Hi, this is probably one of these questions that has been beat to death but I will ask it anyway. I am doing a (very) small game using a couple of articulated figures and rendering then with a (even smaller) scenegraph, something like: push>transform>draw>push>transform>draw>pop>transform>draw>... now it''s time for the big bad and ugly collision detection, but my figures are composed by parts that know position and direction based on their parents position and direction and that''s unsuitable for collisions. My first solution was to retrieve the transformation matrix (I using OpenGL by the way) and applying it to the vertices but it seens I''m repeting GPU job and NVidia docs tell that getting information out of the gpu is very inefficient. mantaining a local tranformation matrix seens to kill the gpu purpose. There is anyway to handle rendering and collision in the same structure, avoiding CPU vector math?

sorry about that but I really didn''t know how to classify this question