2D Rolling Friction for Box2D Based Engine

[crashlander]

I have a 2D physics engine based closely on Box2D. I use distance grids for collision detection in order to have other arbitrary collision shapes beside boxes.

I've noticed when I try to simulate a wheel, the wheel jitters and jumps a lot once it gets moving at even moderate speeds. The collision detection is accurate so I assume its a friction thing?

There had been another post on these forums regarding implementation of a different friction model for rolling objects but I think that post was lost when the website went down a while back.

So, my question: How do I get started implementing a better friction model for rolling objects given the Box2D architecture as a starting point.

-Thanks

[Erin Catto]

Is that a wheel attached to a chassis? In that case it might be joint instability. If it is just a circle rolling on a plane, you should have no jitter with the Box2D algorithm.

[crashlander]

Yes, it was attached to a chassis using a revolute joint. I will mess around with the joint and see if I can smoothing things out.