I am trying to control the orientation of a box in Scene Kit (iOS) using gestures. I am using the translation in x and y to update the x and y rotation of the SCNNode.
After a long search I have realised that x and y rotation will always lead to z rotation, thanks to this excellent post: gamedev stack exchange: I’m rotating an object on two axes, so why does it keep twisting around the third axis?
So I am trying to get the z rotation causes, and then remove this from my object by applying the inverse quaternion however when I rotate the object 90 deg around x, and then 90 deg around Y it behaves VERY weirdly.
It is almost behaving as it is in gimbal lock, but I did not think that using quaternion in the way that I am would cause gimbal lock in this way.
I am sure it is something I am missing, or perhaps I am not able to remove the z rotation in this way.
Thanks!
I have added a video of the strange behaviour here
And the code example is here




