# Linux 113 — half-pipe crest, floor bands, and readiness

Version v220 is on `wip/l111-halfpipe-spline` at the existing `16554cd` base. No commit was made.

## Shape and walk audits

The open-air wall uses a 0.75 m rounded shell, three 0.25 m voxels thick. Wall relief fades across the top 0.25 m instead of ending at the crest. The captures show the needle-like spikes are gone; some low scalloping remains at the voxel scale.

All three owner passage plans pass the 15° forward-grade check. Their maximum sampled grades are 10.391°, 10.687°, and 10.289°. Passage, mouth, floor, and shell audits pass.

The floor bands remain visible. On the exported mesh, upward-facing floor samples along the long open-air run show a median 1.25 m interval and 0.21 m vertical drop (most drops are 0.17–0.25 m). The planned grade there is about 10.43°; a 0.25 m voxel row projects to about 1.36 m along that grade. Control points are spaced a median 9.18 m apart, and a temporary 1 m sampler control reproduced the same audit misses. The measured bands align with voxel rows; they do not match the control-point interval or the 0.75 m slab thickness. They were not removed in this round.

## Captures

[Capture index](captures/INDEX.md) contains 50 L112 before images and 50 L113 after images. All 100 pass the pixel and geometry checks. The set includes mouths, stations, open-air views, and 14 after 4 m wall close-ups; their measured camera distance is 4.00 m within 0.02 m.

## Readiness

Five interleaved runs per cell, all four strates. Each value is median `LOD0–2 / whole-view` seconds in **L109 / L112 / L113** order.

| Strate | W8 near | W8 whole | W12 near | W12 whole |
|---|---:|---:|---:|---:|
| SW | 1.038 / 1.027 / 1.511 | 2.291 / 2.235 / 2.947 | 1.304 / 1.623 / 1.629 | 2.476 / 2.886 / 2.819 |
| FI | 1.081 / 1.122 / 1.238 | 2.123 / 2.081 / 2.267 | 1.080 / 1.187 / 1.187 | 2.048 / 2.168 / 2.132 |
| TN | 1.497 / 1.379 / 1.312 | 2.538 / 2.403 / 2.352 | 1.152 / 1.415 / 1.279 | 2.126 / 2.385 / 2.286 |
| VS | 1.444 / 1.617 / 1.136 | 2.676 / 3.117 / 2.639 | 0.818 / 0.896 / 0.925 | 1.753 / 1.824 / 1.853 |

FI/TN W12 near readiness is 1.187 / 1.279 s for L113 versus 1.080 / 1.152 s for the matched L109 rerun. The speed target was not met.

| Strate | L109 p95/max | L112 p95/max | L113 p95/max candidates per tile |
|---|---:|---:|---:|
| SW | 3 / 21 | 18 / 185 | 14 / 137 |
| FI | 4 / 47 | 22 / 420 | 17 / 297 |
| TN | 4 / 23 | 22 / 116 | 18 / 92 |
| VS | 4 / 16 | 18 / 82 | 12 / 58 |

The second speed design, an exact segment-to-tile distance filter, barely changed L113 candidate counts and did not recover near readiness. It was removed; there was no third design.

## Verification

- Fast tier: PASS, 264 checks.
- Clang/GCC determinism: all 18 W1/W8/W12 hash runs match within each owner configuration.
- Linux `VFHostEditor`: succeeded after timing with `-NoUBA -MaxParallelActions=4`; no `prlimit` was used.
- No commit, push, or stash.