Russ, I'd like to suggest the dxBodyNoGravity flag. (With the enable, disable, and state checking functions.) Currently to disable the gravity on a single body, one has to get its mass, get the world gravity, multiply.. And all that to... disable something happening automatically. That is not nice. I just added this in step.cpp, and obviously it works. Could you add this as well? Do you have any objections? Erwin