Exercise 2: Adjusting Grading Triangulation with a Feature Line

In this exercise, you will use a feature line to break a poorly triangulated grading surface.

The triangles in the area on the right side of the ramp are steeper than desired. These triangles can be corrected by creating a feature line to break the surface in this area.

This exercise continues from Exercise 1: Smoothing Feature Line Arcs.

Use a feature line to adjust surface triangulation

Note:

This exercise uses Grading-7.dwg with the modifications you made in the previous exercise.

1. Click Home tab Layers panel Layer drop-down. Next to the C-TOPO-FEAT-CROSS layer, click .
2. Zoom in to the area to the right of the ramp.

   Notice the polyline between the three circles labeled A, B, and C. You can use the following steps on any polyline. However, this polyline is in a specific location so that you will get the results described in this tutorial.

3. Click Home tab Create Design panel Feature Line drop-down Create Feature Lines From Objects.
4. Click the polyline between Circles A, B, and C. Press Enter.
5. In the Create Feature Lines dialog box, under Site Name, make sure that Grading - Building Pad is selected.
6. Under Conversion Options, make sure that the Erase Existing Entities and Assign Elevations check boxes are selected. Click OK.
7. In the Assign Elevations dialog box, select From Surface. Make sure that the Insert Intermediate Grade Break Points check box is selected. Click OK.
   Tip:

   To reduce processing time when working with larger grading groups, clear the Insert Intermediate Grade Break Points check box. This option adds an elevation point at each point at which the feature line crosses a triangle.

   The polyline is converted to a feature line and breaks the triangulation along the right side of the ramp. The new triangulation creates a more gradual slope in the infill area.

   

To continue this tutorial, go to Exercise 3: Working with Crossing Feature Lines.