Most of the time I don't want a full-blown physics simulation. I just want to move, stop when I hit something, and get the kinda information c_move gives me (normal, point of impact, who I hit).

Even if between some constraints and the like I could do it, I doubt it would be as efficient as a function dedicated to just collision detection.

Finally, c_trace with USE_BOX is a huge part of the issue, and AFAIK PhysX doesn't offer an equivalent function (I'd love to be corrected).

KarBOOM doesn't use any of the c_ or PhysX functions, and I can't see projects of mine in the near future using PhysX or any of the c_ functions, because I'd rather write my own if c_ doesn't pick up the pace.

Jibb