Hi Dirk, just one other comment if you want to submit this to Maxon as a bug report, I would suggest deleting all the other polygons except for just one single one that has the black thing on it (but before yanking the points around), and then sending a file in with just that one n-gon in it as an example of the triangulation problem.

It helps a lot with bug reports to have the most simple data set possible that shows the problem.

It may not be a very easy thing to fix though, it can take a pretty big re-working of the triangulation mechanism to make one that does not back itself into a corner like this.

- Michael