Rigify: implement optional custom pivot controls.

- Add an optional custom pivot between torso and the rest of the spine.
- Add a custom pivot rig that can be used as a parent of the spine.
- Add an optional custom pivot under limb IK controls.

1 files changed, 10 insertions, 2 deletions

diff --git a/rigify/rigs/limbs/leg.py b/rigify/rigs/limbs/leg.py
index dbdd20cb..900af982 100644
--- a/rigify/rigs/limbs/leg.py
+++ b/rigify/rigs/limbs/leg.py
@@ -121,6 +121,14 @@ class Rig(BaseLimbRig):
 
         return name
 
+    def build_ik_pivot(self, ik_name, **args):
+        heel_bone = self.get_bone(self.bones.org.heel)
+        args = {
+            'position': (heel_bone.head + heel_bone.tail)/2,
+            **args
+        }
+        return super().build_ik_pivot(ik_name, **args)
+
     def register_switch_parents(self, pbuilder):
         super().register_switch_parents(pbuilder)
 
@@ -143,7 +151,7 @@ class Rig(BaseLimbRig):
 
     @stage.parent_bones
     def parent_heel_control_bone(self):
-        self.set_bone_parent(self.bones.ctrl.heel, self.bones.ctrl.ik)
+        self.set_bone_parent(self.bones.ctrl.heel, self.get_ik_control_output())
 
     @stage.configure_bones
     def configure_heel_control_bone(self):
@@ -200,7 +208,7 @@ class Rig(BaseLimbRig):
     @stage.parent_bones
     def parent_roll_mch_chain(self):
         chain = self.bones.mch.heel
-        self.set_bone_parent(chain[0], self.bones.ctrl.ik)
+        self.set_bone_parent(chain[0], self.get_ik_control_output())
         self.parent_bone_chain(chain)
 
     @stage.rig_bones