Verify the triangles are not intersecting each others when simplifying

[Makio64]

It would improve a lot the quality if the triangles dont intersect each others :

Here an exemple before / after simplifying where the triangles intersect each other making bad result :

Using this model from sketchfab, all credit to his author : https://sketchfab.com/3d-models/wakfu-fanart-female-iop-854b37afca0c44c9a0302b879a95bfca

[zeux]

This request makes sense but this is fairly unlikely to happen. The simplification reasoning process is local so the simplifier is not aware of the rest of the mesh - it's only making decisions with the knowledge of immediate vertex/triangle neighborhood. I'll keep this open for now, maybe it could be viable to explore at some point as an option; it would make simplification dramatically more expensive and more involved from the robustness perspective.