Maybe don't stress too much about it?
Fish: https://www.shutterstock.com/video/clip-29361571-koi-fancy-c...
In fact not only do they not drag their behinds, the tails turn further than the bodies
Snakes: https://www.youtube.com/watch?v=zEto1-ZTbd4
That's not a dis. The technique in the video is pretty to watch and might be good enough but it just stuck out to me at a glance as unnatural. Like something was off.
TL;DR: animation by simplistic algorithms is a beautiful technique, but a lousy simulator.
For both, simply following the path of the first circle is both a simpler algorithm and closer to natural movement
https://youtu.be/RZtZia4ZkX8?si=vxQ904w_CNXsSoj5
Previous HN discussion:
Beautiful video though, would love to see more content from you.
https://docs.godotengine.org/en/stable/tutorials/performance...
> The animation will be made of four key motions:
A side to side motion
A pivot motion around the center of the fish
A panning wave motion
A panning twist motion
TheRujiK seems to use a very similar animation technique. These creatures also somewhat remind me of the creatures of Spore: https://youtu.be/a87tB__3KEs?si=2Xl3Ub3j-Z3msxm6