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Persistent Spine/Neck "Pop" and Head Vibration During Animation

Rigging General
#1

Screenshot 2025-06-12 123440
Screenshot 2025-06-12 1234401038×860 412 KB
Screenshot 2025-06-12 123504
Screenshot 2025-06-12 1235041029×862 409 KB

I’m currently experiencing a persistent issue with a character rig built using mGear. During spine rotation, whether using FK or IK, I keep encountering a “pop” that causes the head to vibrate in the final animation.

Sometimes I can find a temporary balance by adjusting the IK neck controller (yellow circle around the neck), but after a few frames, the issue reappears. It seems like the neck control goes below the head or locks in a strange way, possibly due to gimbal issues or hierarchy conflicts.

I’ve tried switching Maya versions and using different playback settings, switching from using Euler to quaternions for rotation but the problem remains. To get a usable result, I’m forced to recalibrate the spine every few frames, and manually fix the neck almost frame by frame, which is not ideal, especially for longer shots.

If anyone has encountered this before or has a potential fix or workaround, I would truly appreciate your insight. Thank you in advance!

PD: I didn’t rig it, I’m not a rigger, I bought the rig and wrote to the seller but he just told me “just don’t rotate in that direction”.

#2

LOL :slight_smile:

If you open the script editor, do you see any warnings or cycle dependency warnings? It might be a cycle.

If you’ve disabled cycle checks, Maya might not tell you it’s cycling. You can turn it back on by running this MEL command:

cycleCheck -e on;

And then animate it and see if you get the warning. To turn the warnings back off, run the commend, cycleCheck -e off

I can’t promise a fix or even that I’ll check quickly, but if you want to send me the rig, I’ll download it and see if I can spot the issue. You can DM me a link. I’ll update your user level so you can send a DM.

1 Like
#3

Bonus: The other thing you can do is try to find a parentConstraint in the head or neck area. If the head parentConstraint has more than 2 targets, then it should be set to “Shortest” or “No Flip”. The highest probability is that it is set to “Average”, and that is causing the flipping.

You could try to run this Python script to fix it:

import pymel.core as pm

for each in pm.ls(type='parentConstraint'):
    if len(each.getTargetList()) > 1:
        each.interpType.set(2) # shortest
for each in pm.ls(type='orientConstraint'):
    if len(each.getTargetList()) > 1:
        each.interpType.set(2) # shortest
1 Like
#4

After looking at your scene, I’m afraid I can’t offer a quick fix.

But I can tell you it seems related to DS_Rig_Scenemotionpath56. The worldUpVector seems to be causing the flip.

You could try selecting the node DS_Rig_Scene:neck_C0_2_scl_npo and breaking the connections on translate and rotate. And then zero out 0,0,0,0,0,0 translate and rotate.

I don’t know if that will break some functionality in the rig. But it seems to make it into a basic FK. So you should still be able to animate the head.

#5

Hi, it does, I mean, the problem is solved but now I can’t rotate the Head, the IK control allow me to translate the head but not rotate it. There’s a way to reconnect the FK control with the joint re oriented?