# Procedural Rotation?

Hi, I’m currently working on the rig (just started learning how to do it a couple of days ago hehe) which I think is coming along well. At the moment though I’m trying to get the rotation constraint to work Like what I want to do is for the spine, to be able to rotate one end and have the series of bones each rotate consecutively. So, for example, if I rotate one end bone 90 degrees, the next will turn 60, the one after that 30 etc. But so far I haven’t been able to get it to work grrr. By rotate I mean to rotate like how your own spine does, not something like a whip. Any ideas?

why not use an IK chain?

so, the user moves the bone at the top [the target], and the one at the bottom…

I think that is what you use if you want a hinge in the chain, like an arm. You move the hand bone and the wrist follows that, and the upper arm follows that. What I am talking about would be like if you have 3 bones all vertical, in a straight line. Rotating one around the z-axis would make the nest rotate around the same axis but not as much etc. So the overall shape would be the same (a straight line of bones) but the degree of rotation about the z-axis would be different for each one.
Can that be done with an IK chain? I’m still pretty new to rigging, just so far with my IK chains I haven’t noticed rotation like that. And I was thinking since the degree of rotation would be different at each step in the chain that copy rotation constraints would be needed, with a reduced influence. I tried that but haven’t got it to work.

here’s an old rig i did half a year ago, i just improved it a bit to do what you need (at least a little ).

grab it here:

in case you can’t figure out: Bone.002 has a weighted CopyRot constraint, which uses rotation of Bone.003, which itself is rotation/ik-constrained to the shoulder control object.

for testing, you only need to move/rotate the constrol objects (ellipses and cubes)

if you rotate the shoulders, Bone.003 sticks to them and follows every rotation/movement. Bone.002 also follows rotation, but only to the amount determined by the influence slider in it’s constraint-panel.

hope that helps

Thanks, I’ll have a look at it and see if I can work out how to do it in my rig

Update: I’ve had a look, I see how you did the spine, I think I’ll try and do something similar with mine. I also like how you have the control objects (eg. the rings and cubes) to move the mesh. What I have been doing for the control parts is using certain bones in the armatures (this is what they did in the tutorials I was learning from). I tried to create a cube elbow controller for the elbow to point to (currently using a bone, and it is working fine), but when I swapped the track to contstraint from the bone to the cube, it messed up (even though the cube was in the same place). I’ve also tried moving the cube over the bone and having the bone follow it with a copy location constraint, but it didn’t matter how I set which combination of axis to copy, the bone would be nowhere near the cube.

Is using these objects something that needs to be done to animate? Currently the way I have to test to make sure things are working is to press ctrl+tab so they are blue, select the control bone and move that. Things are working fine here, but in object mode the whole armature is selected instead of the control bone.