Set joints to bind position

gistfile1.txt

# Public domain

import pymel.core as pm
from pymel import core as pm
from maya.api import OpenMaya as om

def getSkinClusterConnection(node):
    for conn in pm.listConnections(node.attr('worldMatrix'), d=True, s=False, p=True, type='skinCluster') or []:
        skinCluster = conn.node()
        idx = conn.index()

    	return skinCluster, idx
    return None, None

def resetToRealBindPose(node, depth=0):
    if not isinstance(node, pm.nodetypes.Joint):
        return

    skinCluster, idx = getSkinClusterConnection(node)
    if not skinCluster:
        # If a joint has no connected skinCluster, we don't have a bind matrix to reset
        # to, but the position of the joint still matters.  Set to the preferred angle
        # instead.
        angle = node.attr('preferredAngle').get()

        # Try to set each axis.  Ignore axes that we can't set, which is usually the "locked or connected"
        # error.  We don't check this first, since sometimes you can set connected attributes, eg. when a
        # joint is constrained but constraint evaluation is turned off in the Modify > Evaluate menu.
        # This is important, so you can disable constraint evaluation and reset to bind pose to return
        # the skeleton to its exact original configuration (eg. to re-mirror weights or re-bind a new mesh).
        for idx, axis in enumerate(('rx', 'ry', 'rz')):
            output = node.attr(axis)
            try:
                output.set(angle[idx])
            except RuntimeError as e:
                pass
    	return

    matrix = skinCluster.attr('bindPreMatrix[%i]' % idx).get()
    matrix = om.MMatrix(matrix)
    matrix = matrix.inverse()
    segmentScaleCompensate = node.attr('segmentScaleCompensate').get()
    pm.xform(node, m=matrix, ws=True)

    # pm.xform turns segmentScaleCompensate on for some reason.  Put it back.
    node.attr('segmentScaleCompensate').set(segmentScaleCompensate)

# listRelatives -ad "returns grandchildren before children", which makes no sense.  It
# should return in either depth first or breadth first order.
def getDescendantsDepthFirst(node, depth=1):
    yield node, depth
    for child in node.getChildren():
        for result in getDescendantsDepthFirst(child, depth+1):
            yield result

def go():
    for node in pm.ls(sl=True):
        for joint, depth in getDescendantsDepthFirst(node):
            resetToRealBindPose(joint, depth)

go()