mirror_transform.py

# Mirror transform

from maya import cmds


def mirror_transforms(nodes):
    """Mirror transforms `nodes` across the YZ axis

    Arguments:
        nodes (list): Transforms to be mirrored

    """

    for node in nodes:
        temp_joint = cmds.createNode('joint')
        temp_ctl = cmds.duplicate(node,
                                  inputConnections=True,
                                  returnRootsOnly=True)

        cmds.parent(temp_joint, node)
        cmds.parent(temp_joint, world=True)
        cmds.parent(temp_ctl, temp_joint)
        mirrored = cmds.mirrorJoint(temp_joint,
                                    mirrorBehavior=True,
                                    mirrorYZ=True)
        mirrored_joint = mirrored.pop(0)
        mirrored_ctl = mirrored.pop(0)

        cmds.parent(mirrored_ctl, world=True)

        cmds.delete([temp_joint, temp_joint, mirrored_joint])

        yield node, mirrored_ctl


def mirror_shapes(nodes):
    """In addition to mirroring transforms, also mirror shapes

    Arguments:
        nodes (list): Transforms with shapes to mirror

    """

    for original, mirrored in mirror_transforms(nodes):
        mirrored_original = cmds.duplicate(original,
                                           name=original + "_duplicate")
        mirrored_group = cmds.createNode('transform',
                                         name=original + "_transform")
        cmds.parent(mirrored_original[0], mirrored_group)
        cmds.setAttr(mirrored_group + ".sx", -1)

        blendshape = cmds.blendShape((mirrored_original[0], mirrored),
                                     origin='world')
        cmds.setAttr(blendshape[0] + "." + mirrored_original[0], 1)
        mirrored_with_shape = cmds.duplicate(mirrored)

        cmds.delete([mirrored, mirrored_group])

        cmds.select(mirrored_with_shape, replace=True)


def mirror_selected_transforms():
    """Interactively mirror transforms"""
    nodes = cmds.ls(sl=1,
                    objectsOnly=True,
                    type='transform',
                    long=True)
    for node in mirror_transforms(nodes):
        pass


def mirror_selected_shapes():
    """Interactively mirror shapes"""
    nodes = cmds.ls(sl=1,
                    objectsOnly=True,
                    type='transform',
                    long=True)
    return mirror_shapes(nodes)

Hijack the Mirror Joint feature of Maya to mirror controls across the YZ axis.

Now also mirrors shapes