Creating Civil 3D Surface from Contours

September 24, 2014 By Leo Lavayen Leave a comment

The question on how to create surfaces from contours has come up lately and decided to create a write up. More than a how-to, I wanted to get into more details on the options when minimizing flat areas.

Surface from Contours

First, the contours MUST have elevations assigned to them. Typically files that come only have contour data provided have NO Civil 3D set up and styles. Optimally as the workflow should be to:

  1. Start by creating a new drawing using a Drawing Template that has a Civil 3D set up (preferably yours).
  2. Insert the drawing that has the contours and explode it.
  3. Create a new Civil 3D TIN surface (from Prospector or Ribbon).
  4. Set values in Create Surface dialog box.
  5. In Prospector, expand + the surface > expand + Definition
  6. Right click on Contours > select Add… > s
  7. Set values in Add Contour Data dialog box.
  8. Select Contours lines (preferably all other layers have been turn off)

Surfaces are great, as soon as x y z values are added, a surface is created.

Minimize Flat Areas Options

The above functionality has been part of the software for quite a long time now. What I wanted this post to add is more detail on #7 above, and show is the different surfaces created using the different combinations of the Minimize flat area options.

x-xx Default Selection

To test, multiple surfaces were created with different combinations. To compare the results surface a profile view with all the profiles were created. The default choices creates the surface that stands out in green below. All the other surface combinations create profiles that line up on top of each other.

2 Profile View

The difference can also be seen in PLAN. Again the default choice creates contours that stands out in green below. All the other surface combinations create contours that line up on top of each other.

3 Plan View

Having experimented with the settings, I am now leaning towards the surface generated using the first 3 check boxes.

xxx- New Selections

Tagged with Contours, Tech Support, Add Contour Data, Infrastructure, Surface, Civil 3D, AutoCAD, AutoCAD Civil 3D, Contour Data

About Leo Lavayen

Cary, NC Infrastructure Technical Consultant

Something Powerful

Tell The Reader More

The headline and subheader tells us what you're offering, and the form header closes the deal. Over here you can explain why your offer is so great it's worth filling out a form for.


  • Bullets are great
  • For spelling out benefits and
  • Turning visitors into leads.

Subscribe to Email Updates

Recent Posts


see all

Follow us on Twitter

Blogs We Follow

At Land's End (Infrastructure)
Being Civil (Infrastructure)
Being Inventive (Manufacturing)
Between the Lines (Design)
Beyond Design (Building)
Cracking The Vault (Manufacturing)
Line//Shape//Design (Autodesk)
Lynn Allen's Blog (Autodesk)
The Revit Clinic (Building)
Up and Ready (Support)
Without A Net (Support)