EM can import 3D geometries in the format of Stereo Lithgraph Data (STL) and triangulated DXF data. Several primitive geometry can be treated in EM software but there might be a case which is not enough to build your complex object with the EM builtin modelar.
STL and DXF are quite popular format in 3D CAD, they are supported with many popular CAD softwares. EM can deal with your practical model by supporting the CAD data. You can import the CAD data but each CAD data file contains only one object with a closed surface. As far as the file satisfy this, files as many as you want can be imported in EM. As for CAD softwares, generally speaking the CAD softwares are very expensive. For your information, several CAD tools with no charge exist. Our recommendation is FreeCAD. The tool's CAD engine is derived from a commercial software and the quality is promissing. We comfirmed that the STL files generated by FreeCAD can be imported to our EM. FreeCAD and EM would give you a good simulation environment for your problem.
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