Hi everyone.. I am writing a car physics class for a demo right now. When it comes to make the car turn left / right, i am wondering in what way does the car tires and body should be modelled, since when a car is turning, its tires will rotate first, followed by the car body. My question is what is the connection between tires rotation and body rotation ? How should we represent them in the model ? my current demo is located at http://christiansenjaya.netfirms.com/cardemo.zip And please post your FPS count and system specs if you tried the demo. Thanks in advance !

Normally, the part of the tire touching the ground is stationary on the ground. When this is the case, you know the directions the front and back of the car will be going.
When the wheels are turned, the rotational speed of the car will be the speed of the car * the angle the wheels are turned / the length (axle to axle). This is a rough approximation - assumes small enough angle and no skidding. If you''re going to be doing burnouts and doughnuts you''d btter ask a more adept physicist.

If I thought a lot harder about it I could work out where all the forces are - after the engine works on the back wheels, friction forced the car forward and friction works with the front wheels so the steering takes effect - that''s a bit hard, maybe someone else might answer it.

The demo didn''t work on my computer. I think I was mising a .dll file, probably a DirectX thing.