# L56 — R24 slice 1: slab + sparse motifs

**Result: PASS.** The native family adds one `flatField` stratum with one monument and one low platform. Fins remain on hold.

## Records and field

Motif vocabulary v3 resolves two version-1 records with placement keyed by `(seed, strate, stable_id)`, route keepouts, band clearance, and 15 m pairwise spacing. Fixture seed is 0; both records attach to the floor at Z = -529.600 m.

- `motif/monolith-01-v1`: rounded capped cylinder, radius 1.4 m (within R20 profile 0.8–2 m), height 24 m; route offset +28 m; placement radius 4 m. Resolved center `(3.922, -33.622, -517.600)` m; record seed `1544480482218982`.
- `motif/platform-01-v1`: rounded-box plinth, half extents `(3.2, 2.8, 0.75)` m; route offset -35 m; placement radius 4 m. Resolved center `(-37.031, 9.940, -528.850)` m; record seed `2227196533846249`.

Both use a 0.55 m geometric rounding radius and 1.6 m cubic smooth-union width (`2√2 × 0.55 = 1.556 m`). The monolith uses a rounded capped-cylinder SDF; the plinth uses a rounded-box SDF. Their fills compose into the flat field with smooth min. Resolved AABBs include the smooth-union padding (`W/6 = 0.267 m`):

- Monolith: `[2.255, 5.588] × [-35.289, -31.956] × [-529.866, -505.333]` m.
- Platform: `[-40.498, -33.564] × [6.873, 13.007] × [-529.866, -527.833]` m.

Cylinder interval bounds use exact radial minima/maxima over each XY box plus the vertical interval; platform bounds use its rounded-box intervals. The BVH contains these bounds and `isTileShapeFree` blocks motif-overlapping tiles. Brute-force checks: 8 boxes, 512 samples, zero misses; 2 all-air and 2 all-solid proofs; both false-proof controls rejected.

## Reachability and surface audit

The final-field passage route passed with 33 points, 5,733 capsule samples, 0 blocked samples, 477 support probes, 0 unsupported probes, and 0 grade failures. Motif route and band keepouts passed.

Whole-surface LOD0 audit covered the monolith foot and cap and platform edges (4,706 tiles; 1,847,639 triangles; 0 degenerate). Fitted radii: foot **0.856 m**, cap **0.728 m**, platform **1.165 m**. Each exceeds 0.5 m. Missing-ROI, sharp-fillet, and empty-mesh controls were rejected.

## Timing, tiers, and determinism

Motif cold timing: first tile **0.076 s**, near ring **0.144 s**, whole view **0.524 s** against the 1.75 s target. Final `verify.py` results: fast **PASS, 167.9 s**; medium **PASS, 961.1 s**; full **PASS, 1,135.3 s**. Full included the 30-cell check and five paired cost checks. Clang and GCC builds used FP contraction off; motif hashes matched at W1/W8/W12 for the monolith and both random cameras, including the camera at the monolith.

## Captures

Both checked visually; each is a 1600×900 JPEG below 300 KB.

- Eye-level monument and cap: [motifs-slice1-eye.jpg](captures/motifs-slice1-eye.jpg) — 27,946 bytes.
- High oblique overview with platform, monolith, spacing, and route: [motifs-slice1-overview.jpg](captures/motifs-slice1-overview.jpg) — 37,756 bytes.

## Hashes and diagnostics

- Source stamp: `5960b761be0110f5d47fea4f56df938e5d70ddba7355d1e2a6d11f15514b217e`.
- Fixture SHA-256: `e9a118f1ce3fe247572899075d31ee421f070566ebd6cef4bd1616da9e84e12c`.
- Resolved layout: `resolved-layout-v3-fnv64:d8c2af75e948357f`.
- Clang binary SHA-256: `c350591d88e706e6e02891428ddb7dd30dc01307fd9ee301798261e462f88129`.
- GCC binary SHA-256: `1fa592d7a7300662981fe42ab40345075f901c965d4a3f3811fc79e8e124f0ae`.
- Owner world SHA-256: `7b095f9bcc6b90133d5a463f99f0b571133b2c549ce1ecf2d64fe9175e41e183`; diff diagnostic clean.
- Eye capture SHA-256: `0266e54e52fcf5eb57b03986fc1dc093437ab36582aec8b2113bc8a43a51bfbe`.
- Overview capture SHA-256: `c2998da1570f587b7ce8598993211098da6e4e7d24cf0284345577246def77b4`.

## Trials and failed runs

**9/15 trials used**: seven evidence/capture attempts failed and two passed. Failures were limited to the initial medium audit missing the platform ROI, the clip-radius safety guard, camera crops that omitted the platform, an overly restrictive fillet upper bound, and one temporary capture-helper `floor` name error. Logs are under `Saved/Linux/l56/`; the final fast, medium, and full tiers passed.

## Orchestrator review (Claude)

Accepted. The stamp matches the final Clang and GCC builds (`5960b761…`); 9 of 15 trials. The monolith reads as an
intentional, cleanly rounded monument; the motif stratum runs at **0.52 s** whole view. **Logged for later:** the
overview shows a dark crescent where the large arrival shaft (the passage structure from the strate above) meets the
floor. Check whether that's a real gap in the field or a render artifact; it isn't part of this round's motifs.