@3dgs_snake, thanks, I hadn't realized that they must both be physX actors. I inserted this line "pXent_settype(me, PH_RIGID, PH_BOX);" as the first line of my action InclineThePlane() and now, the ball doesn't pass through the plane anymore. However, it seems the mass of the ball won't allow the plane to slope to an angle anymore, and that was working before. It's like the ball just presses the plane flat to the ground.