After starting the Split Surface command, proceed as follows.
| 1 | In the Type drop-down list, select the U Parameter method. | 
| 2 | Select the surface.  To change the selected surface, right-click on Surface, choose Reset in the context menu and select another surface. | 
| 3 | A handle and a mini-dialog box are displayed: you can select the isoparametric curve either by explicitly specifying the value or by dragging the handle. A preview is immediately displayed:  Note that you can also simply click on a point of the surface to select the U/V isoparametric curve (depending on which you chose in the Type drop-down list) through that point. To change the point, right-click on Point, select Reset in the context menu and specify another point. | 
| 4 | Click  or  to confirm your selections and split the surface.  Click  to discard your changes. |