# Linux115 report

Source version 223. Floor height now comes from the planner profile `h(s)` on the dense route, using horizontal projection and arc-length interpolation. In-range projections interpolate on their fine segment; out-of-range projections use the global profile lookup. Adjacent fine segments share the same endpoint value. The plan-time grade audit remains enabled: maximum sampled grade was 10.687° (limit 15°).

## Floor zero crossings

Each station has 51 density samples. Offsets below are in millimetres.

| Passage | Station | Max absolute | Median absolute | P95 absolute |
|---|---:|---:|---:|---:|
| 0–1 | 25% | 0.088 | 0.009 | 0.066 |
| 0–1 | 50% | 0.079 | 0.016 | 0.064 |
| 0–1 | 75% | 0.225 | 0.016 | 0.161 |
| 1–2 | 25% | 7.475 | 7.259 | 7.459 |
| 1–2 | 50% | 7.272 | 7.215 | 7.265 |
| 1–2 | 75% | 7.272 | 7.121 | 7.245 |
| 2–3 | 25% | 7.849 | 7.712 | 7.844 |
| 2–3 | 50% | 7.712 | 7.351 | 7.694 |
| 2–3 | 75% | 7.573 | 7.506 | 7.566 |

Maximum offset is 7.849 mm, below the 10 mm target. Full data: [CSV](../../../../Saved/Linux/l115/density-probe/zero-crossing-offsets.csv) and [summary](../../../../Saved/Linux/l115/density-probe/zero-crossing-summary.json).

## Shell probes and captures

The two L114 southwest wall misses were probe-oracle false positives. Both positions were inside an intentionally carved overlapping passage bore, where host air is correct; the audit had only considered the nearest route span when classifying bore interior. The oracle now recognizes interior air on any overlapping route span. No wall gate was relaxed. The final two-strata audit reports 0 wall violations in 31,361 probes (8,848 overlap-interior skips), 0 floor violations, and 0 interior violations.

The final capture set has 23/23 programmatically verified images: 9 rock-floor close-ups and 14 open-air outside/interior close-ups across 7 sections. Quality labels are 18 `pass` and 5 `low_contrast_geometry_visible`; all five still passed visibility verification. [Capture index](captures/capture-index.json).

## Speed

Coarse candidate totals are L109 3,132, L114 14,384, and L115 3,720 (74.1% fewer than L114). The inner sweep still visits 48.95M fine-segment/sample pairs for both L114 and L115, versus 19.81M for L109, so fewer coarse candidates did not reduce fine traversal enough to improve readiness.

Five interleaved measured runs per version followed warm-ups at W8/W12 for all four strata. The host was quiet before timing (1-minute load 1.30; `top` 99% idle). Values below are L115 near-ready median deltas.

| Stratum | W8 vs L109 / L114 | W12 vs L109 / L114 |
|---|---:|---:|
| 0 | +16.8% / +8.7% | +16.8% / +9.2% |
| 1 | +30.4% / +13.0% | +31.1% / +14.5% |
| 2 | +25.2% / +12.4% | +25.9% / +12.0% |
| 3 | +23.8% / +8.6% | +18.1% / +2.9% |

Across the eight strata/worker combinations, median whole-view deltas were +10.7% versus L109 and +4.9% versus L114. Full run data: [timing summary](../../../../Saved/Linux/l115/timing/summary.json).

## Verification

Fast tier passed in 341.1 s, including walkability, passage shell, camera sweeps, native field, and motif capsule reachability. Clang/GCC hashes matched at W1/W8/W12 for all four owner strata groups. The final source stamp is `7eb1fa49f91954c0690173aba4ed832b3594e50531bd4b20690d122970943274`; no Unreal-compiled source changed, so no Unreal build was needed.