The owner proved in game that the tunnel core caused the ribs (voxel.TunnelAblateTunnelCore=1 removes them). Root cause: the core's final reassertion replaced any sufficiently interior sample with a fixed +16 air density, destroying the distance gradient, so marching cubes snapped the surface to the voxel grid (all 385 centre samples saturated). The core now reasserts the continuous -Core.SDF, with bottom polarity from the swept shape. The Catmull-Rom sweep from 0231072 is reverted (it cost 18-30% and did not help); the linear tapered-capsule sweep is restored.
Owner decisions implemented: bTunnelFloorEnabled has no runtime effect (reflected only for asset compatibility, ignored on PostLoad), and the authored slab / graph support-floor paths are detached from generation, so the tunnel's own carved shape is the floor. Winding and dramatic ledges no longer depend on the floor switch. Degrees authoring, its migration, and the 3840-voxel route cap stay. Mouth trim stays behind voxel.TunnelMouthTrim (default off).
Evidence: along owner tunnel 15, 385 samples at 0.25 voxel, periodic surface amplitude floor 3.55 -> 0.50 cm, wall 16.9 -> 1.10 cm, ceiling 8.80 -> 0.69 cm (acceptance < 2 cm); 0/385 samples saturated. Matched-camera render: ribs absent. Canonical walk: Connected, player-fit 41,184 (was 20,830), walk-only 13,879 (was 10,909), mouth gap 0; mesh identical with -voxel.CrtFma3=0. TilePostReachProof, DetSinCos, strate connectivity 16/16, strate crossing: pass. Perf, one S/M/S/M pair vs a rebuilt bf9384a DLL: static 26.10 vs 25.41 s (+2.7%), moving 55.34 vs 53.08 s (+4.2%), request p95 about equal. Treat as a possible small cost to re-measure, not as noise.
Not merged into experimental: waiting for the owner's in-game look.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MmSoF64BbRFmk9C3p1VsBJ
Fr0zkaandClaude Opus 5
4fa3931176