Scale Adjuster
The Scale Adjuster component allows you to adjust the X/Y/Z scales of a specific bone without causing issues with rotated child bones.
When should I use it?
This component is primarily intended for use when fitting clothing not originally designed for your avatar. You can use this to adjust the dimensions of specific bones, without breaking child bones.
When shouldn't I use it?
When adjusting the overall scale of a bone (where X/Y/Z are being adjusted equally), it's usually better to use the normal unity scale tools.
Setting up Scale Adjuster
Simply add the Scale Adjuster component to the bone in question. Now, when you have the scaling tool selected, changes will affect only this one bone.
You can check or uncheck the "Adjust child positions" checkbox to adjust the relative position of child bones when the scale of their parent changes. This is useful when you want to adjust the scale of a bone, but don't want to move the child bones. Note that this adjusts only the position of child bones, and not their scale.
Scale Adjuster supports adjusting the scale of multiple bones by adding the Scale Component to all of the bones in question, then selecting multiple bones before adjusting their scale. However, if these bones are rotated, the scale adjustment won't be perfect, and may not give quite the results you expect.
Scale Adjuster only controls the unity scale tool. The combined Move/Rotate/Scale tool will still affect all children.