Spline IK problem

Support Animation and Rigging
1

I created a tail for a T-rex using a Spline IK. But when I attached it to the pelvic bone, the first bone in the tail doesn’t stay firmly attached to the pelvis It strays a bit. The curve itself stays attached to the pelvis, but the bone is wandering a bit off of the curve.

The vid below shows it…

http://www.youtube.com/watch?v=sH2JOKM67I4

Is there a setting somewhere that I’m missing? What’s odd is that when I select the Chain Offset option in the Spline IK panel, the straying goes away, but the tail is pointed 90 degrees to the side.

Steve S

2

Can you post a simplified version of a Blend with this issue for others to test?

3

Here ya go. Note: What I referred to as the pelvis bone above, is really called the Tailbone in the blend file.

Steve S

Attachments

Splinetest.blend (949 KB)

4

This looks like a slight cyclic-dependency induced “lag”.

See the “tips for nice setups” under:
http://www.blender.org/development/release-logs/blender-254-beta/spline-ik/

IIRC the demo file there should be set up in the right way to demonstrate the way to do this.

5

Thanks for the replies. According to Aligorith’s link, the bone which anchors the curve needs to be in a separate armature. I’ve got it in the same armature as the rest of the rig. I’ll see if that fixes it.

Steve S

6

I think I may use this guy’s technique using b-bones.

A quick test looked pretty good.

Steve S