title: Directx mesh rotation in car
body: <p>I downloaded a model of car in X file.
  Now I wont to render it and rotation the wheels to show that the car and go forward and
  the problem is that the wheels rotate around the car canter instead of their center.
  how can I fixed this problem?
  thank you very much!
  I do not think I need to show the source code because it is irrelevant.</p>