Rigify arm bones rotate/roll when moving arms

Support Animation and Rigging
1

Hello, i am rigging a robot using rigify. when moving the rigify arms, the upper arm bone rotates clockwise when i move the arm forward, and rotates counter clockwise when moving the arm back. How do i stop this?this won’t work for rigging a robot. i would like the upper arm bones to not rotate or roll at all when moving the arms. Even the forearm bones rotate/roll for some reason. How do i stop them from doing this? Thanks.

bone rotation
bone rotation3224×1725 537 KB

2

Hi, this rotation doesn’t happened when i move rigify ik arm forward and back.
The other option will be to use fk instead.

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3

yeah, i have no idea. no settings changed. i just add a rigify arm and the deformatiion bones rotate like that. whether fk or ik and even with a pole target on for the elbow. i started over from scratch and did a custom rig.

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4

It sounds like you’re encountering an issue with the automatic bone roll settings in Rigify. Here are a few steps you can take to address this:

  1. Adjust Bone Roll Manually

    • In Edit Mode, select the bones that are rotating undesirably.
    • Press Ctrl + N and choose “Recalculate Roll” to reset the bone roll. You can also manually adjust the roll by pressing N to bring up the properties panel and adjusting the “Roll” value under the “Transform” tab.

  2. Lock Rotation Axes

    • In Pose Mode, select the bones you want to restrict.
    • Press N to bring up the properties panel, go to the “Transform” tab, and lock the rotation axes you don’t want to change. This can help prevent unwanted rotations during animation.

  3. Use Custom Bone Shapes

    • Sometimes, using custom bone shapes can help visualize and control the bones better. You can create a simple mesh and assign it as a custom shape to the bone in the bone properties.

  4. Check Constraints

    • Ensure that there are no constraints applied to the bones that might be causing the unwanted rotation. You can check this in the bone constraints tab.

  5. IK Pole Targets

    • If you’re using IK (Inverse Kinematics), make sure you have properly set up pole targets to control the direction of the bend. This can help stabilize the rotation of the upper arm and forearm bones.

  6. Re-generate the Rig

    • If the above steps don’t work, you might need to go back to the metarig, adjust the bone rolls there, and then re-generate the rig.

These steps should help you get more control over the bone rotations and make your robot rigging more stable. If you need more detailed guidance, the Blender Artists Community has some useful discussions and tips on similar issues

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5

Thanks for this. i tried all of these. they don’t work. The bones do have a “copy transformations” constraint on them, to something called “upper _arm_tweak” or some other “…tweak” bone etc. but this means i’d have to have a deeper understanding of the rigify rig or script in order to change this. instead of toggling a setting on/off. i don’t think rigify is good for robots…that’s my conclusion.