[ODE] rolling contacts?

[smythst]

ODE only simulates contact (sliding) friction, you can see an example in 
test_friction.cpp However if you want to simulate rolling friction you have to 
do it yourself. If your doing something like a car sim, and you're just 
constantly adding a force to the car to accelerate it, then just scale that 
force by some fraction less than 1 every sim loop. ie: fx *= 0.9;

This isn't terribly accurate but works. This question is also tackled in the 
FAQ section on the community page, have a look.