Extract Civil 3D Surface border using .NET API ExtractBorder() – Part II

By Partha Sarkar

In previous post I shared a C# .NET code snippet on usage of ExtractBorder(). Interestingly, the extracted entities from the ExtractBorder() function can be Polyline, Polyline3d, or Face. In this post we will explore various situations which will return Polyline, Polyline3d, or Face.

Here is a situation when ExtractBorder() will return Polyline3d : If Surface “Border Display Mode” is set to “Use Surface Elevation” Or “Exaggerate Elevation” then the Extracted entity using the ExtractBorder() .NET API is of type Polyline3d.  

Here is a situation when ExtractBorder() will return Polyline :  If Surface “Border Display Mode” is set to “Flatten Elevations” then the Extracted entity using the ExtractBorder() .NET API is of type Polyline.

Here is a situation when ExtractBorder() will return Face : If Surface “Border Display Mode” is set to “Use Surface Elevation” and ‘Datum’ options are set to “Use Datum’ = True and ‘Project Grid to Datum’ = True,  then the Extracted entities will include 3D Face.