Apply View Mask

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

Apply View Mask dialog options

Clip polygon file (.ply)	Specify the polygon file used to define the clip (mask) area. Script Parameter: VIEWCLIP.FILE
Map view	Select the map view to which the clip mask will be applied. Options may include Data, Base, or other available views (for example, Section). Script Parameter: VIEWCLIP.VIEW
Clip all groups	Choose whether to apply the clip mask to all groups in the selected view. Script Parameter: VIEWCLIP.FORCE [0 : No, 1 : Yes (default)]

Application Notes

After changing the view clip area, individual groups within the view can be clipped to the defined limits by enabling their clip attributes. To do this, select the group, right-click, and choose the Clipped option from the pop-up menu.

Polygon Mask Files

• Polygon files are ASCII text files with the default .ply extension.

• Each file contains a list of X,Y coordinates that define one or more polygons.

• Files can include any number of polygons, each with any number of vertices.

• The first and last points of each polygon are assumed to be connected.

File Structure Guidelines:

• Each polygon begins with a line starting with poly # (with P or p in column 1).

• Comment lines begin with / in column 1.

Creating Polygons Interactively

You can create clip polygon files interactively using the digitising tools available in the Map Tools menu.

Example: Single Polygon File

Example: Multiple Polygon File

(Note: The keyword exclusive following a polygon entry, such as poly 3, indicates exclusive regions or holes within a polygon set.)