Grade Features interactive tool

The Grade From Centerline interactive tool, found on the TIN Editing toolbar, is used to add road, levee, and berm-like features to a TIN surface. You provide the centerline of a feature, its width, and the slope angles to use for grading between the feature and the surface. The tool uses these options and synthesizes a design surface and integrates it with the TIN being edited. It optionally writes out the design surface to a new TIN model. TIN grading is used to modify the TIN surface based on grading parameters applied to a selected linear feature. The grading options allow you to incorporate any linear feature like a road centerline, or a berm edge into the TIN surface model interactively. You must select a feature (polyline) first.

To enable the interactive tool a TIN must be selected for editing in the TIN Editing toolbar. Additionally, one or more 2D or 3D line graphics or features must be selected. If more than one feature is selected, then the operation will be carried out on all of the selected features using the same parameters set on the Grade From Centerline dialog.

If an input feature is 2D, it will be profiled on the TIN surface to convert it into a 3D feature before carrying out any grade analysis.

Steps:

1. Click the TIN Editing drop-down menu and click Start Editing TIN.

   To enable the Grade From Centerline tool you must have a TIN open for editing and you need a selected line feature or graphic. The line feature can be 2D or 3D.

2. Once the linear feature is selected, click the TIN Editing drop-down menu on the TIN Editing toolbar and click Grade From Centerline. The Grade From Centerline dialog window appears.
3. Set the desired grading parameters from the Grade From Centerline dialog window. The following section describes each of these parameters.
Height Offset— A constant height added to the feature vertices. The default is 0.0.

Smoothing Tolerance —The tolerance allowed for smoothing the input line. It's a 2D tolerance. Often, coarsely digitized lines change direction too abruptly. Smoothing fits some curvature to make direction changes more gradual. The tolerance is the distance the smoothed line can deviate from the original line. Therefore, the amount of smoothing potential is proportional to the tolerance. A value of 0.0 means no smoothing. The default is 2.5.

Width—The 2D width of the feature. For a road, it's the width of the pavement; for levees and berms, the width their tops. The height of this area will follow the height of the input feature. The default width is 15.0.
Upgrade Angle—The cut slope angle given in percent or degrees. This is used when the input feature, that's been buffered to give it proper width, finds at least a portion of its edge is below the current TIN. A newly graded surface must be made at an upward angle from the edge of the feature to the point where it finally intersects the TIN. The default is a 250% grade.
Downgrade Angle—The fill slope angle given in percent or degrees. This is used when the input feature, that's been buffered to give it proper width, finds at least a portion of its edge is above the current TIN. A newly graded surface must be made at a downward angle from the edge of the feature to the point where it finally intersects the TIN. The default is a 150% grade.
Max Grade Distance—The maximum distance allowed for a graded slope between the edge of the feature and the TIN. Based on local feature geometry, TIN surface geometry, and grade angles the distance required for grading can become too long. The Max Grading Distance is used as a cut-off. Grading for the feature will not take place if it is discovered that a grade distance needed to complete the design exceeds this limit. The default is 100 units.
Create New TINs to Location— The folder to which design surfaces are written. If the option is checked on a new TIN, representing the design surface will be made for each input feature. The design surface is the modified portion of the surface.
4. Select Apply to commit the grade paramters that have been set on the TIN selected for editing.

Note:

• Design surfaces are always integrated with the current edit TIN. If you want the current TIN to be unchanged, and only get the design surface output, execute the tool with the Apply button to get the design surface, and then select Undo Since Last Save from the TIN Editing toolbar drop-down menu.

• It is recommended for the spatial reference, including XY and Z units, to match between the input feature geometry and TIN.