You can manipulate control points and tangent
            handles on the mesh to add precision to your warp effect. Click
            the control points to access their tangent handles, then click the
            tangent handles to change the shape of a patch.
         
         Click the Move button
            to move a vertex, an edge, or a tangent handle.
         
            
               
                  
                  
                  
                     | To: | 
                     Click: | 
                  
                  
                     | Move a control point | 
                     The control point and drag.  Note that the X, Y, and
                           Z coordinates of the selected vertex appear in the corresponding
                           fields in the menu.
                         
                      | 
                  
                  
                     | Move an edge | 
                     Near the centre of the edge and drag. | 
                  
                  
                     | Move a tangent handle | 
                     The corresponding vertex to display its tangents, then
                        click the tangent handle and drag.
                      |