[Bf-funboard] flip quaternion rotations

[Bassam Kurdali]

Hi folks
I just found today an awesome (hidden?) function in blender.
If you press alt-F with a bone selected in pose mode (in the 3d view)
you get to flip the quaternion rotation. I just found out about it by
total accident (hit the wrong key instead of alt-G) and one of our
animators instantly needed!

two questions: 

why doesn't it (or does it?) have a menu entry for discovery.

why isn't it available in the IPO editor, or action editor so you could
do it for multiple keys,

and third question: is it possible that it could autokey? currently you
have to press I.

I'm overjoyed to have found this, but it does seem a tad hidden.

brief explanation:

for every visual rotation there is more than one (maybe it's just two?)
quaternion values available. depending on how you got there, you could
have mirrored quats on two similar or even identical rotations.

as blender goes between the two, the curves will hit the zero point and
bang! you will have one frame where the bone flips, then flips back. to
fix it, you have to "mirror" the quats on one side of the problem, but
editing quats by hand is daunting to most non mathematicians. hence the
beauty of this function.

cheers
Bassam