Rigify: add support for user-defined rig packages and related utilities.

As suggested by @icappielo, and after discussion with @meta-androcto,
I start a public request to commit third-party contributions already
accepted to https://github.com/eigen-value/rigify/tree/rigify_0.6_beta

Specifically, this includes:

* User-defined rig package (feature set) support by @pioverfour.
  This allows users to install pre-packaged rig sets via zip
  files, which become accessible together with built-in rigs,
  as discussed in T52758.

  https://github.com/eigen-value/rigify/pull/1

* Modularization of python script generation, allowing rigs to
  add their own utility functions and operators to the generated
  script. This is critical to make custom rig support really
  useful.

  https://github.com/eigen-value/rigify/pull/5

* The utils.py file is split into multiple modules with a backward
  compatibility proxy for old functions.

* Automatic verification that different rigs don't try to create
  different rig settings with the same name to alleviate increased
  risk of namespace conflicts with custom rigs.

  https://github.com/eigen-value/rigify/pull/7

* New utility class that implements bone layer selection UI.

  https://github.com/eigen-value/rigify/pull/6

* New utilities to replace copy & pasted boilerplate code for
  creating custom properties, constraints and drivers.

  https://github.com/eigen-value/rigify/pull/11

Some other random changes by MAD have likely slipped through.

These changes have already been extensively discussed and accepted
into the branch by @luciorossi, so I see no reason not to commit
them to the official repository to be tested during 2.8 beta.

Reviewers: icappiello

Differential Revision: https://developer.blender.org/D4364

1 files changed, 92 insertions, 44 deletions

diff --git a/rigify/rig_ui_template.py b/rigify/rig_ui_template.py
index 0a2234e1..7265999b 100644
--- a/rigify/rig_ui_template.py
+++ b/rigify/rig_ui_template.py
@@ -18,12 +18,15 @@
 
 # <pep8 compliant>
 
-UI_SLIDERS = '''
-import bpy
-from bpy.props import StringProperty
-from mathutils import Matrix, Vector
-from math import acos, pi, radians
-
+UI_IMPORTS = [
+    'import bpy',
+    'from bpy.props import StringProperty',
+    'import math',
+    'from math import pi',
+    'from mathutils import Euler, Matrix, Quaternion, Vector',
+]
+
+UI_BASE_UTILITIES = '''
 rig_id = "%s"
 
 
@@ -55,7 +58,7 @@ def rotation_difference(mat1, mat2):
     """
     q1 = mat1.to_quaternion()
     q2 = mat2.to_quaternion()
-    angle = acos(min(1,max(-1,q1.dot(q2)))) * 2
+    angle = math.acos(min(1,max(-1,q1.dot(q2)))) * 2
     if angle > pi:
         angle = -angle + (2*pi)
     return angle
@@ -296,6 +299,22 @@ def match_pole_target(ik_first, ik_last, pole, match_bone, length):
     if ang1 < ang2:
         set_pole(pv1)
 
+##########
+## Misc ##
+##########
+
+def parse_bone_names(names_string):
+    if names_string[0] == '[' and names_string[-1] == ']':
+        return eval(names_string)
+    else:
+        return names_string
+
+'''
+
+UTILITIES_FUNC_ARM_FKIK = ['''
+######################
+## IK Arm functions ##
+######################
 
 def fk2ik_arm(obj, fk, ik):
     """ Matches the fk bones in an arm rig to the ik bones.
@@ -391,6 +410,12 @@ def ik2fk_arm(obj, fk, ik):
         match_pose_scale(uarmi, uarm)
         # Rotation Correction
         correct_rotation(uarmi, uarm)
+''']
+
+UTILITIES_FUNC_LEG_FKIK = ['''
+######################
+## IK Leg functions ##
+######################
 
 def fk2ik_leg(obj, fk, ik):
     """ Matches the fk bones in a leg rig to the ik bones.
@@ -519,18 +544,13 @@ def ik2fk_leg(obj, fk, ik):
 
         # Pole target position
         match_pole_target(thighi, shini, pole, thigh, (thighi.length + shini.length))
+''']
 
-
+UTILITIES_FUNC_POLE = ['''
 ################################
 ## IK Rotation-Pole functions ##
 ################################
 
-def parse_bone_names(names_string):
-    if names_string[0] == '[' and names_string[-1] == ']':
-        return eval(names_string)
-    else:
-        return names_string
-
 def rotPoleToggle(rig, limb_type, controls, ik_ctrl, fk_ctrl, parent, pole):
 
     rig_id = rig.data['rig_id']
@@ -589,10 +609,14 @@ def rotPoleToggle(rig, limb_type, controls, ik_ctrl, fk_ctrl, parent, pole):
             func2(**kwargs2)
 
             bpy.ops.pose.select_all(action='DESELECT')
+''']
 
-##############################
-## IK/FK snapping operators ##
-##############################
+REGISTER_OP_ARM_FKIK = ['Rigify_Arm_FK2IK', 'Rigify_Arm_IK2FK']
+
+UTILITIES_OP_ARM_FKIK = ['''
+##################################
+## IK/FK Arm snapping operators ##
+##################################
 
 class Rigify_Arm_FK2IK(bpy.types.Operator):
     """ Snaps an FK arm to an IK arm.
@@ -653,7 +677,14 @@ class Rigify_Arm_IK2FK(bpy.types.Operator):
         finally:
             context.preferences.edit.use_global_undo = use_global_undo
         return {'FINISHED'}
+''']
+
+REGISTER_OP_LEG_FKIK = ['Rigify_Leg_FK2IK', 'Rigify_Leg_IK2FK']
 
+UTILITIES_OP_LEG_FKIK = ['''
+##################################
+## IK/FK Leg snapping operators ##
+##################################
 
 class Rigify_Leg_FK2IK(bpy.types.Operator):
     """ Snaps an FK leg to an IK leg.
@@ -718,7 +749,11 @@ class Rigify_Leg_IK2FK(bpy.types.Operator):
         finally:
             context.preferences.edit.use_global_undo = use_global_undo
         return {'FINISHED'}
+''']
+
+REGISTER_OP_POLE = ['Rigify_Rot2PoleSwitch']
 
+UTILITIES_OP_POLE = ['''
 ###########################
 ## IK Rotation Pole Snap ##
 ###########################
@@ -745,7 +780,47 @@ class Rigify_Rot2PoleSwitch(bpy.types.Operator):
 
         rotPoleToggle(rig, self.limb_type, self.controls, self.ik_ctrl, self.fk_ctrl, self.parent, self.pole)
         return {'FINISHED'}
+''']
+
+REGISTER_RIG_ARM = REGISTER_OP_ARM_FKIK + REGISTER_OP_POLE
+
+UTILITIES_RIG_ARM = [
+    *UTILITIES_FUNC_ARM_FKIK,
+    *UTILITIES_FUNC_POLE,
+    *UTILITIES_OP_ARM_FKIK,
+    *UTILITIES_OP_POLE,
+]
+
+REGISTER_RIG_LEG = REGISTER_OP_LEG_FKIK + REGISTER_OP_POLE
+
+UTILITIES_RIG_LEG = [
+    *UTILITIES_FUNC_LEG_FKIK,
+    *UTILITIES_FUNC_POLE,
+    *UTILITIES_OP_LEG_FKIK,
+    *UTILITIES_OP_POLE,
+]
+
+##############################
+## Default set of utilities ##
+##############################
 
+UI_REGISTER = [
+    'RigUI',
+    'RigLayers',
+    *REGISTER_OP_ARM_FKIK,
+    *REGISTER_OP_LEG_FKIK,
+]
+
+# Include arm and leg utilities for now in case somebody wants to use
+# legacy limb rigs, which expect these to be available by default.
+UI_UTILITIES = [
+    *UTILITIES_FUNC_ARM_FKIK,
+    *UTILITIES_FUNC_LEG_FKIK,
+    *UTILITIES_OP_ARM_FKIK,
+    *UTILITIES_OP_LEG_FKIK,
+]
+
+UI_SLIDERS = '''
 ###################
 ## Rig UI Panels ##
 ###################
@@ -841,30 +916,3 @@ class RigLayers(bpy.types.Panel):
     code += "        row.prop(context.active_object.data, 'layers', index=28, toggle=True, text='Root')\n"
 
     return code
-
-
-UI_REGISTER = '''
-
-classes = (
-    Rigify_Arm_FK2IK,
-    Rigify_Arm_IK2FK,
-    Rigify_Leg_FK2IK,
-    Rigify_Leg_IK2FK,
-    Rigify_Rot2PoleSwitch,
-    RigUI,
-    RigLayers,
-)
-
-def register():
-    from bpy.utils import register_class
-    for cls in classes:
-        register_class(cls)
-
-
-def unregister():
-    from bpy.utils import unregister_class
-    for cls in classes:
-        unregister_class(cls)
-
-register()
-'''