[ODE] Sliding friction for use as car wheels

[James Kett]

Hopefully somebody can help me out with this little problem.

I'm modifying the buggy demo to have 4 wheels and behave more like a
real car. I've got DX8 worknig fine for keyboard and mouse, but I'm
getting stuck trying to modify the contact code to allow for
2-directional sliding friction.

As I understand from the docs, you can specify that friction is
accounted for in 2 different directions.

So I think what I need to do is use the primary friction direction as
the forward traction of the tyre, and then use the secondary direction
for the sideways slip.

So I need to set the primary direction of friction to the rotation of
the wheel around the vertical axis, and then the secondary direction is
automatically set perpendicular to this.

This is the bit I'm stuck on - how do I translate the rotation of the
wheel around Y to the form required to specify the primary friction
direction?

Any help very much appreciated.

James
-- 
James Kett <james.kett@atd.co.uk>