GridSurface.ExtractContoursAt(Double) Method

Extracts the surface contour information from the terrain surface at a specified elevation.

Namespace: Autodesk.Civil.DatabaseServices
Assembly: AeccDbMgd (in AeccDbMgd.dll) Version: 13.8.0.280

Syntax

C#

public ObjectIdCollection ExtractContoursAt(
	double elevation
)

VB

Public Function ExtractContoursAt ( 
	elevation As Double
) As ObjectIdCollection

C++

public:
virtual ObjectIdCollection^ ExtractContoursAt(
	double elevation
) sealed

Parameters

elevation  Double

The specified elevation.

Return Value

ObjectIdCollection
An ObjectIdCollection of the extracted entities. The extracted entities are Polyline objects. If the surface has no contour information, this method returns an empty ObjectIdCollection.

Implements

ITerrainSurfaceExtractContoursAt(Double)

Example

C#

 1// Setup: creates a new, random surface
 2// 
 3TinSurface surface = CreateRandomSurface("Example Surface");
 4
 5// Extracted contours become AutoCAD objects (Polylines) and can be
 6// inspected and manipulated.
 7// 
 8ObjectIdCollection contours;
 9double contourElevation = 50.0;
10contours = surface.ExtractContoursAt(contourElevation);
11write("# of extracted contours: " + contours.Count + "\n");
12int totalVertices = 0;
13for (int i = 0; i < contours.Count; i++)
14{
15    ObjectId contourId = contours[i];
16
17    // Contours are lightweight Polyline objects:
18    Polyline contour = contourId.GetObject(OpenMode.ForRead) as Polyline;
19    write(String.Format("Contour #{0} length:{1}, # of vertices:{2}\n",
20        i, contour.Length, contour.NumberOfVertices));
21    totalVertices += contour.NumberOfVertices;
22}
23
24// Extract contours with smoothing:
25contours = surface.ExtractContoursAt(contourElevation, ContourSmoothingType.AddVertices, 10);
26int totalVerticesSmoothed = 0;
27foreach (ObjectId contourId in contours)
28{
29    Polyline contour = contourId.GetObject(OpenMode.ForRead) as Polyline;
30    totalVerticesSmoothed += contour.NumberOfVertices;
31}
32
33// Compare smoothing by adding vertices:
34write(String.Format("Effects of smoothing:\n  total vertices no smoothing: {0}\n  total vertices with smoothing: {1}\n",
35    totalVertices, totalVerticesSmoothed));

VB

1!ERROR: See log file!

See Also

Reference