nx_meshdist.nx

nx_meshdist.nx -- THE METRIC GAP RULER (form ladder 1785935557; operator 2026-08-05: measure the gap between two objects below the millimetre -- bodies today, screw-to-screw tomorrow). Bidirectional point-to-surface distance between two NXMSH2 meshes, the METRO / DTU convention done sovereignly: candidate->oracle = ACCURACY, oracle->candidate = COMPLETENESS (one direction alone is gameable: a sphere inside the body has perfect accuracy and no completeness). Reported per direction: mean / rms / p95 (the medical HD95) / max, in MICROMETRES, plus F-score-style fractions within 1mm and 0.5mm (the Tanks-and-Temples F@tau shape). All integer math in 10um quanta -- products stay inside i64 by construction (coords <= ~2e5 q, near-cell evaluation bounds |p-a|), so the quantisation floor is 10um, declared in the output. Screws and finer work pass a tighter unit via a future scale arg. ALIGNMENT (declared, never silent): candidate is translated centroid-to-centroid and uniformly scaled by the bbox-height ratio (permil printed). No rotation search in v1 -- both estates' bodies stand y-up. Sampling v1: every k-th triangle CENTROID, k chosen to cap samples (bias declared; area-weighted sampling is the named v2 rung). nx_meshdist <cand.nxmesh> <oracle.nxmesh> [samples] | selftest license_tier: ORIGINAL expect_exit: 0