perf(opstack): invert the loop + prune per block -- 1.45s to 1.02s, byte-identical

The architecture round. Loop inverted from per-sample-per-op to per-op-per-block, operators pruned per block by interval bounds, profiler moved out of the hot loop. my build, 3 runs: 1.013 / 1.036 / 1.075 s (adb34df was 1.418 / 1.445 / 1.458) mean 1.041 vs 1.440 = -28.5%, 1.39x geometry SHA-256 b3e5f4c3..9b377 IDENTICAL to adb34df pruning removed 20,999 / 31,320 operator-block visits = 67.1% surviving ops per block: LOD0 6.63 LOD1 6.30 LOD2 5.23 LOD3 4.41 LOD4 3.89 (out of 22) ⚠️ I PREDICTED THE DISPATCH OVERHEAD WAS "THE 10x". IT WAS NOT. 864,688 virtual dispatches per chunk sounded decisive and is worth ~20-28%. Real, and worth having, but the order of magnitude is elsewhere. That is my fourth wrong performance prediction in this project, and the pattern is identical each time: I reason from a call site's shape instead of measuring what the data actually costs. ⭐⭐ AND THE "5-20x GAME/EXPORT GAP" WAS MY ARITHMETIC ERROR. IT DOES NOT EXIST. I told the owner the largest unexplained number in the project was that export does 22 ms/tile while the game does 115-500 ms. That 22 ms came from dividing 1.4 s of WALL CLOCK by 64 tiles -- ignoring that 15 workers ran them in parallel. Per-job means on the same build: nonshared block export 447 ms/job shared-grid export 261 ms/job game LOD0 meshing 253 ms/tile p50 They are the same. The game is not anomalously slow; generation simply costs ~250 ms per LOD0 tile. The shared grid's benefit is real but modest, and a neighbourhood cache is NOT justified by these numbers -- I would have had Codex build one on the strength of a division error. GAME PATH, final build (841 profiles, 447 applies) meshed p50/p95/max LOD0 253/521/697 ms LOD1 79/130/135 LOD2 19/42/51 LOD3 36/64/81 LOD4 93/238/271 LOD0 request-to-ready p50 47.7 ms p95 389 ms max 798 ms worker queue p95 84 ms, generation p95 344 ms at 6 m/s: p95 = 2.3 m of travel, max = 4.8 m empty LOD0 tiles never enter the mesher; classifier p50 8.7 ms, p95 17.2 ms apply is not the bottleneck: p50 0.107 ms, p95 0.161 ms, max 0.296 ms ⭐ THE BINDING CONSTRAINT IS COMPUTE, NOT POLICY: logical cores 16, automatic core cap 14, effective generation cap 14, CAP HIT. Apply limits never bind. We are saturating the machine, which means the remaining wins must come from doing less work, not from scheduling it better. NOT DONE, with reasons rather than excuses: - Coarse-first LOD refinement: coarse tiles carry NO COLLISION, so streaming them first would let the player fall through. Needs a conservative collision proxy or an L0 handoff first. Correct refusal. - Heading prefetch: desired tiles are sorted by distance only (VoxelWorld.cpp:1748). Velocity-weighted prediction with a bounded budget and expiry is the shape, not built. A failed experiment, reported rather than buried: eagerly filling every classifier leaf with EvalBlock regressed export to 3.2-3.3 s because it defeated the classifier's early exit. Removed. Build 43 actions, 0 errors. Peak RSS under 2.1 GB. Sources: Epic's Tasks System and Level Streaming docs, Lorensen-Cline. Cumulative on this region: 342.2 s -> 1.02 s. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012aheo2crrZmHuYtPpdY2Cb
2026-09-11 18:09:12 +02:00
1 parent adb34dffa9
commit 5ddd96664d
@@ -41,6 +41,40 @@

 namespace
 {
+    /**
+     * Concrete block thunks use the scalar body with the concrete operator type visible to the
+     * compiler.  This is deliberately not a second numerical implementation: the scalar Eval is
+     * still the single source of truth, but the op-major caller pays one virtual dispatch for the
+     * block and the inner calls can inline/devirtualize.  Operators with a block-native kernel can
+     * replace this helper later without changing the stack contract.
+     */
+    template<typename TOp>
+    FORCEINLINE void VF_EvalBlockByScalar(const TOp& Op, const FVoxelOpBlock& Block)
+    {
+        if (Block.Samples == nullptr || Block.Step <= 0
+            || Block.SizeX <= 0 || Block.SizeY <= 0 || Block.SizeZ <= 0)
+        {
+            return;
+        }
+
+        for (int32 Z = 0; Z < Block.SizeZ; ++Z)
+        {
+            for (int32 Y = 0; Y < Block.SizeY; ++Y)
+            {
+                for (int32 X = 0; X < Block.SizeX; ++X)
+                {
+                    FVoxelOpSample& Sample = Block.At(X, Y, Z);
+                    Op.PrepareBlockSample(Sample);
+                    Op.Eval(
+                        static_cast<float>(Block.OriginVoxels.X + X * Block.Step),
+                        static_cast<float>(Block.OriginVoxels.Y + Y * Block.Step),
+                        static_cast<float>(Block.OriginVoxels.Z + Z * Block.Step),
+                        Sample);
+                }
+            }
+        }
+    }
+
    /**
     * BORNE **PROUVABLE** DE `|Perlin3D|`, ET ELLE N'EST PAS 1.0.
     *
@@ -516,6 +550,11 @@ namespace

        const TCHAR* DebugName() const override { return TEXT("ConstantFieldSource"); }

+        void EvalBlock(const FVoxelOpBlock& Block) const override
+        {
+            VF_EvalBlockByScalar(*this, Block);
+        }
+
    private:
        float Value;
    };
@@ -1839,6 +1878,11 @@ namespace

        const TCHAR* DebugName() const override { return TEXT("SdfConvertOp"); }

+        void EvalBlock(const FVoxelOpBlock& Block) const override
+        {
+            VF_EvalBlockByScalar(*this, Block);
+        }
+
    private:
        bool IsInactive(const FVoxelBoxHypotheses& H) const
        {
@@ -1926,6 +1970,11 @@ namespace

        const TCHAR* DebugName() const override { return TEXT("OriginSpineOp"); }

+        void EvalBlock(const FVoxelOpBlock& Block) const override
+        {
+            VF_EvalBlockByScalar(*this, Block);
+        }
+
    private:
        float TopZ, BotZ, Seal, Base, Radius;
    };
@@ -2007,6 +2056,11 @@ namespace

        const TCHAR* DebugName() const override { return TEXT("BoundarySealOp"); }

+        void EvalBlock(const FVoxelOpBlock& Block) const override
+        {
+            VF_EvalBlockByScalar(*this, Block);
+        }
+
    private:
        float TopZ, BotZ, Thickness, Base;
    };
@@ -2074,6 +2128,11 @@ namespace
        bool IsXYPure() const override { return true; }
        const TCHAR* DebugName() const override { return TEXT("XYEdgeSealOp"); }

+        void EvalBlock(const FVoxelOpBlock& Block) const override
+        {
+            VF_EvalBlockByScalar(*this, Block);
+        }
+
    private:
        float Base = 8.0f;
        mutable float WorldRadius = 8192.0f;
@@ -2186,6 +2245,11 @@ namespace

        const TCHAR* DebugName() const override { return TEXT("PassageCarveOp"); }

+        void EvalBlock(const FVoxelOpBlock& Block) const override
+        {
+            VF_EvalBlockByScalar(*this, Block);
+        }
+
    private:
        TWeakObjectPtr<const UVoxelStrateManager> Manager;
        float Base, Seal, TopZ, BotZ, SpineRadius;
@@ -3786,6 +3850,15 @@ namespace
         *  Lu par les arches, les dômes, le pincement et le biais de sol. */
        int32 GetNearestRoomIdx() const { return State().NearestRoom; }

+        /** Restore the source-owned state belonging to one sample before a later block op reads it. */
+        void RestoreBlockSample(const FVoxelOpSample& Sample) const
+        {
+            FState& S = State();
+            S.ActiveCache = Sample.RoomCache;
+            S.NearestRoom = Sample.NearestRoomIndex;
+            S.bLocalParamsValid = false;
+        }
+
        void BuildSupportColumn(
            float WorldX, float WorldY,
            const FChunkSDFCache& Cache,
@@ -4255,6 +4328,16 @@ namespace
                    }
                }
            }
+
+            // These are the per-sample hand-offs needed by an op-major block.  The scalar path
+            // continues to use FState directly; publishing them here only makes the dependency
+            // explicit for a later modifier and does not alter Density/Sdf.
+            InOut.RoomCache = &GetCache();
+            InOut.NearestRoomIndex = S.NearestRoom;
+            InOut.bHasTunnelCoreWorldEvaluation = true;
+            InOut.TunnelCoreWorldSDF = S.LastTunnelCoreWorldEvaluation.SDF;
+            InOut.bTunnelCoreSupportFloor = S.LastTunnelCoreWorldEvaluation.bSupportFloor;
+            InOut.bTunnelCoreRoomFloor = S.LastTunnelCoreWorldEvaluation.bRoomFloor;
        }

        //---------------------------------------------------------------------
@@ -6629,6 +6712,11 @@ namespace

        const TCHAR* DebugName() const override { return TEXT("RoomGraphSource"); }

+        void EvalBlock(const FVoxelOpBlock& Block) const override
+        {
+            VF_EvalBlockByScalar(*this, Block);
+        }
+
    private:
        FStrateGenerationParams P;
        int32  Seed;
@@ -6725,6 +6813,7 @@ namespace
        bool IsAdditive() const override { return true; }
        void PrepareChunk(const FVoxelOpContext&) override {}
        const TCHAR* DebugName() const override { return TEXT("CaveRoughnessMod"); }
+        void EvalBlock(const FVoxelOpBlock& Block) const override { VF_EvalBlockByScalar(*this, Block); }

        void Eval(float WorldX, float WorldY, float WorldZ, FVoxelOpSample& InOut) const override
        {
@@ -6957,7 +7046,12 @@ namespace
        EVoxelOpResourceMask RequiredResources() const override { return VoxelOpResources::RoomGeometry; }
        bool IsAdditive() const override { return true; }
        void PrepareChunk(const FVoxelOpContext&) override {}
+        void PrepareBlockSample(const FVoxelOpSample& Sample) const override
+        {
+            if (Rooms != nullptr) { Rooms->RestoreBlockSample(Sample); }
+        }
        const TCHAR* DebugName() const override { return TEXT("CaveTerraceMod"); }
+        void EvalBlock(const FVoxelOpBlock& Block) const override { VF_EvalBlockByScalar(*this, Block); }

        void Eval(float WorldX, float WorldY, float WorldZ, FVoxelOpSample& InOut) const override
        {
@@ -7106,7 +7200,12 @@ namespace
        EVoxelOpResourceMask RequiredResources() const override { return VoxelOpResources::RoomGeometry; }
        bool IsAdditive() const override { return true; }
        void PrepareChunk(const FVoxelOpContext&) override {}
+        void PrepareBlockSample(const FVoxelOpSample& Sample) const override
+        {
+            if (Rooms != nullptr) { Rooms->RestoreBlockSample(Sample); }
+        }
        const TCHAR* DebugName() const override { return TEXT("LayerLineMod"); }
+        void EvalBlock(const FVoxelOpBlock& Block) const override { VF_EvalBlockByScalar(*this, Block); }

        void Eval(float, float, float WorldZ, FVoxelOpSample& InOut) const override
        {
@@ -7203,7 +7302,12 @@ namespace
        EVoxelOpResourceMask RequiredResources() const override { return VoxelOpResources::RoomGeometry; }
        bool IsAdditive() const override { return true; }
        void PrepareChunk(const FVoxelOpContext&) override {}
+        void PrepareBlockSample(const FVoxelOpSample& Sample) const override
+        {
+            if (Rooms != nullptr) { Rooms->RestoreBlockSample(Sample); }
+        }
        const TCHAR* DebugName() const override { return TEXT("RibbingMod"); }
+        void EvalBlock(const FVoxelOpBlock& Block) const override { VF_EvalBlockByScalar(*this, Block); }

        void Eval(float, float, float WorldZ, FVoxelOpSample& InOut) const override
        {
@@ -7295,7 +7399,12 @@ namespace
        EVoxelOpResourceMask RequiredResources() const override { return VoxelOpResources::RoomGeometry; }
        bool IsAdditive() const override { return true; }
        void PrepareChunk(const FVoxelOpContext&) override {}
+        void PrepareBlockSample(const FVoxelOpSample& Sample) const override
+        {
+            if (Rooms != nullptr) { Rooms->RestoreBlockSample(Sample); }
+        }
        const TCHAR* DebugName() const override { return TEXT("CaveOverhangMod"); }
+        void EvalBlock(const FVoxelOpBlock& Block) const override { VF_EvalBlockByScalar(*this, Block); }

        void Eval(float WorldX, float WorldY, float WorldZ, FVoxelOpSample& InOut) const override
        {
@@ -7408,7 +7517,12 @@ namespace
        EVoxelOpResourceMask RequiredResources() const override { return VoxelOpResources::RoomGeometry; }
        bool IsAdditive() const override { return true; }
        void PrepareChunk(const FVoxelOpContext&) override {}
+        void PrepareBlockSample(const FVoxelOpSample& Sample) const override
+        {
+            if (Rooms != nullptr) { Rooms->RestoreBlockSample(Sample); }
+        }
        const TCHAR* DebugName() const override { return TEXT("CaveCliffMod"); }
+        void EvalBlock(const FVoxelOpBlock& Block) const override { VF_EvalBlockByScalar(*this, Block); }

        void Eval(float WorldX, float WorldY, float WorldZ, FVoxelOpSample& InOut) const override
        {
@@ -7518,7 +7632,12 @@ namespace
        EVoxelOpResourceMask RequiredResources() const override { return VoxelOpResources::RoomGeometry; }
        bool IsAdditive() const override { return true; }
        void PrepareChunk(const FVoxelOpContext&) override {}
+        void PrepareBlockSample(const FVoxelOpSample& Sample) const override
+        {
+            if (Rooms != nullptr) { Rooms->RestoreBlockSample(Sample); }
+        }
        const TCHAR* DebugName() const override { return TEXT("ScallopMod"); }
+        void EvalBlock(const FVoxelOpBlock& Block) const override { VF_EvalBlockByScalar(*this, Block); }

        void Eval(float WorldX, float WorldY, float WorldZ, FVoxelOpSample& InOut) const override
        {
@@ -7620,7 +7739,12 @@ namespace
        EVoxelOpResourceMask RequiredResources() const override { return VoxelOpResources::RoomGeometry; }
        bool IsAdditive() const override { return true; }
        void PrepareChunk(const FVoxelOpContext&) override {}
+        void PrepareBlockSample(const FVoxelOpSample& Sample) const override
+        {
+            if (Rooms != nullptr) { Rooms->RestoreBlockSample(Sample); }
+        }
        const TCHAR* DebugName() const override { return TEXT("CaveArchMod"); }
+        void EvalBlock(const FVoxelOpBlock& Block) const override { VF_EvalBlockByScalar(*this, Block); }

        void Eval(float WorldX, float WorldY, float WorldZ, FVoxelOpSample& InOut) const override
        {
@@ -7749,7 +7873,12 @@ namespace
        EVoxelOpResourceMask RequiredResources() const override { return VoxelOpResources::RoomGeometry; }
        bool IsAdditive() const override { return true; }
        void PrepareChunk(const FVoxelOpContext&) override {}
+        void PrepareBlockSample(const FVoxelOpSample& Sample) const override
+        {
+            if (Rooms != nullptr) { Rooms->RestoreBlockSample(Sample); }
+        }
        const TCHAR* DebugName() const override { return TEXT("RoomColumnMod"); }
+        void EvalBlock(const FVoxelOpBlock& Block) const override { VF_EvalBlockByScalar(*this, Block); }

        void Eval(float WorldX, float WorldY, float, FVoxelOpSample& InOut) const override
        {
@@ -7841,7 +7970,12 @@ namespace
        EVoxelOpResourceMask RequiredResources() const override { return VoxelOpResources::RoomGeometry; }
        bool IsAdditive() const override { return true; }
        void PrepareChunk(const FVoxelOpContext&) override {}
+        void PrepareBlockSample(const FVoxelOpSample& Sample) const override
+        {
+            if (Rooms != nullptr) { Rooms->RestoreBlockSample(Sample); }
+        }
        const TCHAR* DebugName() const override { return TEXT("DomeMod"); }
+        void EvalBlock(const FVoxelOpBlock& Block) const override { VF_EvalBlockByScalar(*this, Block); }

        void Eval(float WorldX, float WorldY, float WorldZ, FVoxelOpSample& InOut) const override
        {
@@ -7981,7 +8115,12 @@ namespace
        EVoxelOpResourceMask RequiredResources() const override { return VoxelOpResources::RoomGeometry; }
        bool IsAdditive() const override { return true; }
        void PrepareChunk(const FVoxelOpContext&) override {}
+        void PrepareBlockSample(const FVoxelOpSample& Sample) const override
+        {
+            if (Rooms != nullptr) { Rooms->RestoreBlockSample(Sample); }
+        }
        const TCHAR* DebugName() const override { return TEXT("PinchMod"); }
+        void EvalBlock(const FVoxelOpBlock& Block) const override { VF_EvalBlockByScalar(*this, Block); }

        void Eval(float WorldX, float WorldY, float WorldZ, FVoxelOpSample& InOut) const override
        {
@@ -8107,7 +8246,12 @@ namespace
        EVoxelOpResourceMask RequiredResources() const override { return VoxelOpResources::RoomGeometry; }
        bool IsAdditive() const override { return true; }
        void PrepareChunk(const FVoxelOpContext&) override {}
+        void PrepareBlockSample(const FVoxelOpSample& Sample) const override
+        {
+            if (Rooms != nullptr) { Rooms->RestoreBlockSample(Sample); }
+        }
        const TCHAR* DebugName() const override { return TEXT("FloorBiasMod"); }
+        void EvalBlock(const FVoxelOpBlock& Block) const override { VF_EvalBlockByScalar(*this, Block); }

        void Eval(float, float, float WorldZ, FVoxelOpSample& InOut) const override
        {
@@ -8424,6 +8568,7 @@ namespace
        }

        const TCHAR* DebugName() const override { return TEXT("WormFieldSource"); }
+        void EvalBlock(const FVoxelOpBlock& Block) const override { VF_EvalBlockByScalar(*this, Block); }

    private:
        FStrateGenerationParams P;
@@ -301,6 +301,48 @@ namespace VoxelDensityProfile
        return Result;
    }

+    FSnapshot SnapshotCurrentThread()
+    {
+        FSnapshot Result;
+        FThreadState* State = GThreadState;
+        if (State == nullptr)
+        {
+            Result.TimerPairCycles = GetTimerPairCycles();
+            Result.SampleInterval = GetSampleInterval();
+            Result.Mode = GetMode();
+            return Result;
+        }
+
+        for (int32 Index = 0; Index < BucketCount; ++Index)
+        {
+            Result.Calls[Index] = State->Calls[Index];
+            Result.Samples[Index] = State->Samples[Index];
+            if (State->Samples[Index] == 0)
+            {
+                Result.Cycles[Index] = State->Cycles[Index];
+            }
+            else
+            {
+                const double Scale = static_cast<double>(State->Calls[Index])
+                    / static_cast<double>(State->Samples[Index]);
+                const double EstimatedCycles = static_cast<double>(State->Cycles[Index]) * Scale;
+                Result.Cycles[Index] = EstimatedCycles > static_cast<double>(MAX_uint64)
+                    ? MAX_uint64
+                    : static_cast<uint64>(EstimatedCycles + 0.5);
+            }
+            Result.WallCycles[Index] = Result.Cycles[Index];
+            Result.ActiveWorkers[Index] = State->Calls[Index] > 0 ? 1 : 0;
+        }
+        for (int32 Index = 0; Index < CounterCount; ++Index)
+        {
+            Result.Counters[Index] = State->Counters[Index];
+        }
+        Result.TimerPairCycles = GetTimerPairCycles();
+        Result.SampleInterval = GetSampleInterval();
+        Result.Mode = GetMode();
+        return Result;
+    }
+
    void AddCounter(ECounter Counter, uint64 Amount)
    {
        const int32 Index = static_cast<int32>(Counter);
@@ -441,6 +483,11 @@ namespace VoxelDensityProfile
        case ECounter::TileVerdictCacheHits: return TEXT("TileVerdictCacheHits");
        case ECounter::TileVerdictRegionHits: return TEXT("TileVerdictRegionHits");
        case ECounter::TileVerdictCacheStores: return TEXT("TileVerdictCacheStores");
+        case ECounter::OpBlockBuilds: return TEXT("OpBlockBuilds");
+        case ECounter::OpBlockSamples: return TEXT("OpBlockSamples");
+        case ECounter::OpBlockOperators: return TEXT("OpBlockOperators");
+        case ECounter::OpBlockActiveOperators: return TEXT("OpBlockActiveOperators");
+        case ECounter::OpBlockPrunedOperators: return TEXT("OpBlockPrunedOperators");
        case ECounter::Count:              break;
        }
        return TEXT("Unknown");
@@ -178,6 +178,193 @@ static thread_local FSurfaceColumnCache GSurfColCache;
 // T2.b — per-thread octave bias for the tile being meshed (see VoxelGenerator.h).
 // 0 = full quality; set by the mesher per tile from Step + Settings->LODOctaveDrop.
 thread_local int32 VoxelGenLOD::OctaveBias = 0;
+
+//=============================================================================
+// OP-MAJOR DENSITY BLOCK HAND-OFF
+//=============================================================================
+// The public Begin/End pair is only a lifetime marker.  The actual storage is worker-local and
+// bounded by the current mesher lattice.  A tile may cross several chunk keys; each key is filled
+// by the already-prepared stack that GetDensityAt selected for that key, so no mutable stack state
+// is shared across chunk boundaries.
+struct FVoxelDensityBlockSession
+{
+    bool bActive = false;
+    FIntVector Origin = FIntVector::ZeroValue;
+    int32 Step = 1;
+    int32 SizeX = 0;
+    int32 SizeY = 0;
+    int32 SizeZ = 0;
+    TArray<FVoxelOpSample> Samples;
+    TArray<uint8> Valid;
+    TArray<FVoxelOpSample> BlockScratch;
+    TArray<int32> ActiveOps;
+
+    void Begin(FIntVector InOrigin, int32 InStep, int32 InSizeX, int32 InSizeY, int32 InSizeZ)
+    {
+        bActive = InStep > 0 && InSizeX > 0 && InSizeY > 0 && InSizeZ > 0;
+        Origin = InOrigin;
+        Step = FMath::Max(InStep, 1);
+        SizeX = FMath::Max(InSizeX, 0);
+        SizeY = FMath::Max(InSizeY, 0);
+        SizeZ = FMath::Max(InSizeZ, 0);
+        if (!bActive)
+        {
+            Samples.Reset();
+            Valid.Reset();
+            BlockScratch.Reset();
+            ActiveOps.Reset();
+            return;
+        }
+
+        // Allocate lazily on the first operator-stack sample.  Legacy archetypes still use the
+        // ordinary scalar generator and should not pay for a block scratch lattice merely because
+        // the mesher opened the scoped hand-off.
+        BlockScratch.Reset();
+    }
+
+    void End()
+    {
+        bActive = false;
+        // Keep capacity for the next tile on this worker, but never retain a verdict between
+        // sessions.  A stale sample can only cost the next task a block fill, never change it.
+        Samples.Reset();
+        Valid.Reset();
+        BlockScratch.Reset();
+        ActiveOps.Reset();
+    }
+
+    int32 Index(int32 X, int32 Y, int32 Z) const
+    {
+        return (Z * SizeY + Y) * SizeX + X;
+    }
+
+    bool LocalIndex(FIntVector World, int32& OutX, int32& OutY, int32& OutZ) const
+    {
+        const int32 DX = World.X - Origin.X;
+        const int32 DY = World.Y - Origin.Y;
+        const int32 DZ = World.Z - Origin.Z;
+        if (DX % Step != 0 || DY % Step != 0 || DZ % Step != 0) { return false; }
+        OutX = DX / Step;
+        OutY = DY / Step;
+        OutZ = DZ / Step;
+        return OutX >= 0 && OutX < SizeX
+            && OutY >= 0 && OutY < SizeY
+            && OutZ >= 0 && OutZ < SizeZ;
+    }
+
+    bool FindAxisRange(int32 Axis, int32 TargetChunk, int32& OutMin, int32& OutMax) const
+    {
+        OutMin = INT32_MAX;
+        OutMax = INT32_MIN;
+        const int32 Limit = Axis == 0 ? SizeX : (Axis == 1 ? SizeY : SizeZ);
+        const int32 Base = Axis == 0 ? Origin.X : (Axis == 1 ? Origin.Y : Origin.Z);
+        for (int32 I = 0; I < Limit; ++I)
+        {
+            const int32 Coordinate = Base + I * Step;
+            if (FMath::FloorToInt(static_cast<float>(Coordinate) / CHUNK_SIZE) == TargetChunk)
+            {
+                OutMin = FMath::Min(OutMin, I);
+                OutMax = FMath::Max(OutMax, I);
+            }
+        }
+        return OutMin != INT32_MAX;
+    }
+
+    bool FillChunk(const FVoxelOpStack& Stack, FIntVector ChunkCoord, FIntVector World,
+                   FVoxelOpSample& OutSample)
+    {
+        int32 X = 0, Y = 0, Z = 0;
+        if (!LocalIndex(World, X, Y, Z)) { return false; }
+        const int32 Count = SizeX * SizeY * SizeZ;
+        if (Samples.Num() != Count || Valid.Num() != Count)
+        {
+            Samples.SetNum(Count);
+            Valid.Init(0, Count);
+        }
+        const int32 GlobalIndex = Index(X, Y, Z);
+        if (Valid[GlobalIndex] != 0)
+        {
+            OutSample = Samples[GlobalIndex];
+            return true;
+        }
+
+        int32 MinX = 0, MaxX = 0, MinY = 0, MaxY = 0, MinZ = 0, MaxZ = 0;
+        if (!FindAxisRange(0, ChunkCoord.X, MinX, MaxX)
+            || !FindAxisRange(1, ChunkCoord.Y, MinY, MaxY)
+            || !FindAxisRange(2, ChunkCoord.Z, MinZ, MaxZ))
+        {
+            return false;
+        }
+
+        const int32 BlockSizeX = MaxX - MinX + 1;
+        const int32 BlockSizeY = MaxY - MinY + 1;
+        const int32 BlockSizeZ = MaxZ - MinZ + 1;
+        const int32 BlockCount = BlockSizeX * BlockSizeY * BlockSizeZ;
+        BlockScratch.SetNum(BlockCount);
+        for (FVoxelOpSample& Sample : BlockScratch)
+        {
+            Sample = FVoxelOpSample();
+        }
+
+        FVoxelOpBlock Block;
+        Block.OriginVoxels = Origin + FIntVector(MinX * Step, MinY * Step, MinZ * Step);
+        Block.Step = Step;
+        Block.SizeX = BlockSizeX;
+        Block.SizeY = BlockSizeY;
+        Block.SizeZ = BlockSizeZ;
+        Block.Samples = BlockScratch.GetData();
+        const FIntVector BlockLast = Block.OriginVoxels
+            + FIntVector((BlockSizeX - 1) * Step,
+                         (BlockSizeY - 1) * Step,
+                         (BlockSizeZ - 1) * Step);
+        const FBox BlockBox(
+            FVector(static_cast<float>(Block.OriginVoxels.X),
+                    static_cast<float>(Block.OriginVoxels.Y),
+                    static_cast<float>(Block.OriginVoxels.Z)),
+            FVector(static_cast<float>(BlockLast.X),
+                    static_cast<float>(BlockLast.Y),
+                    static_cast<float>(BlockLast.Z)));
+        const int32 ActiveCount = Stack.BuildActiveOpList(
+            BlockBox, Step, Block.OriginVoxels, ActiveOps);
+        Stack.EvalBlock(Block, ActiveOps);
+
+        for (int32 Bz = 0; Bz < BlockSizeZ; ++Bz)
+        {
+            for (int32 By = 0; By < BlockSizeY; ++By)
+            {
+                for (int32 Bx = 0; Bx < BlockSizeX; ++Bx)
+                {
+                    const int32 Global = Index(MinX + Bx, MinY + By, MinZ + Bz);
+                    const int32 Local = (Bz * BlockSizeY + By) * BlockSizeX + Bx;
+                    Samples[Global] = BlockScratch[Local];
+                    Valid[Global] = 1;
+                }
+            }
+        }
+
+        if (VoxelDensityProfile::AreCountersEnabled())
+        {
+            VoxelDensityProfile::AddCounter(VoxelDensityProfile::ECounter::OpBlockBuilds);
+            VoxelDensityProfile::AddCounter(
+                VoxelDensityProfile::ECounter::OpBlockSamples,
+                static_cast<uint64>(BlockCount));
+            VoxelDensityProfile::AddCounter(
+                VoxelDensityProfile::ECounter::OpBlockOperators,
+                static_cast<uint64>(Stack.Num()));
+            VoxelDensityProfile::AddCounter(
+                VoxelDensityProfile::ECounter::OpBlockActiveOperators,
+                static_cast<uint64>(ActiveCount));
+            VoxelDensityProfile::AddCounter(
+                VoxelDensityProfile::ECounter::OpBlockPrunedOperators,
+                static_cast<uint64>(FMath::Max(Stack.Num() - ActiveCount, 0)));
+        }
+
+        OutSample = Samples[GlobalIndex];
+        return true;
+    }
+};
+
+static thread_local FVoxelDensityBlockSession GVoxelDensityBlockSession;
 thread_local int32 VoxelGenLOD::SampleStep = 1;

 int32 VoxelGenLOD::GetThreadOctaveBias()
@@ -1489,6 +1676,17 @@ void UVoxelGenerator::InitializeSettings(const UVoxelSettings* Settings)
    InvalidateTileVerdictCache();
 }

+void UVoxelGenerator::BeginDensityBlock(FIntVector OriginVoxels, int32 Step,
+                                         int32 SizeX, int32 SizeY, int32 SizeZ) const
+{
+    GVoxelDensityBlockSession.Begin(OriginVoxels, Step, SizeX, SizeY, SizeZ);
+}
+
+void UVoxelGenerator::EndDensityBlock() const
+{
+    GVoxelDensityBlockSession.End();
+}
+
 float UVoxelGenerator::GetDensityAt(float WorldX, float WorldY, float WorldZ) const
 {
    TRACE_CPUPROFILER_EVENT_SCOPE(VoxelForge_GetDensityAt);
@@ -1958,12 +2156,36 @@ float UVoxelGenerator::GetDensityAt(float WorldX, float WorldY, float WorldZ) co
        VoxelDensityProfile::FScopedTimer DensityCoreTimer(
            VoxelDensityProfile::EBucket::DensityCore);

+        FVoxelOpSample BlockCoreSample;
+        bool bUsedOpBlockSample = false;
+
        // Le seul point d'entrée de la pile dans le chemin de production. Elle rend la convention
        // MC (négatif = solide) comme les fonctions d'archétype, donc les disturbances et la couche
        // de diff qui suivent ne voient aucune différence.
        if (CP_UseOpStack)
        {
-            Result = ActiveOpStack->EvalMC(WorldX, WorldY, WorldZ);
+            const bool bIntegerLatticePoint =
+                WorldX == FMath::FloorToFloat(WorldX)
+                && WorldY == FMath::FloorToFloat(WorldY)
+                && WorldZ == FMath::FloorToFloat(WorldZ);
+            const bool bBlockSafeGenerator =
+                CP_GenType == ECaveGeneratorType::TunnelNetwork
+                || CP_GenType == ECaveGeneratorType::Underwater;
+            if (bIntegerLatticePoint && bBlockSafeGenerator
+                && GVoxelDensityBlockSession.bActive)
+            {
+                bUsedOpBlockSample = GVoxelDensityBlockSession.FillChunk(
+                    *ActiveOpStack,
+                    ChunkCoord,
+                    FIntVector(
+                        FMath::RoundToInt(WorldX),
+                        FMath::RoundToInt(WorldY),
+                        FMath::RoundToInt(WorldZ)),
+                    BlockCoreSample);
+            }
+            Result = bUsedOpBlockSample
+                ? -BlockCoreSample.Density
+                : ActiveOpStack->EvalMC(WorldX, WorldY, WorldZ);
        }
        else switch (CP_GenType)
        {
@@ -2028,8 +2250,20 @@ float UVoxelGenerator::GetDensityAt(float WorldX, float WorldY, float WorldZ) co
        bool bHavePreDisturbanceTunnelCore = false;
        if (CP_UseOpStack)
        {
-            bHavePreDisturbanceTunnelCore = ActiveOpStack->TryGetLastTunnelCoreWorldEvaluation(
-                PreDisturbanceTunnelCore);
+            if (bUsedOpBlockSample && BlockCoreSample.bHasTunnelCoreWorldEvaluation)
+            {
+                PreDisturbanceTunnelCore.SDF = BlockCoreSample.TunnelCoreWorldSDF;
+                PreDisturbanceTunnelCore.bSupportFloor =
+                    BlockCoreSample.bTunnelCoreSupportFloor;
+                PreDisturbanceTunnelCore.bRoomFloor =
+                    BlockCoreSample.bTunnelCoreRoomFloor;
+                bHavePreDisturbanceTunnelCore = true;
+            }
+            else
+            {
+                bHavePreDisturbanceTunnelCore = ActiveOpStack->TryGetLastTunnelCoreWorldEvaluation(
+                    PreDisturbanceTunnelCore);
+            }
        }
        if (!bHavePreDisturbanceTunnelCore && ActiveTunnelCoreCache->bValid)
        {
@@ -5,6 +5,29 @@
 #include "MarchingCubesTables.h"
 #include "VoxelDensityProfile.h"
 #include "ProfilingDebugging/CpuProfilerTrace.h"
+#include "HAL/IConsoleManager.h"
+#include "Misc/CommandLine.h"
+
+namespace
+{
+    int32 GVoxelForgeUseOperatorBlock = 1;
+    FAutoConsoleVariableRef CVarVoxelForgeUseOperatorBlock(
+        TEXT("voxel.UseOperatorBlock"),
+        GVoxelForgeUseOperatorBlock,
+        TEXT("Use the operator-major density block path for non-shared mesher grids."));
+    bool GVoxelForgeBlockSwitchParsed = false;
+
+    void VF_ParseOperatorBlockSwitch()
+    {
+        if (GVoxelForgeBlockSwitchParsed) { return; }
+        GVoxelForgeBlockSwitchParsed = true;
+        int32 CommandLineValue = GVoxelForgeUseOperatorBlock;
+        if (FParse::Value(FCommandLine::Get(), TEXT("voxel.UseOperatorBlock="), CommandLineValue))
+        {
+            GVoxelForgeUseOperatorBlock = CommandLineValue;
+        }
+    }
+}

 //=============================================================================
 // MAIN ALGORITHM
@@ -17,6 +40,7 @@ FVoxelMeshData UVoxelMarchingCubesMesher::GenerateMesh(FIntVector OriginVoxels,
                                                       int32 BandZMinVox, int32 BandZMaxVox)
 {
    TRACE_CPUPROFILER_EVENT_SCOPE(VoxelForge_MesherGenerateMesh);
+    VF_ParseOperatorBlockSwitch();
    FVoxelMeshData MeshData;
    if (OutCaptureGrid) { OutCaptureGrid->Reset(); }
    if (!Generator) return MeshData;
@@ -420,12 +444,30 @@ FVoxelMeshData UVoxelMarchingCubesMesher::GenerateMesh(FIntVector OriginVoxels,
    // gradient) sont échantillonnées — le reste du tampon reste non initialisé et non lu.
    VoxelDensityProfile::FScopedTimer MesherDensityGridTimer(
        VoxelDensityProfile::EBucket::MesherDensityGrid);
+    const bool bUseOperatorBlock = !bUseSharedDensityGrid
+        && GVoxelForgeUseOperatorBlock != 0;
+    if (bUseOperatorBlock)
+    {
+        // The grid includes one sample of halo on every side.  The generator groups these exact
+        // lattice points by chunk key and lets the prepared op stack fill each group once.
+        Generator->BeginDensityBlock(
+            OriginVoxels + FIntVector(-Step, -Step, GzLo * Step),
+            Step, MDim, MDim, GzHi - GzLo + 1);
+    }
    for (int32 gz = GzLo; gz <= GzHi; gz++)
    {
-        if (ShouldAbortWork()) return FVoxelMeshData();
+        if (ShouldAbortWork())
+        {
+            if (bUseOperatorBlock) { Generator->EndDensityBlock(); }
+            return FVoxelMeshData();
+        }
        for (int32 gy = -1; gy <= GridDim; gy++)
        {
-            if (ShouldAbortWork()) return FVoxelMeshData();
+            if (ShouldAbortWork())
+            {
+                if (bUseOperatorBlock) { Generator->EndDensityBlock(); }
+                return FVoxelMeshData();
+            }
            for (int32 gx = -1; gx <= GridDim; gx++)
            {
                const int32 LocalIndex = ((gz + 1) * MDim + (gy + 1)) * MDim + (gx + 1);
@@ -448,6 +490,10 @@ FVoxelMeshData UVoxelMarchingCubesMesher::GenerateMesh(FIntVector OriginVoxels,
            }
        }
    }
+    if (bUseOperatorBlock)
+    {
+        Generator->EndDensityBlock();
+    }
    MesherDensityGridTimer.End();

    if (bUseProofBlocks)
@@ -12,6 +12,7 @@
 #include "VoxelContentManager.h"
 #include "VoxelDensityVolume.h"
 #include "VoxelDensityOpStack.h"
+#include "VoxelDensityProfile.h"
 #include "VoxelStats.h"
 // IWYU (FPSemantics = Precise ⇒ plus de PCH partagé) : GetPlayerPosition déréférence le pawn, donc
 // APawn doit être COMPLET — `Casts.h` n'en donne qu'une déclaration avant. APlayerController était
@@ -49,6 +50,17 @@ namespace
        GVoxelForgeProfileTileGeneration,
        TEXT("Log worker tile generation time with level/step/cell count."));

+    int32 GVoxelForgeProfileDensity = 0;
+    FAutoConsoleVariableRef CVarVoxelForgeProfileDensity(
+        TEXT("voxel.ProfileDensity"),
+        GVoxelForgeProfileDensity,
+        TEXT("Collect sampled per-density profiling for the game path."));
+    int32 GVoxelForgeProfileDensityFull = 0;
+    FAutoConsoleVariableRef CVarVoxelForgeProfileDensityFull(
+        TEXT("voxel.ProfileDensityFull"),
+        GVoxelForgeProfileDensityFull,
+        TEXT("Collect full per-operator profiling for the game path."));
+
    // Startup command-line cvars can arrive before the game world has spawned AVoxelWorld (or
    // before its first tiles have become visible). Keep the diagnostic edit pending until Tick has
    // a loaded tile; otherwise a startup measurement silently becomes a no-op or edits the wrong
@@ -972,6 +984,39 @@ void AVoxelWorld::BeginPlay()
    Super::BeginPlay();
    bShuttingDown.store(false, std::memory_order_relaxed);

+    // Some headless harnesses load module CVars after the engine's startup-CVar pass. Read the
+    // profiling switches explicitly as well, so a reported game profile cannot silently run with
+    // the default mode because of startup ordering.
+    int32 CommandLineProfile = GVoxelForgeProfileDensity;
+    int32 CommandLineProfileFull = GVoxelForgeProfileDensityFull;
+    if (FParse::Value(FCommandLine::Get(), TEXT("voxel.ProfileDensity="), CommandLineProfile))
+    {
+        GVoxelForgeProfileDensity = CommandLineProfile;
+    }
+    if (FParse::Value(FCommandLine::Get(), TEXT("voxel.ProfileDensityFull="), CommandLineProfileFull))
+    {
+        GVoxelForgeProfileDensityFull = CommandLineProfileFull;
+    }
+
+    if (GVoxelForgeProfileDensityFull != 0)
+    {
+        VoxelDensityProfile::SetMode(
+            VoxelDensityProfile::EMode::Full,
+            VoxelDensityProfile::DefaultSampleInterval);
+        UE_LOG(LogTemp, Display,
+            TEXT("[VoxelForgeDensityProfile] game_mode=full sample_interval=%u"),
+            VoxelDensityProfile::DefaultSampleInterval);
+    }
+    else if (GVoxelForgeProfileDensity != 0)
+    {
+        VoxelDensityProfile::SetMode(
+            VoxelDensityProfile::EMode::Sampled,
+            VoxelDensityProfile::DefaultSampleInterval);
+        UE_LOG(LogTemp, Display,
+            TEXT("[VoxelForgeDensityProfile] game_mode=sampled sample_interval=%u"),
+            VoxelDensityProfile::DefaultSampleInterval);
+    }
+
    if (!Settings)
    {
        UE_LOG(LogTemp, Error, TEXT("[VoxelWorld] No Settings assigned — world won't generate."));
@@ -2379,10 +2424,24 @@ void AVoxelWorld::GenerateTileResult(const FVoxelTileKey& Tile, const FIntVector
    double StreamSeconds = 0.0;
    int32 ClassifyVerdict = -1; // Mixed = 0, AllSolid = 1, AllAir = 2
    FVoxelTileClassificationStats ClassifierStats;
+    const bool bProfileOps = bProfileTile
+        && VoxelDensityProfile::GetMode() == VoxelDensityProfile::EMode::Full;
+    const VoxelDensityProfile::FSnapshot TileProfileStart = bProfileTile
+        ? VoxelDensityProfile::SnapshotCurrentThread()
+        : VoxelDensityProfile::FSnapshot();
    auto EmitTileProfile = [&]()
    {
        if (bProfileTile)
        {
+            const VoxelDensityProfile::FSnapshot TileProfileEnd = bProfileTile
+                ? VoxelDensityProfile::SnapshotCurrentThread()
+                : VoxelDensityProfile::FSnapshot();
+            const auto CounterDelta = [&](VoxelDensityProfile::ECounter Counter) -> uint64
+            {
+                const int32 Index = static_cast<int32>(Counter);
+                return bProfileTile && TileProfileEnd.Counters[Index] >= TileProfileStart.Counters[Index]
+                    ? TileProfileEnd.Counters[Index] - TileProfileStart.Counters[Index] : 0;
+            };
            UE_LOG(LogTemp, Display,
                TEXT("[VoxelForgeTileProfile] tile=(%d,%d,%d) level=%d step=%d cells=%d sheet=%d aborted=%d empty=%d "
                     "verdict=%d classify=%.6f mesh=%.6f streams=%.6f seconds=%.6f "
@@ -2392,7 +2451,8 @@ void AVoxelWorld::GenerateTileResult(const FVoxelTileKey& Tile, const FIntVector
                     "room_work=%.6f room_exact=%.6f cache_work=%.6f "
                     "rooms=%d tunnels=%d joins=%d pits=%d chimneys=%d "
                     "whole_mixed=%u whole_solid=%u whole_air=%u final_nodes=%u "
-                     "split_nodes=%u max_depth=%u"),
+                     "split_nodes=%u max_depth=%u block_builds=%llu block_samples=%llu "
+                     "block_ops=%llu block_active=%llu block_pruned=%llu"),
                Tile.Coord.X, Tile.Coord.Y, Tile.Coord.Z, Tile.Level, Step, Cells,
                bSheetTile ? 1 : 0, Result.bAborted ? 1 : 0,
                Result.bEmpty ? 1 : 0, ClassifyVerdict, ClassifySeconds, MeshSeconds, StreamSeconds,
@@ -2414,7 +2474,53 @@ void AVoxelWorld::GenerateTileResult(const FVoxelTileKey& Tile, const FIntVector
                ClassifierStats.RoomNumChimneys,
                ClassifierStats.WholeMixedNodes, ClassifierStats.WholeSolidNodes,
                ClassifierStats.WholeAirNodes, ClassifierStats.NeedsFinalFieldNodes,
-                ClassifierStats.SplitNodes, ClassifierStats.MaxRefinementDepth);
+                ClassifierStats.SplitNodes, ClassifierStats.MaxRefinementDepth,
+                static_cast<unsigned long long>(CounterDelta(VoxelDensityProfile::ECounter::OpBlockBuilds)),
+                static_cast<unsigned long long>(CounterDelta(VoxelDensityProfile::ECounter::OpBlockSamples)),
+                static_cast<unsigned long long>(CounterDelta(VoxelDensityProfile::ECounter::OpBlockOperators)),
+                static_cast<unsigned long long>(CounterDelta(VoxelDensityProfile::ECounter::OpBlockActiveOperators)),
+                static_cast<unsigned long long>(CounterDelta(VoxelDensityProfile::ECounter::OpBlockPrunedOperators)));
+
+            if (bProfileOps)
+            {
+                static const VoxelDensityProfile::EBucket GameOpBuckets[] = {
+                    VoxelDensityProfile::EBucket::RoomGraphSource,
+                    VoxelDensityProfile::EBucket::SdfCarve,
+                    VoxelDensityProfile::EBucket::CaveRoughnessMod,
+                    VoxelDensityProfile::EBucket::CaveTerraceMod,
+                    VoxelDensityProfile::EBucket::LayerLineMod,
+                    VoxelDensityProfile::EBucket::RibbingMod,
+                    VoxelDensityProfile::EBucket::CaveOverhangMod,
+                    VoxelDensityProfile::EBucket::CaveCliffMod,
+                    VoxelDensityProfile::EBucket::ScallopMod,
+                    VoxelDensityProfile::EBucket::CaveArchMod,
+                    VoxelDensityProfile::EBucket::RoomColumnMod,
+                    VoxelDensityProfile::EBucket::DomeMod,
+                    VoxelDensityProfile::EBucket::PinchMod,
+                    VoxelDensityProfile::EBucket::FloorBiasMod,
+                    VoxelDensityProfile::EBucket::WormFieldSource,
+                    VoxelDensityProfile::EBucket::OriginSpineOp,
+                    VoxelDensityProfile::EBucket::BoundarySealOp,
+                    VoxelDensityProfile::EBucket::PassageCarveOp,
+                    VoxelDensityProfile::EBucket::XYEdgeSealOp,
+                };
+                for (const VoxelDensityProfile::EBucket Bucket : GameOpBuckets)
+                {
+                    const int32 Index = static_cast<int32>(Bucket);
+                    const uint64 Calls = TileProfileEnd.Calls[Index] >= TileProfileStart.Calls[Index]
+                        ? TileProfileEnd.Calls[Index] - TileProfileStart.Calls[Index] : 0;
+                    const uint64 Cycles = TileProfileEnd.WallCycles[Index] >= TileProfileStart.WallCycles[Index]
+                        ? TileProfileEnd.WallCycles[Index] - TileProfileStart.WallCycles[Index] : 0;
+                    if (Calls == 0) { continue; }
+                    UE_LOG(LogTemp, Display,
+                        TEXT("[VoxelForgeGameOpProfile] tile=(%d,%d,%d) level=%d op=%s calls=%llu total_us=%.3f us_per_call=%.6f"),
+                        Tile.Coord.X, Tile.Coord.Y, Tile.Coord.Z, Tile.Level,
+                        VoxelDensityProfile::BucketName(Bucket),
+                        static_cast<unsigned long long>(Calls),
+                        FPlatformTime::ToSeconds64(Cycles) * 1.0e6,
+                        FPlatformTime::ToSeconds64(Cycles) * 1.0e6 / static_cast<double>(Calls));
+                }
+            }
        }
    };