Wednesday, July 17, 2013

Tool to split polygons by selection in sequence

Hi There,
I made a couple modifications to a script I wrote a while ago that splits polygon geometry according to selected transforms. It now seems to be working on a real character i'm rigging. Hope you find it helpful. To use need the usual, put script in python search path then import cutGeo, then select two or more transforms (order of selection matters) and type cutGeo.cutGeo(character='nameOfPolyToSplitUp'). Hope you find it helpful.


#splits geo ex: arm or leg using selected transforms

#@author Nathaniel Anozie
#ogbonnawork at

#@note Inspired by Jason Schleifer's Animator Friendly Rigging
#@note Inspired by Hamish Mckenzie (macaronikazoo dot com) learning about for zip in python
#@note Inspired by Kyle Mistlin-Rude (kylemr dot blogspot dot com), learning python list comprehension

#last updated: 07/17/2013 -- fixed wrong direction splitting bug
#last updated: 07/15/2013 -- fixed cutting last user location bug
#last updated: 07/12/2013 -- removed extra stuff and consolidated short and non repeatable defs

import maya.cmds as cmds
import maya.mel as mel

##splits geo ex: arm or leg using selected transforms
def cutGeo(character = 'pCube1'):
    print("[cutGeo] Starting split geo ex: arm or leg using selected transforms ...\n")
    print("[cutGeo] Warning requires order of selected transforms in sequence ...\n")
    print("[cutGeo] Warning Would need to do for arm then for leg separately !!!\n")
    sel = []
    sel =
    if( len(sel) < 2 ):
        print("[cutGeo] Warning Does Not Make Cuts With Only One Selected Thing, Need to select two or more transforms !!!\n")
        return 1
    except TypeError:
        print 'Requires either cvs,locators ... selected so it has positions to cut geometry >>%s'
        return 1
    except TypeError:
        print 'Requires a piece of geometry as input>>'
        return 1
    #so control can be in okay direction, make 1 joint chain using all selected and have it ok orientation
    print("[cutGeo] Computing Cut Positions...\n")
    t = [],replace=True)
    patches =
    t = [cmds.xform(obj, q=True, ws=True, translation = True )  for obj in patches  ]
    #double the end position so can cut up to last user location
    tLast = t[len(t) - 1]
    t.append( tLast)
    print("[cutGeo] Computing Cut Rotations...\n")
    guideJoints = [], clear = True)
    map( lambda x: guideJoints.append( cmds.joint(p=t[x]) ), range(0,len(t)))[0],replace=True)
    print "[makeGuideJoint] Warning Using Default Orientation xzy \n"
    mel.eval('joint -e -oj xzy -secondaryAxisOrient yup -ch -zso;') 


    splitR = [[]] #will hold all cut of geo rotation
    splitT= [[]] #will hold all cut of geo translation
    print('Beginning loop for cut points <<<\n')
    for i in range(0,len(guideJoints)-1):
        jnt = guideJoints[i] #looking at one joint
        #saving data for splitting of geo
        splitRot = cmds.xform(jnt,query=True,ws=True,rotation=True)
        rx = 0
        ry = 90
        rz = splitRot[2]
        print('Joint %s --> %d %d %d\n' %(jnt,rx,ry,rz) )
        splitRotate = [rx,ry,rz]
        splitTranslate = cmds.xform(jnt,query=True,ws=True,translation=True)         
    #make all geo cuts at once so dont have trouble finding separated geos
    splitR = splitR[1:] #need everything but first empty thing
    splitT = splitT[1:]
    splitGeo(character,translation = splitT,rotation = splitR )
    #possibly remove guide joints
    print "[cutGeo] Warning Assumes can easily clean up cut setup joints\n"
    if len(guideJoints) > 0:
        mel.eval('delete '+guideJoints[0])
        #map( lambda x: mel.eval('delete '+guideJoints[x]), range(0,len(guideJoints)))
def cutGeo_unitTest():  
    print "[cutGeo_unitTest] Not Implemented"
##cut a polygon geo at given points. the rotation helps determine normals for cuts try a couple.
#@param character poly
#@param world translation for cut
#@param world euler rotation for cut
def splitGeo(character='pCube1',translation = [[0,0,0]],rotation = [[0,90,0]]):
    for t, r in zip(translation,rotation):
        print '[splitGeo]  Warning Using Rotation %d,%d,%d\n' %(r[0],r[1],r[2])
   , replace=True)
    print("[splitGeo] Only Supporting Mesh\n")
    characterShape =, type = "mesh") #check size is 1,or nurbsSurface
    #finish with all cuts --change offsets to 0 and change extract faces to true
    pCutConnections = cmds.listConnections(characterShape,type = 'polyCut')
    if pCutConnections is not None:
        pCut = pCutConnections
        print "<>"
        return 1
    if len(pCut) > 0:
        pCut = list(set(pCut)) #remove duplicates python 2.5 >
        for obj in pCut:
            cmds.setAttr( obj+'.extractOffsetX', 0.0 )
            cmds.setAttr( obj+'.extractOffsetY', 0.0 )
            cmds.setAttr( obj+'.extractOffsetZ', 0.0 )
            cmds.setAttr( obj+'.extractFaces', 1 )

        #separate the shape ex:  polySeparate -ch 1 pCubeShape2;    
        cmds.polySeparate( characterShape, ch = 1)
def splitGeo_unitTest(): 
    character = cmds.polyCube(w=5)
    splitGeo(character,tSplit = [0,0,0],rSplit = [0,90,0] )