Rigify: support tags in SwitchParentBuilder for default selection.

Allow tagging parents with arbitrary strings to be later used
in selecting the best default parent for a child control.

Also add a tagged parent point at the limb IK control.

6 files changed, 12 insertions, 7 deletions

diff --git a/rigify/rigs/limbs/arm.py b/rigify/rigs/limbs/arm.py
index 98a3c50f..1ac979d0 100644
--- a/rigify/rigs/limbs/arm.py
+++ b/rigify/rigs/limbs/arm.py
@@ -62,7 +62,7 @@ class Rig(BaseLimbRig):
     def register_switch_parents(self, pbuilder):
         super().register_switch_parents(pbuilder)
 
-        pbuilder.register_parent(self, self.bones.org.main[2], exclude_self=True)
+        pbuilder.register_parent(self, self.bones.org.main[2], exclude_self=True, tags={'limb_end'})
 
     def make_ik_ctrl_widget(self, ctrl):
         create_hand_widget(self.obj, ctrl)
diff --git a/rigify/rigs/limbs/leg.py b/rigify/rigs/limbs/leg.py
index 35e68f58..99610a6a 100644
--- a/rigify/rigs/limbs/leg.py
+++ b/rigify/rigs/limbs/leg.py
@@ -145,7 +145,7 @@ class Rig(BaseLimbRig):
     def register_switch_parents(self, pbuilder):
         super().register_switch_parents(pbuilder)
 
-        pbuilder.register_parent(self, self.bones.org.main[2], exclude_self=True)
+        pbuilder.register_parent(self, self.bones.org.main[2], exclude_self=True, tags={'limb_end'})
 
     def make_ik_ctrl_widget(self, ctrl):
         obj = create_foot_widget(self.obj, ctrl)
diff --git a/rigify/rigs/limbs/limb_rigs.py b/rigify/rigs/limbs/limb_rigs.py
index 86fc6be4..dee9a6f4 100644
--- a/rigify/rigs/limbs/limb_rigs.py
+++ b/rigify/rigs/limbs/limb_rigs.py
@@ -375,6 +375,11 @@ class BaseLimbRig(BaseRig):
         if self.rig_parent_bone:
             pbuilder.register_parent(self, self.rig_parent_bone)
 
+        pbuilder.register_parent(
+            self, self.get_ik_control_output(), name=self.bones.ctrl.ik,
+            exclude_self=True, tags={'limb_ik'},
+        )
+
     def build_ik_parent_switch(self, pbuilder):
         ctrl = self.bones.ctrl
 
diff --git a/rigify/rigs/limbs/paw.py b/rigify/rigs/limbs/paw.py
index a13348d1..28374eec 100644
--- a/rigify/rigs/limbs/paw.py
+++ b/rigify/rigs/limbs/paw.py
@@ -107,7 +107,7 @@ class Rig(BaseLimbRig):
     def register_switch_parents(self, pbuilder):
         super().register_switch_parents(pbuilder)
 
-        pbuilder.register_parent(self, self.bones.org.main[3], exclude_self=True)
+        pbuilder.register_parent(self, self.bones.org.main[3], exclude_self=True, tags={'limb_end'})
 
     def make_ik_ctrl_widget(self, ctrl):
         create_foot_widget(self.obj, ctrl)
diff --git a/rigify/rigs/spines/spine_rigs.py b/rigify/rigs/spines/spine_rigs.py
index 9f62595a..25450717 100644
--- a/rigify/rigs/spines/spine_rigs.py
+++ b/rigify/rigs/spines/spine_rigs.py
@@ -99,7 +99,7 @@ class BaseSpineRig(TweakChainRig):
         org_parent = self.get_bone_parent(self.bones.org[0])
         parents = [org_parent] if org_parent else []
 
-        pbuilder.register_parent(self, self.get_master_control_output, name='Torso')
+        pbuilder.register_parent(self, self.get_master_control_output, name='Torso', tags={'torso'})
         pbuilder.build_child(
             self, master_name, exclude_self=True,
             extra_parents=parents, select_parent=org_parent,
@@ -110,8 +110,8 @@ class BaseSpineRig(TweakChainRig):
         self.register_parent_bones(pbuilder)
 
     def register_parent_bones(self, pbuilder):
-        pbuilder.register_parent(self, self.bones.org[0], name='Hips', exclude_self=True)
-        pbuilder.register_parent(self, self.bones.org[-1], name='Chest', exclude_self=True)
+        pbuilder.register_parent(self, self.bones.org[0], name='Hips', exclude_self=True, tags={'hips'})
+        pbuilder.register_parent(self, self.bones.org[-1], name='Chest', exclude_self=True, tags={'chest'})
 
     @stage.parent_bones
     def parent_master_control(self):
diff --git a/rigify/rigs/spines/super_head.py b/rigify/rigs/spines/super_head.py
index 9b85e5b5..65db79cc 100644
--- a/rigify/rigs/spines/super_head.py
+++ b/rigify/rigs/spines/super_head.py
@@ -322,7 +322,7 @@ class Rig(BaseHeadTailRig):
     def register_parent_bones(self):
         rig = self.rigify_parent or self
         builder = SwitchParentBuilder(self.generator)
-        builder.register_parent(rig, self.bones.org[-1], name='Head', exclude_self=True)
+        builder.register_parent(rig, self.bones.org[-1], name='Head', exclude_self=True, tags={'head'})
 
     @stage.configure_bones
     def configure_bbone_chain(self):