Surfaces in AutoCAD Civil 3D

In AutoCAD Civil 3D, you can create surfaces on the Prospector Tab in the Toolspace window by right-clicking on the Surfaces collection, and clicking Create Surface. Or you can also select the same command from the ribbon (Home tab Create Ground Data Panel Surfaces drop-down Create Surface). A dialog box prompts you to assign the surface a name and a style. If you don’t assign the surface a name, it is given a default name which is typically Surface[1]. This default object naming is just one of the useful conventions used in many AutoCAD Civil 3D features.

After supplying a name for the surface and clicking OK, the new surface object is displayed in the Prospector tree. Similar to the Land Desktop Terrain Model Explorer, you can expand the + symbol next to the newly created surface to view the items beneath it and assign the data you want to use to build the surface. You’ll notice that the list of available data types contains primarily the same types that are available in Land Desktop.

By right-clicking on a data type (such as Contours, for example) and adding the necessary data, the surface is automatically built and displayed in model space according to the style settings.

The process of building a surface from contour data in AutoCAD Civil 3D produces far superior results than what can be created with Land Desktop. For example, in AutoCAD Civil 3D, if you display contours on a newly created surface that was created from contour data, the contours will match the original. This is a significant improvement over the surface capabilities in Land Desktop.

Another aspect of AutoCAD Civil 3D surfaces that is important to understand is the surface style. In AutoCAD Civil 3D, the surface is the object, and the contours are subsets of that object. This is another area where the capabilities of AutoCAD Civil 3D far exceed Land Desktop. Because the contours are a subset of the surface, by simply changing the surface style you can present the surface in a wide variety of ways. For example, you can show contours at different intervals, with slope arrows, elevation banding, and more. Showing contours at 1’ and 5’ intervals after they were originally displayed at 2’ and 10’ intervals is as simple as a few clicks. The same is true for displaying components like elevation banding. Performing a similar task in Land Desktop would take many minutes as opposed to just a few seconds in AutoCAD Civil 3D. To display a particular subset of the surface, you need only turn it on in the Display tab for the surface style. To configure a specific subset like contours, simply click on the appropriate tab and set the values as desired.

AutoCAD Civil 3D includes drawing templates that contain numerous predefined surface styles you can choose from or use as a starting point for creating your own.