Constraints can be confusing, and damn are they annoying and unintuitive! So here is an effort to clean things up and hopefully make constraining a little more logical and easy.

This script attempts to consolidate the constraint weights and blend parents into a single switcher.

How do I use it?!

To use it, copy the below and paste it into a new shelf button as a PYTHON script. Then set up your constraints, and select the object with constraints on it. Press your new shelf button and watch the magic happen!


# simplify constraint setup
import maya.cmds as cmds
import re
# create condition node
class condition(object):
#create node
def __init__(self):
self.node = cmds.shadingNode( "condition", au = True)
cmds.setAttr( "%s.ctr" % self.node, 1) #set TRUE to be 1
cmds.setAttr( "%s.cfr" % self.node, 0) #set FALSE to be 0
#set condition value
def set_value(self, value):
cmds.setAttr( "%s.secondTerm" % self.node, value )
return self
#connect input
def connect_in(self, into):
cmds.connectAttr( into, "%s.ft" % self.node, f=True )
return self
#connect output
def connect_out(self, out):
cmds.connectAttr( "%s.ocr" % self.node, out, f=True )
return self
# create clamp node
class clamp(object):
#create node
def __init__(self):
self.node = cmds.shadingNode( "clamp", au = True)
cmds.setAttr( "%s.mxr" % self.node, 1) #set MAX to be 1
#connect input
def connect_in(self, into):
cmds.connectAttr( into, "%s.ipr" % self.node, f=True )
return self
#connect output
def connect_out(self, out):
cmds.connectAttr( "%s.opr" % self.node, out, f=True )
return self
# warning message
def message(mess):
cmds.confirmDialog(t='Yeah, nah bro.', m=mess)
# get working!
sel = cmds.ls(sl=True)
if len(sel) == 1:
sel = sel[0]
for at in ["translate", "rotate"]: #add keyframe if none to force a pairBlend
if not cmds.keyframe( sel, at= at, q=True ):
cmds.setKeyframe( sel, at=at )
blend_reg = re.compile("pairBlend[0-9]+") #regex for getting the blendparent node
const_reg = re.compile("_[a-z]+Constraint[0-9]+")# check contraint is there
opt = {} #menu options - different constraints
children = cmds.listRelatives( sel, typ="transform")
if children:
for child in children: #find constraint
if const_reg.search( child ):
attr = cmds.listConnections( child, p=True, c=True) #find pairBlend
for at in attr:
if blend_reg.search( at ):
opt.setdefault("nothing", set()).add(cmds.listConnections("%s.w" % at.split(".")[0], p=True, d=False )[0])
for node in cmds.listAttr( child, sn= True, st="w*", k=True ): #grab the constraint attributes
attr = "%s.%s" % (child, node)
opt.setdefault(cmds.attributeName(attr, l=True )[0:-2], set()).add(attr)
if opt: #we now have our connection information
dropdown_opt = sorted(list(set(opt.keys()))) # create list of possible connections
dropdown_opt.insert(0, dropdown_opt.pop(dropdown_opt.index("nothing"))) #make sure animation is first
if cmds.objExists( "%s.atch" % sel ): #create or update the drop down button
old_keys = cmds.keyframe( sel, at="atch", q=True ) #update keyframes
old_opt = cmds.addAttr( "%s.atch" % sel, q=True, en=True).split(":")
if old_keys:
print "Updating keyframes..."
old_new = {}
for old in old_opt:
try:
old_new[old_opt.index(old)] = dropdown_opt.index(old)
except ValueError:
old_new[old_opt.index(old)] = "remove" #constraint was removed, mark for removal
for key in old_keys:
old_val = cmds.keyframe( sel, at="atch", t=(key,key), q=True, vc=True)[0]
new_val = old_new[int(old_val)]
if new_val == "remove":
cmds.cutKey( sel, at="atch", cl=True, t=(key,key))
else:
cmds.keyframe( sel, at="atch", e=True, t=(key,key), vc=new_val )
cmds.addAttr( "%s.atch" % sel, e=True, en= ":".join(dropdown_opt) )
else:
cmds.addAttr( ln= "attach_to", sn="atch", k=True, at="enum", en= ":".join(dropdown_opt) )
for i in range(len(dropdown_opt)): #connect up our items
if i: #set up constraints
for link in opt[dropdown_opt[i]]:
condition().set_value(i).connect_in("%s.atch" % sel).connect_out(link)
else: #set up blend node
for link in opt[dropdown_opt[i]]:
clamp().connect_in("%s.atch" % sel).connect_out(link)
cmds.select(sel)
else:
message("Cannot find the constraint.\nEnsure the constraint is under the object in the outliner.")
else:
message("Cannot find the constraint.\nEnsure the constraint is under the object in the outliner.")
else:
message("You can only select one object at a time.")