Objects can be edited in a number of ways. Objects can be deleted or moved. Individual vertices in objects can be inserted, moved, or deleted. Edges of objects can be deleted. New sections can be added to an object. The order of the objects can be changed. Finally, the properties of objects can be changed.

To delete an object, select it and press the delete key on the keyboard. To delete individual vertices, select the vertices and press the delete key. To delete an edge of an object, click on the Delete segment button . Then click on an edge of an object to delete that edge. If deleting an edge will split the object into two separate pieces, each piece will become a separate section of the same object.

One way to move objects or vertices is to select them, hold down the mouse button with the mouse curser on or inside the object, and move the mouse before releasing the mouse button. Another way to move an object or an individual vertex is to double click on the object. Then, on the tab labeled Vertices in the Object Properties dialog box, type in new values for the coordinates of the vertices. When moving individual vertices, if a vertex is moved to within 3 pixels of a vertex on another visible object and the Shift key is held down when the mouse button is released, the vertex that is being moved will be moved to the location of the vertex on the other object.

To insert a vertex, first click on the Insert vertex button . Then click on the edge of an object to insert a vertex at the position where the mouse was clicked. If any object is selected, this procedure will only insert a vertex in the selected object. If no object is selected, this procedure will insert a vertex into the object on which the user clicks.

The Scale, Rotate, and Move Objects dialog box can be used to change the position or geometry of objects.

Changing the Object Order

To change the order of objects, select one or more objects and right-click on them. Select To Front, To Back, Forward One or Back One in the pop-up menu to change the order of the objects. It is also possible to select Object|Rearrange Objects… The Rearrange Objects dialog box will appear. In it, the user can drag objects to new positions. When assigning values to data sets, the order of the objects is important because each object that assigns values at enclosed or intersected locations replaces values assigned previously by the default formula or by a previous object. The order of the objects is important for interpolation only if more than one object is at the same location.

Changing the Object Properties

To edit the properties of one or more objects, select them and then double-click on one of them. The Object Properties dialog box will appear, and the properties can be edited. The user can also display the Object Properties dialog box to edit the properties of a single object by displaying the Show or Hide Objects dialog box and double-clicking on the name of the object. If an object is mentioned in an error or warning message in the Errors and Warnings dialog box, the object can often be selected by right-clicking on the message and choosing an appropriate option from the popup menu.

Adding New Sections to Existing Objects

To add additional sections to an existing object, the user first selects the object and then clicks the Add point sections , Add polyline sections , or Add polygon sections button. Next the user clicks on the view of the model containing the object at the location where a new vertex is desired. When adding polylines or polygons to an existing object, double-clicking or pressing the "Enter" key on the keyboard finishes the polyline or polygon section. A polygon section may also be finished by clicking at the location of the first vertex of the polygon section.

If the Shift button is held down when the mouse button is clicked and there is a vertex on another visible object within 3 pixels of the cursor, the new vertex will be at the same location as the vertex on the other object.

Vertex Values

It is possible to associate a value with a particular vertex by first selecting Obect|Edit|Edit Vertex Values or clicking the Edit vertex values button and then double-clicking on a vertex of the selected object to display the Vertex Values dialog box. Such values can be used in the InterpolatedVertexValue function.

Splitting Objects

If an object contains multiple parts, Object|Edit|Split Selected Objects will make each of the parts a separate object.

If some of the vertices of an object are selected, Object|Edit|Make Selected Vertices a Separate Object will remove those vertices from the selected object and make them a new object.

If some of the vertices of an object are selected, Object|Edit|Split Object at Selected Vertices will break the object into two separate objects. The break will occur at the selected vertices and each object will share the selected vertices.