While exploring the rig, I came across an abundance of bones such as P-Bone and P-P-Bone. They are only used to parent other bones, nothing more.

I would understand if there were few such bones. Then I would think that the purpose of these bones is to organize the structure of the rig. But sometimes these bones are created even for such small things as a finger, an object of an accessory, etc. As a result, we have a bunch of these P-Bones or P-P-Bones.

How do these bones help?

  • $\begingroup$ I've never come across this. Do these rigs all come from the same source? Is there a sample rig you can share? $\endgroup$ Jan 5, 2022 at 14:41
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    $\begingroup$ It does happen to sometimes have bones whose only purpose is to be a reference point for dynamic parenting. Tipically in advanced rigs where you want basically every limb to have options for orientation and location parents, you may want to have bones who are in a specific location/rotation. $\endgroup$
    – L0Lock
    Jan 5, 2022 at 16:17
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    $\begingroup$ I would expect a "P" bone to be, a bone that was a parent of another bone; then, a P P bone would be a parent of a parent. Sometimes you create duplicates of bones for constraint purposes. I couldn't say what the purpose of the P-bones that you are seeing without seeing the rig. $\endgroup$
    – Nathan
    Jan 5, 2022 at 18:00

1 Answer 1


A broad use of this kind of structure is sometimes called "Socket", in which Bone A is child of bone B, and bone B is constrained by Bone C.

In this way when you move C, bone A and B will follow, but you still have the freedom of adjusting bone A (while bone B is constrained and maybe can't be directly moved).

As you're interested in rigging, I suggest you the free YouTube "Humane rigging" course, by Terumag (one of Rigify's creators): it's based on an older version of Blender, but it's easy to translate all valuable informations onto the new releases.


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