Determine the triangle edge length of a TIN dataset for delineation in ArcGIS Pro

Summary

Triangulated irregular networks (TINs) are vector-based geographic data created by triangulating vertices connected by edges. In ArcGIS Pro, the TIN Edge tool can be used to determine the triangle edge length within a TIN dataset. The triangle edge length is required as input when using the Delineate TIN Data Area tool to redefine the data area or interpolation zone of a TIN dataset. This article describes how to determine the triangle edge length of a TIN dataset for area delineation in ArcGIS Pro.

The workflow provided in this article involves converting the 3D triangle edge feature to a 2D feature using the Export Features tool. The length of the 2D triangle edge is then used as the input for the Maximum Edge Length parameter in the Delineate TIN Data Area tool.

Procedure

Note:
The following steps require a 3D Analyst license. Refer to ArcGIS Pro: Use extensions for more information.

1. Open the project with the TIN dataset in ArcGIS Pro.
2. Create the 3D triangle edges of the TIN dataset using the TIN Edge tool.
1. In the Geoprocessing pane, search for and click TIN Edge (3D Analyst Tools).
2. In the TIN Edge pane, for Input TIN, select the TIN dataset from the drop-down list.
3. For Output Feature Class, specify a location and name to export the feature class.
4. For Edge Type, select the preferred type of triangle edge to be exported. Refer to ArcGIS Pro: Parameters for more information.
5. Click Run.

3. Export the 3D TIN edge feature layer to a 2D feature layer.
1. In the Contents pane, right-click the TIN Edge layer from Step 2, hover over Data, and click Export Features.
2. In the Export Features dialog box, for Output Feature Class, specify a location and name to export the feature class.

3. In the Export Features dialog box, click the Environments tab.
4. Expand the Z Values node, and in the Output has Z Values drop-down list, select Disabled.
5. Click OK.

Note:
The triangle edge feature layer must be in a projected coordinate system. If the triangle edge feature layer is represented in the geographic coordinate system, the distance must be calculated in geodesic to avoid using the degree unit for distance. Refer to ArcGIS Pro: Differences between geodesic and planar distance for more information. Add a new double-precision field in the attribute table and calculate the geodesic distance using the Calculate Geometry Attributes tool. 

4. Delineate the TIN data area based on the maximum edge length of the 2D TIN dataset using the Delineate TIN Data Area tool.
1. In the Geoprocessing pane, search for and click Delineate TIN Data Area (3D Analyst Tools).
2. In the Delineate TIN Data Area pane, for Input TIN, select the TIN dataset from the drop-down list.
3. For Maximum Edge Length, specify the maximum 2D length of the TIN dataset. In this example, the maximum edge length is 1022.
4. Click Run.

The image below shows the TIN area delineated based on the maximum edge length of the TIN dataset.