I am trying to write a 3d physics engine for my game, can someone verify if the following is correct: The EXIT VECTOR of an object striking a static plane is the INCOMING VECTOR rotated 180 degrees around the NORMAL of the plane. Is this correct ? Nitzan ------------------------- www.geocities.com/nitzanw www.scorchedearth3d.net -------------------------

Yes, of course you''ll need to negate it as well though