Mesh impossible to trim with breps

With these two breps I want to cut a hole in the mesh;
cannot figure it out; tried several ways; cannot find a solution.

Do you might know what I am doing wrong?
I think it might be the low poly resolutions but by increasing the polygons I continue to struggle with this problem because when trying to cut a hole in the mesh, it still does not work.

So, if you might know a trick, please tell me.
:smiley: (42.2 KB)

The following is an old post with something similar.

Well … this is another “simple” case.

Moving all to 0,0 (better safe than sorry) , converting the breps (the splitters) to meshes (while checking anything imaginable [CombineVertices, Orientation etc etc]) and then attempting to split the mesh … there’s some result for the one splitter (ex brep) but not for the other.

The case needs further investigation.

What do you mean with 0,0 mean?

Is this sarcasm?

Or do you mean that it is a difficult case?

0,0: Some times moving meshes close to global origin helps addressing tolerance issues (not in this case).

Sarcasm: No

Difficult: No.

Solution: haven’t found the time to investigate further (assuming that is not a R bug [Mesh result = M.Split(m);] of some sort).


Found a couple of minutes for writing some primive C# on that matter. Inspect the code: this is either a 100% Karma related case Or there’s some bugs in the Brep to mesh Rhino Method (not to mention in the Split thingy).

Spot LOL results if triangulation is not enabled. (134.0 KB)

PS: for the tiny Mesh Face that is wrongy included to the result don’t bother (we can exclude it very easily via MeshCenter containment etc etc).