>>338114084
https://docs.unity3d.com/2018.4/Documentation/Manual/FBXImporter-Model.html
enable "generate colliders".

VRChat doesn't do anything special for player collisions outside of default unity physics, so reading through basic unity tutorials/manual on collisions is helpful. http://vrchat.wikidot.com/worlds:layers has some docs on the layers that vrchat sets up and the physics collision matrix.