Collision Triangles Over Vehicle Body

I noticed when going into debug mode that when a door is torn off, coltris still cover that area. I then tested this with a cannon ball. As I suspected, the cannon ball crumpled the vehicle after hitting these invisible coltris. Are coltris really necessary over the door area (and of course the hood, trunk, and other breakgroup areas), or could they be removed?

 

This should not be the case. What vehicle did you use for these tests?

Anyway, collision triangles are necessary, otherwise surfaces would have no way of detecting collisions outside of node-against-node impacts. Without coltris, foreign nodes can go through the openings in the net of a jbeam structure pretty much unstopped.

 

I used the default Gavril D-Series

EDIT: I know that coltris are necessary in general, i just meant in that particular area

 

Thank you for satisfying my curiosity