[mbeczynski]

Replaces #7 (closed when its base branch was deleted after merging #6). Same branch, same content.

Changes

• Asphalt — the photo had ~1% albedo (mean 34/255 sRGB), so the road rendered almost black and took ~40% of every frame. Rebrightened in linear space to a realistic ~8–10% and desaturated. New roadSurface shader adds what a 4 m tile cannot have: large-scale patches, polished wheel tracks in every lane, an oil strip, and dust near the kerbs. Road paint and start line were rebaked from the new asphalt (wear thresholds normalised to the old brightness).
• Ground — the texture colour is pulled toward the ground band just below the panorama horizon (e.g. grey sand in front of a white beach), so the 3D ground fades into the photo with no colour seam. City ground is now a pavement (ambientCG PavingStones128, CC0, added to credits) instead of dry grass.
• Haze (bug fix) — the post-process fog never worked: RealityKit passes the post effect an empty depth texture (z = 0 in every pixel; verified with an extreme-fog canary and a depth visualisation, also with MSAA off). Fog now lives in the scenery shaders — ground, road, and every opaque PBR material via the new hazeSurface — with per-region density and range. Post-process fog is disabled so it cannot double up if a device ever provides depth. -haze d,s / -noHaze for tuning (Debug/Family). Photo impostors (trees, unlit) are not hazed yet.
• tools/prep-textures.swift — AO multiply, linear gain with desaturation.

Tests

• swift test: 55 tests, 0 failures; Debug / Family / Release builds succeeded
• Canary: -haze 0.99,20 fogs buildings, walls and road completely (hazy materials in 47–51 models per track)
• Fixed frames (-shotAt 150), 5 regions × race/side camera, before/after compared; garage floor unchanged
• Live 45 s races (city, forest): p95 frame 16.8–16.9 ms (same as before), no crash reports

🤖 Generated with Claude Code

https://claude.ai/code/session_018YYRkMvxEa4GxWLW2SrVyF