How does it simulate "hitting the wall", like visoad did vessel collisions?
I think that if the room shape is simple, like a cube,a box, or a sphere, you can mathematically define its geometry ; track the object position relatively to the center of its diagonals for example and deduce that way when it hits a wall ; provided you have defined x, y & z axis with +/- signs, you can know which wall has been hit. You can even ask for the object vector at the moment of the collision, and deduce a "billard-like" bounce by applying a modified vector.
Not easy, but doable.
uMMu does define such "boxes" for ingress/egress areas.
