Cannos wrote: Another alternative is to just not optimize this mesh
no that should not be an option, newton rely on good mesh quality for good quality simulation.
we need to get the optimizer 100% reliable.
The optimizer works by pattern matching in a graph.
these bugs are caused by cases in the mesh that match some of the pattern that can be recognized for optimization. so some extra test has to be added to discriminate bad matches.
I have narrowed to a set fo 136 triangle by bisection, if you sync the demos you will see the sub mesh that cause it.
136 trangle is still to large a set to debug, I seen thet the case happen when one triangle seen to math agoes the is really far away from it vicinity, which indicate that the mesh maniford is incorrect.
is not productin any warning,
anyway I will try to norrowint down more before start debugging it, but it seem the facts are no adjacent so I will need to make an indirect table to remove faces.
In a way these are very good stress test for the optimizer so I appreciated the repros.