Sometimes I see this function fail (i.e. the triangulation I get from BRep_Tool::Triangulation() afterwards is Null. There is no error message and the only parameter I can see to tweak (the deflection) seems to have no effect on whether it fails or not. It looks like the surface it's failing on has a lot of holes and possibly degeneracies (but since I can't triangulate it I can't really tell). Does anybody have any suggestions on how to approach this type of problem? I'm not sure if I can post an example - the one I am looking at is proprietary.