Fixing the Vehicle class in UE4 starting with NWheel implementation.

[anonymous_user_e6436d8c]

I’m not so good as you guys understanding this whole thing, but, this could help?

The static mesh complex collision uses a regular trimesh which is passed into PhysX. This mesh is never updated at runtime and can be used for scene queries as well as static collision. The mesh is cooked offline so that various optimizations are done, for example building a BVH and cleaning up vertices etc…

A simulated object cannot use this complex collision as PhysX needs to store various values (for example velocity) for each vertex, and this is way too expensive for a trimesh.

In the skeletal mesh per poly case we use a similar approach but we actually need to update the trimesh per frame to match the skinning of the skeltal mesh. This can be fairly expensive as the vertex position needs to be updated. This trimesh is only cooked once offline, so various optimizations like the BVH will not update at runtime.

For these reasons we recommend that you use simple collision whenever possible. Per poly skeletal mesh is a new feature which can be avoided for most cases.

Hope that helps, let me know if you have any further questions.

Complex Collision as simple?

If I understood, we can’t use Complex collision as simple with vehicles, is that right?