- Normal render target (R16G16B16A16_SNORM) as MRT SV_TARGET1 in all 3 pixel
shaders (voxelPS, voxelTopingPS, voxelSmoothPS) for future RT shadow/AO
- BLAS extraction compute shader (voxelBLASExtractCS.hlsl): converts PackedQuad
StructuredBuffer to float3 position buffer for DXR BLAS input
- Blocky BLAS: single BLAS from all GPU-meshed quads (~1.5M triangles)
- Smooth BLAS: single BLAS from smooth vertex buffer directly
- TLAS: 2 instances (blocky + smooth), identity transforms, CreateBuffer2 with
callback to avoid UpdateBuffer on RAY_TRACING flagged buffers
- Fix: Wicked always accesses index_buffer in CreateRaytracingAccelerationStructure
via to_internal() even for non-indexed geometry — provide dummy valid buffer
