SplineIk out pose altered with no movement of the points!


there seems to be a bug in the spline Ik anim graph node that changes the out pose even if no spline Ik points were moved at all.

Please see this forum thread for the full description,

This problem is messing up my rig so it would be great if this could get looked at please?
I would love to be able to use the splineIk as it adds several cool features to my character rigs!


Hey Fredrum,

The previous issue that you sent appeared to be a problem with the setup itself. Spline IK for Pelvis>Spine_03 works as expected for us with the mannequin . Can you please provide an example asset so that we can take a look?

Hi , here is the issue I am talking about. It seems like you can’t feed a in-pose that is not the same as the original .

Here i’m feeding a pose in and NOT moving any points, getting a deformation of the mesh.

Here is a dropbox link with the project creating this.

I’m back at looking more at this now trying to understand what is going on there. It would be really helpful if someone could explain the workings and the intentions of things like the in-pose and the relationship to the original assets’ bone transforms and how all that comes together to form the out pose!?

Here is another experiment I just did.
I made a version of the skel-mesh with the joint_02 pushed a bit back as the Bind Pose.
I made two animations/poses, one with joint_02 pushed forward again making joint chain straight. One other with an additional rotation to that joint.
The first new pose seemed to pass through the splineik without anything changing. (not sure if that is right or not)
The second pose with the additional rotation squiggled the result pose.
Its worth noting that the squiggling happens at the opposite end of the joint chain, to the joint that was actually rotated.

Why would this happen?

I really need that thorough explanation of the splineIk workings.

EDIT: Dropbox link w project: Dropbox - File Deleted - Simplify your life