Add a breakline to a TIN

Available with 3D Analyst license.

To add breaklines to an editable TIN, use the Add Breakline tool from the TIN Editor. Breaklines are lines with height information to enforce natural features, such as lakes, streams, ridges, and valleys.

When the tool is active, the Add TIN Breakline dialog box appears, allowing you to specify properties for the breakline to be created. These properties include the breakline Line Type and Height parameters. Click to enter each vertex, and double-click to finish entering a breakline.

When adding a breakline to a TIN, it is helpful to have the current breaklines drawn. Select the TIN from the Contents pane and click the TIN Layer tab set. Then click the symbology button to open the Symbology pane. From the Symbology pane, click the edges button . Check the Draw using check box, and select Edge Type from the drop-down menu.

Symbolize the layer using points and set the Draw using drop-down menu to Simple.

To add a breakline, follow the steps below:

1. In the Contents pane, select the TIN layer you want to edit.
2. Click the Data tab from the TIN Layer tab set.
3. Click the TIN Editor button .
4. Click the Add Breakline button .

   The Add TIN Breakline dialog box appears.

   

5. Set the properties for the breaklines to be created on the TIN surface.

For Line Type, choose either Hard or Soft. Hard and soft qualifiers for line and polygon feature types are used to indicate whether a distinct break in slope occurs on the surface at their location. A hard line is a distinct break in slope, while a soft line is represented on the surface as a more gradual change in slope.

The Height parameter specifies the height source to be used to generate the breakline on the TIN surface. Choose from As specified, From surface, Max Z from surface, or Min Z from surface.

Height source	Description
As specified	The elevation of the digitized line is added to the surface at a constant specified elevation value set in the height field.
From surface	The elevation of the digitized line is interpolated from the selected locations on the surface.
Max Z from surface	The elevation of the digitized line is interpolated from the maximum height value that is encountered along the line.
Min Z from surface	The elevation of the digitized line is interpolated from the minimum height value that is encountered along the line.

6. Select a point on the TIN surface where the breakline will start.

   The first vertex is digitized on the surface.

7. Continue to add each vertex to the breakline by clicking the desired locations.
8. Double-click to finish entering the new breakline.
9. Click the Save button to save the edits to the current TIN being edited. Once the TIN has been saved, all edits become permanent and cannot be undone. Click the Discard button to discard all unsaved edits. To create a copy of the TIN with the current edits applied, click the Save As New TIN button .
10. Click the Close TIN Editor button to close the TIN Editor when edits are completed.