If you are going to do that, please add also support for Pro|Engineer
It would be very, very great if we can handle 3D-CAD data in OpenERP (welcome PDM-system). But unfortunately all the 3D-specs are closed source, so you have to re-engineer the handling of the data. Or take a license
My overall look is that it isn't hard to create a PDM-system with version / revision control (I'm working the whole day with such a system). I'm not specifically talking about 3D-CAD, but also about documents, files which can be handled by the system.
Specific for 3D-CAD, you have to read into the file to see what parts are in an assembly, so you can create a BOM in OpenERP. You have also look into the different files (assemblies, parts, drawings) to get all the related objects of that file.