concaveHull

Create Concave Hull

The Concave Hull function creates a polygon that represents the area occupied by a set of data points.

Convex

Convex Hull

Non Convex (Concave)

Non Convex (Concave) Hull

A Concave hull describes better the shape of the point cloud than the convex hull

Convex Hull

Concave Hull

Many solutions are possible for the same input data. The result depends on the user defined distance threshold. The larger the threshold, the closer the resulting polygon will be to the Convex Hull.

Source Data

Convex Hull

Concave Hull 1

Concave Hull 2

Parameters

Expression	Explanation
Function Name	CreateConcaveHull
<input dataset>	A String representing the input layer. Must be of Polygon type.
<output dataset>	A String - the full name of the output layer.
<Distance Treshold>	A Double representing the threshold for creating a concave hull - in the units of the spatial reference of the input dataset.

ETGWPath used in the table below is the full path to ETGWRun.exe (E.G. "C:\Program Files\ETSpatial Techniques\ETGeo Wizards\ETGWRun.exe")

Language	Syntax
Python	subprocess.call([ETGWPath, "CreateConcaveHull", "input dataset", "output dataset", "Distance Treshold"])
.NET using ETGWRun.exe	StartInfo.FileName = ETGWPath StartInfo.Arguments = "CreateConcaveHull" "input dataset" "output dataset" "Distance Treshold"
.NET using ETGWOutX.dll	CreateConcaveHull(input dataset, output dataset, Distance Treshold)
ArcPy	arcpy.CreateConcaveHull(input dataset, output dataset, "Distance Treshold")

Notes:

<> - required parameter
{} - optional parameter
See examples for Python , .NET or ArcPy
The argument separator for StartInfo.Arguments is space. If a string might contain a space, you need to double quote it.