Apply View Mask

Use the Map Tools > Masking > Apply View Mask menu option (VIEWCLIP GX) to reset the clip area of a view to a polygon mask file.

Apply View Mask dialog options

Clip polygon file (.ply)	The name of the clip polygon file. Script Parameter: VIEWCLIP.FILE
Map view	The map view on which to apply the clip mask Script Parameter: VIEWCLIP.VIEW
Clip all groups	Force all the groups in the view to be clipped. Script Parameter: VIEWCLIP.FORCE

Application Notes

After changing a view clip area, groups within the view can be clipped to the view clip limits by setting their clip attributes. To do this, select the group to be clipped, press the right mouse button, and select the "clipped" option in the pop-up menu.

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:

Example of a three polygon file:

(Note the exclusive following the poly 3 entry; this indicates exclusive regions or holes in polygon sets.)