Shifts the U = 0 position along a closed curve. This operator has no effect on open curves.
To apply: See Shifting U on Curves [Surface and Curve Modeling].
To redisplay: Select the curve, click the Selection button on the Select panel, then click the Curve Shift icon.
The Curve Shift property editor does not have any parameters of its own, but instead hosts the Curve Point Adaptor Property Editor which specifies a location in U. As you adjust the Position, the boundary jumps from knot to knot.
