Limit Distance Constraint Abnormalities

Hello Blender artist community.

I’ve been frequenting these forums as I’ve been delving into blender the past few months and it was about time that I became a member. Which also means…I have a problem I just couldn’t find an answer to.

My rig is working with a spline IK in which I’ve set up both twist and hook controllers. The controllers that are hooked to the spline I didn’t like having the freedom to wander far off in global space, I wanted the controllers to remain close to the armature that I’m manipulating. To do that I put Limit distance constraints on the controllers, their targets being the bone in which they correspond to on the armature. Everything seemed to work as desired, but something strange happened.

When I right click to cancel changes, or press alt-g the controller doesn’t always return to its neutral position.
It will return if the transformation is within a small distance from the origin, but the spline and armature will keep the undesired changes.
Pressing alt-g several times will get it back to it’s original position, but this is bad for work flow.
Is this an apply issue? Will the undesired changes be something that an automatic key will pick out? Is it all a weird blender illusion, or have I managed to rig something horribly wrong?

Any help is greatly appreciated!

Hmmmm strange. Have you tried possibly changing it from Global to local space?


Thanks for your reply! I experimented with each space combination. Local, world, pose, etc. Each one produced more or less the same odd result. Also noted: if I reset changes (and see the spline still deformed) as soon as I manipulate another controller the deformation automatically snaps back to its proper reset pose.
The bigger problem now is when I tried parenting this part of the armature to another, nothing happens. The spline and armature stay exactly where they are and will not follow the parent.
I’m certain there are other rigs out there that have incorporated two spline IKs. One for a spine, another for a tail, and had them connect properly. Once I take off the spline IK the tail bones follow the parent bone just fine, so the only thing I can think to try now is to start fresh with a new curve and build that part of the rig over again. Maybe it will illuminate where I went wrong.

After starting this up from scratch I think I found the real problem.

I made a new bezier curve and went through the process of rigging up a new Spline IK with my previously created controllers.
As soon as I add the spline IK constraint on to the armature, the spline begins to stick. The limit constraints don’t seem to be the culprit, however when I disconnected them from the last build the spline didn’t seem to stick.
The only thing I can think of now is that the direction of the bones in the tail are opposite to those of the spine, but…that shouldn’t effect the spline in anyway that I’m aware of.

Are there any recommendations for how to rig a tail that is not directly connected to the spine? I’m starting to wonder if I’m going to have to do this the FK way.