hplus0603 said:
Are they (Second Life) still using their server-animation approach, where every object and every joint needs to be driven from the server every frame?
Second Life doesn't control character joints from the server. The server sends updates with position, orientation, velocity, angular velocity, and acceleration, and the client moves the object accordingly. Character animations are entirely client side; the server just tells a character to run a .BVH file, which the client does blindly, without any attention to collisions.
It's also not frame oriented. Server and client are not synchronized at all. Simulation frame rate is 45Hz, while refresh frame rate is up to the client. Which usually goes compute-bound making OpenGL draw calls from a single thread.
The result is that movement control is rather loose and soggy by modern game standards. Roughly the right things happen, but not with the precision one expects from a game today.