After generating a metarig, you have an opportunity to adjust bone positions before the final control rig is generated. This guide covers what you can change, what you should leave alone, and techniques for precise bone placement.

When to Adjust

The snapping algorithm positions metarig bones to match the MetaHuman skeleton automatically. For most characters, the result is ready to use. Consider adjusting when:

• Finger or toe bones don't align well with the mesh
• The character has unusual proportions or a non-standard bind pose
• You want tighter bone placement on the head or jaw
• Heel bones need repositioning for specific footwear

What You Can Change

In Edit Mode on the metarig, you can safely adjust:

Bone Positions

Move bone heads and tails to better fit the character mesh. The most common adjustments:

Bone Lengths

Extending or shortening bones by moving their tails changes proportions in the final rig. This is useful for characters with non-standard limb lengths.

What You Should Not Change

Avoid modifying these aspects of the metarig:

• Bone names — Rigify uses specific bone names to determine rig types. Renaming bones will cause generation to fail.
• Rigify parameters — Each bone has custom properties that tell Rigify what type of control to generate. Don't modify these unless you understand Rigify's parameter system.
• Parent-child relationships — The bone hierarchy defines the rig structure. Breaking connections produces invalid rigs.
• Bone collections — Rigify uses bone collections (Blender 4.x) to organize rig layers. Don't reassign bones to different collections.

Saving a Custom Metarig

If you've made adjustments that you want to reuse for future characters, the addon includes a Save Metarig Template operator:

1. Make sure the metarig is selected and in Edit Mode
2. Run character_control_rig.save_metarig (available in the operator search)
3. The addon encodes the current metarig via Rigify and overwrites resources/metahuman/metarig.py