CreateVisibilityMap()

Creates an area geographic file from a TIN to show the area that is visible from a certain height at a viewpoint.

CreateVisibilityMap(tin t, string db_name, coord point, double height, array options)

Argument	Contents
t	A TIN
db_name	The name of the output geographic file
point	The viewpoint
height	The height above the viewpoint, or 0 for a view from the surface

Option	Type	Contents
Layer Name	String	The name for the new layer
Label	String	The label for the new layer
Buildings	Array	Three element array of strings indicating buildings to use as obstructions, as shown below

Element	Type	Contents
1	String	The name of the building area layer
2	String	The name of the elevation field
3	String	"Yes" to add buildings as obstructions, "No" otherwise

// Open Elevdata.cdf in the Tutorial folder

layer_name = GetLayer()

elevdata_tin = CreateTriangulation(layer_name + "|", {{"Field","Elevation"}})

folder = RunMacro("G30 Tutorial Folder")

viewpoint = Coord(-71213189,42320724)

CreateVisibilityMap(elevdata_tin, folder + "viewshed.dbd", viewpoint, 6.,

{{"Layer Name","Viewshed"}})

Error Type	Meaning
Error	The TIN compound variable is null, or the options are not of the required type

Function	Summary
CreateTriangulation()	Creates a Triangulated Irregular Network (TIN)
CreateContourDB()	Creates a line or area geographic file of the contours derived from a TIN