By properly selecting the handle, you can move the location on the surface thus modifying its shape maintaining its tangency conditions unchanged.
| 1 | Select the surface by clicking on the location you want to edit. A cross handle will be displayed in such location. |
| 2 | Click again on the selected location, which is the center point of the cross handle and has a marker on it. |
| 3 | Drag it to the new position and release the mouse button. The shape of the surface will be modified but its tangency conditions in the selected location remain unchanged.
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