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

13 files changed, 2054 insertions, 0 deletions

diff --git a/rigify/utils/__init__.py b/rigify/utils/__init__.py
new file mode 100644
index 00000000..da4689a9
--- /dev/null
+++ b/rigify/utils/__init__.py
@@ -0,0 +1,31 @@
+# These forwarding imports are for backwards compatibility with legacy code
+# that expects a single utils.py file. New code should import directly from
+# the modules that contain the utilities. Also, don't add more imports here.
+
+from .errors import MetarigError
+
+from .misc import angle_on_plane, linsrgb_to_srgb, gamma_correct, copy_attributes
+
+from .naming import ORG_PREFIX, MCH_PREFIX, DEF_PREFIX, ROOT_NAME
+from .naming import strip_trailing_number, unique_name, org_name, strip_org, strip_mch, strip_def
+from .naming import org, make_original_name, mch, make_mechanism_name, deformer, make_deformer_name
+from .naming import insert_before_lr, random_id
+
+from .bones import new_bone, copy_bone_simple, copy_bone, flip_bone, put_bone, make_nonscaling_child
+from .bones import align_bone_roll, align_bone_x_axis, align_bone_z_axis, align_bone_y_axis
+
+from .widgets import WGT_PREFIX, obj_to_bone, create_widget, write_widget, create_circle_polygon
+
+from .widgets_basic import create_line_widget, create_circle_widget, create_cube_widget, create_chain_widget
+from .widgets_basic import create_sphere_widget, create_limb_widget, create_bone_widget
+
+from .widgets_special import create_compass_widget, create_root_widget
+from .widgets_special import create_neck_bend_widget, create_neck_tweak_widget
+
+from .animation import get_keyed_frames, bones_in_frame, overwrite_prop_animation
+
+from .rig import RIG_DIR, METARIG_DIR, MODULE_NAME, TEMPLATE_DIR, outdated_types, upgradeMetarigTypes
+from .rig import get_rig_type, get_metarig_module, write_metarig, get_resource
+from .rig import connected_children_names, has_connected_children
+
+from .layers import get_layers, ControlLayersOption
diff --git a/rigify/utils/animation.py b/rigify/utils/animation.py
new file mode 100644
index 00000000..ab99282f
--- /dev/null
+++ b/rigify/utils/animation.py
@@ -0,0 +1,84 @@
+#====================== BEGIN GPL LICENSE BLOCK ======================
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+#======================= END GPL LICENSE BLOCK ========================
+
+# <pep8 compliant>
+
+
+#=============================================
+# Keyframing functions
+#=============================================
+
+
+def get_keyed_frames(rig):
+    frames = []
+    if rig.animation_data:
+        if rig.animation_data.action:
+            fcus = rig.animation_data.action.fcurves
+            for fc in fcus:
+                for kp in fc.keyframe_points:
+                    if kp.co[0] not in frames:
+                        frames.append(kp.co[0])
+
+    frames.sort()
+
+    return frames
+
+
+def bones_in_frame(f, rig, *args):
+    """
+    True if one of the bones listed in args is animated at frame f
+    :param f: the frame
+    :param rig: the rig
+    :param args: bone names
+    :return:
+    """
+
+    if rig.animation_data and rig.animation_data.action:
+        fcus = rig.animation_data.action.fcurves
+    else:
+        return False
+
+    for fc in fcus:
+        animated_frames = [kp.co[0] for kp in fc.keyframe_points]
+        for bone in args:
+            if bone in fc.data_path.split('"') and f in animated_frames:
+                return True
+
+    return False
+
+
+def overwrite_prop_animation(rig, bone, prop_name, value, frames):
+    act = rig.animation_data.action
+    if not act:
+        return
+
+    bone_name = bone.name
+    curve = None
+
+    for fcu in act.fcurves:
+        words = fcu.data_path.split('"')
+        if words[0] == "pose.bones[" and words[1] == bone_name and words[-2] == prop_name:
+            curve = fcu
+            break
+
+    if not curve:
+        return
+
+    for kp in curve.keyframe_points:
+        if kp.co[0] in frames:
+            kp.co[1] = value
diff --git a/rigify/utils/bones.py b/rigify/utils/bones.py
new file mode 100644
index 00000000..9002d083
--- /dev/null
+++ b/rigify/utils/bones.py
@@ -0,0 +1,417 @@
+#====================== BEGIN GPL LICENSE BLOCK ======================
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+#======================= END GPL LICENSE BLOCK ========================
+
+# <pep8 compliant>
+
+import bpy
+import math
+from mathutils import Vector, Matrix, Color
+from rna_prop_ui import rna_idprop_ui_prop_get
+
+from .errors import MetarigError
+from .naming import strip_org, make_mechanism_name, insert_before_lr
+
+#=======================
+# Bone collection
+#=======================
+
+class BoneDict(dict):
+    """
+    Special dictionary for holding bone names in a structured way.
+
+    Allows access to contained items as attributes, and only
+    accepts certain types of values.
+    """
+
+    @staticmethod
+    def __sanitize_attr(key, value):
+        if hasattr(BoneDict, key):
+            raise KeyError("Invalid BoneDict key: %s" % (key))
+
+        if (value is None or
+            isinstance(value, str) or
+            isinstance(value, list) or
+            isinstance(value, BoneDict)):
+            return value
+
+        if isinstance(value, dict):
+            return BoneDict(value)
+
+        raise ValueError("Invalid BoneDict value: %r" % (value))
+
+    def __init__(self, *args, **kwargs):
+        super(BoneDict, self).__init__()
+
+        for key, value in dict(*args, **kwargs).items():
+            dict.__setitem__(self, key, BoneDict.__sanitize_attr(key, value))
+
+        self.__dict__ = self
+
+    def __repr__(self):
+        return "BoneDict(%s)" % (dict.__repr__(self))
+
+    def __setitem__(self, key, value):
+        dict.__setitem__(self, key, BoneDict.__sanitize_attr(key, value))
+
+    def update(self, *args, **kwargs):
+        for key, value in dict(*args, **kwargs).items():
+            dict.__setitem__(self, key, BoneDict.__sanitize_attr(key, value))
+
+    def flatten(self):
+        """Return all contained bones as a list."""
+
+        all_bones = []
+
+        for item in self.values():
+            if isinstance(item, BoneDict):
+                all_bones.extend(item.flatten())
+            elif isinstance(item, list):
+                all_bones.extend(item)
+            elif item is not None:
+                all_bones.append(item)
+
+        return all_bones
+
+#=======================
+# Bone manipulation
+#=======================
+
+def new_bone(obj, bone_name):
+    """ Adds a new bone to the given armature object.
+        Returns the resulting bone's name.
+    """
+    if obj == bpy.context.active_object and bpy.context.mode == 'EDIT_ARMATURE':
+        edit_bone = obj.data.edit_bones.new(bone_name)
+        name = edit_bone.name
+        edit_bone.head = (0, 0, 0)
+        edit_bone.tail = (0, 1, 0)
+        edit_bone.roll = 0
+        bpy.ops.object.mode_set(mode='OBJECT')
+        bpy.ops.object.mode_set(mode='EDIT')
+        return name
+    else:
+        raise MetarigError("Can't add new bone '%s' outside of edit mode" % bone_name)
+
+
+def copy_bone_simple(obj, bone_name, assign_name=''):
+    """ Makes a copy of the given bone in the given armature object.
+        but only copies head, tail positions and roll. Does not
+        address parenting either.
+    """
+    #if bone_name not in obj.data.bones:
+    if bone_name not in obj.data.edit_bones:
+        raise MetarigError("copy_bone(): bone '%s' not found, cannot copy it" % bone_name)
+
+    if obj == bpy.context.active_object and bpy.context.mode == 'EDIT_ARMATURE':
+        if assign_name == '':
+            assign_name = bone_name
+        # Copy the edit bone
+        edit_bone_1 = obj.data.edit_bones[bone_name]
+        edit_bone_2 = obj.data.edit_bones.new(assign_name)
+        bone_name_1 = bone_name
+        bone_name_2 = edit_bone_2.name
+
+        # Copy edit bone attributes
+        edit_bone_2.layers = list(edit_bone_1.layers)
+
+        edit_bone_2.head = Vector(edit_bone_1.head)
+        edit_bone_2.tail = Vector(edit_bone_1.tail)
+        edit_bone_2.roll = edit_bone_1.roll
+
+        return bone_name_2
+    else:
+        raise MetarigError("Cannot copy bones outside of edit mode")
+
+
+def copy_bone(obj, bone_name, assign_name=''):
+    """ Makes a copy of the given bone in the given armature object.
+        Returns the resulting bone's name.
+    """
+    #if bone_name not in obj.data.bones:
+    if bone_name not in obj.data.edit_bones:
+        raise MetarigError("copy_bone(): bone '%s' not found, cannot copy it" % bone_name)
+
+    if obj == bpy.context.active_object and bpy.context.mode == 'EDIT_ARMATURE':
+        if assign_name == '':
+            assign_name = bone_name
+        # Copy the edit bone
+        edit_bone_1 = obj.data.edit_bones[bone_name]
+        edit_bone_2 = obj.data.edit_bones.new(assign_name)
+        bone_name_1 = bone_name
+        bone_name_2 = edit_bone_2.name
+
+        edit_bone_2.parent = edit_bone_1.parent
+        edit_bone_2.use_connect = edit_bone_1.use_connect
+
+        # Copy edit bone attributes
+        edit_bone_2.layers = list(edit_bone_1.layers)
+
+        edit_bone_2.head = Vector(edit_bone_1.head)
+        edit_bone_2.tail = Vector(edit_bone_1.tail)
+        edit_bone_2.roll = edit_bone_1.roll
+
+        edit_bone_2.use_inherit_rotation = edit_bone_1.use_inherit_rotation
+        edit_bone_2.use_inherit_scale = edit_bone_1.use_inherit_scale
+        edit_bone_2.use_local_location = edit_bone_1.use_local_location
+
+        edit_bone_2.use_deform = edit_bone_1.use_deform
+        edit_bone_2.bbone_segments = edit_bone_1.bbone_segments
+        edit_bone_2.bbone_easein = edit_bone_1.bbone_easein
+        edit_bone_2.bbone_easeout = edit_bone_1.bbone_easeout
+
+        bpy.ops.object.mode_set(mode='OBJECT')
+
+        # Get the pose bones
+        pose_bone_1 = obj.pose.bones[bone_name_1]
+        pose_bone_2 = obj.pose.bones[bone_name_2]
+
+        # Copy pose bone attributes
+        pose_bone_2.rotation_mode = pose_bone_1.rotation_mode
+        pose_bone_2.rotation_axis_angle = tuple(pose_bone_1.rotation_axis_angle)
+        pose_bone_2.rotation_euler = tuple(pose_bone_1.rotation_euler)
+        pose_bone_2.rotation_quaternion = tuple(pose_bone_1.rotation_quaternion)
+
+        pose_bone_2.lock_location = tuple(pose_bone_1.lock_location)
+        pose_bone_2.lock_scale = tuple(pose_bone_1.lock_scale)
+        pose_bone_2.lock_rotation = tuple(pose_bone_1.lock_rotation)
+        pose_bone_2.lock_rotation_w = pose_bone_1.lock_rotation_w
+        pose_bone_2.lock_rotations_4d = pose_bone_1.lock_rotations_4d
+
+        # Copy custom properties
+        for key in pose_bone_1.keys():
+            if key != "_RNA_UI" \
+            and key != "rigify_parameters" \
+            and key != "rigify_type":
+                prop1 = rna_idprop_ui_prop_get(pose_bone_1, key, create=False)
+                prop2 = rna_idprop_ui_prop_get(pose_bone_2, key, create=True)
+                pose_bone_2[key] = pose_bone_1[key]
+                for key in prop1.keys():
+                    prop2[key] = prop1[key]
+
+        bpy.ops.object.mode_set(mode='EDIT')
+
+        return bone_name_2
+    else:
+        raise MetarigError("Cannot copy bones outside of edit mode")
+
+
+def flip_bone(obj, bone_name):
+    """ Flips an edit bone.
+    """
+    if bone_name not in obj.data.bones:
+        raise MetarigError("flip_bone(): bone '%s' not found, cannot copy it" % bone_name)
+
+    if obj == bpy.context.active_object and bpy.context.mode == 'EDIT_ARMATURE':
+        bone = obj.data.edit_bones[bone_name]
+        head = Vector(bone.head)
+        tail = Vector(bone.tail)
+        bone.tail = head + tail
+        bone.head = tail
+        bone.tail = head
+    else:
+        raise MetarigError("Cannot flip bones outside of edit mode")
+
+
+def put_bone(obj, bone_name, pos):
+    """ Places a bone at the given position.
+    """
+    if bone_name not in obj.data.bones:
+        raise MetarigError("put_bone(): bone '%s' not found, cannot move it" % bone_name)
+
+    if obj == bpy.context.active_object and bpy.context.mode == 'EDIT_ARMATURE':
+        bone = obj.data.edit_bones[bone_name]
+
+        delta = pos - bone.head
+        bone.translate(delta)
+    else:
+        raise MetarigError("Cannot 'put' bones outside of edit mode")
+
+
+def make_nonscaling_child(obj, bone_name, location, child_name_postfix=""):
+    """ Takes the named bone and creates a non-scaling child of it at
+        the given location.  The returned bone (returned by name) is not
+        a true child, but behaves like one sans inheriting scaling.
+
+        It is intended as an intermediate construction to prevent rig types
+        from scaling with their parents.  The named bone is assumed to be
+        an ORG bone.
+    """
+    if bone_name not in obj.data.bones:
+        raise MetarigError("make_nonscaling_child(): bone '%s' not found, cannot copy it" % bone_name)
+
+    if obj == bpy.context.active_object and bpy.context.mode == 'EDIT_ARMATURE':
+        # Create desired names for bones
+        name1 = make_mechanism_name(strip_org(insert_before_lr(bone_name, child_name_postfix + "_ns_ch")))
+        name2 = make_mechanism_name(strip_org(insert_before_lr(bone_name, child_name_postfix + "_ns_intr")))
+
+        # Create bones
+        child = copy_bone(obj, bone_name, name1)
+        intermediate_parent = copy_bone(obj, bone_name, name2)
+
+        # Get edit bones
+        eb = obj.data.edit_bones
+        child_e = eb[child]
+        intrpar_e = eb[intermediate_parent]
+
+        # Parenting
+        child_e.use_connect = False
+        child_e.parent = None
+
+        intrpar_e.use_connect = False
+        intrpar_e.parent = eb[bone_name]
+
+        # Positioning
+        child_e.length *= 0.5
+        intrpar_e.length *= 0.25
+
+        put_bone(obj, child, location)
+        put_bone(obj, intermediate_parent, location)
+
+        # Object mode
+        bpy.ops.object.mode_set(mode='OBJECT')
+        pb = obj.pose.bones
+
+        # Add constraints
+        con = pb[child].constraints.new('COPY_LOCATION')
+        con.name = "parent_loc"
+        con.target = obj
+        con.subtarget = intermediate_parent
+
+        con = pb[child].constraints.new('COPY_ROTATION')
+        con.name = "parent_loc"
+        con.target = obj
+        con.subtarget = intermediate_parent
+
+        bpy.ops.object.mode_set(mode='EDIT')
+
+        return child
+    else:
+        raise MetarigError("Cannot make nonscaling child outside of edit mode")
+
+
+#=============================================
+# Math
+#=============================================
+
+
+def align_bone_roll(obj, bone1, bone2):
+    """ Aligns the roll of two bones.
+    """
+    bone1_e = obj.data.edit_bones[bone1]
+    bone2_e = obj.data.edit_bones[bone2]
+
+    bone1_e.roll = 0.0
+
+    # Get the directions the bones are pointing in, as vectors
+    y1 = bone1_e.y_axis
+    x1 = bone1_e.x_axis
+    y2 = bone2_e.y_axis
+    x2 = bone2_e.x_axis
+
+    # Get the shortest axis to rotate bone1 on to point in the same direction as bone2
+    axis = y1.cross(y2)
+    axis.normalize()
+
+    # Angle to rotate on that shortest axis
+    angle = y1.angle(y2)
+
+    # Create rotation matrix to make bone1 point in the same direction as bone2
+    rot_mat = Matrix.Rotation(angle, 3, axis)
+
+    # Roll factor
+    x3 = rot_mat @ x1
+    dot = x2 @ x3
+    if dot > 1.0:
+        dot = 1.0
+    elif dot < -1.0:
+        dot = -1.0
+    roll = math.acos(dot)
+
+    # Set the roll
+    bone1_e.roll = roll
+
+    # Check if we rolled in the right direction
+    x3 = rot_mat @ bone1_e.x_axis
+    check = x2 @ x3
+
+    # If not, reverse
+    if check < 0.9999:
+        bone1_e.roll = -roll
+
+
+def align_bone_x_axis(obj, bone, vec):
+    """ Rolls the bone to align its x-axis as closely as possible to
+        the given vector.
+        Must be in edit mode.
+    """
+    bone_e = obj.data.edit_bones[bone]
+
+    vec = vec.cross(bone_e.y_axis)
+    vec.normalize()
+
+    dot = max(-1.0, min(1.0, bone_e.z_axis.dot(vec)))
+    angle = math.acos(dot)
+
+    bone_e.roll += angle
+
+    dot1 = bone_e.z_axis.dot(vec)
+
+    bone_e.roll -= angle * 2
+
+    dot2 = bone_e.z_axis.dot(vec)
+
+    if dot1 > dot2:
+        bone_e.roll += angle * 2
+
+
+def align_bone_z_axis(obj, bone, vec):
+    """ Rolls the bone to align its z-axis as closely as possible to
+        the given vector.
+        Must be in edit mode.
+    """
+    bone_e = obj.data.edit_bones[bone]
+
+    vec = bone_e.y_axis.cross(vec)
+    vec.normalize()
+
+    dot = max(-1.0, min(1.0, bone_e.x_axis.dot(vec)))
+    angle = math.acos(dot)
+
+    bone_e.roll += angle
+
+    dot1 = bone_e.x_axis.dot(vec)
+
+    bone_e.roll -= angle * 2
+
+    dot2 = bone_e.x_axis.dot(vec)
+
+    if dot1 > dot2:
+        bone_e.roll += angle * 2
+
+
+def align_bone_y_axis(obj, bone, vec):
+    """ Matches the bone y-axis to
+        the given vector.
+        Must be in edit mode.
+    """
+
+    bone_e = obj.data.edit_bones[bone]
+    vec.normalize()
+    vec = vec * bone_e.length
+
+    bone_e.tail = bone_e.head + vec
diff --git a/rigify/utils/collections.py b/rigify/utils/collections.py
new file mode 100644
index 00000000..25596905
--- /dev/null
+++ b/rigify/utils/collections.py
@@ -0,0 +1,68 @@
+#====================== BEGIN GPL LICENSE BLOCK ======================
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+#======================= END GPL LICENSE BLOCK ========================
+
+# <pep8 compliant>
+
+import bpy
+import math
+
+from .errors import MetarigError
+
+
+#=============================================
+# Collection management
+#=============================================
+
+def find_layer_collection_by_collection(layer_collection, collection):
+    if collection == layer_collection.collection:
+        return layer_collection
+
+    # go recursive
+    for child in layer_collection.children:
+        layer_collection = find_layer_collection_by_collection(child, collection)
+        if layer_collection:
+            return layer_collection
+
+
+def ensure_widget_collection(context):
+    wgts_collection_name = "Widgets"
+
+    view_layer = context.view_layer
+    layer_collection = bpy.context.layer_collection
+    collection = layer_collection.collection
+
+    widget_collection = bpy.data.collections.get(wgts_collection_name)
+    if not widget_collection:
+        # ------------------------------------------
+        # Create the widget collection
+        widget_collection = bpy.data.collections.new(wgts_collection_name)
+        widget_collection.hide_viewport = True
+        widget_collection.hide_render = True
+
+        widget_layer_collection = None
+    else:
+        widget_layer_collection = find_layer_collection_by_collection(view_layer.layer_collection, widget_collection)
+
+    if not widget_layer_collection:
+        # Add the widget collection to the tree
+        collection.children.link(widget_collection)
+        widget_layer_collection = [c for c in layer_collection.children if c.collection == widget_collection][0]
+
+    # Make the widget the active collection for the upcoming added (widget) objects
+    view_layer.active_layer_collection = widget_layer_collection
+    return widget_collection
diff --git a/rigify/utils/errors.py b/rigify/utils/errors.py
new file mode 100644
index 00000000..71295057
--- /dev/null
+++ b/rigify/utils/errors.py
@@ -0,0 +1,34 @@
+#====================== BEGIN GPL LICENSE BLOCK ======================
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+#======================= END GPL LICENSE BLOCK ========================
+
+# <pep8 compliant>
+
+#=======================================================================
+# Error handling
+#=======================================================================
+
+
+class MetarigError(Exception):
+    """ Exception raised for errors.
+    """
+    def __init__(self, message):
+        self.message = message
+
+    def __str__(self):
+        return repr(self.message)
+
diff --git a/rigify/utils/layers.py b/rigify/utils/layers.py
new file mode 100644
index 00000000..1045e493
--- /dev/null
+++ b/rigify/utils/layers.py
@@ -0,0 +1,140 @@
+#====================== BEGIN GPL LICENSE BLOCK ======================
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+#======================= END GPL LICENSE BLOCK ========================
+
+# <pep8 compliant>
+
+import bpy
+
+
+def get_layers(layers):
+    """ Does its best to extract a set of layers from any data thrown at it.
+    """
+    if type(layers) == int:
+        return [x == layers for x in range(0, 32)]
+    elif type(layers) == str:
+        s = layers.split(",")
+        l = []
+        for i in s:
+            try:
+                l += [int(float(i))]
+            except ValueError:
+                pass
+        return [x in l for x in range(0, 32)]
+    elif type(layers) == tuple or type(layers) == list:
+        return [x in layers for x in range(0, 32)]
+    else:
+        try:
+            list(layers)
+        except TypeError:
+            pass
+        else:
+            return [x in layers for x in range(0, 32)]
+
+
+#=============================================
+# UI utilities
+#=============================================
+
+class ControlLayersOption:
+    def __init__(self, name, toggle_name=None, toggle_default=True, description="Set of control layers"):
+        self.name = name
+        self.toggle_default = toggle_default
+        self.description = description
+
+        self.toggle_option = self.name+'_layers_extra'
+        self.layers_option = self.name+'_layers'
+        self.toggle_name = toggle_name if toggle_name else self.toggle_option
+
+    def get(self, params):
+        if getattr(params, self.toggle_option):
+            return list(getattr(params, self.layers_option))
+        else:
+            return None
+
+    def assign(self, params, bone_set, bone_list):
+        layers = self.get(params)
+
+        if layers:
+            for name in bone_list:
+                bone = bone_set[name]
+                if isinstance(bone, bpy.types.PoseBone):
+                    bone = bone.bone
+
+                bone.layers = layers
+
+    def add_parameters(self, params):
+        prop_toggle = bpy.props.BoolProperty(
+            name=self.toggle_name,
+            default=self.toggle_default,
+            description=""
+        )
+
+        setattr(params, self.toggle_option, prop_toggle)
+
+        prop_layers = bpy.props.BoolVectorProperty(
+            size=32,
+            description=self.description,
+            default=tuple([i == 1 for i in range(0, 32)])
+        )
+
+        setattr(params, self.layers_option, prop_layers)
+
+    def parameters_ui(self, layout, params):
+        r = layout.row()
+        r.prop(params, self.toggle_option)
+        r.active = getattr(params, self.toggle_option)
+
+        col = r.column(align=True)
+        row = col.row(align=True)
+
+        bone_layers = bpy.context.active_pose_bone.bone.layers[:]
+
+        for i in range(8):    # Layers 0-7
+            icon = "NONE"
+            if bone_layers[i]:
+                icon = "LAYER_ACTIVE"
+            row.prop(params, self.layers_option, index=i, toggle=True, text="", icon=icon)
+
+        row = col.row(align=True)
+
+        for i in range(16, 24):     # Layers 16-23
+            icon = "NONE"
+            if bone_layers[i]:
+                icon = "LAYER_ACTIVE"
+            row.prop(params, self.layers_option, index=i, toggle=True, text="", icon=icon)
+
+        col = r.column(align=True)
+        row = col.row(align=True)
+
+        for i in range(8, 16):  # Layers 8-15
+            icon = "NONE"
+            if bone_layers[i]:
+                icon = "LAYER_ACTIVE"
+            row.prop(params, self.layers_option, index=i, toggle=True, text="", icon=icon)
+
+        row = col.row(align=True)
+
+        for i in range(24, 32):     # Layers 24-31
+            icon = "NONE"
+            if bone_layers[i]:
+                icon = "LAYER_ACTIVE"
+            row.prop(params, self.layers_option, index=i, toggle=True, text="", icon=icon)
+
+
+ControlLayersOption.FK = ControlLayersOption('fk', description="Layers for the FK controls to be on")
+ControlLayersOption.TWEAK = ControlLayersOption('tweak', description="Layers for the tweak controls to be on")
diff --git a/rigify/utils/mechanism.py b/rigify/utils/mechanism.py
new file mode 100644
index 00000000..90fedd75
--- /dev/null
+++ b/rigify/utils/mechanism.py
@@ -0,0 +1,264 @@
+#====================== BEGIN GPL LICENSE BLOCK ======================
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+#======================= END GPL LICENSE BLOCK ========================
+
+# <pep8 compliant>
+
+import bpy
+
+from rna_prop_ui import rna_idprop_ui_prop_get
+
+#=============================================
+# Constraint creation utilities
+#=============================================
+
+_TRACK_AXIS_MAP =  {
+    'X': 'TRACK_X', '-X': 'TRACK_NEGATIVE_X',
+    'Y': 'TRACK_Y', '-Y': 'TRACK_NEGATIVE_Y',
+    'Z': 'TRACK_Z', '-Z': 'TRACK_NEGATIVE_Z',
+}
+
+def make_constraint(
+        owner, type, target=None, subtarget=None,
+        space=None, track_axis=None, use_xyz=None,
+        **options):
+    """
+    Creates and initializes constraint of the specified type for the owner bone.
+
+    Specially handled keyword arguments:
+
+      target, subtarget: if both not None, passed through to the constraint
+      space            : assigned to both owner_space and target_space
+      track_axis       : allows shorter X, Y, Z, -X, -Y, -Z notation
+      use_xyz          : list of 3 items is assigned to use_x, use_y and use_z options
+      min/max_x/y/z    : a corresponding use_min/max_x/y/z option is set to True
+
+    Other keyword arguments are directly assigned to the constraint options.
+    Returns the newly created constraint.
+    """
+    con = owner.constraints.new(type)
+
+    if target is not None and subtarget is not None:
+        con.target = target
+        con.subtarget = subtarget
+
+    if space is not None:
+        con.owner_space = con.target_space = space
+
+    if track_axis is not None:
+        con.track_axis = _TRACK_AXIS_MAP.get(track_axis, track_axis)
+
+    if use_xyz is not None:
+        con.use_x, con.use_y, con.use_z = use_xyz[0:3]
+
+    for key in ['min_x', 'max_x', 'min_y', 'max_y', 'min_z', 'max_z']:
+        if key in options and 'use_'+key not in options:
+            options['use_'+key] = True
+
+    for p, v in options.items():
+        setattr(con, p, v)
+
+    return con
+
+#=============================================
+# Custom property creation utilities
+#=============================================
+
+def make_property(owner, name, default=0.0, min=0.0, max=1.0, soft_min=None, soft_max=None, description=None):
+    """
+    Creates and initializes a custom property of owner.
+
+    The soft_min and soft_max parameters default to min and max.
+    """
+    owner[name] = default
+
+    prop = rna_idprop_ui_prop_get(owner, name, create=True)
+    prop["min"] = min
+    prop["soft_min"] = soft_min if soft_min is not None else min
+    prop["max"] = max
+    prop["soft_max"] = soft_max if soft_max is not None else max
+    if description:
+        prop["description"] = description
+
+    return prop
+
+#=============================================
+# Driver creation utilities
+#=============================================
+
+def _init_driver_target(drv_target, var_info, target_id):
+    """Initialize a driver variable target from a specification."""
+
+    # Parse the simple list format for the common case.
+    if isinstance(var_info, tuple):
+        # [ (target_id,) subtarget, ...path ]
+
+        # If target_id is supplied as parameter, allow omitting it
+        if target_id is None or isinstance(var_info[0], bpy.types.ID):
+            target_id,subtarget,*refs = var_info
+        else:
+            subtarget,*refs = var_info
+
+        # Simple path string case.
+        if len(refs) == 0:
+            # [ (target_id,) path_str ]
+            path = subtarget
+        else:
+            # If subtarget is a string, look up a bone in the target
+            if isinstance(subtarget, str):
+                subtarget = target_id.pose.bones[subtarget]
+
+            # Use ".foo" type path items verbatim, otherwise quote
+            path = subtarget.path_from_id()
+            for item in refs:
+                path += item if item[0] == '.' else '["'+item+'"]'
+
+        drv_target.id = target_id
+        drv_target.data_path = path
+
+    else:
+        # { 'id': ..., ... }
+        if target_id is not None:
+            drv_target.id = target_id
+
+        for tp, tv in tdata.items():
+            setattr(drv_target, tp, tv)
+
+
+def _add_driver_variable(drv, var_name, var_info, target_id):
+    """Add and initialize a driver variable."""
+
+    var = drv.variables.new()
+    var.name = var_name
+
+    # Parse the simple list format for the common case.
+    if isinstance(var_info, tuple):
+        # [ (target_id,) subtarget, ...path ]
+        var.type = "SINGLE_PROP"
+
+        _init_driver_target(var.targets[0], var_info, target_id)
+
+    else:
+        # Variable info as generic dictionary - assign properties.
+        # { 'type': 'SINGLE_PROP', 'targets':[...] }
+        var.type = var_info['type']
+
+        for p, v in var_info.items():
+            if p == 'targets':
+                for i, tdata in enumerate(v):
+                    _init_driver_target(var.targets[i], tdata, target_id)
+            elif p != 'type':
+                setattr(var, p, v)
+
+def make_driver(owner, prop, index=-1, type='SUM', expression=None, variables={}, polynomial=None, target_id=None):
+    """
+    Creates and initializes a driver for the 'prop' property of owner.
+
+    Arguments:
+      index           : item index for vector properties
+      type, expression: mutually exclusive options to set core driver mode.
+      variables       : either a list or dictionary of variable specifications.
+      polynomial      : coefficients of the POLYNOMIAL driver modifier
+      target_id       : specifies the target ID of variables implicitly
+
+    Specification format:
+        If the variables argument is a dictionary, keys specify variable names.
+        Otherwise names are set to var0, var1... etc:
+
+          variables = [ ..., ..., ... ]
+          variables = { 'var0': ..., 'var1': ..., 'var2': ... }
+
+        Variable specifications are constructed as nested dictionaries and lists that
+        follow the property structure of the original Blender objects, but the most
+        common case can be abbreviated as a simple tuple.
+
+        The following specifications are equivalent:
+
+          ( target, subtarget, '.foo', 'bar' )
+
+          { 'type': 'SINGLE_PROP', 'targets':[( target, subtarget, '.foo', 'bar' )] }
+
+          { 'type': 'SINGLE_PROP',
+            'targets':[{ 'id': target, 'data_path': subtarget.path_from_id() + '.foo["bar"]' }] }
+
+        If subtarget is as string, it is automatically looked up within target as a bone.
+
+        It is possible to specify path directly as a simple string without following items:
+
+          ( target, 'path' )
+
+          { 'type': 'SINGLE_PROP', 'targets':[{ 'id': target, 'data_path': 'path' }] }
+
+        If the target_id parameter is not None, it is possible to omit target:
+
+          ( subtarget, '.foo', 'bar' )
+
+          { 'type': 'SINGLE_PROP',
+            'targets':[{ 'id': target_id, 'data_path': subtarget.path_from_id() + '.foo["bar"]' }] }
+
+    Returns the newly created driver FCurve.
+    """
+    fcu = owner.driver_add(prop, index)
+    drv = fcu.driver
+
+    if expression is not None:
+        drv.type = 'SCRIPTED'
+        drv.expression = expression
+    else:
+        drv.type = type
+
+    if isinstance(variables, list):
+        # variables = [ info, ... ]
+        for i, var_info in enumerate(variables):
+            _add_driver_variable(drv, 'var'+str(i), var_info, target_id)
+    else:
+        # variables = { 'varname': info, ... }
+        for var_name, var_info in variables.items():
+            _add_driver_variable(drv, var_name, var_info, target_id)
+
+    if polynomial is not None:
+        drv_modifier = fcu.modifiers[0]
+        drv_modifier.mode = 'POLYNOMIAL'
+        drv_modifier.poly_order = len(polynomial)-1
+        for i,v in enumerate(polynomial):
+            drv_modifier.coefficients[i] = v
+
+    return fcu
+
+#=============================================
+# Utility mixin
+#=============================================
+
+class MechanismUtilityMixin(object):
+    """
+    Provides methods for more convenient creation of constraints, properties
+    and drivers within an armature (by implicitly providing context).
+
+    Requires self.obj to be the armature object being worked on.
+    """
+
+    def make_constraint(self, bone, type, subtarget=None, **args):
+        assert(self.obj.mode == 'OBJECT')
+        return make_constraint(self.obj.pose.bones[bone], type, self.obj, subtarget, **args)
+
+    def make_property(self, bone, name, **args):
+        assert(self.obj.mode == 'OBJECT')
+        return make_property(self.obj.pose.bones[bone], name, **args)
+
+    def make_driver(self, owner, prop, **args):
+        assert(self.obj.mode == 'OBJECT')
+        return make_driver(owner, prop, target_id=self.obj, **args)
diff --git a/rigify/utils/misc.py b/rigify/utils/misc.py
new file mode 100644
index 00000000..2ca7b016
--- /dev/null
+++ b/rigify/utils/misc.py
@@ -0,0 +1,100 @@
+#====================== BEGIN GPL LICENSE BLOCK ======================
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+#======================= END GPL LICENSE BLOCK ========================
+
+# <pep8 compliant>
+
+import math
+from mathutils import Vector, Matrix, Color
+
+#=============================================
+# Math
+#=============================================
+
+
+def angle_on_plane(plane, vec1, vec2):
+    """ Return the angle between two vectors projected onto a plane.
+    """
+    plane.normalize()
+    vec1 = vec1 - (plane * (vec1.dot(plane)))
+    vec2 = vec2 - (plane * (vec2.dot(plane)))
+    vec1.normalize()
+    vec2.normalize()
+
+    # Determine the angle
+    angle = math.acos(max(-1.0, min(1.0, vec1.dot(vec2))))
+
+    if angle < 0.00001:  # close enough to zero that sign doesn't matter
+        return angle
+
+    # Determine the sign of the angle
+    vec3 = vec2.cross(vec1)
+    vec3.normalize()
+    sign = vec3.dot(plane)
+    if sign >= 0:
+        sign = 1
+    else:
+        sign = -1
+
+    return angle * sign
+
+#=============================================
+# Color correction functions
+#=============================================
+
+
+def linsrgb_to_srgb (linsrgb):
+    """Convert physically linear RGB values into sRGB ones. The transform is
+    uniform in the components, so *linsrgb* can be of any shape.
+
+    *linsrgb* values should range between 0 and 1, inclusively.
+
+    """
+    # From Wikipedia, but easy analogue to the above.
+    gamma = 1.055 * linsrgb**(1./2.4) - 0.055
+    scale = linsrgb * 12.92
+    # return np.where (linsrgb > 0.0031308, gamma, scale)
+    if linsrgb > 0.0031308:
+        return gamma
+    return scale
+
+
+def gamma_correct(color):
+
+    corrected_color = Color()
+    for i, component in enumerate(color):
+        corrected_color[i] = linsrgb_to_srgb(color[i])
+    return corrected_color
+
+
+#=============================================
+# Misc
+#=============================================
+
+def copy_attributes(a, b):
+    keys = dir(a)
+    for key in keys:
+        if not key.startswith("_") \
+        and not key.startswith("error_") \
+        and key != "group" \
+        and key != "is_valid" \
+        and key != "rna_type" \
+        and key != "bl_rna":
+            try:
+                setattr(b, key, getattr(a, key))
+            except AttributeError:
+                pass
diff --git a/rigify/utils/naming.py b/rigify/utils/naming.py
new file mode 100644
index 00000000..3af3d851
--- /dev/null
+++ b/rigify/utils/naming.py
@@ -0,0 +1,136 @@
+#====================== BEGIN GPL LICENSE BLOCK ======================
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+#======================= END GPL LICENSE BLOCK ========================
+
+# <pep8 compliant>
+
+import random
+import time
+import re
+
+ORG_PREFIX = "ORG-"  # Prefix of original bones.
+MCH_PREFIX = "MCH-"  # Prefix of mechanism bones.
+DEF_PREFIX = "DEF-"  # Prefix of deformation bones.
+ROOT_NAME = "root"   # Name of the root bone.
+
+#=======================================================================
+# Name manipulation
+#=======================================================================
+
+
+def strip_trailing_number(s):
+    m = re.search(r'\.(\d{3})$', s)
+    return s[0:-4] if m else s
+
+
+def unique_name(collection, base_name):
+    base_name = strip_trailing_number(base_name)
+    count = 1
+    name = base_name
+
+    while collection.get(name):
+        name = "%s.%03d" % (base_name, count)
+        count += 1
+    return name
+
+
+def org_name(name):
+    """ Returns the name with ORG_PREFIX stripped from it.
+    """
+    if name.startswith(ORG_PREFIX):
+        return name[len(ORG_PREFIX):]
+    else:
+        return name
+
+
+def strip_org(name):
+    """ Returns the name with ORG_PREFIX stripped from it.
+    """
+    if name.startswith(ORG_PREFIX):
+        return name[len(ORG_PREFIX):]
+    else:
+        return name
+org_name = strip_org
+
+
+def strip_mch(name):
+    """ Returns the name with ORG_PREFIX stripped from it.
+        """
+    if name.startswith(MCH_PREFIX):
+        return name[len(MCH_PREFIX):]
+    else:
+        return name
+
+def strip_def(name):
+    """ Returns the name with DEF_PREFIX stripped from it.
+        """
+    if name.startswith(DEF_PREFIX):
+        return name[len(DEF_PREFIX):]
+    else:
+        return name
+
+def org(name):
+    """ Prepends the ORG_PREFIX to a name if it doesn't already have
+        it, and returns it.
+    """
+    if name.startswith(ORG_PREFIX):
+        return name
+    else:
+        return ORG_PREFIX + name
+make_original_name = org
+
+
+def mch(name):
+    """ Prepends the MCH_PREFIX to a name if it doesn't already have
+        it, and returns it.
+    """
+    if name.startswith(MCH_PREFIX):
+        return name
+    else:
+        return MCH_PREFIX + name
+make_mechanism_name = mch
+
+
+def deformer(name):
+    """ Prepends the DEF_PREFIX to a name if it doesn't already have
+        it, and returns it.
+    """
+    if name.startswith(DEF_PREFIX):
+        return name
+    else:
+        return DEF_PREFIX + name
+make_deformer_name = deformer
+
+
+def insert_before_lr(name, text):
+    if name[-1] in ['l', 'L', 'r', 'R'] and name[-2] in ['.', '-', '_']:
+        return name[:-2] + text + name[-2:]
+    else:
+        return name + text
+
+def random_id(length=8):
+    """ Generates a random alphanumeric id string.
+    """
+    tlength = int(length / 2)
+    rlength = int(length / 2) + int(length % 2)
+
+    chars = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
+    text = ""
+    for i in range(0, rlength):
+        text += random.choice(chars)
+    text += str(hex(int(time.time())))[2:][-tlength:].rjust(tlength, '0')[::-1]
+    return text
diff --git a/rigify/utils/rig.py b/rigify/utils/rig.py
new file mode 100644
index 00000000..638194e7
--- /dev/null
+++ b/rigify/utils/rig.py
@@ -0,0 +1,294 @@
+#====================== BEGIN GPL LICENSE BLOCK ======================
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+#======================= END GPL LICENSE BLOCK ========================
+
+# <pep8 compliant>
+
+import bpy
+import importlib
+import importlib.util
+import os
+
+RIG_DIR = "rigs"  # Name of the directory where rig types are kept
+METARIG_DIR = "metarigs"  # Name of the directory where metarigs are kept
+TEMPLATE_DIR = "ui_templates"  # Name of the directory where ui templates are kept
+
+MODULE_NAME = "rigify"  # Windows/Mac blender is weird, so __package__ doesn't work
+
+outdated_types = {"pitchipoy.limbs.super_limb": "limbs.super_limb",
+                  "pitchipoy.limbs.super_arm": "limbs.super_limb",
+                  "pitchipoy.limbs.super_leg": "limbs.super_limb",
+                  "pitchipoy.limbs.super_front_paw": "limbs.super_limb",
+                  "pitchipoy.limbs.super_rear_paw": "limbs.super_limb",
+                  "pitchipoy.limbs.super_finger": "limbs.super_finger",
+                  "pitchipoy.super_torso_turbo": "spines.super_spine",
+                  "pitchipoy.simple_tentacle": "limbs.simple_tentacle",
+                  "pitchipoy.super_face": "faces.super_face",
+                  "pitchipoy.super_palm": "limbs.super_palm",
+                  "pitchipoy.super_copy": "basic.super_copy",
+                  "pitchipoy.tentacle": "",
+                  "palm": "limbs.super_palm",
+                  "basic.copy": "basic.super_copy",
+                  "biped.arm": "",
+                  "biped.leg": "",
+                  "finger": "",
+                  "neck_short": "",
+                  "misc.delta": "",
+                  "spine": ""
+                  }
+
+def upgradeMetarigTypes(metarig, revert=False):
+    """Replaces rigify_type properties from old versions with their current names
+
+    :param revert: revert types to previous version (if old type available)
+    """
+
+    if revert:
+        vals = list(outdated_types.values())
+        rig_defs = {v: k for k, v in outdated_types.items() if vals.count(v) == 1}
+    else:
+        rig_defs = outdated_types
+
+    for bone in metarig.pose.bones:
+        rig_type = bone.rigify_type
+        if rig_type in rig_defs:
+            bone.rigify_type = rig_defs[rig_type]
+            if 'leg' in rig_type:
+                bone.rigfy_parameters.limb_type = 'leg'
+            if 'arm' in rig_type:
+                bone.rigfy_parameters.limb_type = 'arm'
+            if 'paw' in rig_type:
+                bone.rigfy_parameters.limb_type = 'paw'
+            if rig_type == "basic.copy":
+                bone.rigify_parameters.make_widget = False
+
+
+#=============================================
+# Misc
+#=============================================
+
+def get_rig_type(rig_type, base_path=''):
+    return get_resource(rig_type, base_path=base_path)
+
+def get_resource(resource_name, base_path=''):
+    """ Fetches a rig module by name, and returns it.
+    """
+
+    if '.' in resource_name:
+        module_subpath = str.join(os.sep, resource_name.split('.'))
+        package = resource_name.split('.')[0]
+        for sub in resource_name.split('.')[1:]:
+            package = '.'.join([package, sub])
+            submod = importlib.import_module(package)
+    else:
+        module_subpath = resource_name
+
+    spec = importlib.util.spec_from_file_location(resource_name, os.path.join(base_path, module_subpath + '.py'))
+    submod = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(submod)
+    return submod
+
+
+def get_metarig_module(metarig_name, path=METARIG_DIR):
+    """ Fetches a rig module by name, and returns it.
+    """
+
+    name = ".%s.%s" % (path, metarig_name)
+    submod = importlib.import_module(name, package=MODULE_NAME)
+    importlib.reload(submod)
+    return submod
+
+
+def connected_children_names(obj, bone_name):
+    """ Returns a list of bone names (in order) of the bones that form a single
+        connected chain starting with the given bone as a parent.
+        If there is a connected branch, the list stops there.
+    """
+    bone = obj.data.bones[bone_name]
+    names = []
+
+    while True:
+        connects = 0
+        con_name = ""
+
+        for child in bone.children:
+            if child.use_connect:
+                connects += 1
+                con_name = child.name
+
+        if connects == 1:
+            names += [con_name]
+            bone = obj.data.bones[con_name]
+        else:
+            break
+
+    return names
+
+
+def has_connected_children(bone):
+    """ Returns true/false whether a bone has connected children or not.
+    """
+    t = False
+    for b in bone.children:
+        t = t or b.use_connect
+    return t
+
+
+def write_metarig(obj, layers=False, func_name="create", groups=False):
+    """
+    Write a metarig as a python script, this rig is to have all info needed for
+    generating the real rig with rigify.
+    """
+    code = []
+
+    code.append("import bpy\n\n")
+    code.append("from mathutils import Color\n\n")
+
+    code.append("def %s(obj):" % func_name)
+    code.append("    # generated by rigify.utils.write_metarig")
+    bpy.ops.object.mode_set(mode='EDIT')
+    code.append("    bpy.ops.object.mode_set(mode='EDIT')")
+    code.append("    arm = obj.data")
+
+    arm = obj.data
+
+    # Rigify bone group colors info
+    if groups and len(arm.rigify_colors) > 0:
+        code.append("\n    for i in range(" + str(len(arm.rigify_colors)) + "):")
+        code.append("        arm.rigify_colors.add()\n")
+
+        for i in range(len(arm.rigify_colors)):
+            name = arm.rigify_colors[i].name
+            active = arm.rigify_colors[i].active
+            normal = arm.rigify_colors[i].normal
+            select = arm.rigify_colors[i].select
+            standard_colors_lock = arm.rigify_colors[i].standard_colors_lock
+            code.append('    arm.rigify_colors[' + str(i) + '].name = "' + name + '"')
+            code.append('    arm.rigify_colors[' + str(i) + '].active = Color(' + str(active[:]) + ')')
+            code.append('    arm.rigify_colors[' + str(i) + '].normal = Color(' + str(normal[:]) + ')')
+            code.append('    arm.rigify_colors[' + str(i) + '].select = Color(' + str(select[:]) + ')')
+            code.append('    arm.rigify_colors[' + str(i) + '].standard_colors_lock = ' + str(standard_colors_lock))
+
+    # Rigify layer layout info
+    if layers and len(arm.rigify_layers) > 0:
+        code.append("\n    for i in range(" + str(len(arm.rigify_layers)) + "):")
+        code.append("        arm.rigify_layers.add()\n")
+
+        for i in range(len(arm.rigify_layers)):
+            name = arm.rigify_layers[i].name
+            row = arm.rigify_layers[i].row
+            selset = arm.rigify_layers[i].selset
+            group = arm.rigify_layers[i].group
+            code.append('    arm.rigify_layers[' + str(i) + '].name = "' + name + '"')
+            code.append('    arm.rigify_layers[' + str(i) + '].row = ' + str(row))
+            code.append('    arm.rigify_layers[' + str(i) + '].selset = ' + str(selset))
+            code.append('    arm.rigify_layers[' + str(i) + '].group = ' + str(group))
+
+    # write parents first
+    bones = [(len(bone.parent_recursive), bone.name) for bone in arm.edit_bones]
+    bones.sort(key=lambda item: item[0])
+    bones = [item[1] for item in bones]
+
+    code.append("\n    bones = {}\n")
+
+    for bone_name in bones:
+        bone = arm.edit_bones[bone_name]
+        code.append("    bone = arm.edit_bones.new(%r)" % bone.name)
+        code.append("    bone.head[:] = %.4f, %.4f, %.4f" % bone.head.to_tuple(4))
+        code.append("    bone.tail[:] = %.4f, %.4f, %.4f" % bone.tail.to_tuple(4))
+        code.append("    bone.roll = %.4f" % bone.roll)
+        code.append("    bone.use_connect = %s" % str(bone.use_connect))
+        if bone.parent:
+            code.append("    bone.parent = arm.edit_bones[bones[%r]]" % bone.parent.name)
+        code.append("    bones[%r] = bone.name" % bone.name)
+
+    bpy.ops.object.mode_set(mode='OBJECT')
+    code.append("")
+    code.append("    bpy.ops.object.mode_set(mode='OBJECT')")
+
+    # Rig type and other pose properties
+    for bone_name in bones:
+        pbone = obj.pose.bones[bone_name]
+
+        code.append("    pbone = obj.pose.bones[bones[%r]]" % bone_name)
+        code.append("    pbone.rigify_type = %r" % pbone.rigify_type)
+        code.append("    pbone.lock_location = %s" % str(tuple(pbone.lock_location)))
+        code.append("    pbone.lock_rotation = %s" % str(tuple(pbone.lock_rotation)))
+        code.append("    pbone.lock_rotation_w = %s" % str(pbone.lock_rotation_w))
+        code.append("    pbone.lock_scale = %s" % str(tuple(pbone.lock_scale)))
+        code.append("    pbone.rotation_mode = %r" % pbone.rotation_mode)
+        if layers:
+            code.append("    pbone.bone.layers = %s" % str(list(pbone.bone.layers)))
+        # Rig type parameters
+        for param_name in pbone.rigify_parameters.keys():
+            param = getattr(pbone.rigify_parameters, param_name, '')
+            if str(type(param)) == "<class 'bpy_prop_array'>":
+                param = list(param)
+            if type(param) == str:
+                param = '"' + param + '"'
+            code.append("    try:")
+            code.append("        pbone.rigify_parameters.%s = %s" % (param_name, str(param)))
+            code.append("    except AttributeError:")
+            code.append("        pass")
+
+    code.append("\n    bpy.ops.object.mode_set(mode='EDIT')")
+    code.append("    for bone in arm.edit_bones:")
+    code.append("        bone.select = False")
+    code.append("        bone.select_head = False")
+    code.append("        bone.select_tail = False")
+
+    code.append("    for b in bones:")
+    code.append("        bone = arm.edit_bones[bones[b]]")
+    code.append("        bone.select = True")
+    code.append("        bone.select_head = True")
+    code.append("        bone.select_tail = True")
+    code.append("        arm.edit_bones.active = bone")
+
+    # Set appropriate layers visible
+    if layers:
+        # Find what layers have bones on them
+        active_layers = []
+        for bone_name in bones:
+            bone = obj.data.bones[bone_name]
+            for i in range(len(bone.layers)):
+                if bone.layers[i]:
+                    if i not in active_layers:
+                        active_layers.append(i)
+        active_layers.sort()
+
+        code.append("\n    arm.layers = [(x in " + str(active_layers) + ") for x in range(" + str(len(arm.layers)) + ")]")
+
+    if func_name == "create":
+        active_template = arm.rigify_active_template
+        template_name = arm.rigify_templates[active_template].name
+        code.append("\n    # Select proper UI template")
+        code.append("    template_name = '{}'".format(template_name))
+        code.append("    arm_templates = arm.rigify_templates.items()")
+        code.append("    template_index = None")
+        code.append("    for i, template in enumerate(arm_templates):")
+        code.append("        if template[0] == template_name:")
+        code.append("            template_index = i")
+        code.append("            break")
+        code.append("    if template_index is None:")
+        code.append("        template_index = 0 # Default to something...")
+        code.append("    else:")
+        code.append("        arm.rigify_active_template = template_index")
+
+    code.append('\nif __name__ == "__main__":')
+    code.append("    " + func_name + "(bpy.context.active_object)\n")
+
+    return "\n".join(code)
diff --git a/rigify/utils/widgets.py b/rigify/utils/widgets.py
new file mode 100644
index 00000000..184429a3
--- /dev/null
+++ b/rigify/utils/widgets.py
@@ -0,0 +1,168 @@
+#====================== BEGIN GPL LICENSE BLOCK ======================
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+#======================= END GPL LICENSE BLOCK ========================
+
+# <pep8 compliant>
+
+import bpy
+import math
+
+from .errors import MetarigError
+
+WGT_PREFIX = "WGT-"  # Prefix for widget objects
+
+#=============================================
+# Widget creation
+#=============================================
+
+
+def obj_to_bone(obj, rig, bone_name):
+    """ Places an object at the location/rotation/scale of the given bone.
+    """
+    if bpy.context.mode == 'EDIT_ARMATURE':
+        raise MetarigError("obj_to_bone(): does not work while in edit mode")
+
+    bone = rig.data.bones[bone_name]
+
+    mat = rig.matrix_world @ bone.matrix_local
+
+    obj.location = mat.to_translation()
+
+    obj.rotation_mode = 'XYZ'
+    obj.rotation_euler = mat.to_euler()
+
+    scl = mat.to_scale()
+    scl_avg = (scl[0] + scl[1] + scl[2]) / 3
+    obj.scale = (bone.length * scl_avg), (bone.length * scl_avg), (bone.length * scl_avg)
+
+
+def create_widget(rig, bone_name, bone_transform_name=None):
+    """ Creates an empty widget object for a bone, and returns the object.
+    """
+    if bone_transform_name is None:
+        bone_transform_name = bone_name
+
+    obj_name = WGT_PREFIX + rig.name + '_' + bone_name
+    scene = bpy.context.scene
+    collection = bpy.context.collection
+
+    # Check if it already exists in the scene
+    if obj_name in scene.objects:
+        # Move object to bone position, in case it changed
+        obj = scene.objects[obj_name]
+        obj_to_bone(obj, rig, bone_transform_name)
+
+        return None
+    else:
+        # Delete object if it exists in blend data but not scene data.
+        # This is necessary so we can then create the object without
+        # name conflicts.
+        if obj_name in bpy.data.objects:
+            bpy.data.objects[obj_name].user_clear()
+            bpy.data.objects.remove(bpy.data.objects[obj_name])
+
+        # Create mesh object
+        mesh = bpy.data.meshes.new(obj_name)
+        obj = bpy.data.objects.new(obj_name, mesh)
+        collection.objects.link(obj)
+
+        # Move object to bone position and set layers
+        obj_to_bone(obj, rig, bone_transform_name)
+        wgts_group_name = 'WGTS_' + rig.name
+        if wgts_group_name in bpy.data.objects.keys():
+            obj.parent = bpy.data.objects[wgts_group_name]
+
+        return obj
+
+
+def create_circle_polygon(number_verts, axis, radius=1.0, head_tail=0.0):
+    """ Creates a basic circle around of an axis selected.
+        number_verts: number of vertices of the poligon
+        axis: axis normal to the circle
+        radius: the radius of the circle
+        head_tail: where along the length of the bone the circle is (0.0=head, 1.0=tail)
+    """
+    verts = []
+    edges = []
+    angle = 2 * math.pi / number_verts
+    i = 0
+
+    assert(axis in 'XYZ')
+
+    while i < (number_verts):
+        a = math.cos(i * angle)
+        b = math.sin(i * angle)
+
+        if axis == 'X':
+            verts.append((head_tail, a * radius, b * radius))
+        elif axis == 'Y':
+            verts.append((a * radius, head_tail, b * radius))
+        elif axis == 'Z':
+            verts.append((a * radius, b * radius, head_tail))
+
+        if i < (number_verts - 1):
+            edges.append((i , i + 1))
+
+        i += 1
+
+    edges.append((0, number_verts - 1))
+
+    return verts, edges
+
+
+def write_widget(obj):
+    """ Write a mesh object as a python script for widget use.
+    """
+    script = ""
+    script += "def create_thing_widget(rig, bone_name, size=1.0, bone_transform_name=None):\n"
+    script += "    obj = create_widget(rig, bone_name, bone_transform_name)\n"
+    script += "    if obj != None:\n"
+
+    # Vertices
+    if len(obj.data.vertices) > 0:
+        script += "        verts = ["
+        for v in obj.data.vertices:
+            script += "(" + str(v.co[0]) + "*size, " + str(v.co[1]) + "*size, " + str(v.co[2]) + "*size), "
+        script += "]\n"
+
+    # Edges
+    if len(obj.data.edges) > 0:
+        script += "        edges = ["
+        for e in obj.data.edges:
+            script += "(" + str(e.vertices[0]) + ", " + str(e.vertices[1]) + "), "
+        script += "]\n"
+
+    # Faces
+    if len(obj.data.polygons) > 0:
+        script += "        faces = ["
+        for f in obj.data.polygons:
+            script += "("
+            for v in f.vertices:
+                script += str(v) + ", "
+            script += "), "
+        script += "]\n"
+
+    # Build mesh
+    script += "\n        mesh = obj.data\n"
+    script += "        mesh.from_pydata(verts, edges, faces)\n"
+    script += "        mesh.update()\n"
+    script += "        mesh.update()\n"
+    script += "        return obj\n"
+    script += "    else:\n"
+    script += "        return None\n"
+
+    return script
diff --git a/rigify/utils/widgets_basic.py b/rigify/utils/widgets_basic.py
new file mode 100644
index 00000000..aae8f6bb
--- /dev/null
+++ b/rigify/utils/widgets_basic.py
@@ -0,0 +1,123 @@
+#====================== BEGIN GPL LICENSE BLOCK ======================
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+#======================= END GPL LICENSE BLOCK ========================
+
+# <pep8 compliant>
+
+from .widgets import create_widget
+
+# Common Widgets
+
+
+def create_line_widget(rig, bone_name, bone_transform_name=None):
+    """ Creates a basic line widget, a line that spans the length of the bone.
+    """
+    obj = create_widget(rig, bone_name, bone_transform_name)
+    if obj is not None:
+        mesh = obj.data
+        mesh.from_pydata([(0, 0, 0), (0, 1, 0)], [(0, 1)], [])
+        mesh.update()
+
+
+def create_circle_widget(rig, bone_name, radius=1.0, head_tail=0.0, with_line=False, bone_transform_name=None):
+    """ Creates a basic circle widget, a circle around the y-axis.
+        radius: the radius of the circle
+        head_tail: where along the length of the bone the circle is (0.0=head, 1.0=tail)
+    """
+    obj = create_widget(rig, bone_name, bone_transform_name)
+    if obj != None:
+        v = [(0.7071068286895752, 2.980232238769531e-07, -0.7071065306663513), (0.8314696550369263, 2.980232238769531e-07, -0.5555699467658997), (0.9238795042037964, 2.682209014892578e-07, -0.3826831877231598), (0.9807852506637573, 2.5331974029541016e-07, -0.19509011507034302), (1.0, 2.365559055306221e-07, 1.6105803979371558e-07), (0.9807853698730469, 2.2351741790771484e-07, 0.19509044289588928), (0.9238796234130859, 2.086162567138672e-07, 0.38268351554870605), (0.8314696550369263, 1.7881393432617188e-07, 0.5555704236030579), (0.7071068286895752, 1.7881393432617188e-07, 0.7071070075035095), (0.5555702447891235, 1.7881393432617188e-07, 0.8314698934555054), (0.38268327713012695, 1.7881393432617188e-07, 0.923879861831665), (0.19509008526802063, 1.7881393432617188e-07, 0.9807855486869812), (-3.2584136988589307e-07, 1.1920928955078125e-07, 1.000000238418579), (-0.19509072601795197, 1.7881393432617188e-07, 0.9807854294776917), (-0.3826838731765747, 1.7881393432617188e-07, 0.9238795638084412), (-0.5555707216262817, 1.7881393432617188e-07, 0.8314695358276367), (-0.7071071863174438, 1.7881393432617188e-07, 0.7071065902709961), (-0.8314700126647949, 1.7881393432617188e-07, 0.5555698871612549), (-0.923879861831665, 2.086162567138672e-07, 0.3826829195022583), (-0.9807853698730469, 2.2351741790771484e-07, 0.1950896978378296), (-1.0, 2.365559907957504e-07, -7.290432222362142e-07), (-0.9807850122451782, 2.5331974029541016e-07, -0.195091113448143), (-0.9238790273666382, 2.682209014892578e-07, -0.38268423080444336), (-0.831468939781189, 2.980232238769531e-07, -0.5555710196495056), (-0.7071058750152588, 2.980232238769531e-07, -0.707107424736023), (-0.555569052696228, 2.980232238769531e-07, -0.8314701318740845), (-0.38268208503723145, 2.980232238769531e-07, -0.923879861831665), (-0.19508881866931915, 2.980232238769531e-07, -0.9807853102684021), (1.6053570561780361e-06, 2.980232238769531e-07, -0.9999997615814209), (0.19509197771549225, 2.980232238769531e-07, -0.9807847142219543), (0.3826850652694702, 2.980232238769531e-07, -0.9238786101341248), (0.5555717945098877, 2.980232238769531e-07, -0.8314683437347412)]
+        verts = [(a[0] * radius, head_tail, a[2] * radius) for a in v]
+        if with_line:
+            edges = [(28, 12), (0, 1), (1, 2), (2, 3), (3, 4), (4, 5), (5, 6), (6, 7), (7, 8), (8, 9), (9, 10), (10, 11), (11, 12), (12, 13), (13, 14), (14, 15), (15, 16), (16, 17), (17, 18), (18, 19), (19, 20), (20, 21), (21, 22), (22, 23), (23, 24), (24, 25), (25, 26), (26, 27), (27, 28), (28, 29), (29, 30), (30, 31), (0, 31)]
+        else:
+            edges = [(0, 1), (1, 2), (2, 3), (3, 4), (4, 5), (5, 6), (6, 7), (7, 8), (8, 9), (9, 10), (10, 11), (11, 12), (12, 13), (13, 14), (14, 15), (15, 16), (16, 17), (17, 18), (18, 19), (19, 20), (20, 21), (21, 22), (22, 23), (23, 24), (24, 25), (25, 26), (26, 27), (27, 28), (28, 29), (29, 30), (30, 31), (0, 31)]
+        mesh = obj.data
+        mesh.from_pydata(verts, edges, [])
+        mesh.update()
+        return obj
+    else:
+        return None
+
+
+def create_cube_widget(rig, bone_name, radius=0.5, bone_transform_name=None):
+    """ Creates a basic cube widget.
+    """
+    obj = create_widget(rig, bone_name, bone_transform_name)
+    if obj is not None:
+        r = radius
+        verts = [(r, r, r), (r, -r, r), (-r, -r, r), (-r, r, r), (r, r, -r), (r, -r, -r), (-r, -r, -r), (-r, r, -r)]
+        edges = [(0, 1), (1, 2), (2, 3), (3, 0), (4, 5), (5, 6), (6, 7), (7, 4), (0, 4), (1, 5), (2, 6), (3, 7)]
+        mesh = obj.data
+        mesh.from_pydata(verts, edges, [])
+        mesh.update()
+
+
+def create_chain_widget(rig, bone_name, radius=0.5, invert=False, bone_transform_name=None):
+    """Creates a basic chain widget
+    """
+    obj = create_widget(rig, bone_name, bone_transform_name)
+    if obj != None:
+        r = radius
+        rh = radius/2
+        if invert:
+            verts = [(rh, rh, rh), (r, -r, r), (-r, -r, r), (-rh, rh, rh), (rh, rh, -rh), (r, -r, -r), (-r, -r, -r), (-rh, rh, -rh)]
+        else:
+            verts = [(r, r, r), (rh, -rh, rh), (-rh, -rh, rh), (-r, r, r), (r, r, -r), (rh, -rh, -rh), (-rh, -rh, -rh), (-r, r, -r)]
+        edges = [(0, 1), (1, 2), (2, 3), (3, 0), (4, 5), (5, 6), (6, 7), (7, 4), (0, 4), (1, 5), (2, 6), (3, 7)]
+        mesh = obj.data
+        mesh.from_pydata(verts, edges, [])
+        mesh.update()
+
+
+def create_sphere_widget(rig, bone_name, bone_transform_name=None):
+    """ Creates a basic sphere widget, three pependicular overlapping circles.
+    """
+    obj = create_widget(rig, bone_name, bone_transform_name)
+    if obj != None:
+        verts = [(0.3535533845424652, 0.3535533845424652, 0.0), (0.4619397521018982, 0.19134171307086945, 0.0), (0.5, -2.1855694143368964e-08, 0.0), (0.4619397521018982, -0.19134175777435303, 0.0), (0.3535533845424652, -0.3535533845424652, 0.0), (0.19134174287319183, -0.4619397521018982, 0.0), (7.549790126404332e-08, -0.5, 0.0), (-0.1913416087627411, -0.46193981170654297, 0.0), (-0.35355329513549805, -0.35355350375175476, 0.0), (-0.4619397521018982, -0.19134178757667542, 0.0), (-0.5, 5.962440319251527e-09, 0.0), (-0.4619397222995758, 0.1913418024778366, 0.0), (-0.35355326533317566, 0.35355350375175476, 0.0), (-0.19134148955345154, 0.46193987131118774, 0.0), (3.2584136988589307e-07, 0.5, 0.0), (0.1913420855998993, 0.46193960309028625, 0.0), (7.450580596923828e-08, 0.46193960309028625, 0.19134199619293213), (5.9254205098113744e-08, 0.5, 2.323586443253589e-07), (4.470348358154297e-08, 0.46193987131118774, -0.1913415789604187), (2.9802322387695312e-08, 0.35355350375175476, -0.3535533547401428), (2.9802322387695312e-08, 0.19134178757667542, -0.46193981170654297), (5.960464477539063e-08, -1.1151834122813398e-08, -0.5000000596046448), (5.960464477539063e-08, -0.1913418024778366, -0.46193984150886536), (5.960464477539063e-08, -0.35355350375175476, -0.3535533845424652), (7.450580596923828e-08, -0.46193981170654297, -0.19134166836738586), (9.348272556053416e-08, -0.5, 1.624372103492533e-08), (1.043081283569336e-07, -0.4619397521018982, 0.19134168326854706), (1.1920928955078125e-07, -0.3535533845424652, 0.35355329513549805), (1.1920928955078125e-07, -0.19134174287319183, 0.46193966269493103), (1.1920928955078125e-07, -4.7414250303745575e-09, 0.49999991059303284), (1.1920928955078125e-07, 0.19134172797203064, 0.46193966269493103), (8.940696716308594e-08, 0.3535533845424652, 0.35355329513549805), (0.3535534739494324, 0.0, 0.35355329513549805), (0.1913418173789978, -2.9802322387695312e-08, 0.46193966269493103), (8.303572940349113e-08, -5.005858838558197e-08, 0.49999991059303284), (-0.19134165346622467, -5.960464477539063e-08, 0.46193966269493103), (-0.35355329513549805, -8.940696716308594e-08, 0.35355329513549805), (-0.46193963289260864, -5.960464477539063e-08, 0.19134168326854706), (-0.49999991059303284, -5.960464477539063e-08, 1.624372103492533e-08), (-0.4619397521018982, -2.9802322387695312e-08, -0.19134166836738586), (-0.3535534143447876, -2.9802322387695312e-08, -0.3535533845424652), (-0.19134171307086945, 0.0, -0.46193984150886536), (7.662531942287387e-08, 9.546055501630235e-09, -0.5000000596046448), (0.19134187698364258, 5.960464477539063e-08, -0.46193981170654297), (0.3535535931587219, 5.960464477539063e-08, -0.3535533547401428), (0.4619399905204773, 5.960464477539063e-08, -0.1913415789604187), (0.5000000596046448, 5.960464477539063e-08, 2.323586443253589e-07), (0.4619396924972534, 2.9802322387695312e-08, 0.19134199619293213)]
+        edges = [(0, 1), (1, 2), (2, 3), (3, 4), (4, 5), (5, 6), (6, 7), (7, 8), (8, 9), (9, 10), (10, 11), (11, 12), (12, 13), (13, 14), (14, 15), (0, 15), (16, 31), (16, 17), (17, 18), (18, 19), (19, 20), (20, 21), (21, 22), (22, 23), (23, 24), (24, 25), (25, 26), (26, 27), (27, 28), (28, 29), (29, 30), (30, 31), (32, 33), (33, 34), (34, 35), (35, 36), (36, 37), (37, 38), (38, 39), (39, 40), (40, 41), (41, 42), (42, 43), (43, 44), (44, 45), (45, 46), (46, 47), (32, 47)]
+        mesh = obj.data
+        mesh.from_pydata(verts, edges, [])
+        mesh.update()
+
+
+def create_limb_widget(rig, bone_name, bone_transform_name=None):
+    """ Creates a basic limb widget, a line that spans the length of the
+        bone, with a circle around the center.
+    """
+    obj = create_widget(rig, bone_name, bone_transform_name)
+    if obj != None:
+        verts = [(-1.1920928955078125e-07, 1.7881393432617188e-07, 0.0), (3.5762786865234375e-07, 1.0000004768371582, 0.0), (0.1767769455909729, 0.5000001192092896, 0.17677664756774902), (0.20786768198013306, 0.5000001192092896, 0.1388925313949585), (0.23097014427185059, 0.5000001192092896, 0.09567084908485413), (0.24519658088684082, 0.5000001192092896, 0.048772573471069336), (0.2500002384185791, 0.5000001192092896, -2.545945676502015e-09), (0.24519658088684082, 0.5000001192092896, -0.048772573471069336), (0.23097014427185059, 0.5000001192092896, -0.09567084908485413), (0.20786768198013306, 0.5000001192092896, -0.13889259099960327), (0.1767769455909729, 0.5000001192092896, -0.1767767071723938), (0.13889282941818237, 0.5000001192092896, -0.20786744356155396), (0.09567105770111084, 0.5000001192092896, -0.23096990585327148), (0.04877278208732605, 0.5000001192092896, -0.24519634246826172), (1.7279069197684294e-07, 0.5000000596046448, -0.25), (-0.0487724244594574, 0.5000001192092896, -0.24519634246826172), (-0.09567070007324219, 0.5000001192092896, -0.2309698462486267), (-0.13889241218566895, 0.5000001192092896, -0.20786738395690918), (-0.17677652835845947, 0.5000001192092896, -0.17677664756774902), (-0.20786726474761963, 0.5000001192092896, -0.13889244198799133), (-0.23096972703933716, 0.5000001192092896, -0.09567070007324219), (-0.24519610404968262, 0.5000001192092896, -0.04877239465713501), (-0.2499997615814209, 0.5000001192092896, 2.1997936983098043e-07), (-0.24519598484039307, 0.5000001192092896, 0.04877282679080963), (-0.23096948862075806, 0.5000001192092896, 0.09567108750343323), (-0.20786696672439575, 0.5000001192092896, 0.1388927698135376), (-0.1767762303352356, 0.5000001192092896, 0.17677688598632812), (-0.13889199495315552, 0.5000001192092896, 0.2078675627708435), (-0.09567028284072876, 0.5000001192092896, 0.23097002506256104), (-0.048771947622299194, 0.5000001192092896, 0.24519634246826172), (6.555903269145347e-07, 0.5000001192092896, 0.25), (0.04877324402332306, 0.5000001192092896, 0.24519622325897217), (0.09567153453826904, 0.5000001192092896, 0.23096966743469238), (0.13889318704605103, 0.5000001192092896, 0.20786714553833008)]
+        edges = [(0, 1), (2, 3), (4, 3), (5, 4), (5, 6), (6, 7), (8, 7), (8, 9), (10, 9), (10, 11), (11, 12), (13, 12), (14, 13), (14, 15), (16, 15), (16, 17), (17, 18), (19, 18), (19, 20), (21, 20), (21, 22), (22, 23), (24, 23), (25, 24), (25, 26), (27, 26), (27, 28), (29, 28), (29, 30), (30, 31), (32, 31), (32, 33), (2, 33)]
+        mesh = obj.data
+        mesh.from_pydata(verts, edges, [])
+        mesh.update()
+
+
+def create_bone_widget(rig, bone_name, bone_transform_name=None):
+    """ Creates a basic bone widget, a simple obolisk-esk shape.
+    """
+    obj = create_widget(rig, bone_name, bone_transform_name)
+    if obj != None:
+        verts = [(0.04, 1.0, -0.04), (0.1, 0.0, -0.1), (-0.1, 0.0, -0.1), (-0.04, 1.0, -0.04), (0.04, 1.0, 0.04), (0.1, 0.0, 0.1), (-0.1, 0.0, 0.1), (-0.04, 1.0, 0.04)]
+        edges = [(1, 2), (0, 1), (0, 3), (2, 3), (4, 5), (5, 6), (6, 7), (4, 7), (1, 5), (0, 4), (2, 6), (3, 7)]
+        mesh = obj.data
+        mesh.from_pydata(verts, edges, [])
+        mesh.update()
+
+
diff --git a/rigify/utils/widgets_special.py b/rigify/utils/widgets_special.py
new file mode 100644
index 00000000..8e2d7a27
--- /dev/null
+++ b/rigify/utils/widgets_special.py
@@ -0,0 +1,195 @@
+#====================== BEGIN GPL LICENSE BLOCK ======================
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+#======================= END GPL LICENSE BLOCK ========================
+
+# <pep8 compliant>
+
+from .widgets import create_widget
+
+
+def create_compass_widget(rig, bone_name, bone_transform_name=None):
+    """ Creates a compass-shaped widget.
+    """
+    obj = create_widget(rig, bone_name, bone_transform_name)
+    if obj != None:
+        verts = [(0.0, 1.2000000476837158, 0.0), (0.19509032368659973, 0.9807852506637573, 0.0), (0.3826834559440613, 0.9238795042037964, 0.0), (0.5555702447891235, 0.8314695954322815, 0.0), (0.7071067690849304, 0.7071067690849304, 0.0), (0.8314696550369263, 0.5555701851844788, 0.0), (0.9238795042037964, 0.3826834261417389, 0.0), (0.9807852506637573, 0.19509035348892212, 0.0), (1.2000000476837158, 7.549790126404332e-08, 0.0), (0.9807853102684021, -0.19509020447731018, 0.0), (0.9238795638084412, -0.38268327713012695, 0.0), (0.8314696550369263, -0.5555701851844788, 0.0), (0.7071067690849304, -0.7071067690849304, 0.0), (0.5555701851844788, -0.8314696550369263, 0.0), (0.38268327713012695, -0.9238796234130859, 0.0), (0.19509008526802063, -0.9807853102684021, 0.0), (-3.2584136988589307e-07, -1.2999999523162842, 0.0), (-0.19509072601795197, -0.9807851910591125, 0.0), (-0.3826838731765747, -0.9238793253898621, 0.0), (-0.5555707216262817, -0.8314692974090576, 0.0), (-0.7071072459220886, -0.707106351852417, 0.0), (-0.8314700126647949, -0.5555696487426758, 0.0), (-0.923879861831665, -0.3826826810836792, 0.0), (-0.9807854294776917, -0.1950894594192505, 0.0), (-1.2000000476837158, 9.655991561885457e-07, 0.0), (-0.980785071849823, 0.1950913518667221, 0.0), (-0.923879086971283, 0.38268446922302246, 0.0), (-0.831468939781189, 0.5555712580680847, 0.0), (-0.7071058750152588, 0.707107663154602, 0.0), (-0.5555691123008728, 0.8314703702926636, 0.0), (-0.38268208503723145, 0.9238801002502441, 0.0), (-0.19508881866931915, 0.9807855486869812, 0.0)]
+        edges = [(0, 1), (1, 2), (2, 3), (3, 4), (4, 5), (5, 6), (6, 7), (7, 8), (8, 9), (9, 10), (10, 11), (11, 12), (12, 13), (13, 14), (14, 15), (15, 16), (16, 17), (17, 18), (18, 19), (19, 20), (20, 21), (21, 22), (22, 23), (23, 24), (24, 25), (25, 26), (26, 27), (27, 28), (28, 29), (29, 30), (30, 31), (0, 31)]
+        mesh = obj.data
+        mesh.from_pydata(verts, edges, [])
+        mesh.update()
+
+
+def create_root_widget(rig, bone_name, bone_transform_name=None):
+    """ Creates a widget for the root bone.
+    """
+    obj = create_widget(rig, bone_name, bone_transform_name)
+    if obj != None:
+        verts = [(0.7071067690849304, 0.7071067690849304, 0.0), (0.7071067690849304, -0.7071067690849304, 0.0), (-0.7071067690849304, 0.7071067690849304, 0.0), (-0.7071067690849304, -0.7071067690849304, 0.0), (0.8314696550369263, 0.5555701851844788, 0.0), (0.8314696550369263, -0.5555701851844788, 0.0), (-0.8314696550369263, 0.5555701851844788, 0.0), (-0.8314696550369263, -0.5555701851844788, 0.0), (0.9238795042037964, 0.3826834261417389, 0.0), (0.9238795042037964, -0.3826834261417389, 0.0), (-0.9238795042037964, 0.3826834261417389, 0.0), (-0.9238795042037964, -0.3826834261417389, 0.0), (0.9807852506637573, 0.19509035348892212, 0.0), (0.9807852506637573, -0.19509035348892212, 0.0), (-0.9807852506637573, 0.19509035348892212, 0.0), (-0.9807852506637573, -0.19509035348892212, 0.0), (0.19509197771549225, 0.9807849526405334, 0.0), (0.19509197771549225, -0.9807849526405334, 0.0), (-0.19509197771549225, 0.9807849526405334, 0.0), (-0.19509197771549225, -0.9807849526405334, 0.0), (0.3826850652694702, 0.9238788485527039, 0.0), (0.3826850652694702, -0.9238788485527039, 0.0), (-0.3826850652694702, 0.9238788485527039, 0.0), (-0.3826850652694702, -0.9238788485527039, 0.0), (0.5555717945098877, 0.8314685821533203, 0.0), (0.5555717945098877, -0.8314685821533203, 0.0), (-0.5555717945098877, 0.8314685821533203, 0.0), (-0.5555717945098877, -0.8314685821533203, 0.0), (0.19509197771549225, 1.2807848453521729, 0.0), (0.19509197771549225, -1.2807848453521729, 0.0), (-0.19509197771549225, 1.2807848453521729, 0.0), (-0.19509197771549225, -1.2807848453521729, 0.0), (1.280785322189331, 0.19509035348892212, 0.0), (1.280785322189331, -0.19509035348892212, 0.0), (-1.280785322189331, 0.19509035348892212, 0.0), (-1.280785322189331, -0.19509035348892212, 0.0), (0.3950919806957245, 1.2807848453521729, 0.0), (0.3950919806957245, -1.2807848453521729, 0.0), (-0.3950919806957245, 1.2807848453521729, 0.0), (-0.3950919806957245, -1.2807848453521729, 0.0), (1.280785322189331, 0.39509034156799316, 0.0), (1.280785322189331, -0.39509034156799316, 0.0), (-1.280785322189331, 0.39509034156799316, 0.0), (-1.280785322189331, -0.39509034156799316, 0.0), (0.0, 1.5807849168777466, 0.0), (0.0, -1.5807849168777466, 0.0), (1.5807852745056152, 0.0, 0.0), (-1.5807852745056152, 0.0, 0.0)]
+        edges = [(0, 4), (1, 5), (2, 6), (3, 7), (4, 8), (5, 9), (6, 10), (7, 11), (8, 12), (9, 13), (10, 14), (11, 15), (16, 20), (17, 21), (18, 22), (19, 23), (20, 24), (21, 25), (22, 26), (23, 27), (0, 24), (1, 25), (2, 26), (3, 27), (16, 28), (17, 29), (18, 30), (19, 31), (12, 32), (13, 33), (14, 34), (15, 35), (28, 36), (29, 37), (30, 38), (31, 39), (32, 40), (33, 41), (34, 42), (35, 43), (36, 44), (37, 45), (38, 44), (39, 45), (40, 46), (41, 46), (42, 47), (43, 47)]
+        mesh = obj.data
+        mesh.from_pydata(verts, edges, [])
+        mesh.update()
+
+
+def create_neck_bend_widget(rig, bone_name, radius=1.0, head_tail=0.0, bone_transform_name=None):
+    obj = create_widget(rig, bone_name, bone_transform_name)
+    size = 2.0
+    if obj != None:
+        v = [(-0.08855080604553223 * size, 0.7388765811920166 * size, -0.3940150737762451 * size),
+                 (0.08855044841766357 * size, 0.7388765811920166 * size, -0.3940150737762451 * size),
+                 (0.17710095643997192 * size, 0.5611097812652588 * size, -0.6478927135467529 * size),
+                 (-4.0892032870942785e-07 * size, 0.4087378978729248 * size, -0.865501880645752 * size),
+                 (-0.17710143327713013 * size, 0.5611097812652588 * size, -0.6478922367095947 * size),
+                 (0.08855026960372925 * size, 0.5611097812652588 * size, -0.6478924751281738 * size),
+                 (-0.08855092525482178 * size, 0.5611097812652588 * size, -0.6478927135467529 * size),
+                 (-0.6478927135467529 * size, 0.5611097812652588 * size, 0.08855098485946655 * size),
+                 (-0.6478927135467529 * size, 0.5611097812652588 * size, -0.08855020999908447 * size),
+                 (-0.6478924751281738 * size, 0.5611097812652588 * size, 0.17710155248641968 * size),
+                 (-0.865501880645752 * size, 0.4087378978729248 * size, 4.6876743908796925e-07 * size),
+                 (-0.647892951965332 * size, 0.5611097812652588 * size, -0.17710083723068237 * size),
+                 (-0.39401543140411377 * size, 0.7388765811920166 * size, -0.08855029940605164 * size),
+                 (-0.39401543140411377 * size, 0.7388765811920166 * size, 0.08855095505714417 * size),
+                 (0.6478927135467529 * size, 0.5611097812652588 * size, -0.08855059742927551 * size),
+                 (0.6478927135467529 * size, 0.5611097812652588 * size, 0.08855065703392029 * size),
+                 (0.6478924751281738 * size, 0.5611097812652588 * size, -0.17710113525390625 * size),
+                 (0.865501880645752 * size, 0.4087378978729248 * size, -3.264514703005261e-08 * size),
+                 (0.647892951965332 * size, 0.5611097812652588 * size, 0.1771012544631958 * size),
+                 (0.08855065703392029 * size, 0.7388765811920166 * size, 0.3940155506134033 * size),
+                 (-0.08855056762695312 * size, 0.7388765811920166 * size, 0.3940155506134033 * size),
+                 (-0.17710107564926147 * size, 0.5611097812652588 * size, 0.647892951965332 * size),
+                 (2.244429140318971e-07 * size, 0.4087378978729248 * size, 0.865502119064331 * size),
+                 (0.17710131406784058 * size, 0.5611097812652588 * size, 0.6478927135467529 * size),
+                 (-0.08855044841766357 * size, 0.5611097812652588 * size, 0.647892951965332 * size),
+                 (0.08855074644088745 * size, 0.5611097812652588 * size, 0.647892951965332 * size),
+                 (0.3940153121948242 * size, 0.7388765811920166 * size, 0.08855071663856506 * size),
+                 (0.39401519298553467 * size, 0.7388765811920166 * size, -0.08855047821998596 * size),
+                 (-8.416645869147032e-08 * size, 0.8255770206451416 * size, -0.2656517028808594 * size),
+                 (-0.06875583529472351 * size, 0.8255770206451416 * size, -0.2565997838973999 * size),
+                 (-0.13282597064971924 * size, 0.8255770206451416 * size, -0.2300611138343811 * size),
+                 (-0.18784427642822266 * size, 0.8255770206451416 * size, -0.18784409761428833 * size),
+                 (-0.2300613522529602 * size, 0.8255770206451416 * size, -0.1328257918357849 * size),
+                 (-0.256600022315979 * size, 0.8255770206451416 * size, -0.06875564157962799 * size),
+                 (-0.2656519412994385 * size, 0.8255770206451416 * size, 9.328307726264029e-08 * size),
+                 (-0.25660014152526855 * size, 0.8255770206451416 * size, 0.06875583529472351 * size),
+                 (-0.2300613522529602 * size, 0.8255770206451416 * size, 0.13282597064971924 * size),
+                 (-0.18784433603286743 * size, 0.8255770206451416 * size, 0.18784421682357788 * size),
+                 (-0.1328260898590088 * size, 0.8255770206451416 * size, 0.23006129264831543 * size),
+                 (-0.06875592470169067 * size, 0.8255770206451416 * size, 0.256600022315979 * size),
+                 (-1.8761508613351907e-07 * size, 0.8255770206451416 * size, 0.2656519412994385 * size),
+                 (0.06875556707382202 * size, 0.8255770206451416 * size, 0.2566000819206238 * size),
+                 (0.13282573223114014 * size, 0.8255770206451416 * size, 0.23006141185760498 * size),
+                 (0.18784403800964355 * size, 0.8255770206451416 * size, 0.1878443956375122 * size),
+                 (0.23006105422973633 * size, 0.8255770206451416 * size, 0.1328260898590088 * size),
+                 (0.25659990310668945 * size, 0.8255770206451416 * size, 0.06875596940517426 * size),
+                 (0.2656517028808594 * size, 0.8255770206451416 * size, 2.3684407324253698e-07 * size),
+                 (0.25659990310668945 * size, 0.8255770206451416 * size, -0.06875550746917725 * size),
+                 (0.23006117343902588 * size, 0.8255770206451416 * size, -0.13282567262649536 * size),
+                 (0.18784427642822266 * size, 0.8255770206451416 * size, -0.18784397840499878 * size),
+                 (0.13282597064971924 * size, 0.8255770206451416 * size, -0.23006099462509155 * size),
+                 (0.0687558501958847 * size, 0.8255770206451416 * size, -0.2565997838973999 * size), ]
+        edges = [(1, 0), (3, 2), (5, 2), (4, 3), (6, 4), (1, 5), (0, 6), (13, 7), (12, 8), (7, 9), (9, 10), (8, 11),
+                 (27, 14), (26, 15), (14, 16), (16, 17), (15, 18), (17, 18), (10, 11), (12, 13), (20, 19), (22, 21),
+                 (24, 21), (23, 22), (29, 28), (30, 29), (31, 30), (32, 31), (33, 32), (34, 33), (35, 34), (36, 35),
+                 (37, 36), (38, 37), (39, 38), (40, 39), (41, 40), (42, 41), (43, 42), (44, 43), (45, 44), (46, 45),
+                 (47, 46), (48, 47), (49, 48), (50, 49), (51, 50), (28, 51), (26, 27), (25, 23), (20, 24),
+                 (19, 25), ]
+
+        verts = [(a[0] * radius, head_tail, a[2] * radius) for a in v]
+        mesh = obj.data
+        mesh.from_pydata(verts, edges, [])
+        mesh.update()
+
+
+def create_neck_tweak_widget(rig, bone_name, size=1.0, bone_transform_name=None):
+    obj = create_widget(rig, bone_name, bone_transform_name)
+
+    if obj != None:
+        verts = [(0.3535533845424652 * size, 0.3535533845424652 * size, 0.0 * size),
+                 (0.4619397521018982 * size, 0.19134171307086945 * size, 0.0 * size),
+                 (0.5 * size, -2.1855694143368964e-08 * size, 0.0 * size),
+                 (0.4619397521018982 * size, -0.19134175777435303 * size, 0.0 * size),
+                 (0.3535533845424652 * size, -0.3535533845424652 * size, 0.0 * size),
+                 (0.19134174287319183 * size, -0.4619397521018982 * size, 0.0 * size),
+                 (7.549790126404332e-08 * size, -0.5 * size, 0.0 * size),
+                 (-0.1913416087627411 * size, -0.46193981170654297 * size, 0.0 * size),
+                 (-0.35355329513549805 * size, -0.35355350375175476 * size, 0.0 * size),
+                 (-0.4619397521018982 * size, -0.19134178757667542 * size, 0.0 * size),
+                 (-0.5 * size, 5.962440319251527e-09 * size, 0.0 * size),
+                 (-0.4619397222995758 * size, 0.1913418024778366 * size, 0.0 * size),
+                 (-0.35355326533317566 * size, 0.35355350375175476 * size, 0.0 * size),
+                 (-0.19134148955345154 * size, 0.46193987131118774 * size, 0.0 * size),
+                 (3.2584136988589307e-07 * size, 0.5 * size, 0.0 * size),
+                 (0.1913420855998993 * size, 0.46193960309028625 * size, 0.0 * size),
+                 (7.450580596923828e-08 * size, 0.46193960309028625 * size, 0.19134199619293213 * size),
+                 (5.9254205098113744e-08 * size, 0.5 * size, 2.323586443253589e-07 * size),
+                 (4.470348358154297e-08 * size, 0.46193987131118774 * size, -0.1913415789604187 * size),
+                 (2.9802322387695312e-08 * size, 0.35355350375175476 * size, -0.3535533547401428 * size),
+                 (2.9802322387695312e-08 * size, 0.19134178757667542 * size, -0.46193981170654297 * size),
+                 (5.960464477539063e-08 * size, -1.1151834122813398e-08 * size, -0.5000000596046448 * size),
+                 (5.960464477539063e-08 * size, -0.1913418024778366 * size, -0.46193984150886536 * size),
+                 (5.960464477539063e-08 * size, -0.35355350375175476 * size, -0.3535533845424652 * size),
+                 (7.450580596923828e-08 * size, -0.46193981170654297 * size, -0.19134166836738586 * size),
+                 (9.348272556053416e-08 * size, -0.5 * size, 1.624372103492533e-08 * size),
+                 (1.043081283569336e-07 * size, -0.4619397521018982 * size, 0.19134168326854706 * size),
+                 (1.1920928955078125e-07 * size, -0.3535533845424652 * size, 0.35355329513549805 * size),
+                 (1.1920928955078125e-07 * size, -0.19134174287319183 * size, 0.46193966269493103 * size),
+                 (1.1920928955078125e-07 * size, -4.7414250303745575e-09 * size, 0.49999991059303284 * size),
+                 (1.1920928955078125e-07 * size, 0.19134172797203064 * size, 0.46193966269493103 * size),
+                 (8.940696716308594e-08 * size, 0.3535533845424652 * size, 0.35355329513549805 * size),
+                 (0.3535534739494324 * size, 0.0 * size, 0.35355329513549805 * size),
+                 (0.1913418173789978 * size, -2.9802322387695312e-08 * size, 0.46193966269493103 * size),
+                 (8.303572940349113e-08 * size, -5.005858838558197e-08 * size, 0.49999991059303284 * size),
+                 (-0.19134165346622467 * size, -5.960464477539063e-08 * size, 0.46193966269493103 * size),
+                 (-0.35355329513549805 * size, -8.940696716308594e-08 * size, 0.35355329513549805 * size),
+                 (-0.46193963289260864 * size, -5.960464477539063e-08 * size, 0.19134168326854706 * size),
+                 (-0.49999991059303284 * size, -5.960464477539063e-08 * size, 1.624372103492533e-08 * size),
+                 (-0.4619397521018982 * size, -2.9802322387695312e-08 * size, -0.19134166836738586 * size),
+                 (-0.3535534143447876 * size, -2.9802322387695312e-08 * size, -0.3535533845424652 * size),
+                 (-0.19134171307086945 * size, 0.0 * size, -0.46193984150886536 * size),
+                 (7.662531942287387e-08 * size, 9.546055501630235e-09 * size, -0.5000000596046448 * size),
+                 (0.19134187698364258 * size, 5.960464477539063e-08 * size, -0.46193981170654297 * size),
+                 (0.3535535931587219 * size, 5.960464477539063e-08 * size, -0.3535533547401428 * size),
+                 (0.4619399905204773 * size, 5.960464477539063e-08 * size, -0.1913415789604187 * size),
+                 (0.5000000596046448 * size, 5.960464477539063e-08 * size, 2.323586443253589e-07 * size),
+                 (0.4619396924972534 * size, 2.9802322387695312e-08 * size, 0.19134199619293213 * size),
+                 (1.563460111618042 * size, 2.778762819843905e-08 * size, 1.5634593963623047 * size),
+                 (0.8461387157440186 * size, -1.0400220418205208e-07 * size, 2.0427582263946533 * size),
+                 (7.321979467178608e-08 * size, -1.9357810288056498e-07 * size, 2.2110657691955566 * size),
+                 (-0.8461385369300842 * size, -2.3579201524626114e-07 * size, 2.0427582263946533 * size),
+                 (-1.5634597539901733 * size, -3.67581861837607e-07 * size, 1.5634593963623047 * size),
+                 (-2.0427584648132324 * size, -2.3579204366797057e-07 * size, 0.8461383581161499 * size),
+                 (-2.211066246032715 * size, -2.3579204366797057e-07 * size, 9.972505665700737e-08 * size),
+                 (-2.0427589416503906 * size, -1.0400223260376151e-07 * size, -0.8461381196975708 * size),
+                 (-1.5634604692459106 * size, -1.040022183929068e-07 * size, -1.563459873199463 * size),
+                 (-0.8461387753486633 * size, 2.77876033294433e-08 * size, -2.042759418487549 * size),
+                 (4.4872678017782164e-08 * size, 7.00015263532805e-08 * size, -2.211066484451294 * size),
+                 (0.8461388349533081 * size, 2.913672290105751e-07 * size, -2.0427591800689697 * size),
+                 (1.5634608268737793 * size, 2.9136725743228453e-07 * size, -1.563459873199463 * size),
+                 (2.042759895324707 * size, 2.9136725743228453e-07 * size, -0.8461377024650574 * size),
+                 (2.211066722869873 * size, 2.9136725743228453e-07 * size, 1.0554133496043505e-06 * size),
+                 (2.0427587032318115 * size, 1.5957746768435754e-07 * size, 0.8461397886276245 * size), ]
+        edges = [(0, 1), (1, 2), (2, 3), (3, 4), (4, 5), (5, 6), (6, 7), (7, 8), (8, 9), (9, 10), (10, 11),
+                 (11, 12), (12, 13), (13, 14), (14, 15), (0, 15), (16, 31), (16, 17), (17, 18), (18, 19), (19, 20),
+                 (20, 21), (21, 22), (22, 23), (23, 24), (24, 25), (25, 26), (26, 27), (27, 28), (28, 29), (29, 30),
+                 (30, 31), (32, 33), (33, 34), (34, 35), (35, 36), (36, 37), (37, 38), (38, 39), (39, 40), (40, 41),
+                 (41, 42), (42, 43), (43, 44), (44, 45), (45, 46), (46, 47), (32, 47), (48, 49), (49, 50), (50, 51),
+                 (51, 52), (52, 53), (53, 54), (54, 55), (55, 56), (56, 57), (57, 58), (58, 59), (59, 60), (60, 61),
+                 (61, 62), (62, 63), (48, 63), (21, 58), (10, 54), (29, 50), (2, 62), ]
+
+        mesh = obj.data
+        mesh.from_pydata(verts, edges, [])
+        mesh.update()