Freeze bound joints

gistfile1.txt

import pymel.core as pm
from zMayaTools import maya_helpers

# Imported skeletons often have ugly scaling.  We should be able to just turn on move skinned
# joints and freeze transforms, but Maya tries to be helpful and prevents us from doing this.
def get_descendants_depth_first(node, depth=0):
    if not isinstance(node, pm.nodetypes.Transform):
        return

    yield node, depth
    for child in node.getChildren():
        for result in get_descendants_depth_first(child, depth+1):
            yield result
            
def copy_attr(src, dst, attr):
    new_value = src.attr(attr).get()
    old_value = dst.attr(attr).get()
    # Don't set values if they already match.  This avoids throwing errors for locked attributes
    # that haven't changed.
    if new_value == old_value:
        return
    try:
        dst.attr(attr).set(new_value)
    except:
        print('Couldn\'t set %s' % dst)

    
def copy_hierarchy_transforms(to_node, from_node):
    to_tree = list(get_descendants_depth_first(to_node))
    from_tree = list(get_descendants_depth_first(from_node))
    mapping = {}
    # First, check that the trees match and make a mapping from source to target nodes.
    for (to_node, depth), (from_node, unused) in zip(to_tree, from_tree):
        # Don't match up the names for the top-level nodes, since they're usually siblings and
        # can't have the same name.
        if depth > 0 and to_node.nodeName() != from_node.nodeName():
            print('Trees don\'t match (node %s doesn\'t match node %s)' % (to_node, from_node))
            return
        if to_node.__class__ != from_node.__class__:
            print('Trees don\'t match (node %s is %s, node %s is %s)' % (to_node, to_node.__class__, from_node, from_node.__class__))

        mapping[to_node] = from_node
    
    for to_node, unused in to_tree:
        from_node = mapping[to_node]
        for attr in ('t', 'r', 's', 'rotateAxis', 'rotateOrder'):
            copy_attr(from_node, to_node, attr)
        if isinstance(to_node, pm.nodetypes.Joint):
            for attr in ('jointOrient', ):
                copy_attr(from_node, to_node, attr)

def freeze_skinned_joint(node):
    with maya_helpers.restores() as restores:
        # Enable global move skinned joints mode.
        restores.append(maya_helpers.SetAndRestoreCmd(pm.zMoveSkinnedJoints, key='enable', value=True))

        # Create a duplicate of the hierarchy that we can freeze transforms on.
        node2 = pm.duplicate(node)[0]
        
        # Freeze transforms on the transform, removing any scale and moving rotation into jointOrient.  This
        # will propagate changes to the children so the children don't change.
        pm.makeIdentity(node2, apply=True, rotate=True, scale=True)

        # Copy the resulting transforms from node2 to node.
        copy_hierarchy_transforms(node, node2)
        
        # Delete our temporary nodes.
        pm.delete(node2)
    
freeze_skinned_joint(pm.ls(sl=True, type='transform')[0])