As requested by user nil, spawnhost now has a blurb about making physics objects in FTE using the Open Dynamics Engine. I believe this was originally a Darkplaces extension, so much of it should apply to both game engines.
Be warned that this is no cakewalk. The article is intended for advanced QC programmers and game devs. Not everything is spelled out in detail for simple lack of time, and it has “RTFM” in it.
If that doesn’t scare you, read on.