I now have the Bullet vehicle running in our engine and the controls are not too bad for the moment (though I did not yet experiment some of the difficulties mentioned in the forum) and that's cool. However, I have a hard time trying to understand why calcRollingFriction() ALWAYS seems to return a rollingfriction of zero. This seems to make the car decelerates forever if I stop applying force. I admit that my knowledge of the jacobian being extemely far away for now, I am a bit confused about what the function does. Right now, from what I understand, it seems like the car "natural" deceleration is not even caused by the ground friction.
I would be very glad if somebody would show me what is going on and if there would be another way of calculating the rolling friction to have a vehicle that decelerates faster.

Thanks.
Verbo