Wonderbox-inspired lighting overhaul across all 3 pixel shaders:
- Hemisphere ambient (sky blue above, warm brown below) replaces flat ambient
- RT shadows lerp toward blue-violet tint instead of plain darkening (factor 0.55)
- Rim light (fresnel) with warm golden color on silhouettes (30% on vegetation)
- Soft exponential tone mapping + saturation boost in final post-process pass
- CB parameters for all lighting values (skyAmbient, groundAmbient, shadowTint, etc.)
- Fog color/density centralized from CB instead of hardcoded per-shader
- Screenshot mode (CLI "screenshot"): fixed camera, AO convergence, auto-capture
- AO noise stability: world-space hash using voxel center + tangent-axis frac position
- AO distance-weighted falloff: continuous occlusion values instead of binary hit/miss
- Interleaved Gradient Noise replaces world-space hash for ray sampling
- Cranley-Patterson rotation (golden ratio × frameIndex) per frame
- Temporal accumulation: blend 5% current + 95% reprojected history (~20 frames)
- aoHistoryTexture_ persists between frames, copy pre-blur for next frame
- prevViewProjection added to VoxelCB for screen-space reprojection
- Push constants: frameIndex + historyValid for temporal control
- Result: nearly noise-free AO with only 8 rays per pixel
- 8 cosine-weighted hemisphere rays per pixel (inline ray queries, SM 6.5)
- Distance-weighted AO: quadratic falloff (1-hitT/aoRadius)² instead of binary hit/miss
- World-space hash seed: voxel coord + tangent-plane frac position (stable, no flicker)
- Bilateral blur pipeline: 2-pass separable (H+V), radius 6, depth+normal edge-stopping
- 4-pass dispatch: shadow+rawAO → blur H → blur V → apply
- AO written to separate R8_UNORM texture, blurred, then applied to color buffer
- Debug mode (F5 x3): grayscale AO visualization
Add shadow compute shader (voxelShadowCS.hlsl) that traces rays toward
the sun using DXR inline ray queries (RayQuery<>, SM 6.5). Shadows
modulate voxelRT_ in-place via RWTexture2D (no extra render target).
Key fixes to Phase 6.1 BLAS/TLAS infrastructure:
- Sequential index buffer required: Wicked treats IndexCount=0 with
non-null IndexBuffer as "0 indexed triangles" → empty BLAS
- Memory barriers between BLAS→TLAS→RT: without GPUBarrier::Memory()
the TLAS build races with BLAS builds, causing zero ray hits
- inverseViewProjection added to VoxelCB for depth reconstruction
F5 toggles shadows OFF→ON→DEBUG (red=hit, green=miss, blue=backface).
