Im using Bezeir curve to build the racing track in my car racing came.I used 2 Bezeir curves for each loop - inner and outer loops, ie 4 curves totally. However, I cannot bound the car inside the track. Can someone help me? I have been suffer from this problem for few days

Could you explain what you mean by "cannot bound the car inside the track"? Do you mean you are having trouble determining if a point is between two bezier curves?

beziers curves are quite difficult to control, they generate the most aesthetically pleasing curves (apparently!) but they dont go through the control points. However, something like a Catmull-Rom or Hermite spline will, and I have been using the Hermite Spline formula for my racing type game... and it works a beauty...

go look into it, I got the formula from the key-frame animation article in Game-Programming-Gems-Volume-1....

Jack;