You can modify
a surface boundary using its control points. You can deform the boundary by pulling the control point or the mesh line at that point.
Before you begin: Open an existing 3D shape.
Select the surface boundary you wish to edit.
From the Edition section of the action bar, click Control Points .
Control points and lines are displayed along that boundary.
Important:
By default all
control points are selected.
Click a specific point to deform the boundary at this point
only, or select a set of points using the Ctrl-key or
Shift-key while clicking (multi-selection capabilities).
Modify the boundary pulling on its control points or the
mesh line.
Click OK in the Control Points dialog box.
The boundary is modified.
Important:
Only the boundary and its control points are modified. Any other
boundary of the surface is not affected by these modifications.
See also Using Control Points.