yade-dev team mailing list archive

[Václav Šmilauer <eudoxos@xxxxxxxx>]

> I wish there was some flag telling the quaternion to be a UNIT
> quaternion. The library should take care of all that normalizing.
> After all inside its own routines it is calculating length quite
> frequently.
They are supposed to be unit quaternions. Exactly for that reason I
guess Eigen _never_ computes the norm, as it is costly and it thinks it
is more or less unit.

The case for clumps was only for for construction of quaternion
construction from rotation matrix, normal quaternion operations (such as
multiplication) preserve unit length, modulo numerical drift, which is
the same for wm3.
>  Just add a check if != 1.0 and if so, then perform
> a .normalize action.
Contact the Eigen guys, I am sure they will be very happy with that
optimization ;-)

v