Hi, I updated a little relevant section in the Programmer's manual at https://yade-dem.org/sphinx/prog.html#basic-numerics .
> 1) Ori is declared as Quaternionr. So, it should be [q0,q1,q2,q3]. Quaternions are automagically _represented_ as axis-angle, for readability, though internally stored as 4 components (as written in the referenced doc). > 2) I've seen "b2->state->ori.Conjugate()". According to the > Quaternion.inl file, "ori" has to be stored as q0+q1+q2+q3 for the > conjugate to be calculated. same as above > 3) When we declare orientation = [1,0,0,0] are we saying q0=1, q1=0, > q2=0, q3=0? This construction is invalid in both Python and c++. In python: q=Quaternion(1,2,3,4) print q[0],q[1],q[2],q[3] ## show components print q ## show quaternion (as axis,angle) ## note that angle is zero, it must be normalized to be meaningful q.Normalize() print q > There seems to be automatic conversions between [q0,q1,q2,q3] and > [ [axisX,axisY,axisZ],angle ], of which I'm not aware. Can someone > please enlighten me? Example? _______________________________________________ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp