The PhysicsService API documentation does not state anywhere that it is server-sided only. None of the methods or functions state that either. I wasn’t sure if it was server-sided only so I ran a quick test by creating collision groups on the client and that throws an API request error. Would like to see this added to at least the PhysicsService page itself so as to not confuse anyone that might not know.
What’s confusing is CollisionGroupId can be used on the client, meaning there’s no real reason the PhysicsService API shouldn’t? That’s a separate feature request, though.
The PhysicsService API should have been made usable on the client.
For a subset of the APIs at least. Ones used to create CollisionGroups or modify the collision masks for a group are still server side only for hopefully obvious reasons. You should be able to get collision groups by name and assign collision groups to a part on the client though.
I’ll incorporate this information into the docs then. I’ll edit this post when the deed is done.
Edit: Done and done.