FreeCAD

https://en.wikipedia.org/wiki/Comparison_of_computer-aided_design_editors
https://www.turbosquid.com/Search/3D-Models/free/stl

Úkoly
Importing From Sketchup

Collada - SketchUp import

https://www.freecadweb.org/wiki/index.php?title=Extra_python_modules#pyCollada

[marek@Marek-MacBook-Air ~]# cd "/Applications/FreeCAD.app/Contents/lib/python2.7/site-packages"

[marek@Marek-MacBook-Air site-packages]# cat setup.cfg
[install]
prefix=

[marek@Marek-MacBook-Air site-packages]# pip --upgrade pycollada -t .

[marek@Marek-MacBook-Air site-packages]# pip install --upgrade pycollada -t .