In fact, you can change the Collision type between Ellipsoid(yours) and BBox.
Nope.
Its a flag in c_move if i remember correctly. USE_BOX.
That's a c_trace flag that causes c_trace to trace a volume, rather than a line. Ironically the volume it traces is an ellipsoid just like c_move(), not a box.
There used to be a flag for c_move called USE_AABB that caused c_move to use a box instead of an ellipsoid, but it was removed many versions ago because JCL (gamestudio's lead engineer) decided that Gamestudio's collision system was too big.
Gamestudio's implementation of AABB was wimpy anyway; you couldn't adjust the size of the box with min/max but had to be satisfied to use the FAT/NARROW flags, which are really good for nothing. But taking out AABB support was not the right thing to do IMO.
