The Isoparm Segment allows you to interactively describe a segment of
an isoparm.  This variant will find the isosegment of the first
(zeroth counting from zero) primitive in the input group.

Parameters:

    input       - A group field.  Specifies an primitive to apply this to.
    knotu, knotv - The u, v coordinates of the start of the isoparm
                  segment.
    onoff_scale - Whether the scale subhandle is enabled or not.
    scale       - A scalar value representing the weight that should
                  be applied to this isoparm segment.
    useu        - Whether the segment is a u isoparm or a v isoparm.
    width       - The length of the segment.

See Also: Isoparm Segment (1)
