[ODE] finite_rot_axis bugfix

[akio]

Actually, if you take look at the configuration, it allow rotation in x-axis
only - you can see that this is common between the first and the extra
hinge2joint.  The orthogonal configurations in y and z restricts turning in
that direction.

----- Original Message ----- 
From: "akio" <cullum_a at bellsouth.net>
To: "Erwin de Vries" <erwin at vo.com>; <ode at q12.org>
Sent: Sunday, March 14, 2004 6:17 PM
Subject: Re: [ODE] finite_rot_axis bugfix


> 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
> > > >
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> > >
> > >
> > >
> > >
> >
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