- Store shapes in std::vectors rather than TopoDS_Compounds
- Apply transformation only on triangulated meshes or when processing openings
- Store transformations in a gp_GTrsf to allow arbitrary transformations
- Support IfcCartesianTransformationOperator3DnonUniform
- TODO: Create proper class for ShapeList
- TODO: Carefully check for null pointers returned from IfcGeom::convert_shape()