[smokel]

> The rotation formula eludes me.

Interestingly, in a way, rotation is less mystical than the perspective projection. The rotation is linear: x' = Rx, but the perspective projection is non-linear.

This is where things become fun. Next up are homogeneous coordinates or quaternions. Takes a few years of your life to actually enjoy this though :)

[chuckadams]

I get how quaternions beat Euler angles, but I still can't visualize the damn things 8-/

[aleph_minus_one]

> I get how quaternions beat Euler angles, but I still can't visualize the damn things 8-/

And spin groups beat quaternions since they work in every (finite) dimension. :-)

[corysama]

I recently appreciated this vid explaining that 3D translation using the traditional 4x4 transform matrix is performing a shear operation in 4D.

https://youtu.be/x1F4eFN_cos