Added AutoIK.py script

This is a work in progress; take a rig generated by rigify and add IK
and constraints to it.

AutoIK.py

@@ -0,0 +1,140 @@
+import bpy
+
+"""#armature = bpy.data.objects["KeiraRig"].data
+# better:
+armature = bpy.data.armatures["Armature_Keira"]
+armature.bones["IK_Leg_Pole.L"]
+# For clearing parent:
+armature.bones["IK_Leg_Pole.L"].parent
+# For removing deform on control and pole bones
+armature.bones["IK_Leg_Pole.L"].use_deform
+
+# Creating an IK constraint and filling it in:
+bpy.ops.pose.constraint_add(type="IK")
+# Target/pole
+pose.bones["shin.L"].constraints["IK"].target
+pose.bones["shin.L"].constraints["IK"].subtarget
+pose.bones["shin.L"].constraints["IK"].pole_target
+pose.bones["shin.L"].constraints["IK"].pole_subtarget
+# Arguments
+pose.bones["shin.L"].constraints["IK"].chain_count
+pose.bones["shin.L"].constraints["IK"].pole_angle
+
+# Extruding the control bone (there's probably a better way to do this like just extrude()
+# or maybe just add a bone out of thin air and move it so you don't have to deal with parenting and such)
+bpy.ops.armature.extrude_move(ARMATURE_OT_extrude={"forked":False},
+                              TRANSFORM_OT_translate={"value":(0, 0.402255, 0),
+                                                      "constraint_axis":(False, True, False),
+                                                      "constraint_orientation":'GLOBAL',
+                                                      "mirror":False,
+                                                      "proportional":'DISABLED',
+                                                      "proportional_edit_falloff":'SMOOTH',
+                                                      "proportional_size":1,
+                                                      "snap":False,
+                                                      "snap_target":'CLOSEST',
+                                                      "snap_point":(0, 0, 0),
+                                                      "snap_align":False,
+                                                      "snap_normal":(0, 0, 0),
+                                                      "gpencil_strokes":False,
+                                                      "texture_space":False,
+                                                      "remove_on_cancel":False,
+                                                      "release_confirm":False})
+
+# Toggling modes
+bpy.ops.object.posemode_toggle()
+bpy.ops.object.editmode_toggle()
+
+# Selected objects
+bpy.context.scene.objects.active = bpy.data.objects['Sphere.017']
+note: can also just do object.select = True
+
+# Selected bones
+bpy.context.selected_pose_bones
+pbase.bone.select=True
+pbase.bone.select_tail=True
+pbase.bone.select_head=True
+
+# Deselect all
+bpy.ops.pose.select_all(action='DESELECT')
+"""
+# bpy.ops.object.mode_set(mode='POSE')
+# newIK = bpy.ops.pose.constraint_add(type="IK")
+# print(newIK.target)
+
+class AutoIkOrder:
+    def __init__(self, boneName, ikName, createPole, chainLength):
+        self.boneName = boneName
+        self.ikName = ikName
+        self.createPole = createPole
+        self.chainLength = chainLength
+
+# Before running: select any number of rigs
+for selectedRig in bpy.context.selected_objects:
+    # Assume the user has an object with an armature selected
+    armature = selectedRig.data
+
+    # First, make sure we are in pose mode
+    bpy.ops.object.mode_set(mode='POSE')
+
+    # Next, make sure no bones are selected
+    bpy.ops.pose.select_all(action='DESELECT')
+    
+    autoIkOrders = [AutoIkOrder('shin', 'IK_Leg', False, 2)]
+    for order in autoIkOrders:
+        # Mirror operations to both sides
+        for side in ['.L', '.R']:
+            boneName = '{}{}'.format(order.boneName, side)
+            bone = armature.bones[boneName]
+
+            # Change to edit mode to create IK bones
+            bpy.ops.object.mode_set(mode='EDIT')
+            # Next, make sure no bones are selected
+            bpy.ops.armature.select_all(action='DESELECT')
+            
+            # Create target bone
+            targetBoneName = '{}_Target{}'.format(order.ikName, side)
+            targetBone = armature.edit_bones.new(name=targetBoneName)
+            # New bone has zero length and will be removed until resized
+            targetBone.head = bone.head
+            targetBone.tail = bone.head
+            targetBone.tail[1] -= 0.3
+            # Target bones do not deform mesh
+            targetBone.use_deform = False
+            
+            # Create pole bone
+            poleBoneName = '{}_Pole{}'.format(order.ikName, side)
+            poleBone = None
+            if order.createPole:
+                pass
+
+            # Change to pose mode for IK (this also saves bones in edit_bones)
+            bpy.ops.object.mode_set(mode='POSE')
+
+            # Next, make sure no bones are selected
+            bpy.ops.pose.select_all(action='DESELECT')
+
+            poseBone = selectedRig.pose.bones[boneName]
+            
+            # Select the bone (this might not be necessary)
+            bone.select = True
+
+            # Make the pose bone active
+            armature.bones.active = armature.bones[boneName]
+
+            # Create IK constraint
+            bpy.ops.pose.ik_add()
+            # Target/pole
+            print(poseBone.name)
+            print(bpy.context.active_pose_bone)
+            poseBone.constraints[0].target = selectedRig
+            poseBone.constraints[0].subtarget = targetBoneName
+            if order.createPole:
+                poseBone.constraints[0].pole_target = selectedRig
+                poseBone.constraints[0].pole_subtarget = poleBoneName
+            # Arguments
+            poseBone.constraints[0].chain_count = order.chainLength
+            # TODO: Is this how degrees are actually specified?
+            poseBone.constraints[0].pole_angle = 90.0
+
+            # Deselect pose bone now that we're finished
+            bone.select = False