I have a question with finding the position of a point in relationship to an object; instead of world space. I am familiar with matrices but i can''t figure out what exactly needs to be done. I have the following Position of object Direction object is facing (vector) Position of point I need to find Position of point based on the coordinate system of the object (relative position) ex. point is (0,0,0) object is (0,0,10)&facing (-1,0,0) the point is theirfore at (-10,0,0) relative to the object. but how is this determined? I know their is a simple solution but for the moment it is beyond me any help is appreciated. Thanks, Maurice