Collision.HasOverlap re-triangulates both polygons on every call; Qwen
measured that as its dominant cost (over 400 s -> ~110 s on a 219-part
job once cached). TriangulatedRegion (from Qwen's TriSet) triangulates a
part once and takes translation as a parameter; it returns null when it
cannot decide so callers fall back to Collision, which stays the
reference. EdgeGridPolygon (from Qwen's FastPoly) certifies clearly
disjoint shells and never reports Clear for an overlap. A seeded harness
of 100,000 decisions (concave shapes, arcs, holes, touching contacts)
finds 0 mismatches against Collision.HasOverlap.
Co-Authored-By: Codex <noreply@openai.com>
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>