBudgetMinutes;
     bool bSurfaceRoughnessOverride = false;
     float SurfaceRoughness = 0.0f;
+    bool bTunnelWarpStrengthOverride = false;
+    float TunnelWarpStrength = 0.0f;
     bool bRoughnessNoiseTypeOverride = false;
     EVoxelNoiseType RoughnessNoiseType = EVoxelNoiseType::FBM;
     bool bRoughnessFrequencyOverride = false;
@@ -322,6 +371,13 @@ struct FExploreArguments
     int32 PassageFloorWrites = 1;
     bool bRenderCameraOverride = false;
     FVector RenderCamera = FVector::ZeroVector;
+    bool bRenderTargetOverride = false;
+    FVector RenderTarget = FVector::ZeroVector;
+    bool bDensitySlice = false;
+    FVector DensitySliceOrigin = FVector::ZeroVector;
+    FVector DensitySliceDirection = FVector::ForwardVector;
+    int32 DensitySliceSamples = 257;
+    float DensitySliceStep = 0.5f;
 
     bool IsDensityProfilingEnabled() const
     {
@@ -349,9 +405,11 @@ bool ParseArguments(const FString& Params, FExploreArguments& OutArguments, FStr
     FString ModesText = TEXT("render,walk,export");
     FString OutText;
 
-    FParse::Value(*Params, TEXT("seed="), OutArguments.Seed);
+    OutArguments.bSeedOverride = FParse::Value(*Params, TEXT("seed="), OutArguments.Seed);
     FParse::Value(*Params, TEXT("archetype="), ArchetypeText);
     FParse::Value(*Params, TEXT("slot="), OutArguments.Slot);
+    FParse::Value(*Params, TEXT("strateref="), OutArguments.StrateReference);
+    FParse::Value(*Params, TEXT("settingsref="), OutArguments.SettingsReference);
     FParse::Value(*Params, TEXT("modes="), ModesText);
     // FParse::Value treats a comma as a command-line separator in some UE commandlet
     // launch paths. Recover the complete token so both -modes=walk,export and the
@@ -427,6 +485,11 @@ bool ParseArguments(const FString& Params, FExploreArguments& OutArguments, FStr
     const bool bSurfaceRoughnessParsed = FParse::Value(
         *Params, TEXT("surfaceroughness="), OutArguments.SurfaceRoughness);
     OutArguments.bSurfaceRoughnessOverride = bSurfaceRoughnessSpecified;
+    const bool bTunnelWarpStrengthSpecified = Params.Contains(
+        TEXT("tunnelwarp="), ESearchCase::IgnoreCase);
+    const bool bTunnelWarpStrengthParsed = FParse::Value(
+        *Params, TEXT("tunnelwarp="), OutArguments.TunnelWarpStrength);
+    OutArguments.bTunnelWarpStrengthOverride = bTunnelWarpStrengthSpecified;
     FString RoughnessNoiseTypeText;
     const bool bRoughnessNoiseTypeSpecified = Params.Contains(
         TEXT("roughnesstype="), ESearchCase::IgnoreCase);
@@ -510,6 +573,53 @@ bool ParseArguments(const FString& Params, FExploreArguments& OutArguments, FStr
         }
     }
     OutArguments.bRenderCameraOverride = bRenderCameraSpecified;
+
+    FString RenderTargetText;
+    const bool bRenderTargetSpecified = Params.Contains(
+        TEXT("rendertarget="), ESearchCase::IgnoreCase);
+    bool bRenderTargetParsed = false;
+    if (bRenderTargetSpecified)
+    {
+        const int32 TargetOffset = Params.Find(TEXT("rendertarget="), ESearchCase::IgnoreCase);
+        if (TargetOffset != INDEX_NONE)
+        {
+            RenderTargetText = Params.Mid(TargetOffset + 13);
+            const int32 TargetEnd = RenderTargetText.Find(TEXT(" "));
+            if (TargetEnd != INDEX_NONE)
+            {
+                RenderTargetText.LeftInline(TargetEnd);
+            }
+            RenderTargetText.TrimQuotesInline();
+            bRenderTargetParsed = ParseRenderCamera(RenderTargetText, OutArguments.RenderTarget);
+        }
+    }
+    OutArguments.bRenderTargetOverride = bRenderTargetSpecified;
+
+    FString DensitySliceText;
+    const bool bDensitySliceSpecified = Params.Contains(
+        TEXT("densityslice="), ESearchCase::IgnoreCase);
+    bool bDensitySliceParsed = false;
+    if (bDensitySliceSpecified)
+    {
+        const int32 SliceOffset = Params.Find(TEXT("densityslice="), ESearchCase::IgnoreCase);
+        if (SliceOffset != INDEX_NONE)
+        {
+            DensitySliceText = Params.Mid(SliceOffset + 13);
+            const int32 SliceEnd = DensitySliceText.Find(TEXT(" "));
+            if (SliceEnd != INDEX_NONE)
+            {
+                DensitySliceText.LeftInline(SliceEnd);
+            }
+            DensitySliceText.TrimQuotesInline();
+            bDensitySliceParsed = ParseDensitySlice(
+                DensitySliceText,
+                OutArguments.DensitySliceOrigin,
+                OutArguments.DensitySliceDirection,
+                OutArguments.DensitySliceSamples,
+                OutArguments.DensitySliceStep);
+        }
+    }
+    OutArguments.bDensitySlice = bDensitySliceSpecified;
     int32 FailureFocusRender = 0;
     FParse::Value(*Params, TEXT("failurefocus="), FailureFocusRender);
     OutArguments.bFailureFocusRender = FailureFocusRender != 0;
@@ -656,6 +766,14 @@ bool ParseArguments(const FString& Params, FExploreArguments& OutArguments, FStr
         OutError = TEXT("surfaceroughness must be finite and greater than or equal to zero.");
         return false;
     }
+    if (OutArguments.bTunnelWarpStrengthOverride
+        && (!bTunnelWarpStrengthParsed
+            || !FMath::IsFinite(OutArguments.TunnelWarpStrength)
+            || OutArguments.TunnelWarpStrength < 0.0f))
+    {
+        OutError = TEXT("tunnelwarp must be finite and greater than or equal to zero.");
+        return false;
+    }
     if (OutArguments.bRoughnessNoiseTypeOverride && !bRoughnessNoiseTypeParsed)
     {
         OutError = TEXT("roughnesstype must be FBM, Ridged, Mixed, or Cellular.");
@@ -704,9 +822,11 @@ bool ParseArguments(const FString& Params, FExploreArguments& OutArguments, FStr
     if (OutArguments.bTunnelFloorGentleOverride
         && (!bTunnelFloorGentleParsed
             || !FMath::IsFinite(OutArguments.TunnelFloorGentle)
-            || OutArguments.TunnelFloorGentle < 0.0f))
+            || OutArguments.TunnelFloorGentle < 0.0f
+            || OutArguments.TunnelFloorGentle
+                > VoxelPassageGeometry::TunnelFloorGentleSlopeMaximumDegrees))
     {
-        OutError = TEXT("tunnelfloorgentle must be finite and non-negative.");
+        OutError = TEXT("tunnelfloorgentle must be finite degrees in [0,90].");
         return false;
     }
     if (OutArguments.bTunnelFloorLedgesOverride
@@ -756,6 +876,17 @@ bool ParseArguments(const FString& Params, FExploreArguments& OutArguments, FStr
         OutError = TEXT("rendercamera must be three finite comma-separated voxel coordinates.");
         return false;
     }
+    if (OutArguments.bRenderTargetOverride && !bRenderTargetParsed)
+    {
+        OutError = TEXT("rendertarget must be three finite comma-separated voxel coordinates.");
+        return false;
+    }
+    if (OutArguments.bDensitySlice && !bDensitySliceParsed)
+    {
+        OutError = TEXT(
+            "densityslice must be origin x,y,z, direction x,y,z, sample count, and positive step.");
+        return false;
+    }
 
     if (OutText.IsEmpty())
     {
@@ -946,15 +1077,58 @@ struct FExploreWorld
 
     bool Build(const FExploreArguments& Arguments, FString& OutError)
     {
-        const int32 NumStrates = Arguments.Slot + 2;
+        const bool bUseAuthoredSettings = !Arguments.SettingsReference.IsEmpty();
+        const bool bUseAuthoredStrate = !Arguments.StrateReference.IsEmpty();
+        UVoxelStrateDefinition* AuthoredDefinition = nullptr;
+        if (bUseAuthoredStrate)
+        {
+            AuthoredDefinition = LoadObject<UVoxelStrateDefinition>(
+                nullptr, *Arguments.StrateReference);
+            if (AuthoredDefinition == nullptr)
+            {
+                OutError = FString::Printf(
+                    TEXT("Could not load staged strate asset '%s'."),
+                    *Arguments.StrateReference);
+                return false;
+            }
+        }
+
+        if (bUseAuthoredSettings)
+        {
+            UVoxelSettings* AuthoredSettings = LoadObject<UVoxelSettings>(
+                nullptr, *Arguments.SettingsReference);
+            if (AuthoredSettings == nullptr)
+            {
+                OutError = FString::Printf(
+                    TEXT("Could not load staged settings asset '%s'."),
+                    *Arguments.SettingsReference);
+                return false;
+            }
+            Settings = TStrongObjectPtr<UVoxelSettings>(
+                DuplicateObject<UVoxelSettings>(AuthoredSettings, GetTransientPackage()));
+            if (!Settings.IsValid())
+            {
+                OutError = TEXT("Could not duplicate the staged settings asset into the transient package.");
+                return false;
+            }
+        }
+        else
+        {
+            Settings = TStrongObjectPtr<UVoxelSettings>(
+                NewObject<UVoxelSettings>(GetTransientPackage(), NAME_None, RF_Transient));
+        }
+
+        const int32 NumStrates = bUseAuthoredSettings
+            ? FMath::Max(Settings->TotalStrates, Arguments.Slot + 2)
+            : Arguments.Slot + 2;
         if (NumStrates > MaxSyntheticStrates)
         {
             OutError = TEXT("The synthetic layout would exceed the commandlet strate cap.");
             return false;
         }
 
-        Settings = TStrongObjectPtr<UVoxelSettings>(
-            NewObject<UVoxelSettings>(GetTransientPackage(), NAME_None, RF_Transient));
+        if (!bUseAuthoredSettings)
+        {
             Settings->Seed = Arguments.Seed;
             Settings->TotalStrates = NumStrates;
             Settings->InterStrateGapChunks = 0;
@@ -962,12 +1136,39 @@ struct FExploreWorld
             Settings->EdgeSealThickness = 64.0f;
             Settings->OriginSpineRadius = 14.0f;
             Settings->bOpenSurfaceEntry = true;
+        }
+        else if (Arguments.bSeedOverride)
+        {
+            Settings->Seed = Arguments.Seed;
+        }
+        // The transient fixed-definition layout may need to extend an authored settings asset
+        // for a requested interior slot. Keep that duplicate's advertised count consistent; the
+        // loaded package remains untouched.
+        Settings->TotalStrates = NumStrates;
 
+        if (bUseAuthoredStrate)
+        {
+            // The owner’s snapshot states that every slot uses DA_Strate3. Clone it per slot so
+            // commandlet overrides never mutate a loaded package or leak between slots.
+            Settings->StratePool.Reset();
+            Settings->FixedStrates.Reset();
+        }
         Definitions.Reserve(NumStrates);
         for (int32 Index = 0; Index < NumStrates; ++Index)
         {
-            UVoxelStrateDefinition* Definition = NewObject<UVoxelStrateDefinition>(
+            UVoxelStrateDefinition* Definition = bUseAuthoredStrate
+                ? DuplicateObject<UVoxelStrateDefinition>(
+                    AuthoredDefinition, GetTransientPackage())
+                : NewObject<UVoxelStrateDefinition>(
                     GetTransientPackage(), NAME_None, RF_Transient);
+            if (Definition == nullptr)
+            {
+                OutError = FString::Printf(
+                    TEXT("Could not create transient strate definition for slot %d."), Index);
+                return false;
+            }
+            if (!bUseAuthoredStrate)
+            {
                 Definition->StrateName = FText::FromString(FString::Printf(
                     TEXT("VoxelForgeExplore_%s_slot%d"),
                     ArchetypeName(Index == Arguments.Slot
@@ -997,13 +1198,121 @@ struct FExploreWorld
                 {
                     Definition->GenerationParams.WormStrength = Arguments.WormStrength;
                 }
+            }
 
             const TSoftObjectPtr<UVoxelStrateDefinition> SoftDefinition(Definition);
             Settings->FixedStrates.Add(Index, SoftDefinition);
+            if (!bUseAuthoredStrate)
+            {
                 Settings->StratePool.Add(SoftDefinition);
+            }
             Definitions.Add(TStrongObjectPtr<UVoxelStrateDefinition>(Definition));
         }
 
+        auto ApplyTargetOverrides = [&Arguments](UVoxelStrateDefinition* Definition) -> bool
+        {
+            if (Definition == nullptr) { return false; }
+            const ECaveGeneratorType TargetArchetype = Definition->GeneratorType;
+            if (Arguments.bSurfaceRoughnessOverride)
+            {
+                switch (TargetArchetype)
+                {
+                case ECaveGeneratorType::FlatPlain:
+                case ECaveGeneratorType::CrystalChamber:
+                    Definition->SlabParams.FloorRoughness = Arguments.SurfaceRoughness;
+                    Definition->SlabParams.CeilingRoughness = Arguments.SurfaceRoughness;
+                    break;
+                case ECaveGeneratorType::Maze:
+                    Definition->MazeParams.SurfaceRoughness = Arguments.SurfaceRoughness;
+                    break;
+                case ECaveGeneratorType::SurfaceWorld:
+                    Definition->SurfaceParams.SurfaceRoughness = Arguments.SurfaceRoughness;
+                    break;
+                case ECaveGeneratorType::VerticalShafts:
+                    Definition->VerticalShaftParams.SurfaceRoughness = Arguments.SurfaceRoughness;
+                    break;
+                case ECaveGeneratorType::FloatingIslands:
+                    Definition->FloatingIslandParams.SurfaceRoughness = Arguments.SurfaceRoughness;
+                    break;
+                case ECaveGeneratorType::TunnelNetwork:
+                case ECaveGeneratorType::Underwater:
+                default:
+                    Definition->GenerationParams.SurfaceRoughness = Arguments.SurfaceRoughness;
+                    break;
+                }
+            }
+            if (Arguments.bRoughnessNoiseTypeOverride
+                || Arguments.bRoughnessFrequencyOverride)
+            {
+                if (TargetArchetype != ECaveGeneratorType::TunnelNetwork
+                    && TargetArchetype != ECaveGeneratorType::Underwater)
+                {
+                    return false;
+                }
+                if (Arguments.bRoughnessNoiseTypeOverride)
+                {
+                    Definition->GenerationParams.RoughnessNoiseType = Arguments.RoughnessNoiseType;
+                }
+                if (Arguments.bRoughnessFrequencyOverride)
+                {
+                    Definition->GenerationParams.RoughnessFrequency = Arguments.RoughnessFrequency;
+                }
+            }
+            FStrateGenerationParams& TunnelParams = Definition->GenerationParams;
+            if (Arguments.bTunnelWarpStrengthOverride)
+            {
+                if (TargetArchetype != ECaveGeneratorType::TunnelNetwork
+                    && TargetArchetype != ECaveGeneratorType::Underwater)
+                {
+                    return false;
+                }
+                TunnelParams.TunnelWarpStrength = Arguments.TunnelWarpStrength;
+            }
+            if (Arguments.bTunnelFloorEnabledOverride)
+            {
+                TunnelParams.bTunnelFloorEnabled = Arguments.TunnelFloorEnabled != 0;
+            }
+            if (Arguments.bTunnelFloorTerracingOverride)
+            {
+                TunnelParams.bTunnelFloorTerracingEnabled = Arguments.TunnelFloorTerracing != 0;
+            }
+            if (Arguments.bTunnelFloorStepOverride)
+            {
+                TunnelParams.TunnelFloorTerraceStepHeight = Arguments.TunnelFloorStep;
+            }
+            if (Arguments.bTunnelFloorMaxLedgeOverride)
+            {
+                TunnelParams.TunnelFloorMaxLedgeHeight = Arguments.TunnelFloorMaxLedge;
+            }
+            if (Arguments.bTunnelFloorGentleOverride)
+            {
+                TunnelParams.TunnelFloorGentleSlopeThreshold = Arguments.TunnelFloorGentle;
+            }
+            if (Arguments.bTunnelFloorLedgesOverride)
+            {
+                TunnelParams.TunnelFloorLedgeCountPreference = Arguments.TunnelFloorLedges;
+            }
+            if (Arguments.bTunnelFloorMaxLedgesOverride)
+            {
+                TunnelParams.TunnelFloorMaxLedges = Arguments.TunnelFloorMaxLedges;
+            }
+            if (Arguments.bRoomMouthRiseOverride)
+            {
+                TunnelParams.RoomMouthRiseStrength = Arguments.RoomMouthRise;
+            }
+            if (Arguments.bRoomMouthRiseBlendOverride)
+            {
+                TunnelParams.RoomMouthRiseBlendVoxels = Arguments.RoomMouthRiseBlend;
+            }
+            return true;
+        };
+        if (!Definitions.IsValidIndex(Arguments.Slot)
+            || !ApplyTargetOverrides(Definitions[Arguments.Slot].Get()))
+        {
+            OutError = TEXT("The target definition rejected a commandlet override.");
+            return false;
+        }
+
         Manager = TStrongObjectPtr<UVoxelStrateManager>(
             NewObject<UVoxelStrateManager>(GetTransientPackage(), NAME_None, RF_Transient));
         if (!Manager->Initialize(Settings.Get(), Settings->Seed))
@@ -1028,104 +1337,40 @@ struct FExploreWorld
             OutError = TEXT("The requested target slot has no resolved definition.");
             return false;
         }
-        if (Arguments.bSurfaceRoughnessOverride)
-        {
-            // This is deliberately applied after layout construction and only to the target slot's
-            // resolved definition. Passage placement and every neighbouring strate retain their
-            // authored/default values; only the sampled target field gets the experiment knob.
-            switch (Arguments.Archetype)
-            {
-            case ECaveGeneratorType::FlatPlain:
-            case ECaveGeneratorType::CrystalChamber:
-                Target.Definition->SlabParams.FloorRoughness = Arguments.SurfaceRoughness;
-                Target.Definition->SlabParams.CeilingRoughness = Arguments.SurfaceRoughness;
-                break;
-            case ECaveGeneratorType::Maze:
-                Target.Definition->MazeParams.SurfaceRoughness = Arguments.SurfaceRoughness;
-                break;
-            case ECaveGeneratorType::SurfaceWorld:
-                Target.Definition->SurfaceParams.SurfaceRoughness = Arguments.SurfaceRoughness;
-                break;
-            case ECaveGeneratorType::VerticalShafts:
-                Target.Definition->VerticalShaftParams.SurfaceRoughness = Arguments.SurfaceRoughness;
-                break;
-            case ECaveGeneratorType::FloatingIslands:
-                Target.Definition->FloatingIslandParams.SurfaceRoughness = Arguments.SurfaceRoughness;
-                break;
-            case ECaveGeneratorType::TunnelNetwork:
-            case ECaveGeneratorType::Underwater:
-            default:
-                Target.Definition->GenerationParams.SurfaceRoughness = Arguments.SurfaceRoughness;
-                break;
-            }
-        }
-        if (Arguments.bRoughnessNoiseTypeOverride
-            || Arguments.bRoughnessFrequencyOverride)
-        {
-            if (Arguments.Archetype != ECaveGeneratorType::TunnelNetwork
-                && Arguments.Archetype != ECaveGeneratorType::Underwater)
-            {
-                OutError = TEXT(
-                    "roughnesstype/roughnessfrequency are only supported by TunnelNetwork or Underwater.");
-                return false;
-            }
-            if (Arguments.bRoughnessNoiseTypeOverride)
-            {
-                Target.Definition->GenerationParams.RoughnessNoiseType =
-                    Arguments.RoughnessNoiseType;
-            }
-            if (Arguments.bRoughnessFrequencyOverride)
-            {
-                Target.Definition->GenerationParams.RoughnessFrequency =
-                    Arguments.RoughnessFrequency;
-            }
-        }
-        // Floor controls are applied only to the requested target definition.  They are
-        // commandlet overrides for measured archetype comparisons; authored assets still carry
-        // the defaults/rolled values in FStrateGenerationParams.
-        FStrateGenerationParams& TargetTunnelParams = Target.Definition->GenerationParams;
-        if (Arguments.bTunnelFloorEnabledOverride)
-        {
-            TargetTunnelParams.bTunnelFloorEnabled =
-                Arguments.TunnelFloorEnabled != 0;
-        }
-        if (Arguments.bTunnelFloorTerracingOverride)
-        {
-            TargetTunnelParams.bTunnelFloorTerracingEnabled =
-                Arguments.TunnelFloorTerracing != 0;
-        }
-        if (Arguments.bTunnelFloorStepOverride)
-        {
-            TargetTunnelParams.TunnelFloorTerraceStepHeight = Arguments.TunnelFloorStep;
-        }
-        if (Arguments.bTunnelFloorMaxLedgeOverride)
-        {
-            TargetTunnelParams.TunnelFloorMaxLedgeHeight = Arguments.TunnelFloorMaxLedge;
-        }
-        if (Arguments.bTunnelFloorGentleOverride)
-        {
-            TargetTunnelParams.TunnelFloorGentleSlopeThreshold = Arguments.TunnelFloorGentle;
-        }
-        if (Arguments.bTunnelFloorLedgesOverride)
-        {
-            TargetTunnelParams.TunnelFloorLedgeCountPreference = Arguments.TunnelFloorLedges;
-        }
-        if (Arguments.bTunnelFloorMaxLedgesOverride)
-        {
-            TargetTunnelParams.TunnelFloorMaxLedges = Arguments.TunnelFloorMaxLedges;
-        }
-        if (Arguments.bRoomMouthRiseOverride)
-        {
-            TargetTunnelParams.RoomMouthRiseStrength = Arguments.RoomMouthRise;
-        }
-        if (Arguments.bRoomMouthRiseBlendOverride)
-        {
-            TargetTunnelParams.RoomMouthRiseBlendVoxels = Arguments.RoomMouthRiseBlend;
-        }
+        const ECaveGeneratorType TargetArchetype = Target.Definition->GeneratorType;
+        const FStrateGenerationParams& ReportParams = Target.Definition->GenerationParams;
+        UE_LOG(LogTemp, Display,
+            TEXT("[VoxelForgeExplore][OwnerAssets] strate=%s settings=%s slot=%d "
+                 "seed=%d height_chunks=%d archetype=%s opstack=%d "
+                 "floor_enabled=%d floor_terracing=%d floor_step=%.9g max_ledge=%.9g "
+                 "gentle_slope_degrees=%.9g gentle_gradient=%.9g route_cap=%.9g "
+                 "wind_wave_cap=%d "
+                 "ledge_preference=%d max_ledges=%d tunnel_warp=%.9g terrain_ops=%d terrace_step=%.9g "
+                 "layer_spacing=%.9g rib_spacing=%.9g"),
+            bUseAuthoredStrate ? *Arguments.StrateReference : TEXT("synthetic"),
+            bUseAuthoredSettings ? *Arguments.SettingsReference : TEXT("synthetic"),
+            Arguments.Slot, Settings->Seed, Target.Definition->StrateHeightInChunks,
+            ArchetypeName(TargetArchetype), Target.Definition->bUseOperatorStack ? 1 : 0,
+            ReportParams.bTunnelFloorEnabled ? 1 : 0,
+            ReportParams.bTunnelFloorTerracingEnabled ? 1 : 0,
+            ReportParams.TunnelFloorTerraceStepHeight,
+            ReportParams.TunnelFloorMaxLedgeHeight,
+            ReportParams.TunnelFloorGentleSlopeThreshold,
+            VoxelPassageGeometry::TunnelFloorGradientFromDegrees(
+                ReportParams.TunnelFloorGentleSlopeThreshold),
+            VoxelPassageGeometry::TunnelFloorMaximumRouteLengthVoxels,
+            VoxelPassageGeometry::TunnelFloorMaximumWindWaves,
+            ReportParams.TunnelFloorLedgeCountPreference,
+            ReportParams.TunnelFloorMaxLedges,
+            ReportParams.TunnelWarpStrength,
+            Target.Definition->TerrainOperations.Num(),
+            ReportParams.TerraceStepHeight,
+            ReportParams.LayerLineSpacing,
+            ReportParams.RibbingSpacing);
         TargetBottomWorldZ = Target.BottomChunkZ * CHUNK_SIZE;
         TargetTopWorldZ = (Target.TopChunkZ + 1) * CHUNK_SIZE;
         TargetBoundarySealThickness = BoundarySealForArchetype(
-            *Target.Definition, Arguments.Archetype);
+            *Target.Definition, TargetArchetype);
         if (TargetTopWorldZ <= TargetBottomWorldZ)
         {
             OutError = TEXT("The target strate has no positive voxel-space height.");
@@ -1315,6 +1560,22 @@ struct FExploreExportOutput
     bool bTruncated = false;
 };
 
+struct FExploreDensitySliceOutput
+{
+    FString Status;
+    FString RefusalReason;
+    FString FileName;
+    int32 SampleCount = 0;
+    int32 FiniteSampleCount = 0;
+    int32 NonFiniteSampleCount = 0;
+    int32 ZeroCrossingCount = 0;
+    int32 SaturatedSampleCount = 0;
+    float MinDensity = 0.0f;
+    float MaxDensity = 0.0f;
+    float MaxAbsDensity = 0.0f;
+    double Seconds = 0.0;
+};
+
 struct FExploreProfilerComparison
 {
     bool bAvailable = false;
@@ -1335,6 +1596,7 @@ struct FExploreRunOutput
     FExploreRenderOutput Render;
     FExploreWalkOutput Walk;
     FExploreExportOutput Export;
+    FExploreDensitySliceOutput DensitySlice;
     double BudgetSeconds = 0.0;
     double ElapsedSeconds = 0.0;
     double WalkSeconds = 0.0;
@@ -2776,7 +3038,12 @@ bool RunRender(
     OutOutput.bAllCamerasPlayerFit = true;
     FVector RouteFocus = FVector::ZeroVector;
     int32 RouteFocusCount = 0;
-    if (CameraSeedWalk.bHasArrival)
+    if (Arguments.bRenderTargetOverride)
+    {
+        RouteFocus = Arguments.RenderTarget;
+        RouteFocusCount = 1;
+    }
+    else if (CameraSeedWalk.bHasArrival)
     {
         RouteFocus += CameraSeedWalk.ArrivalVoxels;
         ++RouteFocusCount;
@@ -4136,6 +4403,7 @@ void WriteTunnelFloorOverrides(
     {
         Writer.WriteValue(TEXT("gentle_slope"),
             static_cast<double>(Arguments.TunnelFloorGentle));
+        Writer.WriteValue(TEXT("gentle_slope_units"), TEXT("degrees"));
     }
     Writer.WriteValue(TEXT("ledge_count_override"), Arguments.bTunnelFloorLedgesOverride);
     if (Arguments.bTunnelFloorLedgesOverride)
@@ -4434,6 +4702,100 @@ bool RunExport(
     return !OutOutput.bTruncated;
 }
 
+bool RunDensitySlice(
+    const FExploreArguments& Arguments,
+    FExploreWorld& World,
+    FExploreDensitySliceOutput& OutOutput,
+    FExploreBudget& Budget)
+{
+    OutOutput = FExploreDensitySliceOutput();
+    OutOutput.FileName = TEXT("density_slice.csv");
+    OutOutput.SampleCount = Arguments.DensitySliceSamples;
+    const double StartSeconds = FPlatformTime::Seconds();
+    FString Csv;
+    Csv.Reserve(Arguments.DensitySliceSamples * 96);
+    Csv += TEXT("index,x_voxels,y_voxels,z_voxels,density\r\n");
+
+    float PreviousDensity = 0.0f;
+    bool bHavePreviousDensity = false;
+    float MinDensity = TNumericLimits<float>::Max();
+    float MaxDensity = -TNumericLimits<float>::Max();
+    float MaxAbsDensity = 0.0f;
+    for (int32 Index = 0; Index < Arguments.DensitySliceSamples; ++Index)
+    {
+        if ((Index & 127) == 0 && Budget.ShouldStop(TEXT("density-slice")))
+        {
+            OutOutput.Status = TEXT("truncated");
+            OutOutput.RefusalReason = TEXT("The wall-clock budget stopped the density slice.");
+            OutOutput.Seconds = FPlatformTime::Seconds() - StartSeconds;
+            return false;
+        }
+
+        const FVector Position = Arguments.DensitySliceOrigin
+            + Arguments.DensitySliceDirection
+                * (Arguments.DensitySliceStep * static_cast<float>(Index));
+        const float Density = World.Generator->GetDensityAt(
+            Position.X, Position.Y, Position.Z);
+        Csv += FString::Printf(
+            TEXT("%d,%.9g,%.9g,%.9g,%.9g\r\n"),
+            Index, Position.X, Position.Y, Position.Z, Density);
+
+        if (!FMath::IsFinite(Density))
+        {
+            ++OutOutput.NonFiniteSampleCount;
+            bHavePreviousDensity = false;
+            continue;
+        }
+        ++OutOutput.FiniteSampleCount;
+        MinDensity = FMath::Min(MinDensity, Density);
+        MaxDensity = FMath::Max(MaxDensity, Density);
+        MaxAbsDensity = FMath::Max(MaxAbsDensity, FMath::Abs(Density));
+        if (FMath::Abs(Density) >= 0.999f)
+        {
+            ++OutOutput.SaturatedSampleCount;
+        }
+        if (bHavePreviousDensity
+            && ((PreviousDensity < 0.0f && Density > 0.0f)
+                || (PreviousDensity > 0.0f && Density < 0.0f)))
+        {
+            ++OutOutput.ZeroCrossingCount;
+        }
+        PreviousDensity = Density;
+        bHavePreviousDensity = true;
+    }
+
+    if (OutOutput.FiniteSampleCount > 0)
+    {
+        OutOutput.MinDensity = MinDensity;
+        OutOutput.MaxDensity = MaxDensity;
+        OutOutput.MaxAbsDensity = MaxAbsDensity;
+    }
+    const FString Path = FPaths::Combine(Arguments.OutDirectory, OutOutput.FileName);
+    if (!FFileHelper::SaveStringToFile(
+            Csv, *Path, FFileHelper::EEncodingOptions::ForceUTF8WithoutBOM))
+    {
+        OutOutput.Status = TEXT("error");
+        OutOutput.RefusalReason = TEXT("Could not write density_slice.csv.");
+        OutOutput.Seconds = FPlatformTime::Seconds() - StartSeconds;
+        return false;
+    }
+    OutOutput.Status = TEXT("ok");
+    OutOutput.Seconds = FPlatformTime::Seconds() - StartSeconds;
+    UE_LOG(LogTemp, Display,
+        TEXT("[VoxelForgeDensitySlice] file=%s samples=%d finite=%d non_finite=%d "
+             "zero_crossings=%d saturated=%d min=%.9g max=%.9g max_abs=%.9g "
+             "origin=(%.3f,%.3f,%.3f) direction=(%.6f,%.6f,%.6f) step=%.6g"),
+        *Path, OutOutput.SampleCount, OutOutput.FiniteSampleCount,
+        OutOutput.NonFiniteSampleCount, OutOutput.ZeroCrossingCount,
+        OutOutput.SaturatedSampleCount, OutOutput.MinDensity,
+        OutOutput.MaxDensity, OutOutput.MaxAbsDensity,
+        Arguments.DensitySliceOrigin.X, Arguments.DensitySliceOrigin.Y,
+        Arguments.DensitySliceOrigin.Z, Arguments.DensitySliceDirection.X,
+        Arguments.DensitySliceDirection.Y, Arguments.DensitySliceDirection.Z,
+        Arguments.DensitySliceStep);
+    return true;
+}
+
 void WritePlayerDimensions(FExploreJsonWriter& Writer, const TCHAR* Key)
 {
     Writer.WriteObjectStart(Key);
@@ -4459,7 +4821,7 @@ FString BuildExploreJson(
     TSharedRef<FExploreJsonWriter> Writer =
     TJsonWriterFactory<TCHAR, TCondensedJsonPrintPolicy<TCHAR>>::Create(&Json);
     Writer->WriteObjectStart();
-    Writer->WriteValue(TEXT("schema_version"), 6);
+    Writer->WriteValue(TEXT("schema_version"), 7);
     Writer->WriteValue(TEXT("tool"), TEXT("VoxelForgeExplore"));
     Writer->WriteValue(TEXT("read_only_generation"), true);
 
@@ -4534,6 +4896,12 @@ FString BuildExploreJson(
     Writer->WriteValue(TEXT("sample_stacks_interval_us"),
         static_cast<double>(Arguments.SampleStacksIntervalUs));
     Writer->WriteValue(TEXT("profile_lod"), Arguments.bProfileLod);
+    Writer->WriteValue(TEXT("density_slice_requested"), Arguments.bDensitySlice);
+    Writer->WriteValue(TEXT("render_target_override"), Arguments.bRenderTargetOverride);
+    if (Arguments.bRenderTargetOverride)
+    {
+        WriteJsonVector(*Writer, TEXT("render_target_voxels"), Arguments.RenderTarget, 1.0f);
+    }
     Writer->WriteValue(TEXT("op_bounds"), Arguments.bOpBounds);
     Writer->WriteValue(TEXT("budget_minutes"), static_cast<double>(Arguments.BudgetMinutes));
     Writer->WriteValue(TEXT("out_directory"), Arguments.OutDirectory);
@@ -4549,6 +4917,27 @@ FString BuildExploreJson(
         Arguments.bBlockEarlyOut ? 1 : 0));
     Writer->WriteObjectEnd();
 
+    Writer->WriteObjectStart(TEXT("density_slice"));
+    Writer->WriteValue(TEXT("status"), Output.DensitySlice.Status);
+    Writer->WriteValue(TEXT("file"), Output.DensitySlice.FileName);
+    Writer->WriteValue(TEXT("refusal_or_error"), Output.DensitySlice.RefusalReason);
+    Writer->WriteValue(TEXT("sample_count"), Output.DensitySlice.SampleCount);
+    Writer->WriteValue(TEXT("finite_sample_count"), Output.DensitySlice.FiniteSampleCount);
+    Writer->WriteValue(TEXT("non_finite_sample_count"), Output.DensitySlice.NonFiniteSampleCount);
+    Writer->WriteValue(TEXT("zero_crossing_count"), Output.DensitySlice.ZeroCrossingCount);
+    Writer->WriteValue(TEXT("saturated_sample_count"), Output.DensitySlice.SaturatedSampleCount);
+    Writer->WriteValue(TEXT("min_density"), static_cast<double>(Output.DensitySlice.MinDensity));
+    Writer->WriteValue(TEXT("max_density"), static_cast<double>(Output.DensitySlice.MaxDensity));
+    Writer->WriteValue(TEXT("max_abs_density"), static_cast<double>(Output.DensitySlice.MaxAbsDensity));
+    Writer->WriteValue(TEXT("seconds"), Output.DensitySlice.Seconds);
+    if (Arguments.bDensitySlice)
+    {
+        WriteJsonVector(*Writer, TEXT("origin_voxels"), Arguments.DensitySliceOrigin, 1.0f);
+        WriteJsonVector(*Writer, TEXT("direction"), Arguments.DensitySliceDirection, 1.0f);
+        Writer->WriteValue(TEXT("step_voxels"), static_cast<double>(Arguments.DensitySliceStep));
+    }
+    Writer->WriteObjectEnd();
+
     Writer->WriteObjectStart(TEXT("summary"));
     const double SummaryMeshSeconds = Arguments.bExport
         ? Output.Export.MeshSeconds
@@ -4615,6 +5004,13 @@ FString BuildExploreJson(
     Writer->WriteObjectStart(TEXT("tile_ledger"));
     Writer->WriteValue(TEXT("order"), TEXT("z_then_y_then_x"));
     Writer->WriteValue(TEXT("tile_cells"), CHUNK_SIZE);
+    int32 TileLod = 0;
+    for (int32 SampleStep = Arguments.ExportStep; SampleStep > 1; SampleStep >>= 1)
+    {
+        ++TileLod;
+    }
+    Writer->WriteValue(TEXT("sample_step"), Arguments.ExportStep);
+    Writer->WriteValue(TEXT("lod"), TileLod);
     Writer->WriteValue(TEXT("tile_count"), World.ExploreMeshTileCount);
     Writer->WriteValue(TEXT("completed_tiles"), World.ExploreMeshTilesCompleted);
     Writer->WriteArrayStart(TEXT("tiles"));
@@ -4629,6 +5025,8 @@ FString BuildExploreJson(
         Writer->WriteValue(TEXT("x"), TileX);
         Writer->WriteValue(TEXT("y"), TileY);
         Writer->WriteValue(TEXT("z"), TileZ);
+        Writer->WriteValue(TEXT("sample_step"), Arguments.ExportStep);
+        Writer->WriteValue(TEXT("lod"), TileLod);
         Writer->WriteValue(TEXT("triangle_count"), World.ExploreTileTriangleCounts[TileIndex]);
         Writer->WriteValue(TEXT("geometry_hash"), World.ExploreTileGeometryHashes[TileIndex]);
         Writer->WriteObjectEnd();
@@ -5750,7 +6148,26 @@ int32 RunExploreCase(const FString& Params, FString* OutJson)
         return 1;
     }
 
+    FExploreRunOutput Output;
     bool bRequestedModeFailed = false;
+    if (Arguments.bDensitySlice)
+    {
+        const double Start = FPlatformTime::Seconds();
+        const bool bDensitySliceOk = !Budget.bTruncated
+            && RunDensitySlice(Arguments, World, Output.DensitySlice, Budget);
+        if (!bDensitySliceOk && !Budget.bTruncated)
+        {
+            bRequestedModeFailed = true;
+            UE_LOG(LogTemp, Error,
+                TEXT("[VoxelForgeExplore] density slice failed: %s"),
+                *Output.DensitySlice.RefusalReason);
+        }
+        UE_LOG(LogTemp, Display,
+            TEXT("[VoxelForgeExplore] density slice %.3fs (%s)"),
+            FPlatformTime::Seconds() - Start,
+            bDensitySliceOk ? TEXT("ok")
+                : (Budget.bTruncated ? TEXT("truncated") : TEXT("error")));
+    }
     if (Arguments.bOpBounds)
     {
         const double Start = FPlatformTime::Seconds();
@@ -5837,7 +6254,6 @@ int32 RunExploreCase(const FString& Params, FString* OutJson)
         }
     }
 
-    FExploreRunOutput Output;
     if (Budget.ShouldStop(TEXT("setup")))
     {
         UE_LOG(LogTemp, Warning,