
QuaterNet: A Quaternion-Based Recurrent Model for Human Motion - adamnemecek
https://github.com/facebookresearch/QuaterNet
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babel_
Wait, so previous ones didn't consult the literature for animation systems and
how (at least the ones I know) most of them nowadays use quaternions because
of discontinuities and gotchas? That seems weird, even if you don't care about
ik, quaternions have very nice properties for animation systems, and only add
an extra variable (4 vs 3) so aren't too much of an overhead compared to
reduced error handling or going all the way to 3x3 matrices.

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mikedh
I assumed that too until I read this slightly grouchy but very interesting
thread:
[https://github.com/KhronosGroup/glTF/issues/1515](https://github.com/KhronosGroup/glTF/issues/1515)

~~~
miohtama
Did they in the end settle with quarternions as glTF is an export format (same
playback on different apps) and not an authoring format?

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skocznymroczny
Rotations in GLTF are specified with quaternions.

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amelius
I was wondering about the advantage of quaternions over matrix/vector algebra,
and found this quite interesting post:

[https://stackoverflow.com/questions/8919086/why-are-
quaterni...](https://stackoverflow.com/questions/8919086/why-are-quaternions-
used-for-rotations)

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notbob
Recurrent neural networks for modeling physical systems are starting to really
come into their own. We have a few exciting years ahead of us.

