I want to start experimenting with SmartFox Server and Unity for a very small test to get my multiplayer feet wet. I've done some server coding in the past (with SFS), but it was with a Flash client, and my world representation was a 2d tilemap on the server. So my biggest brain hurdle at the moment is how do you handle world representation/interaction on the server when the world is 3d geometry? Who does collision testing? What about triggers? What about gravity? If it's client side, how can the server verify that it's correct? If it's server side, how should it be implemented? Will I have to use a Java version of PhysX or is there something really obvious and simple that I'm missing? I really only want simple gravity and collision testing. I don't need full networked physics. Any thoughts on these matters will be humbly and gratefully received.