IfcTriangulatedFaceSet and IfcPolygonalFaceSet used CoordIndex values to
index Coordinates.CoordList directly, ignoring the optional PnIndex
attribute. When PnIndex is present it remaps point references, so a
CoordIndex value i must resolve as CoordList[PnIndex[i-1]-1] (both 1-based).
Without the indirection any model carrying a PnIndex was built from the wrong
points.
Add a resolve() helper in both mappings that applies the PnIndex indirection
when present and is a plain bounds-checked lookup otherwise, with bounds
checks at both index levels. When PnIndex is absent the behavior is unchanged.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Petru Conduraru
3e55c5126c