The issue is not bad blender's behavior but difficulties with
understanding what is going on when certain rotation models are used.
When animating rotations we often use our intuition and expect some
behavior because we know our particular case.
Algorithms don't know exactly what our goal is.
F-curves for quaternions:
I don't know anybody who use individual animation curves when working
with quaternions, but this doesn't mean that there's no one doing it.
I simply didn't have a chance to meet such person.
However I've heard some day that at least few people on the face of
this
What i expected was a smooth motion, but
instead it goes straight up (to 2nd key) and continues with a curve that
_bends downward_ to key 3. Given that it has to move trough the keys i
would have at least expected a linear motion (shortest path) from key
2 to key 3.
The interpolation is not
Yes, you're right. But I think that this is not really the kind of
interpolation an animator would want to have in this case. As an
animator I would prefer a direction interpolation and a separate roll
interpolation. Ideally both rotations (as in your example files) would
follow the same path
But I think that this is not really the kind of
interpolation an animator would want to have
in this case. As an animator I would prefer
a direction interpolation and a separate roll
interpolation.
Believe me, as an animator and rigger, I have thought about this
problem a lot. But it's not
Rotations in 3D are just a horrible beast, and I think it is non trivial
to figure out what constitutes a 'nice' interpolation across all cases,
perhaps not even possible. You might be to use hierachies to isolate
axis for some very specific setups, however:
way how it could be correctly
I don't know if this is a known issue. But i tried the following. I made
a key for a leg (restpose), bended it forward (xrot 90°, second key)
and moved it to the side (zrot 90°, third key), and then added a fourth
key (restposition again). What i expected was a smooth motion, but
instead it
