1# Collision-to-mesh re-audit — fresh CUA vs generated CI23Audit date: 2026-08-09 4Gallery: `?endless=1&peers=0&gallery=1` 5Inventory: 119/119 registry variants selected explicitly with collision enabled67The cache-contaminated run was discarded. This report is based on a fresh hard-reloaded gallery bundle. Per-piece results are in [`collision-mesh-reaudit.csv`](./collision-mesh-reaudit.csv); the original failure inventory and prior-art technique map remain in [`collision-mesh-audit.md`](./collision-mesh-audit.md).89## Verdict1011No critical or high collision-to-mesh regression was reproduced. The repaired gallery visibly resolves the four known classes:1213- Wide collision now fills `straight-wide` and tapers correctly through both funnel lengths and reversed variants.14- `straight-hole` has a real open bore. All 12 drop variants use authored annulus/cup/shaft/receiver compounds instead of the old five-slab generic tube.15- Corners, bends, curves, helixes, waves, bumps, S-curves, and their reversed/mirrored variants track the visible floor boundary without the former turn under/overcut.16- Ribbon guard tops now sit close to the rendered rim rather than forming a tall invisible wall.1718| Fresh CUA result | Pieces | Interpretation |19|---|---:|---|20| pass | 103 | Visible driven surface, width, rim, and any opening/junction agree with the render mesh |21| pass with confidence gap | 15 | 12 drop and 3 diamond compounds look correct on the driven surface, but CI does not measure their full collision-to-render distance |22| conditional | 1 | `cross-over` is a quiet phantom and intentionally has no isolated proxy; it relies on the co-located `cross` composite in production |2324## CUA-to-CI comparison2526The generated suites passed: 3 collision-metric tests plus 5 width-parity tests. They report 3,009 ribbon rings, worst signed floor error `0.0405` world units at `slant-d`, 13 open bores with lip decks, and a passing four-port cross composite. The complete project suite is also green: 170 tests, 0 failures; `deno task check` passes.2728| Area | Fresh CUA | Generated tooling | Assessment |29|---|---|---|---|30| Regular/curved ribbons | Floors and rims visually align for forward, reverse, and mirror variants | Ring floor, lateral span, and cap budgets | Strong agreement |31| Wide/funnels | Full width and both taper directions align | Dedicated entry/exit width assertions | Strong agreement |32| Hole/drop topology | All 13 bores are visibly open; drop cups and receiver yaw look authored | Bore-clear and lip-deck point probes | Agreement on topology |33| Cross | Four-way floor is present and all mouths are open | Deck, mouth, and corner probes | Strong agreement |34| Drop compound shape | Octagonal compound visually follows the cup/shaft far better than the prior generic stack | No compound-to-render distance metric | CI coverage gap |35| Diamonds | Driven top deck and branches align; slab boxes remain broader below the sculpted mesh | No dedicated diamond geometry metric | CI coverage gap |36| `cross-over` | Ghosted host mesh, no proxy by design | No isolated collision metric | Production-pair dependency |3738## What the regression does and does not prove3940The ribbon test is useful, but its `across 119 variants` output should not be read as 119 direct render-mesh comparisons. It iterates the registry, silently skips bench-build failures, and measures only `mesh` proxies; slab-only compounds are skipped by the ring loop. Its truth source is the centerline plus measured profile constants, not render triangles or a sampled render surface. The broad lateral (`0.55..1.40`) and cap (`0.30..0.80`) windows also permit drift that a direct distance metric would catch.4142Recommended next regression: sample both the rendered collider reference and collision surface, then assert directed surface distance (or signed-distance/occupancy probes) separately for driveable floor, wall/rim, aperture boundary, and underside. At minimum, add per-piece coverage accounting so every variant reports which metric family actually evaluated it, plus dedicated drop and diamond compound probes.4344## Prior-art technique map4546The baseline report already documents the relevant prior art and links: variable cross-section sweeps (T1), explicit hole contours and authored topology (T2), sagitta/error-bounded turn tessellation (T3), simplified concave static meshes and mesh cooking (T4), compound convex decomposition/CoACD (T5), solver margins separated from geometry (T6), and shared bench/runtime construction with asset assertions (T7). Those recommendations still apply; the current remediation visibly implements T1, T2, T3, T6, and T7, with authored compound geometry in the T5 role for drops and junctions.