[ODE] Steering and rolling wheels

[Sergio Casas Yrurzum]

Hi, Nate

> > About the strange jumping of your robot, the only thing I could guess
> > at was that it has something to do with how ODE calculates friction,
> > or perhaps it's an oddity about how the wheel collides with the floor
> > when you 'roll' and 'steer' at the same time.
>
> Or perhaps the wheels are colliding with the chassis, or with each other?
> Do they appear to touch?

No, I think they don't.

>If so, is there any code in the collision
> callback to prevent contact joints from being created between the wheels
> and the chassis?
> If not, how about putting some code into the collision callback to see
> if such joints are being created?

It seems not to be that. Seems something about friction because I've set the
rear wheels geometries as spheres instead of capped cylinders and works
better. Not using AddRelTorque( ) improves it too.

Thanks anyway, Nate.