Update collider verticies about bevy_xpbd

[Jondolf]

To clarify, I think you can get a mutable reference to a trimesh collider's internal shape like this:

// This mutable variant of get_shape doesn't exist yet but I'll add it now
let shape = collider.get_shape_mut().as_trimesh_mut().unwrap();

It returns a GenericTriMesh, but vertices is private and I'm not seeing a way to get a mutable reference unless I'm missing something.

[Jondolf]

I'm not super familiar with Parry's internals, but I'm not sure if it's currently possible to modify the trimesh shape without creating a new trimesh instance, as I'm not seeing any methods for doing that in SharedShape or TriMesh. As far as I know, the shape has to be replaced with a new one if you want to change the geometry.

[Shatur]

Got it, should be reported to Parry then.