Here's a video of what I'm talking about

I'll also explain in text:

I have a tail with 8 bones, and I need the bones to follow a curve to allow for smooth animation. But when using spline IK, the bones stretch and scale instead of retaining their scale, even with "Y Stretch" disabled.

I cannot use Bendy Bones (B-Bones), as this model and animation is for a game engine that doesn't support that deform feature. I don't want to use standard FK, as that's a pain to animate with a long tail with many bones. and using standard IK for just the tail tip, or IK for multiple parts of the tail is unstable to animate and isn't desirable. And I don't want to settle with the spline IK as is when it stretches, as the scaling will cause issues for the game engine export.

I've disabled "Y-Stretch", and I've looked into every other setting regarding the Spline IK constraint and the settings for the Curve itself as much as I could, and nothing seems to have solved my issue.

I'm not too sure what other options I have. Is there any way to configure a Spline IK to never scale and still properly follow the curve, or is there an alternate method to rigging and/or animating a tail like this that I haven't mentioned?

  • $\begingroup$ A simple solution, which I don't know if you will be able to apply in this case, is to use 2.79 instead 2.80, in which IK Spline is working well and no stretching is happening. I always have many troubles when rigging in 2.80, hope everything will be fixed as soon as possible. $\endgroup$ – josh sanfelici Apr 4 at 8:17
  • $\begingroup$ 2.79 and under still has this issue. Pretty sure this has been a long standing problem, and 2.8 hasn't changed anything about how Spline IK works. $\endgroup$ – DJTHED Apr 4 at 17:54

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