The UV Unwrap handle describes the space in which to perform the UV
Unwrap functions.

Parameters:

    input       - A group field.  The centroid of this group is used
                  as the default origin.
    onoff       - Whether the handle is enabled, 1 means enable.
    projplanes  - How many planes to project with.
    px, py, pz  - The pivot of the projection orientation.
    ref_input   - The reference input to project with.
    rx, ry, rz  - The rotation of the projection orientation in degrees.
    trs_order   - The translate/rotate/scale order.
    tx, ty, tz  - The translation of the projection orientation.
    xyz_order   - The order to apply the rx, ry, and rz angles.

See Also: None.
