< Process‎ | Addons‎ | Rigify

Bone Utilities (rigify.utils.bones)

This module provides utilities for working with bones.

BoneDict class

This subclass of dict allows access to its contents via attribute access syntax, in addition to the regular dictionary indexing.

It is intended for storing bone names, so it only allows storing strings, lists and other BoneDicts. Assigning a regular dict will automatically convert it into a BoneDict.


Returns all names in the dictionary as a flat list. The key argument can be used to only extract names stored under a specific key, e.g. bones.flatten('ctrl').

Main Bone Utilities

These functions and a mixin class used by BaseRig deal with creation of bones.


get_bone(obj, name)
Returns an EditBone or PoseBone, depending on the currently active mode.
new_bone(obj, name)
Creates a new bone with the given name, and returns the actual name of the new bone.
copy_bone(obj, old_name, new_name, parent=False, bbone=False, length=None, scale=None)
Copies a bone under a new name, including its location, orientation, and layers, and returns the actual new name.
If parent is true, copies its parent, connect and inherit options.
If bbone is true, copies the edit mode B-Bone settings.
The length parameter allows replacing the length after copy, while scale is multiplied.
copy_bone_properties(obj, old_name, new_name)
Copies Pose mode properties from the old to the new bone, including the rotation mode, locks and custom properties.

BoneUtilityMixin class

This class provides bone creation and parenting tools as methods for the class inheriting from it.

The inheriting class must have an obj field referencing the armature object.

self.register_new_bone(new_name, old_name=None) callback
This method should be overridden if the class needs to track newly created or copied bones, e.g. it's done by BaseRig. It is called by other methods of this class, but does nothing by default.
Returns an EditBone or PoseBone, depending on the currently active mode.
Creates a new bone, and registers it.
self.copy_bone(old_name, new_name, parent=False, bbone=False, length=None, scale=None)
Copies a bone using the copy_bone function described above, and registers it.
self.copy_bone_properties(old_name, new_name)
Copies Pose mode bone properties via the copy_bone_properties function described above.
self.rename_bone(old_name, new_name)
Renames the bone, returning the actual new name, and registers it.
Returns the name of the parent of the specified bone, or None.
self.set_bone_parent(name, parent_name, use_connect=False, inherit_scale=None)
Sets the parent of the specified bone. If use_connect is None, it is left unchanged. The inherit_scale parameter allows setting the Inherit Scale option.
self.parent_bone_chain(name_list, use_connect=None, inherit_scale=None)
Connects the bones in the list into a parented chain, using set_bone_parent.

Bone Placement

flip_bone(obj, name)
Swaps the head and tail of the bone.
flip_bone_chain(obj, name_list)
Flips a connected chain of bones, including its parent-child links. All children of the bones have use_connect cleared.
put_bone(obj, name, pos, matrix=None, length=None, scale=None)
Moves the bone to the specified position, without changing orientation.
The matrix parameter allows using a 3x3 or 4x4 matrix to also set the bone orientation. If a matrix is used, pos may be set to None to leave the position unchanged, or use the location from the 4x4 matrix.
The length or scale parameters allow replacing or scaling the length of the bone.
is_same_position(obj, name1, name2)
Checks if the heads of the bones are in the same location (with epsilon).
is_connected_position(obj, name1, name2)
Checks if the tail of the first and the head of the second bone are in the same location (with epsilon).
copy_bone_position(obj, old_name, new_name, length=None, scale=None)
Copies the position and orientation from the old to the new bone. Optionally replaces or scales the length.
align_bone_orientation(obj, name, target_name)
Copies the orientation from the target bone.
align_bone_roll(obj, name, target_name)
Copies the roll from the target bone.
align_bone_x_axis(obj, name, vector)
Rolls the bone to aim the X axis in the specified direction.
align_bone_z_axis(obj, name, vector)
Rolls the bone to aim the Z axis in the specified direction.
align_bone_y_axis(obj, name, vector)
Rotates the bone to aim the Y axis in the specified direction.
compute_chain_x_axis(obj, name_list)
Computes a vector perpendicular to the primary plane of the bone chain.
align_chain_x_axis(obj, name_list)
Aligns the X axis of the bones to the result of compute_chain_x_axis.
align_bone_to_axis(obj, name, axis, length=None, roll=0, flip=False)
Aligns the Y axis of the bone to the global axis ('x','y','z','-x','-y','-z'), optionally adjusting the length, flipping it before aligning, and setting the roll.

B-Bone Utilities

disable_bbones(obj, name_list)
Clears the segment counts of all the bones to disable the B-Bone behavior.
connect_bbone_chain_handles(obj, name_list)
Connects the bones into a chain via 'ABSOLUTE' custom handles.