Coverage: the broad missing patch on far tiles was GPU skirt depth using the LOD key
step instead of the exported coarse mesher step (800 vs 1,600 cm at (6,2,0,lod3)).
Fixed; tile pixel-identical to CPU, 680/680 + 64/64 triangles, 1,434 GPU-eligible
tiles (was 1,082). Audits: hashes w1/w8, walk 5,642/5,642, thin/protected 0 diffs
vs CPU and WARP, survival 6.15 GB.
Adaptive start: CPU owns the first view while the shader queue is pending.
My runs outside the sandbox (Step17.exe, interleaved):
CPU 1.375 / 1.363 / 1.354 s
GPU 2.040 (first launch of build; 0 GPU tiles, CPU worker sum 6.98 vs 5.05 s)
/ 1.279 / 1.337 / 1.328 s
Cached warm-up queue now 329-632 ms (step 16: ~3 ms), so GPU took 258 tiles
once and 0 twice: cached GPU ~= CPU, a regression from step 16's 1.26 s.
First launch improved 3.09 -> 2.04 s but still loses to CPU. Also adds
STEP16_REPORT.md, missed in 666dfb8.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MmSoF64BbRFmk9C3p1VsBJ
Fr0zkaandClaude Opus 5.5
6f2d33e0a9