Change bone axis orientation I was wondering if anyone knows an answer to this simple question. Googling did not give me satisfactory solutions. I have never dealt with bones previously, and they seem to be rather complicated.

The question is as follows:

Consider the following bone axis orientation (pose mode selected):



The Y-axis is oriented along the bone length. What I need for the script is to make the X-axis orient along the bone length. Basically, I need to rotate the whole axis system 90 degrees around Z-axis.

I would really love to have this orientation for the script. Converting the script itself would be highly problematic. 

To conclude with: Can I rotate the pivot 90 degrees around the Z-axis?

I would very much appreciate if anyone replies to this. 

Cheers!
Duplicate one of your bones and rotate 90 degrees on the Z axis. This will be the object from which we will make the desired set of axes.



Open the properties panel using N and press control + alt + spacebar to create a custom axis. In the properties panel under "Transform Orientation" you can rename your custom axis, here I've named it "x = y and y = x".



Now select your original bones, X and Y have traded axes. In the 3D window footer, you can see we are now using the custom orientation created.