ml_puppet.py 文件源码

def matchPoleVectorControl(jointChain, pv=None, doSnap=True):
    '''
    Position a pole vector based on a 3-joint chain

    '''

    def distanceBetween(a,b):
        difference = [x-y for x,y in zip(a,b)]
        return math.sqrt(sum([x**2 for x in difference]))    

    p1 = mc.xform(jointChain[0], query=True, rotatePivot=True, worldSpace=True)
    p2 = mc.xform(jointChain[1], query=True, rotatePivot=True, worldSpace=True)
    p3 = mc.xform(jointChain[2], query=True, rotatePivot=True, worldSpace=True)

    mag1 = distanceBetween(p2,p1)
    mag2 = distanceBetween(p3,p2)

    #these are all temporary nodes
    loc = mc.spaceLocator(name='TEMP#')[0]

    mc.pointConstraint(jointChain[0], loc, weight=mag2)
    mc.pointConstraint(jointChain[2], loc, weight=mag1)
    mc.aimConstraint(jointChain[1], loc, aimVector=(1,0,0), upVector=(0,1,0), worldUpType='object', worldUpObject=jointChain[0])

    pCenter = mc.xform(loc, query=True, rotatePivot=True, worldSpace=True)
    pPV = mc.xform(pv, query=True, rotatePivot=True, worldSpace=True)
    pvDist = distanceBetween(pPV,pCenter)

    loc2 = mc.spaceLocator(name='TEMP#')[0]
    loc2 = mc.parent(loc2, loc)[0]
    mc.setAttr(loc2+'.translate', (pvDist),0,0)

    if doSnap:
        snap(pv, loc2)
        mc.delete(loc)
    else:
        #for matching a range
        return loc, loc2