All I want is free shoulder movement

Hello,
I’ve spent the last 3 days setting up an avatar to fit my proportions perfectly.
The only issue that remains is that the shoulder bones refuse to rotate forward or backwards in any meaningful capacity, causing the arm length to be insufficient when reaching forward.

Any ideas as to how I could possibly fix this?

(I have tried upping the shoulder front/back rotation caps from 15 to 75 when setting up the rig in unity but to no avail)

Did you parent correctly between the arm and the shoulder in the rig?

Yes, Had to double check since i used the “T pose new” preset armature but yes, it is parented correctly.

Hmm can you show the screenshots about the shoulders in the hierarchy and rig in Unity?




Here you go, tried to get as much of the relevant info as possible.

Hmm strange, guess probably the ik system problem within vrc

Hmm, do you have other avatars whose shoulders do rotate the way you’re wanting?

Could try importing them side-by-side in blender to look for any differences.

It looks fine at first glance to me, though the shoulders bones do seem a bit further down than I’m used to. That’s probably fine though, depending on the weight paints.

When you say “depending on the weight paint” does that mean that the weight paint can have an impact on how the bones move?

The weight paint is fine visually, and knowing how the shoulder movement is supposed to look from posing in blender I can tell that the shoulder simply don’t move forward or back at all while the model is in VRchat.

You may be experiencing gimbal lock. Make sure the bone rolls are zeroed. If that doesn’t help, you may need to try experimenting with custom ik poses. You can start with the ik pose in the example and slightly adjust shoulder angles, then set that as your custom ik pose.

Right, I’ve never heard about this so how would I go about doing so?

Here’s how to clear bone rolls: https://youtu.be/2sfTEBAl8sA?t=2493 (note timestamp)

This whole video is golden for making sure your rig is set up properly.