Through the Interface

June’s Plugin of the Month: Dimension Patrol

Thanks again to Stephen Preston, our DevTech Americas Manager, for developing this very useful little utility. You can find an earlier version of this code – which I’d converted to C# and extended to cover text entities – in this previous post.

June’s Plugin of the Month is now live: Dimension Patrol for AutoCAD. This one was kicked off by a suggestion from Shaan Hurley: a tool for designers and CAD Managers to quickly check drawings for dimensions with overridden text (which, logically enough, could mean the dimensions no longer accurately reflect their associated distance or value).

Sometimes the best applications are the simplest, and this one is certainly elegant in its simplicity. To be fair, though, it’s depending on the Overrule mechanism introduced in AutoCAD 2010 - hence the requirement to use AutoCAD 2010 or above – which provides you with a great deal of control over object behaviour.

Here are the important VB.NET source files from the project (which is, of course, provided with the plugin’s download from Labs).

Firstly the myPlugin.vb file:

Imports System

Imports Autodesk.AutoCAD.Runtime

Imports Autodesk.AutoCAD.ApplicationServices

Imports Autodesk.AutoCAD.DatabaseServices

Imports Autodesk.AutoCAD.Geometry

Imports Autodesk.AutoCAD.EditorInput

 

' This line is not mandatory, but improves loading performance

 

<Assembly: ExtensionApplication(GetType(DimensionPatrol.MyPlugin))>

 

Namespace DimensionPatrol

 

  ' This class is instantiated by AutoCAD once and kept alive for

  '  the duration of the session.

 

  Public Class MyPlugin

    Implements IExtensionApplication

 

    ' Declare member variables - note they are Shared

    '  (don't require class instance to access them)

 

    Private Shared mOverrule As DimPatrolDrawOverrule

    Private Shared WithEvents mDocs As DocumentCollection

    Private Shared mOldOverruleState As Boolean

 

    Private Shared ReadOnly Property DimPatrolVal() As Short

      Get

        Return MyCommands.DimPatrolVal

      End Get

    End Property

 

    Private Shared ReadOnly Property DimPatrolColVal() As Short

      Get

        Return MyCommands.DimPatrolColVal

      End Get

    End Property

 

    ' Called by AutoCAD to initialize the addin.

    ' This is where we setup our overrule.

 

    Public Sub Initialize() _

      Implements IExtensionApplication.Initialize

 

      Try

 

        ' Add demand loading info to registry

 

        DemandLoading.RegistryUpdate.RegisterForDemandLoading()

 

        ' Initialize 'withevents' variables to activate events

 

        mDocs = Application.DocumentManager

 

        ' Register overrule

 

        mOverrule = New DimPatrolDrawOverrule

        Overrule.AddOverrule(RXObject.GetClass(GetType(Dimension)), _

                            mOverrule, False)

        mOverrule.SetCustomFilter()

        mOldOverruleState = Overrule.Overruling

        Overrule.Overruling = True

 

        ' In case this app is loaded midway through a session,

        '  we need to honor values of DimPatrol and DimPatrolColor

        '  and setup the current document

 

        UpdateDoc(mDocs.MdiActiveDocument)

 

      Catch ex As Autodesk.AutoCAD.Runtime.Exception

 

        CleanUp(ex)

 

      End Try

 

    End Sub

 

    ' Our addin only terminates when AutoCAD quits -

    '  you can't dynamically unload .NET DLLs.

    ' (So one could argue that this tidy up is unnecessary).

 

    Public Sub Terminate() Implements IExtensionApplication.Terminate

 

      CleanUp(Nothing)

 

    End Sub

 

    ' Tidy up our stuff (unregister overrules etc).

    ' Called by Terminate method, and also in response to an

    '  exception to disable addin if there's a problem.

 

    Private Shared Sub CleanUp(ByVal ex As  _

                              Autodesk.AutoCAD.Runtime.Exception)

 

      ' If this is being called by an exception handler,

      '  then we politely inform user of the problem.

 

      If Not ex Is Nothing Then

        MsgBox("Dimension Patrol has encountered an error and " & _

              "is disabling itself.", MsgBoxStyle.Critical, "Oops!")

      End If

 

      ' Deactivate event handlers

 

      mDocs = Nothing

 

      ' Unregister overrule

 

      If Not mOverrule Is Nothing Then

        Overrule.RemoveOverrule( _

          RXObject.GetClass(GetType(Dimension)), mOverrule)

      End If

 

      ' We assume here that no other addin that uses overrules was

      '  loaded since our addin initialized.

 

      Overrule.Overruling = mOldOverruleState

 

    End Sub

 

 

    ' Called by  myCommands class to tell this class that value of

    '  DimPatrolColor variable has changed.

    ' (That's why its a Friend method)

 

    Friend Shared Sub DimPatColorVar_Changed()

 

      Try

 

        Dim doc As Document = _

          Application.DocumentManager.MdiActiveDocument

 

        ' Set stored value of color for this document so we know

        '  color change has been processed for this doc.

 

        Dim oldDimPatColVal As Short = _

          UpdateDocData(doc, "DimPatrolColor", DimPatrolColVal)

 

        ' Regen drawing if color has changed & DimPatrol sysvar = 1

        ' (Color changes while we're not drawing our custom graphics

        '  don't have any effect until DimPatrol is next changed and

        '  this doc is active/activated).

 

        If (DimPatrolVal) And (oldDimPatColVal <> DimPatrolColVal) _

          Then

          doc.Editor.Regen()

        End If

 

      Catch ex As Autodesk.AutoCAD.Runtime.Exception

        CleanUp(ex)

      End Try

 

    End Sub

 

    ' Called by  myCommands class to tell this class that value of

    '  DimPatrolColor variable has changed

    ' (That's why its a Friend method)

 

    Friend Shared Sub DimPatVar_Changed()

 

      Try

 

        ' Update active document with new value of DimPatrol to show

        '  we've regened it since the value was last changed

 

        Dim doc As Document = _

          Application.DocumentManager.MdiActiveDocument

        UpdateDocData(doc, "DimPatrol", DimPatrolVal)

 

        ' Whatever else happens, if we've changed the value of

        '  DimPatrol then we must regen the current document to

        '  display changed graphics.

 

        doc.Editor.Regen()

 

      Catch ex As Autodesk.AutoCAD.Runtime.Exception

        CleanUp(ex)

      End Try

 

    End Sub

 

 

    ' When user switches document we want to respond to possible

    '  changes to DimPatrol and DimPatrolColor in that document

 

    Private Shared Sub mDocs_DocumentActivated(ByVal sender As _

      Object, ByVal e As Autodesk.AutoCAD.ApplicationServices. _

      DocumentCollectionEventArgs) Handles mDocs.DocumentActivated

 

      Try

 

        UpdateDoc(e.Document)

 

      Catch ex As Autodesk.AutoCAD.Runtime.Exception

        CleanUp(ex)

      End Try

 

    End Sub

 

    ' Updates userdata key 'varName' in document 'doc' to value 'val'

    ' Returns old value (or 0 if there wasn't an old value)

 

    Private Shared Function UpdateDocData(ByVal doc As Document, _

      ByVal varName As String, ByVal val As Short) As Short

 

      Dim oldVal As Short

 

      If doc.UserData.ContainsKey(varName) Then

 

        ' Update value of key-value pair

 

        oldVal = doc.UserData.Item(varName)

        If oldVal <> val Then

          doc.UserData.Item(varName) = val

        End If

      Else

 

        ' Add key-value pair if it didn't exist

 

        doc.UserData.Add(varName, val)

        oldVal = 0

      End If

 

      Return oldVal

 

    End Function

 

 

    ' Check userdata attached to document (where we store value of

    '  DimPatrol and DimPatrolColor when doc was last active).

    ' If userdata isn't there, or if it differs from current values,

    '  then we must regen the drawing.

 

    Private Shared Sub UpdateDoc(ByVal doc As Document)

 

      ' Update old DimPatrol value to show changes to this doc have

      '  been processed

 

      Dim oldDimPatVal As Short = UpdateDocData(doc, "DimPatrol", _

                                                DimPatrolVal)

 

      ' Update old DimPatrolColor value to show changes to this doc

      '  have been processed

 

      Dim oldDimPatColVal As Short = UpdateDocData(doc, _

        "DimPatrolColor", DimPatrolColVal)

 

      ' If DimPatrol sysvar has changed, or DimPatrolColor has

      '  changed when DimPatrol = 1, then we must regen the drawing

 

      If (oldDimPatVal <> DimPatrolVal) Or ((DimPatrolVal) And _

        (oldDimPatColVal <> DimPatrolColVal)) Then

 

        doc.Editor.Regen()

      End If

 

    End Sub

  End Class

 

 

    ' This is the one and only overrule used by this utility

 

  Public Class DimPatrolDrawOverrule

    Inherits Autodesk.AutoCAD.GraphicsInterface.DrawableOverrule

 

    ' Overrule WorldDraw so we can draw our additional graphics

    '  (solid color block covering the Dimension's extents)

 

    Public Overrides Function WorldDraw(ByVal drawable As  _

      Autodesk.AutoCAD.GraphicsInterface.Drawable, _

      ByVal wd As Autodesk.AutoCAD.GraphicsInterface.WorldDraw) _

      As Boolean

 

      Try

 

        ' We know this overrule is only registered for Dimensions,

        '  so we cast without checking.

 

        Dim dm As Dimension = drawable

 

        ' Now we want to draw a colored box around Dimension's

        '  extents()

 

        Dim ext As Extents3d = dm.Bounds

        Dim maxPt As Point3d = ext.MaxPoint

        Dim minPt As Point3d = ext.MinPoint

        Dim pts As New Point3dCollection

 

        ' These are the vertices of the highlight box

 

        pts.Add(New Point3d(minPt.X, minPt.Y, minPt.Z))

        pts.Add(New Point3d(minPt.X, maxPt.Y, minPt.Z))

        pts.Add(New Point3d(maxPt.X, maxPt.Y, minPt.Z))

        pts.Add(New Point3d(maxPt.X, minPt.Y, minPt.Z))

 

        ' Store current filltype and set to FillAlways

 

        Dim oldFillType As  _

          Autodesk.AutoCAD.GraphicsInterface.FillType = _

          wd.SubEntityTraits.FillType

        wd.SubEntityTraits.FillType = _

          Autodesk.AutoCAD.GraphicsInterface.FillType.FillAlways

 

        ' Store old graphics color and set to the color we want

 

        Dim oldColor As Short = wd.SubEntityTraits.Color

        wd.SubEntityTraits.Color = MyCommands.DimPatrolColVal

 

        ' Draw the filled polygon

 

        wd.Geometry.Polygon(pts)

 

        ' Restore old settings

 

        wd.SubEntityTraits.FillType = oldFillType

        wd.SubEntityTraits.Color = oldColor

 

      Catch ex As Autodesk.AutoCAD.Runtime.Exception

 

        ' Mop up any exception here so at least the Dimension can try

        '  to draw itself

 

        Application.DocumentManager.MdiActiveDocument.Editor. _

        WriteMessage( _

          vbLf & "Error highlighting changed dimension: " _

          & ex.ErrorStatus.ToString & vbLf)

      End Try

 

      ' Let the overruled Drawable draw itself.

 

      Return MyBase.WorldDraw(drawable, wd)

 

    End Function

 

    ' This function is called if we call SetCustomFilter on our

    '  overrule to check if the overrule should be applied for each

    ' entity.

    ' We add our own code to return true if the Dimension passed in

    '  is one we want to highlight.

 

    Public Overrides Function IsApplicable( _

      ByVal overruledSubject As RXObject) As Boolean

 

      Try

 

        ' If its a Dimension, we check if the text has been manually

        '  changed. But only if DimPatrol sysvar is set to 1

 

        If (MyCommands.DimPatrolVal) And _

          (TypeOf overruledSubject Is Dimension) Then

 

          Dim dm As Dimension = overruledSubject

          If dm.DimensionText <> "" Then

            Return True

          End If

        End If

 

      Catch ex As Autodesk.AutoCAD.Runtime.Exception

 

        ' Mop up any exception here so at least the Dimension can try

        '  to draw itself

 

        Application.DocumentManager.MdiActiveDocument.Editor. _

        WriteMessage(vbLf & "Error testing dimension: " _

                    & ex.ErrorStatus.ToString & vbLf)

      End Try

 

      ' We only get to here if object isn't a Dimension and it didn't

      '  contain overridden text

 

      Return False

 

    End Function

 

  End Class

 

End Namespace

And secondly the myCommands.vb file:

Imports System

Imports Autodesk.AutoCAD.Runtime

Imports Autodesk.AutoCAD.ApplicationServices

Imports Autodesk.AutoCAD.DatabaseServices

Imports Autodesk.AutoCAD.Geometry

Imports Autodesk.AutoCAD.EditorInput

 

' This line is not mandatory, but improves loading performance

 

<Assembly: CommandClass(GetType(DimensionPatrol.MyCommands))>

 

Namespace DimensionPatrol

 

  ' Container class for our commands

  ' All methods and properties in this class are Shared,

  '  so this class is never instantiated by AutoCAD.

 

  Public Class MyCommands

 

    ' Member variables to store values of DIMPATROL and

    ' DIMPATROLCOLOR

 

    Private Shared mDimPatrol As Short = 0

    Private Shared mDimPatrolColor As Short = 1

 

    ' This property is also used by MyPlugin and

    ' DimPatrolDrawOverrule - hence use of 'Friend'

 

    Friend Shared Property DimPatrolVal() As Short

 

      Get

        Return mDimPatrol

      End Get

 

      Private Set(ByVal value As Short)

 

        mDimPatrol = value

 

        ' Tell MyPlugin that value of DimPatrol has changed

 

        MyPlugin.DimPatVar_Changed()

 

      End Set

 

    End Property

 

    ' This property is also used by MyPlugin and

    ' DimPatrolDrawOverrule - hence use of 'Friend'

 

    Friend Shared Property DimPatrolColVal() As Short

 

      Get

        Return mDimPatrolColor

      End Get

 

      Private Set(ByVal value As Short)

 

        mDimPatrolColor = value

 

        ' Tell MyPlugin that value of DimPatrolColor has changed

 

        MyPlugin.DimPatColorVar_Changed()

 

      End Set

 

    End Property

 

 

    ' Turn dimension patrol on (1) or off (0)

 

    <CommandMethod("ADNPLUGINS", "DIMPATROL", CommandFlags.Modal)> _

    Public Shared Sub DIMPATROL()

 

      Try

 

        ' Prompt for new value

 

        Dim ed As Editor

        ed = Application.DocumentManager.MdiActiveDocument.Editor

        Dim opts As New  _

          PromptIntegerOptions("Enter new value for DIMPATROL")

        opts.DefaultValue = DimPatrolVal

        opts.LowerLimit = 0

        opts.UpperLimit = 1

        Dim res As PromptIntegerResult = ed.GetInteger(opts)

 

        ' Only update stored value if user has entered a different

        '  value()

 

        If (res.Status = PromptStatus.OK) _

          And (res.Value <> DimPatrolVal) Then

 

          DimPatrolVal = res.Value

 

        End If

 

      Catch ex As Autodesk.AutoCAD.Runtime.Exception

        Application.DocumentManager.MdiActiveDocument. _

          Editor.WriteMessage( _

            vbLf & "Error changing DIMPATROL value: " & _

            ex.ErrorStatus.ToString & vbLf)

      End Try

 

    End Sub

 

 

    ' Allow user to set highlight color for manually edited

    ' dimensions. Color index can be set within range 1-7.

 

    <CommandMethod("ADNPLUGINS", "DIMPATROLCOLOR", _

                  CommandFlags.Modal)> _

    Public Shared Sub DIMPATROLCOLOR()

 

      Try

 

        ' Prompt for new value

 

        Dim ed As Editor

        ed = Application.DocumentManager.MdiActiveDocument.Editor

        Dim opts As New  _

          PromptIntegerOptions("Enter new value for DIMPATROLCOLOR")

        opts.DefaultValue = DimPatrolColVal

        opts.LowerLimit = 1

        opts.UpperLimit = 7

        Dim res As PromptIntegerResult = ed.GetInteger(opts)

 

        ' Only update stored value if user has entered a different

        '  value

 

        If (res.Status = PromptStatus.OK) _

          And (res.Value <> DimPatrolColVal) Then

 

          DimPatrolColVal = res.Value

 

        End If

 

      Catch ex As Autodesk.AutoCAD.Runtime.Exception

        Application.DocumentManager.MdiActiveDocument.Editor. _

          WriteMessage( _

            vbLf & "Error changing DIMPATROLCOLOR value: " _

            & ex.ErrorStatus.ToString & vbLf)

      End Try

 

    End Sub

 

 

    'Remove demand load settings from registry

 

    <CommandMethod("ADNPLUGINS", "REMOVEDP", CommandFlags.Modal)> _

    Public Shared Sub RemoveDP()

 

      DemandLoading.RegistryUpdate.UnregisterForDemandLoading()

 

      Dim ed As Editor = _

        Autodesk.AutoCAD.ApplicationServices.Application _

        .DocumentManager.MdiActiveDocument.Editor()

      ed.WriteMessage(vbCr + _

        "Dimension Patrol will not be loaded" _

        + " automatically in future editing sessions.")

 

    End Sub

 

  End Class

 

End Namespace

We can set the DIMPATROL value to 1 to turn on checking for problematic dimensions. Here’s are some problematic dimensions from an Xrefed drawing (which is why the red is slightly dimmed):

There’s still time to fill out the 2010 API wishlist surveys

As mentioned in this previous post, the following API wishlist surveys are currently live:

AutoCAD®
AutoCAD® Civil 3D®
AutoCAD® Map 3D®
Revit®
Autodesk Inventor®
Autodesk Navisworks®

We’ve had around 500 responses across the various surveys, but to give a few more people the chance to respond, we’ve extended the deadline until June 11th, 2010.

To give you an idea of how the voting is looking so far, here’s a summary of the responses against the survey’s “money” question (5. From the following list of possible AutoCAD API enhancements, please choose three areas that you recommend we make our top priority for the next release or two of AutoCAD.):

Using Photosynth to generate a few sparse point clouds

While on my way to San Francisco, last weekend, I had a 7-hour layover in Washington D.C. Given the amount of time available to me I decided to head from Dulles into the centre of the city and do something fun: I ended up choosing to visit the Natural History Museum at The Smithsonian, which proved to be really interesting even to my somewhat bleary eyes.

Part of my motivation was to try to capture something for bringing into Photosynth (as I’d borrowed my wife’s digital SLR for taking some snaps at the wedding I was attending in Las Vegas). I’m becoming increasingly fascinated with the field of computer vision (I’ve talked in the past about some of the possibilities it brings to our industry), and am doing what I can to get to know more about it, which will prove especially important if I end up talking about it at AU.

Before I show – and talk about – the results of these efforts, here are the basic steps for creating a Photosynth.

Firstly you clearly need to take pictures. I won’t give much advice on how to do this – as I seem not to be getting the best results, myself – but the trick appears to be to make sure you take enough pictures of a chosen target that has a lot of “features” which can be matches between these images. A point needs to be shared across a minimum of three photos taken from different angles, it seems, for it to be coordinated properly in 3D space.

Once you have a set of snaps, go to the Photosynth website and select the “Upload” button at the top-right of the page followed by the “Create a Synth” button on the following page (at you will need to log in via your Microsoft Live login). You should see a UI allowing you to select images and name your synth:

Once you’ve specified basic information for your synth and have selected the photos to use, you can choose the “Synth” button, which will fire off a sequence of operations:

 

Now despite the fact that there’s a web service providing access to Photosynth data, a lot of the heavy lifting needed to create the synth (such as extracting the image features and matching them across the various images) is performed in the “Synther” part of the Photosynth client, while the photos themselves are being uploaded: a systems architecture apparently known as edge computing. While in some ways being an efficient use of computing resources, this approach does appear to limit the ability to just use the web service to create synths – something I would love to do – which is a shame. [If someone is able to tell me I’m wrong about this, I’ll very happily buy them a beer. :-)]

It’s also important to note that the algorithm used to match features between images is non-linear – in this case each image needs to be compared with each of the others, from what I understand, which makes it an n-squared problem – so you will see the time taken get proportionally longer as you add images to your set. I’m very interested as to why the decision was made to run these operations locally, rather than to just throw them at “the cloud”. Perhaps the economics behind a potentially high-usage service such as Photosynth doesn’t/didn’t lend itself to performing such operations centrally, and that it makes sense for the client to take a share of the burden.

I created a few synths of skeletons from images taken at The Smithsonian:

Oh deer A skinny bird A scary looking beast

None of these synths came out especially well, in my opinion: they have quite low “synthiness” scores, which reflects how many of the images contributed to the point cloud, probably because I felt a bit foolish taking more than 30 or so pictures of any one thing in a museum and also the varying effects of the flash probably hampered the ability to stitch these images together.

One more thing to bear in mind: Photosynth really only provides a “sparse” point cloud – the points needed to help coordinate the camera positions of the various images. It’s clearly possible to sample more points to create a more dense cloud once you have accurate camera positions, but this isn’t currently the focus of the Photosynth service, and so expectations should be set appropriately. That’s not to say it’s not possible to create clouds of 1M+ points using Photosynth – I’ve seen that happen – but it really takes a lot of dedication to get up to that level of detail.

As Blaise Aguera y Arcas states, it’s possible to densify point clouds coming out of systems such as Photosynth – by using tools such as MVSCPC – but for that you need that camera location information (which does appear to be accessible, based on the latest version of Christoph Hausner’s exporter). Just as point clouds are really only a by-product of Photosynth, for a 3D editing system with computer vision/photogrammetry integrated more closely, the need to make use of the base point cloud is reduced: you could be generating a mesh or even some more appropriate 3D geometry instead.

Near the end of my week in the Bay Area, I spent some time chatting about this field with Brian Mathews, the VP of Autodesk Labs. Brian is a scarily bright fellow with deep insights into many different areas of technology. To demo something his team is working on – once again, watch this space :-) – he took a set of photos that I’ve also uploaded into Photosynth:

Kean’s head

To get a feel for the results, here’s a screenshot of the point cloud inside AutoCAD. You can try this yourself using the Photosynth import plugin I’ve shown in recent posts. It’s a very light point cloud – just 9,425 points from the 31 source images – but at least it looks like me from a distance. :-)

Thanks to Nate Lawrence for pointing me at a related discussion on some of the above issues (I’d been planning a post along these lines, but when Nate pinged me it reminded me of some relevant resources he listed therein).

The end of a very interesting week

One of my oldest friends – we’ve known each other since we were three years old – decided to get married in Las Vegas this week. My friend, his fiancée and his parents flew across from the UK, but others of us flew across from Switzerland and even New Zealand to attend the event.

Now between Autodesk University and other events, I’ve probably averaged a week in Las Vegas a year for the last decade. So I didn’t really want to spend a full week in Vegas, but neither did I want to make the trip across for just a couple of days. I ended up choosing to fly across to San Francisco and spend a few days there either side of the wedding – from there I flew out to Vegas on Tuesday evening and came back on Thursday morning, which ended up being just about perfect, timing-wise.

The week itself went very well: aside from the time in Vegas I managed to spend some really good time with members of the ADN team in San Rafael, as well as members of our Engineering teams between San Rafael and San Francisco. Some of the information I’ve received – especially that related to some interesting technology soon to be available on Autodesk Labs – I’ll be sharing in the coming weeks, so watch this space.

Now while I don’t travel as much as some people, I do it enough to believe I’m usually efficient about it. Today, however, I messed up quite badly. When travelling purely for work I use our corporate travel booking system and *always* check in online in advance of the flight. As this was a personal trip, I booked it via a local, online ticket site, and got a fairly restrictive ticket – and accordingly priced – ticket. All of which would have been fine, but for some reason this ticket did not come with the ability to check in online, only at the airport. That, coupled with the fact that I was “on the home stretch” and had finished a busy (but very productive) week, led to me mistiming my arrival at the airport: I somehow managed to misread my itinerary and planned my arrival at SFO for the time my onward flight was due to be leaving Dulles (Washington D.C.). I realised my mistake at exactly the time my first flight was departing from SFO – and I was still hours from the airport.

United Airlines were very helpful: they explained my ticket was valid to be changed – for a fee, understandably – but only for exactly the same routing. The only problem being the next available combination of flights to get me back to Geneva was on Tuesday, which would have been a big problem from a personal perspective. It seemed my options were to wait until Tuesday or to buy a new ticket (United said a one-way ticket would cost around $3,000, although a quick check online confirmed cheaper options were available – I’d probably be able to get a flight back with a different company for $1,500).

With the (somewhat small) comfort that I at least knew the worst-case scenario, I headed for the airport. I arrived at about 11:30am, and it was nearly noon by the time I saw a ticketing agent. Thankfully United came through: just while I was at the counter a seat became available on the 1pm to Dulles, and they were also able to book me on tomorrow’s red-eye from IAD to GVA.

I had just enough time to get through security, buy some food for the flight and then go online and book a room for the night in Washington. And for some reason – despite the flight being close to full – I ended up being seated on my own in an exit aisle. So all’s well that (nearly, anyway) ends well.

Monday’s a holiday in Neuchatel and I’m taking another day off on Tuesday to spend time with my family, so please expect a few more days of radio silence: unless I manage to write something while I’m staying overnight in Washington I’ll be back online later in the week.

Voting open for AU 2010 sessions

I’ve submitted three sessions for this year’s Autodesk University:

Getting to know AutoCAD's Plugins of the Month (a 60-minute virtual class, session ID 1681)

Synopsis:

The Autodesk Developer Network (ADN) team has been publishing "Plugins of the Month" on Autodesk Labs for over a year. Each of these plugins extends an Autodesk products in a useful or interesting way, and is provided with full source code! Attend this session for an introduction to the various AutoCAD plugins that have been published (with a brief mention of those published for other products). We will take a detailed look at the source code of a few of the most popular plugins, to help explain their architecture and implementation.

Learning objectives:

• Understand the reasons for the "Plugin of the Month" initiative
• Get to know the various plugins that are available, as well as how to install and use them
• See how to run the plugins from the Visual Studio debugger to aid learning
• Gain familiarity with the structure of the plugins' source projects, to help with extending them for your own purposes
• Understand the mechanics behind a few of the published plugins

Target audience:

AutoCAD users with an interest in learning more about programming, and how they might use .NET to tailor AutoCAD to their specific business needs.

Point clouds on a shoestring (a 60-minute lecture, session ID 1670)

Synopsis:

Always wanted to play around with point clouds but your boss won't buy you an expensive laser scanner? Come along to this entertaining session to see how it's possible to use *free* technology - such as Microsoft's Photosynth - to generate 3D point clouds from 2D photographs. See a live demonstration of a real-world object being "captured" using nothing but a digital SLR and brought into AutoCAD 2011 as a 3D point cloud. We will also spend some time looking at AutoCAD 2011's point cloud capabilities and the state of "reality capture" technology in the industry. A separate session by the same presenter in the Customization & Programming track will take a look under the hood of the technology shown in this session.

Learning objectives:

• Understand how free services such as Microsoft's Photosynth can generate 3D point clouds from sets of 2D photos
• See how you can bring community-generated point clouds into AutoCAD
• Watch the process of capturing a point cloud from a real-world object simply by taking and uploading a set of photos
• Learn about AutoCAD 2011's point cloud capabilities
• Get to know more about the state of the industry regarding "reality capture" (laser scanning, photogrammetry, etc.)

Target audience:

Anyone interested in learning about point clouds and seeing how they can be generated and used - for free - with tools such as Microsoft Photosynth and AutoCAD 2011.

Integrate F# into your C# or VB.NET application for an 8x performance boost (a 60-minute lecture, session ID 5899)

Synopsis:

Come to this session to understand how F#, the new programming language from Microsoft, can be used to achieve huge performance gains in applications managing multiple, asynchronous tasks. We'll start by taking a look at the architecture of the sample shown in the "Point clouds on a shoestring" session, understanding how the application was designed to download and process multiple "point cloud" files from Microsoft's Photosynth web service. We'll see how the introduction of F# into this application boosted the performance by 8 times. While taking a look under the hood of the "Point clouds on a shoestring" application, we'll discuss the benefits of using the Windows Presentation Foundation (WPF) when designing a modern GUI. We'll also spend time looking at additional techniques such as the use of an advanced browser component to monitor HTTP traffic during a browsing session and isolating a modeless UI in a separate executable to increase portability across 32- and 64-bit platforms.

Learning objectives:

• Find out how to combine C# and F# in the same .NET application
• Understand how F# can be used to speed up parallel or asynchronous tasks
• See the benefits of using WPF to create a modern graphical user interface
• Learn how the csExWb2 component can be used to monitor HTTP traffic during an embedded browsing session
• Get a feel for the "reality capture" capabilities of services such as Microsoft's Photosynth

Target audience:

VB.NET/C# developers who are interested in learning about the benefits of F#. Attendees of the "Point cloud on a shoestring" session who are not programmers themselves but are interested in a deeper look at the application should be prepared to sit through some in-depth technical discussions.

If you find these topics interesting, and are eligible to vote for online classes (and I admit I’m not sure on the eligibility criteria), please do so at the online voting site, which will remain open until this Friday, May 21st.

Adding keyword handling to AutoCAD .NET’s GetSelection()

I received this question by email over the weekend:

How does the Editor-Method GetSelection works with Keywords. I can’t get it to work and there are no information found in the internet (nothing in your blog, nothing in forums).

Here’s some C# code that does just this:

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.EditorInput;

using Autodesk.AutoCAD.Runtime;

 

namespace MyApplication

{

  public class Commands

  {

    [CommandMethod("SELKW")]

    public void GetSelectionWithKeywords()

    {

      Document doc =

        Application.DocumentManager.MdiActiveDocument;

      Editor ed = doc.Editor;

 

      // Create our options object

 

      PromptSelectionOptions pso =

        new PromptSelectionOptions();

 

      // Add our keywords

 

      pso.Keywords.Add("FIrst");

      pso.Keywords.Add("Second");

 

      // Set our prompts to include our keywords

 

      string kws = pso.Keywords.GetDisplayString(true);

      pso.MessageForAdding =

        "\nAdd objects to selection or " + kws;

      pso.MessageForRemoval =

        "\nRemove objects from selection or " + kws;

 

      // Implement a callback for when keywords are entered

 

      pso.KeywordInput +=

        delegate(object sender, SelectionTextInputEventArgs e)

        {

          ed.WriteMessage("\nKeyword entered: {0}", e.Input);

        };

 

      // Finally run the selection and show any results

 

      PromptSelectionResult psr =

        ed.GetSelection(pso);

 

      if (psr.Status == PromptStatus.OK)

      {

        ed.WriteMessage(

          "\n{0} object{1} selected.",

          psr.Value.Count,

          psr.Value.Count == 1 ? "" : "s"

        );

      }

    }

  }

}

When we run the SELKW command (after building the code into a DLL and NETLOADing it), we see a fairly classic selection prompt with our keywords enabled:

Command: SELKW

Add objects to selection or [FIrst/Second]: Specify opposite corner: 12 found

Add objects to selection or [FIrst/Second]: FI

Keyword entered: FIrst

Add objects to selection or [FIrst/Second]: S

Keyword entered: Second

Add objects to selection or [FIrst/Second]: Third

*Invalid selection*

Expects a point or

Window/Last/Crossing/BOX/ALL/Fence/WPolygon/CPolygon/Group/Add/Remove/Multiple/Previous/Undo/AUto/SIngle

Add objects to selection or [FIrst/Second]: R

Remove objects from selection or [FIrst/Second]: Specify opposite corner: 3 found, 3 removed, 9 total

Remove objects from selection or [FIrst/Second]: FI

Keyword entered: FIrst

Remove objects from selection or [FIrst/Second]: S

Keyword entered: Second

Remove objects from selection or [FIrst/Second]: Third

*Invalid selection*

Expects a point or

Window/Last/Crossing/BOX/ALL/Fence/WPolygon/CPolygon/Group/Add/Remove/Multiple/Previous/Undo/AUto/SIngle

Remove objects from selection or [FIrst/Second]:

9 objects selected.

I chose “FI” as the shortcut for “First” to avoid a conflict with the standard selection process’ “Fence” option. It doesn’t make sense to set a default keyword, as in any case the act of using the Enter key terminates the selection rather than causing a default keyword to be selected. We can see that when the two valid keywords are entered, our KeywordInput event is fired, but that when an invalid keyword (such as “Third”) is entered, a prompt is displayed explaining the default keyword options. To get different behaviour you can implement pso.InvalidInput (at which point you might, for instance, complement the core selection keywords with your own before presenting them to the user).

Populating a tree view inside AutoCAD with sheet set data using .NET - Part 2

I didn’t realise when I created the last post (with code borrowed from Fenton) that this would become a multi-part series – otherwise I’d clearly have called the earlier post “Part 1”. :-)

A comment from Harold Comerro requested information on getting more from the DST than was previously shown. Today’s post extends the previous code to create two different slices of the data: a “Sheets View” and a “Database View”, both hosted in the same palette set.

Here’s the updated C# code:

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.EditorInput;

using Autodesk.AutoCAD.Runtime;

using Autodesk.AutoCAD.Windows;

using acApp =

  Autodesk.AutoCAD.ApplicationServices;

using ACSMCOMPONENTS18Lib;

using System.Windows.Forms;

using System;

 

namespace MyApplication

{

  public class Commands

  {

    static PaletteSet ps = null;

    static UserControl1 sheetsControl = null;

    static UserControl1 dbControl = null;

 

    [CommandMethod("SSTREE")]

    public void PopulateCustomSheetTree()

    {

      // Check the state of the paletteset

 

      if (ps == null)

      {

        // Then create it

 

        ps = new PaletteSet("Custom Sheet Tree");

 

        // Create and add our "sheets" view

 

        sheetsControl = new UserControl1();

        ps.Add("Sheets View", sheetsControl);

        sheetsControl.treeView1.ShowNodeToolTips = true;

 

        // Create and add our "database" view

 

        dbControl = new UserControl1();

        ps.Add("Database View", dbControl);

        dbControl.treeView1.ShowNodeToolTips = true;

      }

 

      ps.Visible = true;

 

      // Get the AutoCAD Editor

 

      Editor ed =

        acApp.Application.DocumentManager.MdiActiveDocument.Editor;

 

      // Get the SheetSet Manager

 

      AcSmSheetSetMgr mgr = new AcSmSheetSetMgr();

 

      // Create a new SheetSet Database

 

      AcSmDatabase db = new AcSmDatabase();

 

      // Try and load a default DST file...

 

      try

      {

        db =

          mgr.OpenDatabase(

            @"C:\Program Files\Autodesk\AutoCAD 2011\Sample\" +

            @"Sheet Sets\Architectural\IRD Addition.dst",

            true

          );

      }

      catch (System.Exception ex)

      {

        ed.WriteMessage(ex.ToString());

        return;

      }

 

      // Lock the db for processing

 

      db.LockDb(db);

 

      // Create our root item in the "database" tree view

 

      TreeNode dbRoot = new TreeNode(db.GetFileName());

      dbControl.treeView1.Nodes.Add(dbRoot);

 

      // Process the items owned by the database

 

      try

      {

        ProcessItems(db, false, dbRoot);

      }

      catch { }

 

      // Create our root item in the "sheets" tree view

 

      AcSmSheetSet ss = db.GetSheetSet();

      TreeNode sheetsRoot = new TreeNode(ss.GetName());

      sheetsControl.treeView1.Nodes.Add(sheetsRoot);

 

      // Use the sheet enumerator to process the contents

 

      try

      {

        ProcessEnumerator(ss.GetSheetEnumerator(), true, sheetsRoot);

      }

      catch { }

 

      db.UnlockDb(db, true);

      mgr.Close(db);

 

      // Expand our trees

 

      sheetsControl.treeView1.ExpandAll();

      dbControl.treeView1.ExpandAll();

    }

 

    // A number of functions to take advantage of different

    // AcSm enumerator interfaces

 

    void ProcessEnumerator(

      IAcSmEnumComponent iter, bool useEnum, TreeNode root

    )

    {

      IAcSmComponent item = iter.Next();

      while (item != null)

      {

        ProcessItem(item, useEnum, root);

 

        item = iter.Next();

      }

    }

 

    void ProcessEnumerator(

      IAcSmEnumPersist iter, bool useEnum, TreeNode root

    )

    {

      IAcSmPersist pers = iter.Next();

      IAcSmComponent item = pers as IAcSmComponent;

      while (pers != null)

      {

        if (item != null)

          ProcessItem(item, useEnum, root);

 

        pers = iter.Next();

        item = pers as IAcSmComponent;

      }

    }

 

    void ProcessEnumerator(

      IAcSmEnumSheetSelSet iter, bool useEnum, TreeNode root

    )

    {

      IAcSmSheetSelSet selset = iter.Next();

      IAcSmComponent item = selset as IAcSmComponent;

      while (selset != null)

      {

        if (item != null)

          ProcessItem(item, useEnum, root);

 

        selset = iter.Next();

        item = selset as IAcSmComponent;

      }

    }

 

    void ProcessEnumerator(

      IAcSmEnumSheetView iter, bool useEnum, TreeNode root

    )

    {

      IAcSmSheetView shv = iter.Next();

      IAcSmComponent item = shv as IAcSmComponent;

      while (shv != null)

      {

        if (item != null)

          ProcessItem(item, useEnum, root);

 

        shv = iter.Next();

        item = shv as IAcSmComponent;

      }

    }

 

    // A function to loop through and process a set of

    // items via their ownership hierarchy

 

    void ProcessItems(

      IAcSmPersist pers, bool useEnum, TreeNode root

    )

    {

      System.Array arr;

      pers.GetDirectlyOwnedObjects(out arr);

      if (arr != null)

      {

        foreach (object obj in arr)

        {

          IAcSmPersist item = obj as IAcSmPersist;

          if (item != null)

            ProcessItem(item, useEnum, root);

        }

      }

    }

 

    // Our main processing function which is called by

    // all the others, sooner or later

 

    void ProcessItem(

      IAcSmPersist item, bool useEnum, TreeNode root

    )

    {

      string type = item.GetTypeName();

      switch (type)

      {

        case "AcSmDatabase":

          {

            AcSmDatabase db = (AcSmDatabase)item;

 

            TreeNode tn = AddTreeNode(root, "Database", type);

            if (useEnum)

            {

              IAcSmEnumPersist enumerator =

                db.GetEnumerator();

              ProcessEnumerator(enumerator, useEnum, tn);

            }

            else

            {

              ProcessItems(db, useEnum, tn);

            }

          }

          break;

 

        case "AcSmSheetSet":

          {

            AcSmSheetSet ss = (AcSmSheetSet)item;

 

            TreeNode tn = AddTreeNode(root, "Sheet set", type);

            if (useEnum)

            {

              IAcSmEnumComponent enumerator =

                (IAcSmEnumComponent)ss.GetSheetEnumerator();

              ProcessEnumerator(enumerator, useEnum, tn);

            }

            else

            {

              ProcessItems(ss, useEnum, tn);

            }

          }

          break;

 

        case "AcSmSheetSelSets":

          {

            AcSmSheetSelSets selsets = (AcSmSheetSelSets)item;

 

            TreeNode tn =

              AddTreeNode(root, "Sheet selection sets", type);

            IAcSmEnumSheetSelSet enumerator =

              selsets.GetEnumerator();

            ProcessEnumerator(enumerator, useEnum, tn);

          }

          break;

 

        case "AcSmSubset":

          {

            AcSmSubset subset = (AcSmSubset)item;

            string subName = subset.GetName();

 

            if (!String.IsNullOrEmpty(subName))

            {

              TreeNode tn = AddTreeNode(root, subName, type);

              IAcSmEnumComponent enumerator =

                (IAcSmEnumComponent)subset.GetSheetEnumerator();

              ProcessEnumerator(enumerator, useEnum, tn);

            }

          }

          break;

 

        case "AcSmSheet":

          {

            AcSmSheet sh = (AcSmSheet)item;

            string shName = sh.GetName();

 

            if (!String.IsNullOrEmpty(shName))

            {

              TreeNode tn = AddTreeNode(root, shName, type);

              if (useEnum)

              {

                AcSmSheetViews shvs = sh.GetSheetViews();

                ProcessItem(shvs, useEnum, tn);

              }

              else

              {

                ProcessItems(sh, useEnum, tn);

              }

            }

          }

          break;

 

        case "AcSmSheetViews":

          {

            AcSmSheetViews shvs = (AcSmSheetViews)item;

 

            TreeNode tn = AddTreeNode(root, "Sheet views", type);

            if (useEnum)

            {

              IAcSmEnumSheetView enumerator = shvs.GetEnumerator();

              ProcessEnumerator(enumerator, useEnum, tn);

            }

            else

            {

              ProcessItems(shvs, useEnum, tn);

            }

          }

          break;

 

        case "AcSmSheetView":

          {

            AcSmSheetView sv = (AcSmSheetView)item;

            string svName = sv.GetName();

 

            if (!String.IsNullOrEmpty(svName))

              AddTreeNode(root, svName, type);

          }

          break;

 

        case "AcSmViewCategories":

          {

            AcSmViewCategories cats = (AcSmViewCategories)item;

 

            TreeNode tn =

              AddTreeNode(root, "View categories", type);

            if (useEnum)

            {

              IAcSmEnumComponent enumerator =

                (IAcSmEnumComponent)cats.GetEnumerator();

              ProcessEnumerator(enumerator, useEnum, tn);

            }

            else

            {

              ProcessItems(cats, useEnum, tn);

            }

          }

          break;

 

        case "AcSmViewCategory":

          {

            AcSmViewCategory cat = (AcSmViewCategory)item;

            AddTreeNode(

              root,

              "View category: " + cat.GetName(),

              type

            );

          }

          break;

 

        case "AcSmCustomPropertyBag":

          {

            AcSmCustomPropertyBag bag =

              (AcSmCustomPropertyBag)item;

 

            TreeNode tn =

              AddTreeNode(root, "Custom property bag", type);

            if (useEnum)

            {

              IAcSmEnumComponent enumerator =

                (IAcSmEnumComponent)bag.GetPropertyEnumerator();

              ProcessEnumerator(enumerator, useEnum, tn);

            }

            else

            {

              ProcessItems(bag, useEnum, tn);

            }

          }

          break;

 

        case "AcSmCustomPropertyValue":

          {

            AcSmCustomPropertyValue pv =

              (AcSmCustomPropertyValue)item;

 

            AddTreeNode(

              root,

              "Custom property value: " + pv.GetValue().ToString(),

              type

            );

          }

          break;

 

        case "AcSmCalloutBlocks":

          {

            AcSmCalloutBlocks blks = (AcSmCalloutBlocks)item;

 

            TreeNode tn = AddTreeNode(root, "Callout blocks", type);

            if (useEnum)

            {

              IAcSmEnumComponent enumerator =

                (IAcSmEnumComponent)blks.GetEnumerator();

              ProcessEnumerator(enumerator, useEnum, tn);

            }

            else

            {

              ProcessItems(blks, useEnum, tn);

            }

          }

          break;

 

        case "AcSmCalloutBlockReferences":

          {

            AcSmCalloutBlockReferences refs =

              (AcSmCalloutBlockReferences)item;

 

            TreeNode tn =

              AddTreeNode(root, "Block references", type);

            if (useEnum)

            {

              IAcSmEnumComponent enumerator =

                (IAcSmEnumComponent)refs.GetEnumerator();

              ProcessEnumerator(enumerator, useEnum, tn);

            }

            else

            {

              ProcessItems(refs, useEnum, tn);

            }

          }

          break;

 

        case "AcSmAcDbBlockRecordReference":

          {

            AcSmAcDbBlockRecordReference brr =

              (AcSmAcDbBlockRecordReference)item;

 

            AddTreeNode(

              root,

              "Block record reference: " + brr.GetName(),

              type

            );

          }

          break;

 

        case "AcSmAcDbLayoutReference":

          {

            AcSmAcDbLayoutReference lr =

              (AcSmAcDbLayoutReference)item;

 

            AddTreeNode(

              root,

              "Layout reference: " + lr.GetName(),

              type

            );

          }

          break;

 

        case "AcSmFileReference":

          {

            AcSmFileReference fr = (AcSmFileReference)item;

 

            AddTreeNode(

              root,

              "Layout reference: " + fr.GetFileName(),

              type

            );

          }

          break;

 

        case "AcSmAcDbViewReference":

          {

            AcSmAcDbViewReference vr = (AcSmAcDbViewReference)item;

 

            AddTreeNode(

              root,

              "View reference: " + vr.GetName(),

              type

            );

          }

          break;

 

        case "AcSmObjectReference":

          {

            AcSmObjectReference or =

              (AcSmObjectReference)item;

 

            AddTreeNode(

              root,

              "Object reference: " +

              or.GetReferencedObject().GetTypeName(),

              type

            );

          }

          break;

 

        case "AcSmProjectPointLocations":

          {

            AcSmProjectPointLocations ppls =

              (AcSmProjectPointLocations)item;

 

            TreeNode tn =

              AddTreeNode(root, "ProjectPoint locations", type);

            if (useEnum)

            {

              IAcSmEnumComponent enumerator =

                (IAcSmEnumComponent)ppls.GetEnumerator();

              ProcessEnumerator(enumerator, useEnum, tn);

            }

            else

            {

              ProcessItems(ppls, useEnum, tn);

            }

          }

          break;

 

        case "AcSmPublishOptions":

          {

            AcSmPublishOptions opts = (AcSmPublishOptions)item;

 

            AddTreeNode(root, "Publish options", type);

          }

          break;

 

        case "AcSmResources":

          {

            AcSmResources res = (AcSmResources)item;

 

            TreeNode tn = AddTreeNode(root, "Resources", type);

            if (useEnum)

            {

              IAcSmEnumComponent enumerator =

                (IAcSmEnumComponent)res.GetEnumerator();

              ProcessEnumerator(enumerator, useEnum, tn);

            }

            else

            {

              ProcessItems(res, useEnum, tn);

            }

          }

          break;

 

        default:

          {

            Document doc =

              acApp.Application.DocumentManager.MdiActiveDocument;

            Editor ed = doc.Editor;

            ed.WriteMessage("\nMissed Type = " + type);

          }

          break;

      }

    }

 

    private TreeNode AddTreeNode(

      TreeNode root, string name, string tooltip

    )

    {

      // Create a new node on the tree view with a tooltip

 

      TreeNode node = new TreeNode(name);

      node.ToolTipText = tooltip;

 

      // Add it to what we have

 

      root.Nodes.Add(node);

      return node;

    }

  }

}

The code uses two different approaches for parsing the data: the first is via enumerators retrieved from the objects themselves (used by the “Sheets View”) and the second works purely via ownership (“Database View”). Each item’s tooltip shows the underlying COM class, to help understand the structure. I do agree with Tony that this approach – as you can see from the above code – does start to get unwieldy. With any luck I’ll provide a more streamlined approach to this in a future post in this series.

Let’s see what happens when we run the updated SSTREE command:

That’s it for today. Now that Tony has clarified a mistaken assumption in my last post, I expect I’ll take a look at implementing the UI via data-binding with WPF, when I get some time. This should also demonstrate the benefits of a more elegant approach to extracting and presenting the data.

More translated AutoCAD VBA to VB.NET Migration DevTVs

In this previous post I mentioned a couple of additional translations of the VBA migration DevTV that were in progress. Here is an updated list of the various ones we now have available, including links to German, Spanish and Japanese versions:

English	view	download (44.7 MB)
Chinese	view	download (88.9 MB)
French	view	download (39 MB)
Portuguese	view	download (80.3 MB)
Russian	view	download (39.3 MB)
German	view	download (42.4 MB)
Spanish	view	download (52.9 MB)
Japanese		MP4 download (66.9 MB) WMV download (78.5 MB)

A big thanks to Augusto Gonçalves, Jeremy Tammik, Shigekazu Saito and Katsuaki Takamizawa for their hard work on these additional sessions.

API wishlist surveys for Autodesk products

This year’s API wishlist surveys for the following products are now ready:

AutoCAD®
AutoCAD® Civil 3D®
AutoCAD® Map 3D®
Revit®
Autodesk Inventor®
Autodesk Navisworks®

My team runs these surveys year on year, and year on year Autodesk’s various Engineering teams deliver upon them (and not just AutoCAD’s). It really is worth providing us with your input: it’s one of the most direct ways to influence the direction of the Autodesk products you customize or for which you develop applications. Tell us which APIs are most important to you: your feedback will not fall on deaf ears. And if you (optionally) provide your email address in the survey, I’ll send you a copy of the results once they’ve been compiled.

The surveys will remain open until May 30th, 2010. Thanks in advance for your feedback!

Populating a tree view inside AutoCAD with sheet set data using .NET

A big thank you to Fenton Webb, from DevTech Americas, for providing the code which was the basis for this post. Thanks, Fents! :-)

Fenton sent a version of this code recently to an ADN member who was interested in duplicating the information shown in AutoCAD’s Sheet Set Manager inside a custom, palette-hosted tree-view dialog. Fenton’s version made use of WPF: I’ve dumbed it down a little to use WinForms, but may do a follow-up post using WPF (although the WPF TreeView doesn’t appear to support data-binding, so I may well decide not to bother).

I have made some other changes to Fenton’s code, and if there are any bugs they’re likely to be mine rather than his. I fleshed out some of the various item types, but as I haven’t yet been able to see them in action (I’m not even sure there was any real need to do so), they may need some further work or even stripping out.

Anyway, here’s the C# code. To make it work your project will need a reference to acsmcomponents18.tlb (or acsmcomponents17.tlb if using AutoCAD 2007-2009) as well as AcMgd.dll, AcDbMgd.dll and the standard .NET components that Visual Studio may be looking for when building the project.

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.EditorInput;

using Autodesk.AutoCAD.Runtime;

using Autodesk.AutoCAD.Windows;

using acApp =

  Autodesk.AutoCAD.ApplicationServices;

using ACSMCOMPONENTS18Lib;

using System.Windows.Forms;

using System;

 

namespace MyApplication

{

  public class Commands

  {

    static PaletteSet ps = null;

    static UserControl1 userControl = null;

 

    [CommandMethod("SSTREE")]

    public void PopulateCustomSheetTree()

    {

      // Check the state of the paletteset

 

      if (ps == null)

      {

        // Then create it

 

        ps = new PaletteSet("Custom Sheet Tree");

        userControl = new UserControl1();

        ps.Add("MySheetView", userControl);

      }

 

      ps.Visible = true;

 

      // Get the AutoCAD Editor

 

      Editor ed =

        acApp.Application.DocumentManager.MdiActiveDocument.Editor;

 

      // Get the SheetSet Manager

 

      AcSmSheetSetMgr mgr = new AcSmSheetSetMgr();

 

      // Create a new SheetSet Database

 

      AcSmDatabase db = new AcSmDatabase();

 

      // Try and load a default DST file...

 

      try

      {

        db =

          mgr.OpenDatabase(

            @"C:\Program Files\Autodesk\AutoCAD 2011\Sample\" +

            @"Sheet Sets\Architectural\IRD Addition.dst",

            true

          );

      }

      catch (System.Exception ex)

      {

        ed.WriteMessage(ex.ToString());

        return;

      }

 

      // Lock the db for processing

 

      db.LockDb(db);

 

      AcSmSheetSet ss = db.GetSheetSet();

 

      // Create a root item in the TreeView,

      // the name of the SheetSet

 

      TreeNode root = new TreeNode(ss.GetName());

      userControl.treeView1.Nodes.Add(root);

 

      ProcessEnumerator(ss.GetSheetEnumerator(), root);

 

      db.UnlockDb(db, true);

      mgr.Close(db);

    }

 

    void ProcessEnumerator(IAcSmEnumComponent iter, TreeNode root)

    {

      IAcSmComponent item = iter.Next();

      while (item != null)

      {

        string type = item.GetTypeName();

        switch (type)

        {

          case "AcSmSubset":

            try

            {

              AcSmSubset subset = (AcSmSubset)item;

              string subName = subset.GetName();

 

              if (!String.IsNullOrEmpty(subName))

              {

                TreeNode tn = AddTreeNode(root, subName);

                IAcSmEnumComponent enumerator =

                  (IAcSmEnumComponent)subset.GetSheetEnumerator();

                ProcessEnumerator(enumerator, tn);

              }

            }

            catch { }

            break;

 

          case "AcSmSheet":

            try

            {

              AcSmSheet sh = (AcSmSheet)item;

              string shName = sh.GetName();

 

              if (!String.IsNullOrEmpty(shName))

              {

                TreeNode tn = AddTreeNode(root, shName);

                IAcSmEnumComponent enumerator =

                  (IAcSmEnumComponent)sh.GetSheetViews();

                ProcessEnumerator(enumerator, tn);

              }

            }

            catch { }

            break;

 

          case "AcSmSheetViews":

            try

            {

              AcSmSheet sh = (AcSmSheet)item;

              string shName = sh.GetName();

 

              if (!String.IsNullOrEmpty(shName))

              {

                TreeNode tn = AddTreeNode(root, shName);

                IAcSmEnumComponent enumerator =

                  (IAcSmEnumComponent)sh.GetSheetViews();

                ProcessEnumerator(enumerator, tn);

              }

            }

            catch { }

            break;

 

          case "AcSmSheetView":

            try

            {

              AcSmSheetView sv = (AcSmSheetView)item;

              string svName = sv.GetName();

 

              if (!String.IsNullOrEmpty(svName))

                AddTreeNode(root, svName);

            }

            catch { }

            break;

 

          case "AcSmCustomPropertyValue":

            AcSmCustomPropertyValue pv =

              (AcSmCustomPropertyValue)item;

 

            AddTreeNode(

              root,

              "Custom property value: " + pv.GetValue().ToString()

            );

            break;

 

          case "AcSmObjectReference":

            AcSmObjectReference or =

              (AcSmObjectReference)item;

 

            AddTreeNode(

              root,

              "Object reference: " +

              or.GetReferencedObject().GetTypeName()

            );

            break;

 

          case "AcSmCustomPropertyBag":

            try

            {

              AcSmCustomPropertyBag bag =

                (AcSmCustomPropertyBag)item;

 

              TreeNode tn = AddTreeNode(root, "Custom property bag");

              IAcSmEnumComponent enumerator =

                (IAcSmEnumComponent)bag.GetPropertyEnumerator();

              ProcessEnumerator(enumerator, tn);

            }

            catch { }

            break;

 

          case "AcSmAcDbLayoutReference":

            AcSmAcDbLayoutReference lr =

              (AcSmAcDbLayoutReference)item;

 

            AddTreeNode(

              root,

              "Layout reference: " + lr.GetName()

            );

            break;

 

          case "AcSmFileReference":

            AcSmFileReference fr = (AcSmFileReference)item;

 

            AddTreeNode(

              root,

              "Layout reference: " + fr.GetFileName()

            );

            break;

 

          case "AcSmAcDbViewReference":

            AcSmAcDbViewReference vr = (AcSmAcDbViewReference)item;

 

            AddTreeNode(

              root,

              "View reference: " + vr.GetName()

            );

            break;

 

          case "AcSmResources":

            try

            {

              AcSmResources res = (AcSmResources)item;

 

              TreeNode tn = AddTreeNode(root, "Resources");

              IAcSmEnumComponent enumerator =

                (IAcSmEnumComponent)res.GetEnumerator();

              ProcessEnumerator(enumerator, tn);

            }

            catch { }

            break;

 

          default:

            Document doc =

              acApp.Application.DocumentManager.MdiActiveDocument;

            Editor ed = doc.Editor;

            ed.WriteMessage("\nMissed Type = " + type);

            break;

        }

        item = iter.Next();

      }

    }

 

    private TreeNode AddTreeNode(TreeNode root, string name)

    {

      // Create a new node on the tree view

 

      TreeNode node = new TreeNode(name);

 

      // Add it to what we have

 

      root.Nodes.Add(node);

      return node;

    }

  }

}

You’ll need to add a new UserControl to your project and a TreeView to that, setting the Dock property to fill. Be sure to keep the default names as UserControl1 and treeView1. Other than than, no UI work is needed.

Here’s what happens when we run the SSTREE command along and load the hard-coded DST file into the SheetSet Manager (displayed with the SSM command) for comparison:

 

Clearly more could be done to make the UI look the same (icons, etc.), but this post is more about recursively parsing a SheetSet’s tree rather than anything else. If you come across any issues as you try this out with other data stored in DST files, be sure to post a comment.