title: Move object by Bezier Curve, combine with Rotation
body: <p>My engine (AndEngine) provides the modifier to move an object by Bezier Curve path, just by providing 3 or 4 points co-ordinate.</p>
  
  <p>In my game, I move some birds with determined 3 points. However, it looks fake because the birds always point to a direction.</p>
  
  <p>This looks like a mathematical question, but I think I should post at StackOverflow instead of Math Exchange: How to determine the rotation angle (in radian or degree) for the birds at a time?</p>