How to Scale a Custom Bone Shape in Blender

Custom bone shapes in Blender improve rig visibility and usability by replacing standard octahedral bones with custom 3D meshes. Scaling these shapes is essential for keeping your viewport organized, ensuring controllers are easily selectable without affecting the actual bone transforms or animation data. You can scale a custom bone shape using the bone's Viewport Display properties in Pose Mode or by modifying the original mesh object in Edit Mode.

This method scales the visual display of the bone in Pose Mode without altering the original custom mesh object.

  1. Select your armature and switch to Pose Mode (Ctrl + Tab).
  2. Select the bone containing the custom shape you want to resize.
  3. Open the Bone Properties tab (green bone icon) in the Properties panel on the right.
  4. Scroll down and expand the Viewport Display section.
  5. Under the Custom Object settings, locate the Scale X, Y, and Z fields (or the overall scale factor depending on your Blender version).
  6. Click and drag or input specific numerical values into the scale fields to adjust the custom shape's size along each axis.

Note: You can also adjust the Location and Rotation settings in this same panel to align the custom shape perfectly relative to the bone.

Method 2: Scaling the Custom Mesh Object in Edit Mode

If you want to permanently change the base size of the custom shape object used by the bone, modify the mesh directly.

  1. Switch to Object Mode.
  2. Select the original mesh object that was assigned as the custom bone shape.
  3. Press Tab to enter Edit Mode.
  4. Press A to select all vertices of the mesh.
  5. Press S to scale the mesh to your desired size (you can constrain to an axis by pressing X, Y, or Z after pressing S).
  6. Press Tab to exit Edit Mode.

Scaling the mesh in Edit Mode updates its dimensions without altering the object's origin point or transform scale, automatically updating the bone controller's size across your armature.