Global control spline iK rotation issue

[Darrel_Leigh]

Hey, i am fairly new to Maya and have an issue where my spline ik will roll and twist as i rotate the global control in the y direction. my spline iK is set to roll when the controller is rotated in the z direction.

I'm not really sure what else to say but i will attach the file if anyone can help me out, thanks in advance. 

Edited by user request
Discussion_Admin

[Darrel_Leigh · Accepted solution]

I have since solved my issue

[Anonymous]

So what did you do? I think I have exactly the same issue with my current project. Could you help me out?

[Darrel_Leigh]

Hey, I can't remember for this particular project what I did, however if you search: Creating a Character Rig by Maya Learning Channel on Youtube, you'll get a fantastic tutorial all about rigging. I believe it's part 3 for the torso. 

[Anonymous]

The issue I have been having is that the global rig controls do not twist the IK Spline (which I am using for a spine control). To solve this issue make sure that the WorldMatrix from your control handles is connected to the IK Spline WorldUpMatrix and WorldUpMatrixEnd, because if it is connect from the XformMatrix it will take local space rotations. This can be achieved from the Node Editor.

[Anonymous]

Did you ever find a fix for this? i am having the same problem with the solver.

[pejey1]

I had a similar issue so I constrained a curve to a controller and used an expression to roll the IKhandle:

IKhandle.roll = constrainedCurve.rotateY  *-1;  (It could be connected directly if I wouldn't need negative number. Also, I could use a multiply/divide node instead of the expression but this was just suitable for my script.)

Now my joints rotates with the controller 🙂