i3DLocationToScreen(Vector3,Vector3,OBJ_X)
   Vector3 = screen location. Return data.
             Resulting coordinates specify a screen location using
             the same convention used for iObjectLocationSet()
             when the object is a Sprite, a ValuePrint or a TextPrint object.
             NOTE: if the source 3d location is outside the viewing
             frustum returned 2d coordinates will be outside the screen.
             NOTE: if the source 3d location is behind the camera,
             returned 2d coordinates will be both 1000000000.
   Vector3 = source 3d location to convert to screen coordinates.
   OBJ_X = camera object to be used as a reference.