Bug 1 — Missing parts (mirror/repeated instances):
- id(solid.TShape()) is unreliable in OCP: each call creates a new
Python wrapper, so id() always differs even for the same TShape.
Replaced with IsSame() for correct TShape-pointer deduplication.
- TopExp_Explorer(SOLID) misses free shells/faces in assemblies.
Fix: run BRepMesh baseline on full root compound first (catches all
face types), then GMSH overrides per unique solid for better seam
topology. REVERSED solids keep BRepMesh to avoid inverted Jacobians.
Bug 2 — GLB 7× too large (21 MB vs OCC 3 MB):
- CharacteristicLengthMax = linear_deflection × 50 (was ×15)
matches OCC effective edge length on curved surfaces (~5 mm).
- MinimumCirclePoints = min(12, ...) (was min(20, ...))
- Result: GMSH 91% of OCC file size (target ≤120% ✓)
Verified on rolling bearing STEP: same 4 skipped nodes as OCC,
25 unique GMSH tessellations (IsSame deduplication), no OOM.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Hartmut
638b93bb1e