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unfortunately, IIUC, GA doesn't handle scaling. It's ironic the picture of a T-POSE in that article is a cartoon like character. Cartoon animation is full of "s

unfortunately, IIUC, GA doesn't handle scaling. It's ironic the picture of a T-POSE in that article is a cartoon like character. Cartoon animation is full of "squash and stretch" which means lots of animation of scale.

AnthonBerg 6y ago
I’m still only circling geometric algebra – could you give me some leads on GA not handling scaling? I’ve understood it such that it did, but I’d love to dig into it however it is :) Thanks!
- amelius 6y ago
  You probably want projective geometric algebra. http://projectivegeometricalgebra.org/ http://projectivegeometricalgebra.org/
  - AnthonBerg 6y ago
    Perfect! Thank you so much!
- DonHopkins 6y ago
  You should try triangulating geometric algebra too! ;)
  - AnthonBerg 6y ago
    :kiss: MWAH :heart:
bsenftner 6y ago
Squash and stretch is not implemented with scaling. In fact, for any rational animation system (meaning one that a non-engineer digital artist can actually use) the use of scaling is simply not available in the system. Scaling in a hierarchical animation system is a guaranteed method to fuck up an untold large number of additional systems such as the physics/dynamics associated with the scaled character as well as any geometry attached to the character, as well as any sub-systems which use the now-scaled character for decision triggers. There are simply too many inter-dependent systems that rely on aspects of the environment, such as the scale of objects, to remain consistent for the entire illusion of a consistent world to be maintained. Speaking from experience: I've written dozens of 3D animation systems for games and film VFX. I've been writing 3D animation systems since the 80's.
- gfxgirl 6y ago
  So have I. I can assure you there is scaling in every game and VFX I've worked on since the late 90s
  - bsenftner 6y ago
    You may have scaling in your tools, but under the hood the transformation pipeline treats the result as a translation. Scales cause physics and dynamics issues, which are linked to too many related systems. That's why tools that scale have a "bake" operation afterwards, that baking is transforming scales into translations so runtime and scene logic can use a uniform coordinate space.
    - gfxgirl 6y ago
      Not my experience. Have shipped several AAA games with scaling, no baking.

AnthonBerg 6y ago

I’m still only circling geometric algebra – could you give me some leads on GA not handling scaling? I’ve understood it such that it did, but I’d love to dig into it however it is :) Thanks!

amelius 6y ago
You probably want projective geometric algebra. http://projectivegeometricalgebra.org/ http://projectivegeometricalgebra.org/
- AnthonBerg 6y ago
  Perfect! Thank you so much!
DonHopkins 6y ago
You should try triangulating geometric algebra too! ;)
- AnthonBerg 6y ago
  :kiss: MWAH :heart:

bsenftner 6y ago

Squash and stretch is not implemented with scaling. In fact, for any rational animation system (meaning one that a non-engineer digital artist can actually use) the use of scaling is simply not available in the system. Scaling in a hierarchical animation system is a guaranteed method to fuck up an untold large number of additional systems such as the physics/dynamics associated with the scaled character as well as any geometry attached to the character, as well as any sub-systems which use the now-scaled character for decision triggers. There are simply too many inter-dependent systems that rely on aspects of the environment, such as the scale of objects, to remain consistent for the entire illusion of a consistent world to be maintained. Speaking from experience: I've written dozens of 3D animation systems for games and film VFX. I've been writing 3D animation systems since the 80's.

gfxgirl 6y ago
So have I. I can assure you there is scaling in every game and VFX I've worked on since the late 90s
- bsenftner 6y ago
  You may have scaling in your tools, but under the hood the transformation pipeline treats the result as a translation. Scales cause physics and dynamics issues, which are linked to too many related systems. That's why tools that scale have a "bake" operation afterwards, that baking is transforming scales into translations so runtime and scene logic can use a uniform coordinate space.
  - gfxgirl 6y ago
    Not my experience. Have shipped several AAA games with scaling, no baking.