Infrastructure Modeling DevBlog

Creating Civil 3D TIN Surface from Contours (Polylines) using .NET API

By Partha Sarkar

You have a DWG file with contour lines which are actually polylines with elevation values and you want to create a Civil 3D TIN Surface using those Polylines.

Here is a screenshot which shows few Polylines in a DWG file :

 

 

 

If want to create a Civil 3D TIN Surface using these Polylines, first you need to create an empty TinSurface by using TinSurface.Create() API and then using SurfaceOperationAddContour.AddContours() API you need to add the Polylines to the TinSurface. 

Here is a C#.NET code snippet :

// Get the AutoCAD Editor

Editor ed = AcadApp.DocumentManager.MdiActiveDocument.Editor;

Database db = AcadApp.DocumentManager.MdiActiveDocument.Database;

CivilDocument civilDoc = CivilApplication.ActiveDocument;

using (Transaction trans = db.TransactionManager.StartTransaction())

{

 

  try

  {

    // Select a Surface style to use

    ObjectId styleId = civilDoc.Styles.SurfaceStyles["Slope Banding (2D)"];

 

    //Contour Entities collection

    ObjectIdCollection contourEntitiesIdColl = newObjectIdCollection();

 

    // In the following line I use a custom function GetContourEntities()

    // which creates a collection of all the contour polyline Ids

    contourEntitiesIdColl = GetContourEntities();

 

    if (styleId != null && contourEntitiesIdColl != null)

    {

      // Create an empty TIN Surface

      ObjectId surfaceId = TinSurface.Create("TIN_Surface_From_Contours", styleId);

      TinSurface surface = trans.GetObject(surfaceId, OpenMode.ForWrite) asTinSurface;

 

      //public SurfaceOperationAddContour AddContours( ObjectIdCollection contourEntities, double midOrdinateDistance,

      // double maximumDistance,  double weedingDistance,  double weedingAngle )

 

      surface.ContoursDefinition.AddContours(contourEntitiesIdColl, 1.0, 100.00, 15.0, 4.0);           

 

    }  

 

    trans.Commit();

  }

 

  catch (System.Exception ex)

  {

    // handle the exception

    ed.WriteMessage("Surface Creation from Contours Failed !" + "  " +  ex.Message);

  }

 

}

 

 

And a TinSurface created using Polylines :

 

Adding Bands data to Civil 3D Profile View using .NET API

By Partha Sarkar

In this example we see how to add Profile View data bands to a Profile View in AutoCAD Civil 3D using .NET API.

Here we add the band for the top band. In AutoCAD Civil 3D "Profile View Properties" dialog box, you will notice 'Location' drop down box under the 'List of Bands' and it has two options -  'Top of Profile View' or 'Bottom of Profile View'. In this example I am going to add a new band in the 'Top of Profile View'.

 

Top of Profile View before adding the data band :

 

 

And After adding the data band :

 

And here is the C# .NET code snippet : 

Database db = AcadApp.DocumentManager.MdiActiveDocument.Database;

using (Transaction trans = db.TransactionManager.StartTransaction())

{

  CivilDocument civilDoc = CivilApplication.ActiveDocument;

 

  //open the profile view

  ProfileView pv = trans.GetObject(pvId, OpenMode.ForWrite) asProfileView;

 

  //get the style of the first Bottom Bands         

  ObjectId bandStyleId = pv.Bands.GetBottomBandItems()[0].BandStyleId;

 

  //now access the collection of top band

  ProfileViewBandItemCollection topBandItems = pv.Bands.GetTopBandItems();         

 

  //add a new one (using the above style)

  topBandItems.Add(bandStyleId);

 

  //now Set the Top Bands

  pv.Bands.SetTopBandItems(topBandItems);         

 

  trans.Commit();

 

}

Updating Civil 3D Corridor BaseLineRegion Start and End Stations using API

By Partha Sarkar

In this earlier blog post, I demonstrated how to Add / Remove BaseLineRegion in AutoCAD Civil 3D using .NET API. In one of the questions in AutoCAD Civil 3D Customization Forum, I see a developer having an issue in editing the Corridor Baseline Region start and end station. In the Civil 3D API reference document I see the BaselineRegion.StartStation and BaselineRegion.EndStation properties are Get and Set i.e. we can Get the station values as well as we Set them. I thought to give it a try to confirm they are working as per the API reference doc and I do find we can Get as well as Set the station values.

 

Here is the working C# .NET code snippet : 

Corridor corridor = trans.GetObject(corridorId, OpenMode.ForWrite) asCorridor;           

 

// Get the BaselineRegionCollection

BaselineRegionCollection baselineRegionColl = corridor.Baselines[0].BaselineRegions;

 

// Get the BaselineRegion to update the Start and End Station

BaselineRegion baselineregion = baselineRegionColl["Corridor Region (1)"];

 

if (baselineregion != null)

{

  ed.WriteMessage("\n BaseLineRegion Start Station Before Update : " + baselineregion.StartStation.ToString());

  ed.WriteMessage("\n BaseLineRegion End   Station Before Update : " + baselineregion.EndStation.ToString());

 

  // update the stations Value

 

  baselineregion.StartStation = 50.00;

  baselineregion.EndStation = 568.00;

 

  //rebuild the corridor

  corridor.Rebuild();

 

  ed.WriteMessage("\n BaseLineRegion Start Station After Update : " + baselineregion.StartStation.ToString());

  ed.WriteMessage("\n BaseLineRegion End   Station After Update : " + baselineregion.EndStation.ToString());

 

}           

 

And the result in AutoCAD Civil 3D 2014 :

 

AUTOCAD CIVIL 3D 2014 Developer’s Guide

By Partha Sarkar

AUTOCAD CIVIL 3D 2014 Developer’s Guide link given in this earlier blog post as well as in AutoCAD Civil 3D Services & Support page is temporarily unavailable.

If you are looking for the working link for immediate reference, here it is :

AUTOCAD CIVIL 3D 2014 Developer’s Guide

Get the Civil 3D Label Expression using .NET API

By Partha Sarkar

In AutoCAD Civil 3D, by using expressions, we can set up separate mathematical formulas using the existing properties. Expressions are unique to a particular label style type. Only those properties that are relevant to the label style type are available in the Expressions dialog box. 

After you set up expressions, they are available in the Properties list in the Text Component Editor so that you can add them to label styles. In effect, expressions become new properties that you can use to compose a label style.

 

 

 

Now if you want to access the expression formula / string used for a particular Label style using API, its simple, you need to get the ExpressionCollection for that Label Styles collection.

Here is a C# .NET code snippet demonstrating how to access an expression formula used for AlignmentLabelStyles :

using (Transaction trans = db.TransactionManager.StartTransaction())

{

  // Get the desired Lable Styles collection

  LabelStyleCollection lblStyleColl = civilDoc.Styles.LabelStyles.AlignmentLabelStyles.GeometryPointLabelStyles;

 

  // Now get the Expression collection

  // Expressions are unique to a particular label style type.

  ExpressionCollection expColl = lblStyleColl.Expressions;

 

  try

  {

    foreach (Expression lblExp in expColl)

    {

      ed.WriteMessage("\n Expression Name : " + lblExp.Name);

      ed.WriteMessage("\n Expression String : " + lblExp.ExpressionString);

    }

    trans.Commit();

  }

 

  catch (Autodesk.AutoCAD.Runtime.Exception ex)

  {

    ed.WriteMessage("\n Exception message :" + ex.Message);

  }

 

}