[ODE] Car Braking Problem

[kurimail]

Well, i have tried the FDIR1 settings that carworld makes and i must
say... that it works!. The results are amazing. The rotation of the car is
restricted in some way, but anyway i think the results are better than
before. I need more testing, but looks like a more robust friction mode.

Thanks!

>
> If you're not setting the fdir1 correctly (and setting the flag in the
> contact) then that's almost surely your problem. Carworld, the ODE car
> sample application with source, does this; you could grep the source:
>
> http://www.mindcontrol.org/~hplus/carworld/
>
> Cheers,
>
> 			/ h+
>
>
> KuRi wrote:
>> Thanks for your answers. It looks (like you say) like a contact problem,
>> because with no contacts the problem dissapear. But i don't understand
>> why
>> the error depends on the Y Angle of the car. Perhaps it is a round
>> problem.
>> Can someone post one example with code of setting the fdir1 to the
>> rolling
>> tyre direction, etc...? I have tried that with no results...
>>
>> Thanks again. KuRiX
>>
>> ----- Original Message -----
>> From: "Matthew D. Hancher" <mdh at email.arc.nasa.gov>
>> To: <ode at q12.org>
>> Sent: Monday, June 27, 2005 10:23 PM
>> Subject: [ODE] Re: Car Braking Problem
>>
>>
>>
>>>>When i brake (dBodyAddTorque), the car turns to the right or to the
>>>>left
>>>>depending on the Y Axis Angle.
>>>
>>>Perhaps this is a product of ODE's friction model, which is simplified
>>>in ways that make it anisotropic.  You can address this somewhat by
>>>cleverly setting the contact's friction direction, rather than letting
>>>ODE pick it arbitrarily.  When you generate each contact joint between
>>>a wheel and the ground, set the fdir1 field of the dContact structure to
>>>be a unit vector that is in the direction of horizontal motion of the
>>>wheel geom, and set the dContactFDir1 bit in the contact flags.
>>>
>>>Matt
>>>
>>>Matt Hancher
>>>Intelligent Systems Division
>>>NASA Ames Research Center
>>>mdh at email.arc.nasa.gov
>>>
>>>_______________________________________________
>>>ODE mailing list
>>>ODE at q12.org
>>>http://q12.org/mailman/listinfo/ode
>>
>>
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