[ODE] How to Avoid Walls when using 4 spheres and box for a Car

[Jon Watte (ODE)]

> anyway, everybody talks about using rays for the wheels, but then how i
> control suspension, steer and speed/acceleration???

You apply a force in each corner, the magnitude of which is a function 
of how deep the ray has penetrated; this function determines your 
suspension.

To accelerate, you apply a force in each corner that has a driving 
wheel, in the direction of that wheel's "turn".

To steer, you use an anisotropic friction model in a contact joint you 
create for the ray intersection, or you just poke the corners of the box 
using forces based on wheel heading.

For slip, you can similarly measure sideways versus longitudinal 
velocity, and total force applied per corner, to give you fishtailing, 
donuts, and all the rest of arcade car racing goodness.

Cheers,

			/ h+