General editing commands

General editing commands such as coping, duplicating, deleting are applicable for curves and surface primitives.

> Deleting curves and surface primitives

In order to delete curves or surface primitives, first select the objects to delete, and select "Clear" item from menu, or press delete key. When a curve or a surface primitive is deleted, the control points on it are also deleted. But, the control points shared by other curves or surface primitives are not deleted. Likewise, all the nodes allocated on the deleted curve are removed, but nodes shared by other curves or meshes cannot be deleted. In this context, a meshed curve cannot be deleted. In order to delete a meshed curve, all the meshes associated with the curve should be deleted in advance.

> Copying curves and surface primitives

In order to copy curves or surface primitives, select the objects to copy, and select "Copy" item from menu. The copied objects are stored in the computer memory and can be pasted later.

> Cutting curves and surface primitives

Cutting deletes the selected objects, and at the same time, stores the deleted objects in the computer memory. This is done by "Cut" command in menu, and has the same effect as deleting after copying the selected objects. n Pasting curves and surface primitives "Paste" command in menu pastes the objects which have been stored in th computer memory by "Cut" or "Copy" command.