My cardboard box is having a bad time: each time I drive a vehicle into it (even at low speed), nodes get stuck into it. I do have triangles defined. Any help? The box is just made out of 4 nodes at each corner. - - - Updated - - - Bump This is the Structure.
I guess you have checked the triangle debug mode to see that there are no holes in the surface? Triangle orientation (clockwise or counterclockwise node order) matters, a bit like in RoR. I don't remember which way it goes, but one side is thicker than the other and can handle collisions with more force. No way to check the orientation for now, other than manually from the node names.