wheel contact point

[flo]

Hey,

I need some explanations about converting car coordinate information into world coordinate system.
Actually I want to get the contact point of a wheel (e.g. front left wheel) on the track.
So I took the the current position of the car (chassispos), which I assume is the centre of mass and added a vector to the front left wheel (wheel-FL position) mulitplied by the cars current chassis orientation.
It is near the contact point but something is still wrong.
So my question is:
Which point does the "wheel position vector" point at?
I thought maybe I have to add the roll-height or the wheel radius in negative z-direction(in car coordinate system)?

Thanks!