Create Polygon PLY File

Use the option Create Polygon PLY File (POLYDEF GX) from the Database Tools > Window Data or Map Tools > CAD Tools menus to create a new polygon file or add polygons to an existing polygon file. Polygon files are used in a number of dialogs for purposes such as masking and area selections.

The option is also available with the Airborne Quality Control extension under the Airborne QC > Generate Flight Path Plan menu.

Create Polygon PLY File dialog options

Polygon file name (.ply)	Specify the name of the polygon file to create or append to.
Inclusive or Exclusive?	Exclusive polygons define areas to be excluded from the mask, which can be useful for defining holes in the area. Exclusive polygons are not supported on their own; you must always put them inside a larger inclusive polygon to obtain consistent results.
[New file]	Click this button to create a new polygon file.
[Append]	Click this button to append a new polygon to the existing polygon file.

Application Notes

You will be able to define a polygon using the mouse in the currently active map window.

Use Exclusive polygons to define holes in the data.

Polygons are ASCII files with default extension .ply. A polygon file contains a list of X,Y coordinates that define one or more polygons. The file may contain any number of polygons, and each polygon may have any number of vertices. The first and last points in each polygon are assumed to connect. If the file will contain more than one polygon, each polygon must start with a line 'poly #' ('p' or 'P' in column 1). Comment lines are indicated by a '/' in column 1.

Clip polygon files may also be generated interactively by using the digitising tools in the Map Tools menu.

Example of a single polygon file: