Rigify: allow aligning IK control location channels to world space.

For IK controls that move freely in space without being tied to
a parent it makes sense to align the location channels to world
(or root), while keeping rotation channels aligned to the limb
end orientation.

Blender already has a Local Location parenting option for this
very use case, but Rigify wasn't using it. This adjusts the
switchable parent mechanism so that the option works as intended,
and provides a Rigify option that controls its value for IK controls.

Note that now it is possible to enable the Local Location option
directly on the control bones after generation and it will work
correctly - it is not required to enable IK Local Location.

1 files changed, 14 insertions, 0 deletions

diff --git a/rigify/utils/bones.py b/rigify/utils/bones.py
index 16cf62de..10a8926d 100644
--- a/rigify/utils/bones.py
+++ b/rigify/utils/bones.py
@@ -482,6 +482,20 @@ def align_bone_orientation(obj, bone_name, target_bone_name):
     bone1_e.roll = bone2_e.roll
 
 
+def set_bone_orientation(obj, bone_name, orientation):
+    """ Aligns the orientation of bone to target bone or matrix. """
+    if isinstance(orientation, str):
+        align_bone_orientation(obj, bone_name, orientation)
+
+    else:
+        bone_e = obj.data.edit_bones[bone_name]
+
+        matrix = Matrix(orientation).to_4x4()
+        matrix.translation = bone_e.head
+
+        bone_e.matrix = matrix
+
+
 def align_bone_roll(obj, bone1, bone2):
     """ Aligns the roll of two bones.
     """