> I see that there is my formula, which I derived when I was working on > snow last year. I still remember discussing with Bruno about this > exact problem :) > > /* Moment Rotation Law */ > Quaternionr delta( b1->state->ori * phys->initialOrientation1.conjugate() > *phys->initialOrientation2 * b2->state->ori.conjugate()); //relative > orientation
> It calculates rotation difference between two spheres using > quaternions. The motivation to use both bending and twisting is > because quaternions cover ALL possible types of rotations. Just to note that this formula will "fail" if the relative rotation of a particle will be more than 180 degrees (the quaternion will take it the other way around, as it goes always the shortest way). v _______________________________________________ Mailing list: https://launchpad.net/~yade-users Post to : [email protected] Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
