geometry-validation

name	geometry-validation
description	Domain knowledge for mesh validation thresholds and definitions. Use when adding or reviewing checks in core.py.

Definitions

• Watertight: every edge is shared by exactly 2 faces, and the mesh has no boundary edges.
• Non-manifold edge: an edge shared by 3+ faces.
• Degenerate face: triangle area < 1e-8 (mesh units^2), or two shared vertices (zero-length edge).

Units

Assume millimetres unless the file specifies otherwise.

Tolerance

Use math.isclose with rel_tol=1e-6 for area/volume comparisons in tests -- never exact float equality.