Difference of Polygons

The Features | New Features | Difference of Polygons command creates new polygons that do not contain overlapping portions of the selected objects. Polygons, rectangles, rounded rectangles, and ellipses can be used with the Difference of Polygons command. When the selected objects do not overlap, the created polygons duplicate the selected objects.

 

Clicking the Difference of Polygons command or right-clicking the selection and clicking Edit Boundaries | Difference of Polygons in the context menu opens the Difference of Polygons dialog. The original objects are removed unless the Keep original objects option is checked in the Difference of Polygons dialog. When the Keep original objects option is checked, the new polygons are created without overlapping areas, and the original objects remain unchanged.

 

These two polygons are selected.

After Difference of Polygons, two new polygons are created without the intersecting area.

 

Creating a Difference of Polygons:

To create a difference of polygons:

  1. Select two or more polygons.

  2. Click the Features | New Features | Difference of Polygons command, or right-click the polygons and click Edit Boundaries | Difference of Polygons in the context menu.

  3. Select whether to keep the original objects in the Difference of Polygons dialog.

  4. Click OK in the Difference of Polygons dialog to create new polygons without the overlapped areas.

 

You may wish to keep the original objects if the overlapping areas need to be represented by a polygon. For example, using the Difference of Polygons command with Keep original objects checked, then using the Intersect Polygons command with Keep original objects unchecked results in separate polygons representing overlapping and non-overlapping portions of the original objects.

 

 

See Also

Union Polygons

Intersect Polygons

Difference of Polygons Dialog

Split Islands/Lakes

Combine Islands/Lakes

Features Tab Commands