[ODE] Car Physics with a couple errors

[Jon Watte (ODE)]

You have to do at least this, each time you want to set a limit:

   Set high stop to "HI"
   Set low stop to "LO"
   Set high stop to "HI" again

The reason is that the joint does not allow inconsistent constraints to
be set, even for a short while, and silently rejects the first "HI" if
it's lower than the previous "LO" value. This is true for all joints.

I've provided a patch for this (to set them both if inconsistency is
detected) but that never got merged.

Good reference reading:

http://q12.org/cgi-bin/wiki.pl?ODE_Wiki_Area
http://ode.org/cgi-bin/wiki.pl?FrequentlyAskedQuestions
http://ode.org/cgi-bin/wiki.pl?TipsAndTricks

Sadly, the description of this problem seems to have fallen off the
Wiki, so I re-added it.

mseare at concretegames.com wrote:
> I don't see it in the FAQ either. 
> 
> Regardless, if we need to set the hi and lo stops twice, should the 
> calls to do so be one right after another?  Or one set of calls when we 
> create the joints, and then another set of calls during an update?
> 
> -Michael
> 
> -----Original Message-----
> From: ode-bounces at q12.org [mailto:ode-bounces at q12.org] On Behalf Of 
> Jaroslav Sinecky
> Sent: Wednesday, July 06, 2005 8:09 AM
> To: ode at q12.org
> Subject: RE: [ODE] Car Physics with a couple errors
> 
> 
> 
>  > You probably haven't set the lo and hi stops TWICE, which is necessary
>  > because of an implementation issue in the joint. This is mentioned in
>  > the FAQ, btw.
> 
> Really? I had no idea about this... In what FAQ is that mentioned, I have
> just rechecked the doc and didn't find it. Is it true just for hinge2
> joints?
> 
> Thanks,
> Jaroslav
> 
>  >
>  > You might also want to check out the code at
>  > http://www.mindcontrol.org/~hplus/carworld/ which is a working car built
>  > much like yours, tuned to allow maneuvering at moderately high speeds
>  > without flipping over.
>  >
>  > Cheers,
>  >
>  >                       / h+
>  >
>  >
> 
> _______________________________________________
> ODE mailing list
> ODE at q12.org
> http://q12.org/mailman/listinfo/ode
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> ODE mailing list
> ODE at q12.org
> http://q12.org/mailman/listinfo/ode