[ODE] Feedback from contact joints.. ?

[Amund Børsand]

Hi, I'm trying to implement differentials in my car, and then I need to
know how much resistance the wheels get from the ground. First I thought
I could do this by getting the feedback from the wheel hinge (I'm
currently using hinge2's with Fmax to rotate the wheels), but I need to
know the resistance _before_ the wheel has turned. So I thought what I
needed was to know how much force the ground applies to the wheel. But
there are twenty-something contact joints, and as I understand they are
dynamically created each time the collision detection is done, so I
don't know if it will work to set twenty feedback structures in the
start of the program, and anyway it would be a very heavy way to do it,
and as I understand, ODE has to calculate a lot of extra stuff when a feedback
structure is assigned to a joint.

Or maybe this doesn't solve my problem anyway?

-- 
Amund Børsand <amund@c2i.net>