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ifcOpenShell : Open Source IFC Library/Framework & Geometry Conversion

ifcOpenShell (

This is an Open Source projects, written in C++ and which uses the Open Source OpenCASCADE or OCC libraries for all geometric work (info on It is currently available as Source code and some basic programs are written:

  • a 3ds Max IFC Importer (as a max plugin), compiled into a DLL (but renamed for max);
  • a Blender IFC Import script (in Python);
  • a standalone convertor to translate IFC geometry into a Wavefront OBJ file.
They use a common parser library and the OCC libraries.

I was mostly interested to the approach of both the setup of IFC classes and the integration with the geometry kernel. Currently, the focus seems to be on extracting the geometric objects from IFC files, to use in other software, e.g. for 3D Visualization.

For me, the more interesting aspect would be the other way around: having complex, freeform geometry and convert this into valid IFC models for analysis purposes.

Compilation Problems

It is currently working fine in Windows and should compile on Linux, but I had problems with OSX compilation. From my (limited) understanding, this is due to the use of an outdated GCC version in OSX, when compared to Linux distributions. However, switching to a compiler not provided by Apple is not trivial. Moreover, during compilation, my whole system is getting really slow and memory is eaten quickly. So I have not been able to use it in OSX (yet).


  1. Hi Stefan,

    I've investigated the compilation issues on OSX. As you guessed correctly, they were related to the older version of gcc shipped with XCode 3. The relevant changes are in the repository.

    Btw, there are tickets in the feature request tracker that deal with the creation of IFC files:

    Kind regards,
    IfcOpenShell admin


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