[ODE] finite_rot_axis bugfix

[akio]

A trick to prevent rear wheels from angling is to create two
dJointCreateHinge2 joints for each rear wheel, and only allow rotation in
single axis, e.g.
1) first set of hinge2axis (y = up)
        dJointSetHinge2Axis1(m_aJointId[i], 0, 1, 0);
        dJointSetHinge2Axis2(m_aJointId[i], 1, 0, 0);
2) second
         dJointSetHinge2Axis1(m_aExtraJointId[j], 0, 0, 1);   // -- note -- 
z = -1 for opposite side
         dJointSetHinge2Axis2(m_aExtraJointId[j], 1, 0, 0);

This restricts any rotation in x or z, but will allow rotation in y-axis.
Makes it very stable to control, and you cannot apply any velocity to the
extra joints.

Akio


----- Original Message ----- 
From: "Erwin de Vries" <erwin at vo.com>
To: <ode at q12.org>
Sent: Sunday, March 14, 2004 6:03 PM
Subject: Re: [ODE] finite_rot_axis bugfix


> No unfortunately it doesnt prevent it from happening. If anyone has
> suggestions on how to fix or minimize this, i would like to hear them.
>
> Erwin
>
> ----- Original Message ----- 
> From: "akio" <cullum_a at bellsouth.net>
> To: "Erwin de Vries" <erwin at vo.com>
> Sent: Sunday, March 14, 2004 11:50 PM
> Subject: Re: [ODE] finite_rot_axis bugfix
>
>
> > Does this explain why the rear wheels angle(rotate) in axis 1 even when
> > LoStop and HiStop is set to 0?
> >
> > ----- Original Message ----- 
> > From: "Erwin de Vries" <erwin at vo.com>
> > To: <ode at q12.org>
> > Sent: Sunday, March 14, 2004 4:22 PM
> > Subject: [ODE] finite_rot_axis bugfix
> >
> >
> > > Hi,
> > >
> > > Line 237 in step.cpp redefines the 'irv' vector, which causes random
> > > behavior in the case the finite rotation axis is used. Has noone ever
> used
> > > this option? I will commit the changes to CVS soon.
> > >
> > > Erwin
> > >
> > > _______________________________________________
> > > ODE mailing list
> > > ODE at q12.org
> > > http://q12.org/mailman/listinfo/ode
> >
> >
> >
> >
>
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