Automatic conversion of IFC models v2x3 to CityGML LOD3 (but LOD2 and LOD4 are possible too).

Description of what can be done with this code is in the MSc thesis of Sjors Donkers entitled Automatic generation of CityGML LoD3 building models from IFC models.

The code is split in 2 parts:

1. ifc2off: converts the relevant geometries in an IFC file to a set of polygons in an OFF file. Dependencies: IfcOpenShell and OpenCascade.
2. off2cityml: converts the OFF file to a valid LOD3 CityGML file. Dependencies: CGAL