Projection of an object to a clipped plane



is it possible to get a top projection down to that clipped Z plane without having to run boolean operations?

I put together a function that creates projections of single faces, if a face is below the clipping plane I'm ignoring them but maybe there's something faster available.
The purpose of that is to detect and remove collisions from faces that are on the clipping Z plane.

(sorry about the other thread, I will continue with it once I have time)

Markus R.'s picture

here's a picture about what we need to do.

I'm mostly working on the FreeCAD Path support (generating paths for CNC cutting).
Currently the way collision detection is integrated is by extruding the surface which has to be cut and the main body will be cut from it - it's a very slow process.

I have some tests with simple projections and was able to get the processing time down from 27 seconds to 6 seconds.
However in that case I used to cut the crossing faces with a 3d object that was generated below the cutting plane (so also not optimal)
While it's easy to project faces which are above the cutting plane, faces which cross the plane need some additional logic.