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[Bruno Chareyre <question234062@xxxxxxxxxxxxxxxxxxxxx>]

Question #234062 on Yade changed:
https://answers.launchpad.net/yade/+question/234062

Bruno Chareyre posted a new comment:
>you can track it directly from python with O.bodies[id].state.rot()

In fact state.rot() is first computing a quaternion, then converting to
axisAngle. As pointed out by kelaogui, it will not work for very large
rotations (more than 2*pi).

>It gives the same result than recording the cumulative rotation in
python for each time step with rot = rot_prev + angVel*dt .

I don't think so. state.rot() is always exact, while "rot =
rot_prev+angVel*dt" is only correct when the rotation axis is constant
(else it becomes completely wrong for large rotations, even if each
increment is small). That is why I was asking the equations.

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