AEC DevBlog

Where is the Navisworks SDK

By Saikat Bhattacharya

The Navisworks SDK can be located at the root installation folder of Navisworks on your system typically under –

<Navisworks Manage install location>\api\

If you install using the default install path locations, you might find it under -

C:\Program Files\Autodesk\Navisworks Manage 2013\api

Setting Load Case parameter value

By Katsuaki Takamizawa

Setting Load case parameter value

If you see ‘Load Case’ parameter in Property window in UI, it is listed in dropdown list. However, this parameter is defined in the element Id and not in Integer index. You can find Load Case elements using the element filer. You can filter with LoadCase class and then Name property to find the one you need. You can then set the element  Id as following where pointLoad is Point Load element and idLoadCase is the element Id of Load Case element.

pointLoad.Parameter(
Parameters.BuiltInParameter.LOAD_CASE_ID).
Set(IdLoadCase).

Please note the built-in parameter has been changed from LOAD_CASE_NUMBER to LOAD_CASE_ID for a more meaningful name.

You can easily can find these using RevitLookUp tool.

Persistent item ID of Navisworks objects

By Saikat Bhattacharya

Is there any way to identify a node or a path that is persistent across model changes and sessions? 

If you need stable, unique IDs on elements, the best bet is to use some attribute. If you are working with DWG files, you can use the Entity Handle attribute. If you are using MicroStation v8 files, you can use the Element ID. In an ArchiCAD model, you use GUIDs etc.

Keeping your ribbon tab displayed for selection

By Katsuaki Takamizawa

The contextual tab will be displayed with the selection. For example, [Modify| Walls] tab is displayed when a wall is selected with a cursor. However, you might not want this happen in some cases.  For instance, you want to keep your plug-in’s ribbon tab displayed when an element is selected.

Unfortunately, you can not achieve this using API. But you can go to R>Options dialog>”User Interface” tab and unclick the “Display the contextual tab on selection”. Then, The tab stays with the selection.

Creating dimensions

By Katsuaki Takamizawa

We have CreateDimensions SDK sample. This sample shows you how to create dimensions by simplifying the part of finding geometry references from the analytical line of a wall. However, the sample does not work in Revit 2013 (and 2012) since it has not incorporated the change. The geometries of the analytical model have to be accessed from the analytical model of each element.

If you replace the part of Command.cs in the sample with the following code, the sample will find the geometries from the analytical mode and creates the dimension.

  //get out all the walls in this array, and create a dimension from its start to its end
  for (int i = 0; i < m_walls.Count; i++)
  {
      Wall wallTemp = m_walls[i] as Wall;
      if (null == wallTemp)
      {
        continue;
      }

      //get location curve
      Location location = wallTemp.Location;
      LocationCurve locationline = location as LocationCurve;
      if (null == locationline)
      {
      continue;
      }

      //New Line

      Line newLine = null;

      //get reference
      ReferenceArray referenceArray = new ReferenceArray();

      AnalyticalModel analyticalModel = wallTemp.GetAnalyticalModel();
      IList<Curve> activeCurveList = 
        analyticalModel.GetCurves(
        AnalyticalCurveType.ActiveCurves);
      foreach (Curve aCurve in activeCurveList)
      {
        // find non-vertical curve from analytical model
        if (aCurve.GetEndPoint(0).Z == 
          aCurve.GetEndPoint(1).Z)
          newLine = aCurve as Line;
        if (aCurve.GetEndPoint(0).Z != 
          aCurve.GetEndPoint(1).Z)
        {
          AnalyticalModelSelector amSelector = 
            new AnalyticalModelSelector(aCurve);
          amSelector.CurveSelector = 
            AnalyticalCurveSelector.StartPoint;
          referenceArray.Append(
            analyticalModel.GetReference(amSelector));
        }
        if (2 == referenceArray.Size)
            break;
      }
      if (referenceArray.Size != 2)
      {
          m_errorMessage += "Did not find two references";
          return false;
      }
      try
      {
        //try to add new a dimension
        Autodesk.Revit.UI.UIApplication app = 
          m_revit.Application;
        Document doc = app.ActiveUIDocument.Document;

        Autodesk.Revit.DB.XYZ p1 = new XYZ(
            newLine.get_EndPoint(0).X + 5,
            newLine.get_EndPoint(0).Y + 5,
            newLine.get_EndPoint(0).Z);
        Autodesk.Revit.DB.XYZ p2 = new XYZ(
            newLine.get_EndPoint(1).X + 5,
            newLine.get_EndPoint(1).Y + 5,
            newLine.get_EndPoint(1).Z);

        Line newLine2 = app.Application.Create.
          NewLine(p1, p2, true);
        Dimension newDimension = doc.Create.NewDimension(
          doc.ActiveView, newLine2, referenceArray);
    }
      // catch the exceptions
      catch (Exception ex)
      {
          m_errorMessage += ex.ToString();
          return false;
      }
  }

Please do not confused with this sample. You can create dimension for elements not in the analytical model, of course. The most difficult part is to find geometry references which you want to attach the dimension. Thanks to Jeremy that his API blogs introduce how to find geometry references with some typical use cases.

http://thebuildingcoder.typepad.com/blog/2011/02/dimension-walls-by-iterating-faces.html
http://thebuildingcoder.typepad.com/blog/2011/02/dimension-walls-using-findreferencesbydirection.html

Please note that currently geometry references can not be found in symbolic lines using API while they can be dimensioned using UI.

Floor creation methods

By Katsuaki Takamizawa

I got this inquiry and would like to share with you because I was also confused. Both NewFloor and NewSlab method creates a Floor element. The question was what is the difference?. The only difference is that NewSlab method can create a Floor with a slope.

Retrieving a base profile from a space object that has holes and arcs using .NET

By Mikako Harada

Issue

I have a Space object in AutoCAD Architecture and I need to extract its contour to export to another data format. The problems appear when the Space object has "holes".  I also don't know how to calculate the points on an arc. 

Solution

A profile is simply a collection  of closed outlines called Ring, which is defined in 2D.   The first one is the outer most ring.  Others are holes in the profile.  To obtain the profile information, follow the steps:

1. From the Space object, GetProfile with Baseline option 
2. Iterate through Rings collection
3. For each Ring, get the Segments or Segment2dCollection.  (AecGeSegment2d)
4. For each Segment, you should be able to get the segment info, such as start point, end point and bulge.

In case a segment is an arc, you can get bulge information from each segment or use EvaluatePoint() method to obtain a point on an arc if needed.  Below is a sample code written in VB.NET that demonstrates this.

   Public Sub ShowSpaceProfile()

 

    ''  first, get the basic objects

   

    Dim ed As Editor = Application.DocumentManager.MdiActiveDocument.Editor

    Dim db As Database = HostApplicationServices.WorkingDatabase

    Dim tm As TransactionManager = db.TransactionManager

    Dim tr As Transaction = tm.StartTransaction()

 

    ''  select a space

   

    Dim selOpt As New Autodesk.AutoCAD.EditorInput.PromptEntityOptions("Select a space")

    selOpt.SetRejectMessage("Not a space")

    selOpt.AddAllowedClass(GetType(Space), True)

 

    Dim selRes As PromptEntityResult = ed.GetEntity(selOpt)

    If selRes.Status <> PromptStatus.OK Then

      ed.WriteMessage("failed to get a space")

      Exit Sub

    End If

 

    ''  we got a space. Open it for read.

   

    Dim pSpace As Space = tr.GetObject(selRes.ObjectId, AcDb2.OpenMode.ForRead)

 

    Try

 

      ''  get a base profile

      Dim pProfile As Profile = pSpace.BaseProfile

      Dim ecsEnt As Matrix3d = pSpace.Ecs

 

      ''  loop through the rings.  The first one is outer most rings.

      For Each aRing As Ring In pProfile.Rings

        For Each aSeg As Segment2d In aRing.Segments

          ''  once you come to this point,

          ''  you can get information about each line segment. 

          ''  here we draw a temporary drawings.  see the helper function below. 

          displaySegment(aSeg, ecsEnt)

        Next

      Next

 

      tr.Commit()

 

    Catch ex As Exception

      ed.WriteMessage("Error in ShowSpaceProfile: " + ex.Message + vbLf)

      tr.Abort()

    Finally

      tr.Dispose()

    End Try

 

  End Sub

 

  ''  a helper function to display a segment in a temporary graphics

 

  Sub displaySegment(ByVal aSeg As Segment2d, ByVal ecsEnt As Matrix3d)

 

    Dim ed As Editor = Application.DocumentManager.MdiActiveDocument.Editor

 

    Dim pt1 As New Point3d(aSeg.StartPoint.X, aSeg.StartPoint.Y, 0.0)

    Dim pt2 As New Point3d(aSeg.EndPoint.X, aSeg.EndPoint.Y, 0.0)

    pt1 = pt1.TransformBy(ecsEnt)

 

    ''  draw a temporary graphics depending on if the given a segment is a line or curve.

    ''  if you have an arc, you can use bulge, or evaluate sub-divided points. 

    If aSeg.IsCurveCircularArc2d Then

      Dim n As Integer = 10 '' number of divisions to draw arc as a collection of lines.                         

      Dim dt As Double = (aSeg.EndParameter - aSeg.StartParameter) / n

 

      For i As Integer = 1 To n

        Dim pt As Point2d = aSeg.EvaluatePoint(i * dt)

        pt2 = New Point3d(pt.X, pt.Y, 0.0)

 

        pt2 = pt2.TransformBy(ecsEnt)

        ed.DrawVector(pt1, pt2, 1, True)

        pt1 = pt2

      Next

 

    Else

      pt2 = pt2.TransformBy(ecsEnt)

      ed.DrawVector(pt1, pt2, 5, True)

    End If

  End Sub

Refresh project navigator

By Mikako Harada

Issue

Using AutoCAD Architecture (ACA) .NET API, is there any way through the code to refresh the project navigator so that it will show the latest folder/files after I make a new drawing in my program? Alternatively, but less desirable, is there a function that will close then re-open the project navigator? This will seem to also have the side effect of refreshing the data.

Solution

ACA .NET Project API is not exposed to the level that we wish to have. Current usage is largely at the file system level, and API functionality which related UI is very limited. A workaround is to call a command _AecRefreshProject from your program. 

As an FYI, below is a summary of currently exposed API regarding Project API:

What you can do with Project API

• Able to create and work with projects
• All support is at the file system level
• No UI interaction and you must be careful to initiate API calls appropriately because the UI may not interact well with your API calls.

Project API's

• Autodesk.Aec.Project – The main project class.
• Autodesk.Aec.ProjectBaseManager – The system wide Project Manager. This contains many utility methods to manipulate projects.
• Autodesk.Aec.ProjectBaseServices – A helper class used to obtain the single ProjectBaseManager object.
• Autodesk.Aec.ProjectConfiguration – Contains information about the project (such as the name, description, and number).

UI Interaction from API requires the use of commands

• _AecProjectNavigator – This a documented command that will display the project navigator palette. If there is no "current" project, the command will also run the Project Browser dialog.
• _AecRefreshProject – This refreshes the palette. Note that the API has a different method to reload a project, but is different than this command. This command does the same as the refresh project button on the palette.
• _AecSetCurrentProject – This is an important command for the API user. This is currently the only way to properly set a project as current from the API.
• _AecCloseProjectNavigator – Closes the project navigator palette. Note it only closes the dialog and the same project is still open and current.
• _AecProjectNavigatorToggle – Simply toggles the project navigator palette on or off.

 

DimensionSegment.Suffix fails to set when the number of segments is one

By Mikako Harada

Issue

I'm trying to add suffix to a dimension through the DimensionSegment.Suffix property. When the dimension has multiple segments, it works. However, when the dimension is composed of a single segment, it fails. Is this a bug?

Solution

There is another property Suffix at the Dimension level (as opposed to DimensionSegment level). When there is only one segment in the given dimension, you will need to use Dimension level Suffix property. This is as designed (although one might question about design...).

Create new type

By Joe Ye

In many cases, we would like to create new types, for instance dimension type, and use different font, color... It is not possible for developers to find methods in Autodesk.Revit.Creation.Document class to do that. Then how to create new type then?

Normally Revit document resident elements are created via the methods in Autodesk.Revit.Creation.Document class. However there is no method in this class to create new types, for example, DimensionType, WallType, FloorType...
The way to create new Revit types is different from other elements. Type class provides Duplicate(string name) method to create new types . It is this method that we can use to duplicate a new type, which has the same parameter values and property values but different name from the original type. Then changing the new type's parameters and properties to what you want.

Here is the code to show the steps to create a new DimensionType object.

 

[TransactionAttribute(TransactionMode.Manual)]

[RegenerationAttribute(RegenerationOption.Manual)]

public class RevitCommand : IExternalCommand

{

  public Result Execute(ExternalCommandData commandData,

     ref string messages, ElementSet elements)

  {

    UIApplication app = commandData.Application;

    Document doc = app.ActiveUIDocument.Document;

 

    //get a exising dimension type.

    FilteredElementCollector collector ;

    collector = new FilteredElementCollector(doc);

    collector.OfClass(typeof(DimensionType));

    DimensionType dimType = null;

    foreach (Element elem in collector)

    {

 

      if (elem.Name == "Linear Dimension Style")

      {

        dimType = elem as DimensionType;

        break;

      }

    }

    DimensionType newType = dimType.Duplicate("NewType");

    if (newType != null)

    {

      Transaction trans = new Transaction(doc, "ExComm");

      trans.Start();

      newType.get_Parameter(BuiltInParameter.LINE_PEN).Set(2);

 

      //You can change more here.

 

      doc.Regenerate();

      trans.Commit();

    }

    return Result.Succeeded;

  }

}