Physicalized skinned mesh for animations

[philpax]

At present, objects with animations do not update their physics representation when the animation plays back. This causes issues for more complex meshes where it's expected the individual components can physically interact with other objects in the world.

For these, we should split up the collider into its constituent parts/objects/limbs, and then update them with the animation. Note that this will require running the animation on the server, so there's some challenges there.

[FredrikNoren]

So this issues can be broken up a bit;

• [ ] 1) Spawning skeletons/bones on the server
• [ ] 2) Running animations on skeletons on the server
• [ ] 3) Attaching arbitrary colliders to bones on the server; i.e. attach sphere with radius 5 to head bone. This can at this stage be by hand by someone, but they would have to do it for each limb they want to represent
• [ ] 4) Automatically creating colliders for the skeleton on the server based on the character mesh, and/or importing them from some other software. (To make step 3 easier)
• [ ] 5) Computing a skinmesh collider each frame; i.e. taking the meshes of the character and apply skinning to them based on the current skeleton pose. I'm not sure if this is useful or not; it's probably quite heave to update the entire mesh collider each frame (although this is the most accurate version).

1/2/3 are all quite simple to do; we just need to run some systems on the server and we need a bit of code to spawn "only" a skeleton. 5 is also quite easy to do in its most basic form (the cpu mesh already support applying a skin to it). 4. Is a bit more uncertain.