Control point grouping is provided to help with the movement of multiple control points. Grouping allows the movement of a number of control points that move as a whole whenever a single control point from the group is moved. To group several control points simply select the points that you wish to be in the group and choose Group from the Controls menu or type Ctrl + G.

Note: It is possible for you to group together several groups that have been previously created, to create a single group of control points.

The Ungroup function performs the reverse of the Group function. Choose the group that you wish to ungroup by selecting a control point from within the group. Choose Ungroup from the Controls menu.

Single control points cannot be marked as grouped – you must select at least two control points to group them. If a control point is grouped to another which is subsequently deleted (by, for example, deleting the surface, row or column in which the control point lies) the remaining control point will become ungrouped unless there are other, undeleted, control points in the same group.

It is important not to confuse the functions of the Group command and the Compact command. Group allows you to move control points simultaneously, even if they occupy different positions in space. Compact forces several control points to the same position in space, but does not force them to move simultaneously. If you wish to have several control points occupy one position and move together, you will need to select the Compact command followed by the Group command.

See also Compacting Control Points on page 136.