[ODE] Collision: number of intersection points

[Thomas Thueer]

Hi

I have a question regarding the number of points returned by dCollide(....).
- It surprises me that the collision of a sphere with a flat surface has 
only one single point of intersection in ODE, whereas I'd assume that 
you need several points to describe such an intersection (of circular 
form). Can anyone tell me something about this?
- Actually, my problem is that I do not get enough traction between 
wheels and ground. So I thought if there were more contact points, I 
could create more contact joints, which would then increase the traction 
(like having wider wheels on a car increases friction). Could this be a 
solution or does rigid body simulation work non-intuitive with respect 
to this problem?

Any help would be highly appreciated. Thanks.
Thomas