3 ms·

'Obviously a huge part of this is the error propagation that we get down the joint chain... but" This shouldn't be glossed over and a proper consideration of t

by djmips 2y ago

'Obviously a huge part of this is the error propagation that we get down the joint chain... but" This shouldn't be glossed over and a proper consideration of the error metric here is key to storing quality animation with fewer bits, lower bandwidth and higher performance.

doctorpangloss 2y ago
Fitting joints onto a text-prompted Sora-generated video: could "transformers" not make all this stuff obsolete too? You might need the motion capture data for ground truth to fit joints, but maybe not to generate animation itself.
rcxdude 2y ago
It does feel like joint rotations are probably not a great representation for processing animation data. And it's not generally how the motion is captured, nor does it seem to be how the human eye analyses it. But I don't know what an alternative would look like, and I'm pretty sure smarter people than I have spent a lot of time thinking about it.
- djmips 2y ago
  The joint rotation / skinning concept is about compression and ability to playback a stored animation rapidly. It has also been done by storing the entire posed mesh per frame and interpolating between meshes. It follows from digitizing the articulated armatures of stop motion animation which preceeded CGI. Some of the first CGI was input using metal jointed armatures with potentiometers in every joint which is a form of 'rigid' transforms. I'm not sure what you are thinking about when you say it's not a great representation for processing animation data but I speculate that you mean it's not a great representation for how a flesh and blood creature moves and you'd be right. Advanced CGI can sometimes tackle a more thorough simulation of the musculature, complex joints, tendons, ligaments, and the physical dynamics of these all being controlled by a brain. A lot of soft body physical interactions as well. The sheer amount of processing and data needed for such a real simulation is why the cheating approximations are used for interactive simulations and games. See https://www.wetafx.co.nz/research-and-tech/technology/tissue https://www.wetafx.co.nz/research-and-tech/technology/tissue

by djmips 2y ago

doctorpangloss 2y ago

Fitting joints onto a text-prompted Sora-generated video: could "transformers" not make all this stuff obsolete too? You might need the motion capture data for ground truth to fit joints, but maybe not to generate animation itself.

rcxdude 2y ago

It does feel like joint rotations are probably not a great representation for processing animation data. And it's not generally how the motion is captured, nor does it seem to be how the human eye analyses it. But I don't know what an alternative would look like, and I'm pretty sure smarter people than I have spent a lot of time thinking about it.

djmips 2y ago
The joint rotation / skinning concept is about compression and ability to playback a stored animation rapidly. It has also been done by storing the entire posed mesh per frame and interpolating between meshes. It follows from digitizing the articulated armatures of stop motion animation which preceeded CGI. Some of the first CGI was input using metal jointed armatures with potentiometers in every joint which is a form of 'rigid' transforms. I'm not sure what you are thinking about when you say it's not a great representation for processing animation data but I speculate that you mean it's not a great representation for how a flesh and blood creature moves and you'd be right. Advanced CGI can sometimes tackle a more thorough simulation of the musculature, complex joints, tendons, ligaments, and the physical dynamics of these all being controlled by a brain. A lot of soft body physical interactions as well. The sheer amount of processing and data needed for such a real simulation is why the cheating approximations are used for interactive simulations and games. See https://www.wetafx.co.nz/research-and-tech/technology/tissue https://www.wetafx.co.nz/research-and-tech/technology/tissue