hello.

I'm learning how to rig a porpoise using KineFX/APEX.
I want to rig it so that the body follows a curve in the shape of a sine wave, to mimic the porpoise "porpoising" repeatedly in and out of the water.
Here is video reference of the swimming behavior I want to mimic:
https://youtu.be/Y6SFPsRfSRA?si=w0rYgXskxCe37B6C [youtu.be]

I found this ancient Houdini snake rig tutorial that shows the functionality I'm looking for.
https://youtu.be/Eo6Lue1TMZU?si=-EILM4iKgUK5zkim [youtu.be]
Can someone point me to an example of how to do this in KineFX/APEX? 🙏🏽

Thanks

The content library might cover your needs:

https://www.sidefx.com/contentlibrary/character-switching/ [www.sidefx.com]

https://www.sidefx.com/contentlibrary/elephant-trunk-sine-wave/ [www.sidefx.com]

https://www.sidefx.com/contentlibrary/kinefxapex-workflow/ [www.sidefx.com]

https://www.sidefx.com/contentlibrary/elephant-seal-fem/ [www.sidefx.com]

PHENOMDESIGN
The content library might cover your needs:

https://www.sidefx.com/contentlibrary/character-switching/ [www.sidefx.com]

https://www.sidefx.com/contentlibrary/elephant-trunk-sine-wave/ [www.sidefx.com]

https://www.sidefx.com/contentlibrary/kinefxapex-workflow/ [www.sidefx.com]

https://www.sidefx.com/contentlibrary/elephant-seal-fem/ [www.sidefx.com]

Hi PHENOMDESIGN, thanks for the suggested examples. I'll check them out.

For something like the snake, you can also try using the rig::CurveConstraint node that allows you to create transforms constrained to a curve at a particular u value.

edward
For something like the snake, you can also try using the rig::CurveConstraint node that allows you to create transforms constrained to a curve at a particular u value.

Thanks, Edward.
However, the documentation for the APEX curve constraint is sparse:
http://127.0.0.1:48626/nodes/apex/rig--CurveConstraint [127.0.0.1]

It would be helpful if someone could point me to an example of the usage of this function.

The other challenge is that I would need to constrain each joint along the spine of the porpoise to the curve.
This means I would need to calculate the distance along the curve as a U value based on the distance between the joints along the porpoise's spine.
Does anyone have any examples of how to do that?
Thanks

Hopefully this helps, Its a simple script that calculates the offsets and makes sure that the scale stays consistent.

william_harley
Hopefully this helps, Its a simple script that gets calculates the offsets and makes sure that the scale stays consistent.

Image Not Found

Hi william_harley. This is very insightful!
Many thanks!