OK SidV, sorry I haven’t got back to this yet.
B-Bones are unfortunately no solution for this as they require a strict hierachy and therefore you just end up with another FKspine. Correct me if i’am wrong.
This I will have to explore and think about. I will say this: all stretchy/bendy rigs I have seen use b-bones, and they all have been created before splineIK was added to blender.
The point is to have 2 independant controllers. Beside the refresh issue you can pose and key it however you want. I dont see a major road block here Randy. Even tho the system console throws out dependency loops.
The road block here is when you move into animating. Ideally it’s best to have all animation controllers be contained in 1 armature object. When animating, you’ll be working in the dopesheet editor to lay down initial keys, secondary keys, etc… At some point in time you might move into the f-curve editor to tweak the animation curves for final polish. Dopesheet has 4 modes: dopesheet mode shows all keys in the scene, camera movements, object movements, armature keys, etc… The GreasePencil mode - skip this. Shapekey mode is for mesh shapekeys. It has all the keyframes for shapekeys on mesh objects, or morphs - think of a ball that you animate the verts to squash as a hand grasps it. Action mode is for working with armatures, all your poses of the rig and keyframes exist here.
In the action editor you see all the keyframes for the current armature. If you are using more than one armature to control the rig, as you switch from one rig to the other, only the current rig’s keyframes are displayed. So if you want to move keyframes for more than one rig, it can be a pain. Move keys for one rig, select other rig, move keys… Sure you could do this in dopesheet mode, but then you have other keys not needed, like camera keys. yes you can filter that stuff out, but why filter it out if you don’t have to by using 1 control rig?
The example you posted is outdated. It’s from before the 2.5x re-write and improvements to blender. At that point in development there was no dopesheet to view all keys. Moving keys to adjust timing would have been a nightmare with that rig as in that you couldn’t move all keyframes at the same time.
Anyhow, took me some time to come up with this, but I’m using 2 armatures and 2 armature modifiers on the same mesh and they are working. It uses 1 control armature and 1 spline ik armature. 2 armature modifiers on the mesh. Each armature modifier is set to work on a vertex group, ‘armature’ or ‘splineIK’ groups on the mesh. Then each bone has a vetex group that controls it. It works decent. The splineIK chain has copy rot constraints targeting the chest and hip controllers at varying levels of influence to handle twist.
I say it works, it’s not perfect. For some reason, I am encountering problems with weight painting the vertex groups. I have to explore what my problems are.
From what I know, if it were me. I think I would use 1 armature as a deform armature, and 1 rig as a control rig. The deform rig would have all the splineIK chains (cause I think you want a few) and other mesh deforming bones. Then the control rig would be keyframed and control the deform rig.
Anyhow, I’m interested to see what you might come up with…
rig_test.blend (628 KB)