OpenSCAD is quite polished (for a programmatic mesh modeler). There is a soft-fork which adds Python: https://pythonscad.org/ https://pythonscad.org/ which I

OpenSCAD is quite polished (for a programmatic mesh modeler). There is a soft-fork which adds Python: https://pythonscad.org/ https://pythonscad.org/ which I've found quite useful: https://github.com/WillAdams/gcodepreview https://github.com/WillAdams/gcodepreview in particular, working up a facility to write out DXFs w/ arcs