Orient Joint (Demystified)

I for one have always struggled to understand how this dialogue box works, and when I finally do figure it out, I forget how it works agian.

So to concrete its functionality in user friendly history, here is the instruction manual:

1.) The radio buttons have all the possible sequences of axis to choose from.
2.) The first axis in the sequence will be the one that points down the joint chain (in most cases (apart from mocap which uses the Y axis) this will be the X axis).

3.) The second axis will point in whichever direction you have set the "Second axis world orientation" option to. For example, if it's set to -y, the second axis in the sequence will point in the world orientation of -y.

4.) So the third axis in the sequence will trail along behind and point in the appropriate direction.

This little box has always been one of lifes little mysteries, I hope this settles our differences and we can live in harmony together for ever more.