Adding Breaklines to a Civil 3D Surface

I see a number of Civil 3D users adding a surface smoothing edit to smooth contours. Surface smoothing often creates a very large TIN Surface (Triangulated Irregular Network) and CAD file. A construction contractor may also have a difficult time working with a large TIN and CAD file if used for Machine Control. Breaklines can be added to a surface to create a cleaner TIN and contour lines.

Here are the steps:
Once the breaklines have been modeled and are ready to be added to a surface, adjust the Supplementing Factors in the Add Breaklines dialog box. The following settings work well but adjust them as needed.

• Turn on and set the Distance to 10.00’.
• Set the Mid-ordinate Distance to 0.01’.

Below are the links explaining the Supplementing Factor Distance and Mid-ordinate Distance from Autodesk’s Help file.

Autodesk Civil 3D Help: Supplementing Factors

Autodesk Civil 3D Help: Mid-ordinate Distance


Below are images of a surface with the default settings.

 

 

 

 

Below are images of a surface with the adjusted settings. Additional editing may need to be added to smooth the contours.

 

 

Let me know if you have any questions. 

How to create a Civil 3D 2015 surface from an ESRI shape (shp) file.

In this tutorial, I’ll demonstrate how to create a Civil 3D 2015 surface from an ESRI shape (.shp) file. I believe this feature was introduced in Civil 3D 2014.

1. Create a new drawing containing Civil 3D surface styles.
2. Zoom to the project location.
3. Set the project coordinate system. For this example, my project is located in Virginia so I’m using VA83-SF for a coordinate system code.
4. Click the Surfaces pull down on the Create Ground Data panel of the ribbon.
5. Click Create Surface from GIS Data to launch the wizzard.

6. Create Surface from GIS Data – Object Options.
     a. Type a name for the surface.
     b. The description is optional.
     c. Set the surface style.
     d. Set the layer to your standards.
     e. The render material is optional.
     f. Click Next.

7. Create Surface from GIS Data – Connect to Data.
     a. Click the SHP radio button.
     b. Click the box with the three dots and locate the shape file.
     c. Click the Login button.

8. Create Surface from GIS Data – Schema and Coordinates.
     a. Check the box next to the shape file name.
     b. Set the coordinate system for the data if needed and the drawing if you have not done so.
     c. Click Next.

9. Create Surface from GIS Data – Geospatial Query.
     a. Click the Window radio button.
     b. Click the selection button to the right.
     c. Select an area around the project limits. I usually select an area larger than the project.
     d. Click the Crossing radio button.
     e. Click Next.

10. Create Surface from GIS Data – Data Mapping.
     a. Not all GIS data is created equal. Look for Elevation or Elev. in the GIS Filed column.
     b. Click the Civil3D Property field to the right and select the data. My data is called Elevation.
     c. Click Finish

11. The finished object is a usable Civil 3D surface with elevations

Let me know if you have any questions.