# L64 Linux baseline

## Empty top-strate result

**SurfaceWorld is not empty.** U2’s gate report says its sampled top window had 0 triangles, but does not give the camera/window coordinates. With the current owner file (SHA-256 `f42f96adca58…`), the correct SurfaceWorld windows mesh on Clang: the file `viewer_start` `(0, 0, -496 m)` gives 9/27 nonempty LOD0 tiles and 36,864 triangles; the resolved route arrival `(38.75, 70.75, -374.121 m)` gives 9/27 and 25,672; the departure mouth `(-6.75, 25.25, -376.307 m)` gives 11/27 and 33,582. The binding is `SurfaceWorld-native`; the 57 boundary probes had 0 dispatch disagreements. This points to the gate’s sample window placement, not an empty field or wrong generator binding. The precise U2 sample point cannot be confirmed from its report.

There is a separate owner-plan defect: strict layout validation rejects `passage/0-1/0` because its lower mouth is at z = −822.06 m, 78.56 m below FloatingIslands’ content band (bottom −743.5 m; that point is in TunnelNetwork). The plan’s passage audit also fails; details are below.

## Bisect

All 57 commits in `a176d07^..3202193` were exported and built with Clang 19, `-ffp-contract=off`, `-j12`, taskset CPUs 0–11, a 6 GiB address-space limit, and `TMPDIR` under `Saved/`. 56 built. `3e443bf` (L37/R1) fails to compile on an extra `)`; its following L37 fix `7f2d84d` builds. The timing matrix has 402 successful runs: three shuffled/interleaved passes per recipe and data/commit configuration. Every run used the same view `(−12, −118, −20 m)`, 12 workers, `--force-generate`, clip radius 3, max clip level 8, LOD8 step 0, hash off. The fixed data was `3202193` (`7b095f9b…`) for every commit; commits before L24 also ran the pre-L24 file (`289cd755…`).

**Not Core.** On fixed data, SurfaceWorld LOD0 worker time per tile is 10.05 ms at L14 and 12.78 ms at L61 (1.27×); whole-view is 4.31 s and 5.02 s (1.16×). The summed worker time across LOD0–8 is 31.2 s and 38.7 s (1.24×). This does not reproduce the Windows roughly 2× per-tile rise, so the cause is on the Unreal side: U1 or the adapter’s Core driving path. No Core fix was made; `Source/` was untouched.

`W/F/N/Σ/L0` below means whole-view seconds / first-tile seconds / near-ring seconds / summed worker-seconds across LOD0–8 / LOD0 worker-ms per tile. Each parenthesized percent is the delta against L14 for the same recipe and data file. L0 steps mark upward changes of at least 10% versus the previous successful commit in that dataset. For LOD0 p50/p95, builds before L55 lack tile-drain counters; later values are from separate `--instrument-tile-drain` passes on the same view/data (SW then FI, ms). Those opt-in passes have force-generation off, as required for the counters, and do not contribute to the timing medians.

| Round | Commit | Data | SW W/F/N/Σ/L0 (Δ%) | FI W/F/N/Σ/L0 (Δ%) | L0 step ≥10% | LOD0 p50/p95 SW; FI (ms) |
|---|---|---|---|---|---|---|
| L14 | `a176d07` | 3202193 | 4.31 (+0%) / 1.71 (+0%) / 1.76 (+0%) / 31.2 (+0%) / 10.05 (+0%) | 23.57 (+0%) / 3.21 (+0%) / 3.61 (+0%) / 236.6 (+0%) / 166.93 (+0%) | — | — |
| L14 | `a176d07` | pre-L24 | 4.53 (+0%) / 1.61 (+0%) / 1.67 (+0%) / 34.6 (+0%) / 11.71 (+0%) | 26.34 (+0%) / 3.91 (+0%) / 4.70 (+0%) / 291.3 (+0%) / 236.10 (+0%) | — | — |
| L15 | `a6cd7cf` | 3202193 | 4.26 (-1%) / 1.44 (-16%) / 1.49 (-15%) / 32.1 (+3%) / 10.50 (+5%) | 23.88 (+1%) / 3.67 (+15%) / 4.30 (+19%) / 249.3 (+5%) / 179.96 (+8%) | — | — |
| L15 | `a6cd7cf` | pre-L24 | 2.96 (-35%) / 1.33 (-17%) / 1.36 (-18%) / 19.4 (-44%) / 5.30 (-55%) | 27.50 (+4%) / 3.62 (-7%) / 4.33 (-8%) / 297.1 (+2%) / 247.25 (+5%) | — | — |
| L16 | `9a7c87e` | 3202193 | 3.59 (-17%) / 1.60 (-6%) / 1.65 (-6%) / 23.9 (-23%) / 8.47 (-16%) | 23.94 (+2%) / 3.92 (+22%) / 4.26 (+18%) / 256.3 (+8%) / 182.06 (+9%) | — | — |
| L16 | `9a7c87e` | pre-L24 | 4.49 (-1%) / 1.75 (+9%) / 1.81 (+9%) / 32.7 (-5%) / 10.08 (-14%) | 26.57 (+1%) / 3.66 (-6%) / 4.65 (-1%) / 271.7 (-7%) / 231.16 (-2%) | SW ↑90.2% | — |
| L17 | `8704129` | 3202193 | 3.95 (-8%) / 1.51 (-12%) / 1.56 (-11%) / 29.9 (-4%) / 9.06 (-10%) | 24.71 (+5%) / 3.95 (+23%) / 4.67 (+29%) / 264.2 (+12%) / 176.04 (+5%) | — | — |
| L17 | `8704129` | pre-L24 | 2.93 (-35%) / 0.87 (-46%) / 0.94 (-44%) / 26.0 (-25%) / 8.88 (-24%) | 25.58 (-3%) / 2.40 (-38%) / 3.11 (-34%) / 278.4 (-4%) / 231.14 (-2%) | — | — |
| L18 | `dcf0763` | 3202193 | 4.08 (-5%) / 1.55 (-9%) / 1.60 (-9%) / 31.4 (+1%) / 10.92 (+9%) | 29.75 (+26%) / 3.56 (+11%) / 4.42 (+22%) / 317.7 (+34%) / 257.73 (+54%) | SW ↑20.5%, FI ↑46.4% | — |
| L18 | `dcf0763` | pre-L24 | 4.02 (-11%) / 1.65 (+3%) / 1.70 (+2%) / 28.4 (-18%) / 6.94 (-41%) | 25.67 (-3%) / 4.14 (+6%) / 4.96 (+6%) / 258.9 (-11%) / 177.66 (-25%) | — | — |
| L19 | `811c4b7` | 3202193 | 4.79 (+11%) / 1.80 (+5%) / 1.85 (+5%) / 36.5 (+17%) / 12.45 (+24%) | 26.15 (+11%) / 2.54 (-21%) / 3.15 (-13%) / 283.8 (+20%) / 235.00 (+41%) | SW ↑14.1% | — |
| L19 | `811c4b7` | pre-L24 | 3.51 (-23%) / 0.80 (-50%) / 0.86 (-49%) / 32.4 (-6%) / 9.34 (-20%) | 25.38 (-4%) / 3.94 (+1%) / 4.64 (-1%) / 259.8 (-11%) / 213.94 (-9%) | SW ↑34.6%, FI ↑20.4% | — |
| L20 | `6f9c7bd` | 3202193 | 4.52 (+5%) / 1.74 (+2%) / 1.78 (+1%) / 33.3 (+7%) / 12.08 (+20%) | 23.30 (-1%) / 2.36 (-27%) / 3.22 (-11%) / 253.6 (+7%) / 173.02 (+4%) | — | — |
| L20 | `6f9c7bd` | pre-L24 | 4.32 (-5%) / 1.65 (+2%) / 1.69 (+1%) / 31.9 (-8%) / 10.91 (-7%) | 22.85 (-13%) / 2.18 (-44%) / 3.41 (-27%) / 229.8 (-21%) / 170.36 (-28%) | SW ↑16.8% | — |
| L20 review | `5d5447d` | 3202193 | 4.76 (+11%) / 1.63 (-4%) / 1.70 (-3%) / 35.1 (+13%) / 11.85 (+18%) | 25.93 (+10%) / 3.91 (+22%) / 4.78 (+33%) / 275.4 (+16%) / 227.96 (+37%) | FI ↑31.8% | — |
| L20 review | `5d5447d` | pre-L24 | 4.50 (-1%) / 1.65 (+3%) / 1.72 (+3%) / 34.5 (-0%) / 11.83 (+1%) | 27.01 (+3%) / 3.09 (-21%) / 3.87 (-18%) / 284.0 (-3%) / 225.37 (-5%) | FI ↑32.3% | — |
| L21 | `8753f6d` | 3202193 | 4.26 (-1%) / 1.50 (-12%) / 1.56 (-11%) / 33.0 (+6%) / 11.30 (+12%) | 26.21 (+11%) / 3.80 (+19%) / 5.09 (+41%) / 268.6 (+14%) / 192.22 (+15%) | — | — |
| L21 | `8753f6d` | pre-L24 | 3.78 (-17%) / 1.02 (-37%) / 1.12 (-33%) / 33.1 (-4%) / 10.18 (-13%) | 23.71 (-10%) / 3.73 (-5%) / 4.60 (-2%) / 260.3 (-11%) / 196.70 (-17%) | — | — |
| L22 | `55c26a0` | 3202193 | 4.01 (-7%) / 1.48 (-13%) / 1.55 (-12%) / 28.9 (-7%) / 10.23 (+2%) | 35.34 (+50%) / 4.74 (+48%) / 5.49 (+52%) / 369.9 (+56%) / 240.61 (+44%) | FI ↑25.2% | — |
| L22 | `55c26a0` | pre-L24 | 4.13 (-9%) / 1.58 (-2%) / 1.64 (-2%) / 30.4 (-12%) / 11.32 (-3%) | 33.67 (+28%) / 3.50 (-11%) / 4.07 (-13%) / 360.8 (+24%) / 273.30 (+16%) | SW ↑11.2%, FI ↑38.9% | — |
| L23 | `71d09a8` | 3202193 | 3.38 (-21%) / 1.54 (-10%) / 1.60 (-9%) / 22.0 (-29%) / 9.67 (-4%) | 33.92 (+44%) / 3.21 (+0%) / 3.77 (+4%) / 359.9 (+52%) / 234.50 (+40%) | — | — |
| L23 | `71d09a8` | pre-L24 | 4.34 (-4%) / 1.70 (+6%) / 1.76 (+5%) / 31.5 (-9%) / 10.93 (-7%) | 30.60 (+16%) / 4.29 (+10%) / 5.16 (+10%) / 316.1 (+9%) / 222.51 (-6%) | — | — |
| L24 | `cb9236c` | 3202193 | 2.83 (-34%) / 0.95 (-44%) / 1.03 (-42%) / 17.5 (-44%) / 6.50 (-35%) | 36.87 (+56%) / 4.38 (+37%) / 5.18 (+44%) / 404.1 (+71%) / 298.88 (+79%) | FI ↑27.5% | — |
| L25 | `ef789aa` | 3202193 | 4.29 (-0%) / 1.72 (+1%) / 1.78 (+1%) / 30.8 (-1%) / 10.86 (+8%) | 36.36 (+54%) / 2.18 (-32%) / 2.88 (-20%) / 387.8 (+64%) / 286.83 (+72%) | SW ↑67.0% | — |
| L26 | `37a2230` | 3202193 | 4.06 (-6%) / 1.69 (-1%) / 1.76 (-0%) / 32.4 (+4%) / 7.90 (-21%) | 43.11 (+83%) / 4.54 (+42%) / 5.28 (+46%) / 456.7 (+93%) / 325.35 (+95%) | FI ↑13.4% | — |
| L27 | `07b3fe2` | 3202193 | 4.10 (-5%) / 1.44 (-16%) / 1.49 (-16%) / 32.2 (+3%) / 9.12 (-9%) | 40.19 (+71%) / 3.68 (+15%) / 4.79 (+33%) / 441.3 (+87%) / 255.16 (+53%) | SW ↑15.4% | — |
| L28 | `f23ab7b` | 3202193 | 4.44 (+3%) / 1.72 (+1%) / 1.78 (+1%) / 32.1 (+3%) / 10.38 (+3%) | 32.25 (+37%) / 3.55 (+11%) / 4.26 (+18%) / 339.3 (+43%) / 248.36 (+49%) | SW ↑13.9% | — |
| L29 | `63c7e56` | 3202193 | 2.55 (-41%) / 0.72 (-58%) / 0.75 (-58%) / 21.5 (-31%) / 6.19 (-38%) | 34.47 (+46%) / 2.83 (-12%) / 3.64 (+1%) / 376.1 (+59%) / 265.76 (+59%) | — | — |
| L30 | `103d8b4` | 3202193 | 4.41 (+2%) / 1.59 (-7%) / 1.65 (-6%) / 32.1 (+3%) / 10.65 (+6%) | 36.40 (+54%) / 4.25 (+33%) / 4.96 (+37%) / 387.8 (+64%) / 303.13 (+82%) | SW ↑72.0%, FI ↑14.1% | — |
| L31 | `28069f0` | 3202193 | 3.12 (-27%) / 1.55 (-9%) / 1.61 (-8%) / 18.8 (-40%) / 7.23 (-28%) | 37.60 (+60%) / 4.14 (+29%) / 5.17 (+43%) / 407.7 (+72%) / 296.35 (+78%) | — | — |
| L32 | `d0158c6` | 3202193 | 4.88 (+13%) / 1.57 (-8%) / 1.71 (-3%) / 37.2 (+19%) / 12.07 (+20%) | 34.29 (+46%) / 2.85 (-11%) / 3.31 (-8%) / 362.5 (+53%) / 229.88 (+38%) | SW ↑66.9% | — |
| L33 | `b7a47be` | 3202193 | 2.65 (-38%) / 0.86 (-49%) / 0.89 (-50%) / 21.3 (-32%) / 9.38 (-7%) | 31.98 (+36%) / 2.91 (-9%) / 3.84 (+7%) / 350.3 (+48%) / 257.32 (+54%) | FI ↑11.9% | — |
| L34 | `49e29fc` | 3202193 | 4.40 (+2%) / 1.53 (-11%) / 1.58 (-10%) / 34.5 (+11%) / 10.81 (+8%) | 36.15 (+53%) / 4.22 (+31%) / 5.02 (+39%) / 378.7 (+60%) / 252.48 (+51%) | SW ↑15.3% | — |
| L35 | `ba01707` | 3202193 | 4.80 (+11%) / 1.77 (+4%) / 1.84 (+4%) / 36.0 (+15%) / 7.08 (-30%) | 35.01 (+49%) / 4.17 (+30%) / 4.96 (+37%) / 390.0 (+65%) / 289.50 (+73%) | FI ↑14.7% | — |
| L36 | `8be1c4d` | 3202193 | 3.67 (-15%) / 1.03 (-40%) / 1.08 (-39%) / 34.2 (+10%) / 10.92 (+9%) | 34.93 (+48%) / 2.72 (-15%) / 3.21 (-11%) / 384.8 (+63%) / 266.69 (+60%) | SW ↑54.2% | — |
| L37/R1 | `3e443bf` | 3202193 | — | — | compile fail | — |
| L37 fix/R2 | `7f2d84d` | 3202193 | 4.42 (+3%) / 1.73 (+1%) / 1.78 (+1%) / 32.2 (+3%) / 10.07 (+0%) | 38.96 (+65%) / 4.48 (+40%) / 5.25 (+46%) / 417.3 (+76%) / 259.39 (+55%) | — | — |
| R3 | `945225d` | 3202193 | 4.86 (+13%) / 1.85 (+8%) / 1.91 (+9%) / 35.3 (+13%) / 10.69 (+6%) | 33.96 (+44%) / 2.68 (-17%) / 3.43 (-5%) / 374.9 (+58%) / 266.08 (+59%) | — | — |
| L38/R4 | `cf57c87` | 3202193 | 3.14 (-27%) / 1.34 (-22%) / 1.36 (-23%) / 21.5 (-31%) / 5.96 (-41%) | 37.38 (+59%) / 4.72 (+47%) / 5.58 (+55%) / 396.3 (+67%) / 252.07 (+51%) | — | — |
| R5 | `88c54ea` | 3202193 | 3.37 (-22%) / 1.46 (-15%) / 1.56 (-11%) / 30.5 (-2%) / 11.09 (+10%) | 39.45 (+67%) / 3.52 (+10%) / 4.89 (+36%) / 416.6 (+76%) / 265.16 (+59%) | SW ↑85.8% | — |
| L39/R6 | `753cc9c` | 3202193 | 3.32 (-23%) / 0.86 (-50%) / 0.88 (-50%) / 21.7 (-31%) / 9.49 (-5%) | 37.03 (+57%) / 4.41 (+37%) / 5.56 (+54%) / 389.5 (+65%) / 232.40 (+39%) | — | — |
| L40/R7 | `efa9e89` | 3202193 | 4.57 (+6%) / 1.62 (-5%) / 1.68 (-4%) / 35.3 (+13%) / 10.78 (+7%) | 38.63 (+64%) / 3.39 (+6%) / 3.89 (+8%) / 412.4 (+74%) / 306.46 (+84%) | SW ↑13.6%, FI ↑31.9% | — |
| L41/R8 | `1abee91` | 3202193 | 4.30 (-0%) / 1.71 (+0%) / 1.81 (+3%) / 26.8 (-14%) / 8.08 (-20%) | 38.25 (+62%) / 2.88 (-10%) / 3.42 (-5%) / 413.8 (+75%) / 324.95 (+95%) | — | — |
| L42/R9 | `2566f53` | 3202193 | 4.37 (+1%) / 1.51 (-11%) / 1.56 (-11%) / 34.1 (+9%) / 10.05 (+0%) | 37.43 (+59%) / 2.15 (-33%) / 2.48 (-31%) / 427.7 (+81%) / 306.73 (+84%) | SW ↑24.4% | — |
| R9 | `497e974` | 3202193 | 4.55 (+6%) / 1.75 (+2%) / 1.79 (+2%) / 33.5 (+7%) / 10.31 (+3%) | 35.69 (+51%) / 4.87 (+52%) / 5.68 (+57%) / 372.0 (+57%) / 257.01 (+54%) | — | — |
| L43/R10 | `422dd77` | 3202193 | 3.54 (-18%) / 1.60 (-6%) / 1.69 (-4%) / 23.7 (-24%) / 8.14 (-19%) | 37.50 (+59%) / 2.92 (-9%) / 3.37 (-7%) / 401.3 (+70%) / 320.95 (+92%) | FI ↑24.9% | — |
| L44 | `036bd53` | 3202193 | 3.48 (-19%) / 0.95 (-44%) / 1.03 (-41%) / 30.2 (-3%) / 10.30 (+3%) | 36.78 (+56%) / 4.32 (+35%) / 5.20 (+44%) / 390.7 (+65%) / 239.12 (+43%) | SW ↑26.6% | — |
| L45/R12 | `f13b145` | 3202193 | 4.50 (+5%) / 1.67 (-2%) / 1.75 (-1%) / 33.9 (+9%) / 10.38 (+3%) | 38.59 (+64%) / 4.50 (+40%) / 5.26 (+46%) / 410.7 (+74%) / 300.28 (+80%) | FI ↑25.6% | — |
| L46/R13 | `e016f6a` | 3202193 | 4.15 (-4%) / 1.93 (+13%) / 2.01 (+14%) / 31.3 (+1%) / 9.64 (-4%) | 38.45 (+63%) / 4.10 (+28%) / 4.99 (+38%) / 406.5 (+72%) / 296.82 (+78%) | — | — |
| L47/R14 | `c091e44` | 3202193 | 4.70 (+9%) / 1.84 (+8%) / 1.90 (+8%) / 35.6 (+14%) / 10.76 (+7%) | 39.16 (+66%) / 4.03 (+26%) / 4.72 (+31%) / 420.2 (+78%) / 274.84 (+65%) | SW ↑11.6% | — |
| L48/R15 | `3073d1b` | 3202193 | 4.66 (+8%) / 1.54 (-10%) / 1.65 (-7%) / 37.4 (+20%) / 11.89 (+18%) | 37.86 (+61%) / 3.98 (+24%) / 4.82 (+33%) / 406.9 (+72%) / 289.92 (+74%) | SW ↑10.5% | — |
| R16 | `6110f11` | 3202193 | 4.72 (+10%) / 1.47 (-14%) / 1.59 (-10%) / 33.1 (+6%) / 10.39 (+3%) | 35.86 (+52%) / 2.42 (-25%) / 3.66 (+1%) / 400.1 (+69%) / 284.96 (+71%) | — | — |
| R17 | `b9ccff4` | 3202193 | 3.78 (-12%) / 1.33 (-22%) / 1.36 (-22%) / 34.4 (+10%) / 10.78 (+7%) | 38.70 (+64%) / 4.79 (+49%) / 5.58 (+55%) / 409.9 (+73%) / 282.19 (+69%) | — | — |
| L50/R18-R19 | `ca85e87` | 3202193 | 4.95 (+15%) / 1.76 (+3%) / 1.84 (+4%) / 38.2 (+22%) / 11.85 (+18%) | 36.53 (+55%) / 4.80 (+50%) / 5.20 (+44%) / 381.1 (+61%) / 251.21 (+50%) | — | — |
| L51/R20 | `7555025` | 3202193 | 4.44 (+3%) / 1.61 (-6%) / 1.67 (-5%) / 33.8 (+8%) / 10.63 (+6%) | 18.33 (-22%) / 2.32 (-28%) / 2.80 (-22%) / 174.2 (-26%) / 180.36 (+8%) | — | — |
| L51 | `c42c785` | 3202193 | 4.47 (+4%) / 1.61 (-6%) / 1.67 (-5%) / 32.2 (+3%) / 9.50 (-5%) | 14.36 (-39%) / 2.78 (-13%) / 3.17 (-12%) / 140.5 (-41%) / 131.17 (-21%) | — | — |
| L52/R21 | `408c14b` | 3202193 | 4.49 (+4%) / 1.58 (-7%) / 1.65 (-6%) / 35.5 (+14%) / 11.05 (+10%) | 12.50 (-47%) / 4.75 (+48%) / 5.20 (+44%) / 102.9 (-57%) / 125.17 (-25%) | SW ↑16.3% | — |
| L53/R22 | `20f6c98` | 3202193 | 4.42 (+3%) / 1.66 (-3%) / 1.83 (+4%) / 29.4 (-6%) / 9.54 (-5%) | 11.57 (-51%) / 3.77 (+17%) / 4.18 (+16%) / 112.4 (-52%) / 134.18 (-20%) | — | — |
| L54/R23 | `9458217` | 3202193 | 4.62 (+7%) / 1.50 (-12%) / 1.56 (-12%) / 35.6 (+14%) / 11.17 (+11%) | 14.71 (-38%) / 4.59 (+43%) / 5.11 (+42%) / 123.4 (-48%) / 137.96 (-17%) | SW ↑17.1% | — |
| L54 | `e35a77f` | 3202193 | 2.66 (-38%) / 0.77 (-55%) / 0.81 (-54%) / 22.6 (-27%) / 8.05 (-20%) | 12.72 (-46%) / 2.50 (-22%) / 3.18 (-12%) / 94.6 (-60%) / 92.67 (-44%) | — | — |
| L55/R24 | `aee1487` | 3202193 | 4.16 (-3%) / 1.73 (+1%) / 1.79 (+2%) / 27.7 (-11%) / 8.99 (-11%) | 10.74 (-54%) / 1.45 (-55%) / 1.65 (-54%) / 111.8 (-53%) / 146.17 (-12%) | SW ↑11.7%, FI ↑57.7% | 4.65/11.20; 94.70/122.83 |
| L56/R25 | `4e64b75` | 3202193 | 3.11 (-28%) / 0.76 (-55%) / 0.79 (-55%) / 28.0 (-10%) / 10.12 (+1%) | 9.68 (-59%) / 2.65 (-17%) / 3.23 (-10%) / 87.3 (-63%) / 95.93 (-43%) | SW ↑12.5% | 4.61/11.62; 97.07/124.52 |
| L57/R26 | `1e3e04b` | 3202193 | 5.11 (+19%) / 1.59 (-7%) / 1.67 (-5%) / 43.7 (+40%) / 14.12 (+41%) | 12.83 (-46%) / 2.48 (-23%) / 2.83 (-21%) / 125.4 (-47%) / 130.60 (-22%) | SW ↑39.6%, FI ↑36.1% | 4.77/11.47; 86.41/114.69 |
| L58/R27 | `6c6cc37` | 3202193 | 3.72 (-14%) / 0.93 (-46%) / 0.98 (-44%) / 33.5 (+7%) / 10.09 (+0%) | 9.00 (-62%) / 1.93 (-40%) / 2.13 (-41%) / 85.1 (-64%) / 95.95 (-43%) | — | 4.62/11.10; 86.08/114.90 |
| R28 | `fbae82e` | 3202193 | 4.85 (+13%) / 1.85 (+8%) / 1.90 (+8%) / 35.9 (+15%) / 11.24 (+12%) | 10.47 (-56%) / 2.18 (-32%) / 2.42 (-33%) / 99.6 (-58%) / 109.15 (-35%) | SW ↑11.5%, FI ↑13.8% | 4.71/11.40; 85.49/114.11 |
| L60 | `c0c204b` | 3202193 | 3.22 (-25%) / 1.46 (-14%) / 1.49 (-16%) / 21.0 (-33%) / 8.59 (-15%) | 11.36 (-52%) / 2.61 (-19%) / 2.99 (-17%) / 101.0 (-57%) / 96.22 (-42%) | — | 5.21/11.99; 85.26/114.07 |
| L61/R31 | `1359578` | 3202193 | 5.02 (+16%) / 1.79 (+5%) / 1.86 (+6%) / 38.7 (+24%) / 12.78 (+27%) | 13.38 (-43%) / 2.92 (-9%) / 3.26 (-10%) / 126.2 (-47%) / 131.47 (-21%) | SW ↑48.8%, FI ↑36.6% | 5.01/11.65; 85.11/113.95 |
| R32 | `3202193` | 3202193 | 3.69 (-14%) / 1.61 (-6%) / 1.71 (-3%) / 27.2 (-13%) / 11.06 (+10%) | 12.73 (-46%) / 2.60 (-19%) / 2.94 (-18%) / 124.2 (-48%) / 131.70 (-21%) | — | 4.89/11.24; 86.41/114.52 |

## Four-strate U2 baseline

The local mesh windows are all nonempty and deterministic at W1/W8/W12 on Clang and GCC. Each hash vector matched across all six compiler/worker configurations. The cost numbers are medians of three W12 full-view runs using the comparable clip-radius-3 speed-matrix configuration, with each camera in the named stratum. Because the owner plan fails strict ownership and passage validation, these full-view cost runs use a temporary diagnostic binary that continues after those validators; no in-tree Core or Unreal `Source/` file was changed; the bypass is confined to `Saved/Linux/l64/u2cost/export`. The cost cameras were SW `viewer_start` `(0, 0, -496 m)`, FI passage-1 upper mouth `(19.166, -14.200, -732.201 m)`, TN passage-1 lower mouth `(19.166, -14.200, -753.374 m)`, and VS passage-2 lower mouth `(−20.063, −5.068, −900.354 m)`. The SW local mesh window above is the resolved route arrival, not its cost camera.

| Strate (chunks; content band) | Core generator path | Local window (nonempty/27; triangles) | Determinism | Whole-view W/F/N/Σ/L0 | Arrival→departure audit |
|---|---|---|---|---|---|
| SW (0…−63; −503.5…7.5 m) | SurfaceWorld-native | route spawn: 9/27; 25,672 | W1/W8/W12 Clang/GCC: PASS | 6.34/0.63/0.80/68.8/60.39 | SW route fails: 24/33 points unsupported; SW→FI interface fails |
| FI (−64…−93; −743.5…−504.5 m) | compiled-analytic/FloatingIslands (legacy) | passage 1 upper mouth: 21/27; 93,149 | W1/W8/W12 Clang/GCC: PASS | 8.41/0.53/0.97/95.1/74.21 | SW→FI lower mouth out of band; FI→TN interface fails |
| TN (−94…−109; −871.5…−744.5 m) | compiled-analytic/TunnelNetwork (legacy) | passage 1 lower mouth: 13/27; 65,248 | W1/W8/W12 Clang/GCC: PASS | 6.50/0.53/0.79/71.6/56.33 | FI→TN and TN→VS interfaces fail |
| VS (−110…−125; −999.5…−872.5 m) | compiled-analytic/VerticalShafts (legacy) | passage 2 lower mouth: 5/27; 4,761 | W1/W8/W12 Clang/GCC: PASS | 3.39/0.52/0.54/34.6/14.51 | TN→VS: 3 unsupported; floor ripple 3.57 cm > 2.5 cm |

Across the three interface audits, 0/3 passages passed. In addition to the out-of-band 0–1 mouth, passage 1–2 has floor ripple 4.78 cm (2.5 cm limit), and 2–3 has 3.57 cm ripple; unsupported/blocked samples also remain. Native caves and lattice are not enabled in this plan; TN and VS use their legacy analytic evaluators.

## Failed runs

- Historical build `3e443bf` (L37/R1) failed at `ShapeWorldInternal.h:1554` with an extra `)`; the next L37 fix built and was measured. The corrected bisect has 402/402 successful timing runs. An earlier discarded invocation used unsupported `--data=` syntax and was replaced by the positional data path.
- `verify.py --tier fast --out Saved/Linux/l64` in the copied legacy-plan shadow reached the motif fixture and exited 1: `motif-slice1-capsule-reachability-clang` rejected its motif override because it did not resolve to a SurfaceWorld strate. Its hard-coded two-strata style map does not validate U2; U2 boundary, determinism, and passage audits are reported above. A first stale-source-stamp refusal was corrected by copying the L37 audit script into the shadow.
- The first U2 whole-view SW pass exited at the passage walkability gate (`65/7,729` samples solid). The cost table reruns use the same diagnostic binary for all four strata with route validation bypassed, and retain the audit failure. A first build attempt also used a nonexistent `TMPDIR`; it was corrected and the diagnostic build passed.

Evidence is under `Saved/Linux/l64`: `runs-spawn-correct.json` and `runs-spawn-correct/`, `profiles-spawn.json`, `u2probe/determinism.json`, `u2probe/passage-audit-clang.log`, `u2probe/boundary-dispatch.log`, `u2cost/speed-cost.json`, and `verify-fast.log`.

## Orchestrator review (Claude)

**The bisect timings are inflated by machine contention.** I was building Unreal Engine on cores 12–19 during this
round (memory bandwidth and disk I/O), and adjacent commits swing ±40%. A clean re-measure on a quiet machine
(6 interleaved runs each, same binaries, data `owner_world-3202193.json`, same command and camera):

| Build | Whole view (median of 6) | Worker-s, LOD0–8 | LOD0 ms/tile |
|---|---:|---:|---:|
| L14 `a176d07` | ≈1.55 s | 12.62 | 3.99 |
| L61 `1359578` | ≈1.72 s | 14.65 | 4.99 |

**Core regressed about +16% in worker time and +25% per LOD0 tile, not ×2.** The owner's Windows trace shows about
33 ms per LOD0 tile p95, roughly 6× Core's per-tile cost here, so most of the Windows regression is on the Unreal side
or isn't a like-for-like comparison (R33: U1's trace was not a controlled A/B, at 2,578 tiles). Core's own +16% is
plausibly R33 suspect #1: per-sample `ApplyResolvedStrateComposition` (L23) plus the per-sample passage loop (L37).
**The new four-strate plan has real defects:**
- passage 0–1's lower mouth is out of FI's band;
- all three interfaces fail their audits;
- FI, TN and VS run on legacy evaluators;
- the full view costs 3.4–8.4 s per strate.

Next: get the Linux UE build to compile, then trace the Unreal path itself for L14 vs HEAD here.