Bruno Chareyre said: (by the date of Mon, 12 Jul 2010 11:40:12 +0200)
>
> > - CohFrictLaw : Eigen is returning nan quaternions after trivial
> > operations, it is workarounded in the law.
> >
> Raising attention on this fix, as other functors could have the same
> problem.
>
> Take quaternions q1init,q1, q2init,q2, with q1 (resp. q2) close to
> q1init (resp. q2init). In that case,
> AngleAxisr(q1*q1init.conjugate*q2init*q2.conjugate) will sometimes
> return nan rotation while it should be null.
>
> The fix in cohesiveFrictionalContactLaw.cpp:133 is :
> if (isnan(aa.angle())) aa.angle()=0;
OMG, guys. we need to either modify eigen, or write a wrapper for
quaternions. It is not possible to put such stupid lines everywhere
in the code. Same goes about quaternions losing their norm()==1.0
> Bruno
>
> p.s. This is the sort a jokes I was expecting from eigen move, when I
> was asking for strong testing... It took me 2 hours to find the
> problem. Who knows if there are other surprises left?
>
> p.s.2 : There is I think a potential memory leak with functions below,
> are they used?
> +//FIXME : risk of memory leak with these "new"?
> static Quaternionr* Quaternionr_fromAxisAngle(const Vector3r& axis, const
> Real angle){ return new Quaternionr(AngleAxisr(angle,axis)); }
> static Quaternionr* Quaternionr_fromAngleAxis(const Real angle, const
> Vector3r& axis){ return new Quaternionr(AngleAxisr(angle,axis)); }
use bzr blame to find who wrote this. This code is crazy wrong.
--
Janek Kozicki http://janek.kozicki.pl/ |
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