The Building Coder

Secret Series 2, CAD Link Status and DWG Blocks

Joshua Lumley shares video #2 in his secret series, access to the CAD link status string and block in DWG export – Secrets of Revit API coding part 2 – Video 2 in the secret series – Getting CAD link status – Making blocks in Revit DWG export... Read more →

Foreground Image Import and Visible DWG Geometry

Today, we explore how to retrieve visible DWG geometry, i.e., geometry elements contained in a CAD import instance on a layer that is visible in the currently active view, and how to import an image to the foreground instead of the default background setting – Retrieve CAD import geometry on visible layer – Import image using foreground option... Read more →

MergedViews and Exporting to a Single DWG

Some insight on the use of the MergedViews property provided by the DGN, DWG and DWG export options classes and other ideas to export multiple views into a single DWG file – Question: I want to combine and export multiple views into one single DWG file. I set the option MergedViews, but the code still generates multiple DWG files for the views... Read more →

Forge Webinars on Design Automation and BIM360

The Forge webinar series continues. The recording of session 5 on the Design Automation API held by Albert Szilvasy is now available. For code samples on Design Automation, please refer to Albert's tutorials and the Developer-Autodesk Forge Platform samples on GitHub, filtering for Design.automation... Read more →

Avoid CAD Import in RFA, AAG16 and Endtrip

Some interesting topics of the day for this first cloudy one after a truly wonderful Indian summer – Avoid imported CAD content in RFA family definitions – Advances in Architectural Geometry 2016 – Endtrip full sound replacement... Read more →

DLL Signature, BIM 2 in UK and AutoCAD.NET

A couple of quick topics to start the week – Add-in DLL signature – BIM 2 in the UK – Communication between AutoCAD and Revit... Read more →

Modelling Small Details

I am back from the BIM Programming conference and workshops in Madrid and rather flooded, so here is just a quick note on how to you can model small details in Revit, courtesy of Jose Ignacio Montes of Avatar BIM. As you are perfectly well aware, Revit will not allow you to model things smaller than 1/8th of an inch directly in the project environment. Jose presents a simple workaround using an imported DWG file... Read more →

RealDWG, AutoCAD I/O, View & Data API Meetup

Are you interested in reading or writing DWG files directly, without installing AutoCAD? Querying? Viewing? Editing? Would you like to expand your solutions to support mobile devices and the web? Would you like to avoid implementing different or new application code to support desktop, mobile and web apps? Hear about the most efficient, reliable and robust solutions at the upcoming 'I Love DWG' meetup in Prague next Tuesday evening, September 8, using RealDWG, AutoCAD I/O and the View and Data API for DWG viewing and manipulation on any device, regardless of mobile, desktop, OS... Read more →

A360 Viewer Widget and Selecting a DWG Export Setup

Today, let's look at the new A360 embeddable viewer widget and selecting a DWG export setup. A360 Embeddable Viewer Widget The Autodesk View and Data API makes easy it to interactively view and explore a 3D model in the browser without any further software whatsoever. As I just mentioned in the discussion on 50 ways to view your model, the new A360 Viewer Widget simplifies it further still, using a widget that can be embedded in web pages to view... Read more →

List All Import Instances

Have you ever wondered whether you have any duplicate imported CAD instances in your model? My colleague Nikolay Shulga from the Revit development team implemented a nice little end user utility to answer this question. By the way, Nikolay and I go back a long time, way back in the beginning of the IAI and IFC project, decades ago, in previous lives... In Nikolay's own words: A while ago I wrote a prototype app to list ImportInstance objects in a... Read more →

DWG Issues and Various Other Updates

One of the highlights mentioned in the overview of the Revit 2014 API is the FreeForm element API that enables modification of solid geometry imported from DWG or SAT. Several other new DWG and DXF related features include import of DXF markup, import and link of SAT and SketchUp, and access to the DWG, IFC and DGN layer, linetype, lineweight, font and pattern tables. One result of these enhancements is the possibility to access 3D coordinates in DWG import for... Read more →

Launching AutoCAD within a Revit Add-in

We looked at the topic of running AutoCAD inside a Revit add-in way back in 2008, in the grey and dusty beginnings of this blog. Many developers have made use of that since then, and the topic is still important for all those who have significant functionality running inside an AutoCAD application and wish to make use of or enhance it by connecting it with their Revit add-in. Therefore, it is about time to dig that out and have a... Read more →

Porting an AutoCAD Application

AutoCAD and Revit are very different animals, as we already pointed out a couple of times in the past. Exaggerating just a little, you might say that Revit manages a BIM and ensures its consistency at all times, so there are no exceptions to anything ever, meaning nothing can be overridden. Moreover, almost all Revit geometry is parametrically driven, so there is no way to tweak the model geometry either, except of course by changing the official parameter values. This... Read more →

Polylines in Imported DWG Files

I still keep discovering functionality in Revit 2012 API that I have not yet discussed here, such as the following important enhancement: Previous versions of the Revit API failed to retrieve polyline data from imported DWG files. The polylines were represented by an internal Revit class which was not exposed through the API, so the geometry retrieval simply ignored these objects. Happily, that changed in the Revit 2012 API with the introduction of the PolyLine class. As stated by the... Read more →

ImportExport Update

I mentioned some features of the ImportExport SDK sample in previous posts, e.g. on porting it from C# to VB, setting the DWG export filename, modifying the DWF export filename, and exporting a 3D view to 2D DWF. Now Kurt Schrempp ran into a little problem with this sample. He says: I solved my problem. Here is the issue: When you try to export as DWG, it requires and gives you options to define the layer mapping. If you don't... Read more →

Refresh Element Graphics Display

Here is a little issue with an interesting workaround that I encountered in the past in similar incarnations in other CAD software packages besides Revit, so it is worthwhile making a note of this for potential future use almost anywhere. The issue has to do with refreshing the graphics display of individual elements in the Revit user interface. Committing the transaction, explicit regeneration, and even calling RefreshActiveView does not help. One additional thing that sometimes does help in similar situations... Read more →

Explode a DWG

After yesterday's very practical note on creating a pipe cap, here is another slightly less practical note from Rudolf Honke of acadGraph CADstudio GmbH, who picked up on Sami's comment on subscribing to UI Automation events. Sami asks: Question: Is it possible to explode an imported DWG file using the API? Answer: After showing the mechanism of invoking commands twice, I do think this can be achieved. Just like all other ribbon elements, also the 'Explode' buttons are accessible via... Read more →

Read DWG Settings and Content Location from INI File

Autumn is here in full now, grey and wet outside. The beautiful yellow leaves are turning brown and soggy. We had a wonderful sunny weekend, though, and I lay on the grass in the sunshine watching the distant mountains yesterday... In a completely different vein, today is the final day for submitting the Autodesk University material! I'm still not completely done... Meanwhile, here are two quick cases handled by Joe Ye quite a while back which both ended up resorting... Read more →

AutoCAD 2010 DWG Export

Today is a public holiday in Neuchâtel, the jeûne fédéral or Federal Fast holiday. I will use that for a hike in the Swiss mountains, that I so sorely neglected and missed this summer. Meanwhile, here is a simple question on the AutoCAD file format version used for DWG export. Question: How can I set the AutoCAD 2010 version as the destination file format for DWG export? The ACADVersion enumeration only has options for 2000, 2004, and 2007. In the... Read more →

DWG and DXF Export Xdata Specification

I am still on my diving vacation on Ko Tao. Unfortunately, the visibility under water was really terrible yesterday, and diving conditions are not that good in general. The rain that normally falls in November never came last year and now the water is warmer than usual. The corals that enter into a symbiosis with certain algae which give them their colour have shed their guests and are all white, or even worse, covered in dirt and grey or green.... Read more →

DWG Export Filename

Here is a question handled by Joe Ye that I thought might be of general interest. It makes use of the Revit SDK sample ImportExport converted to VB.NET. We mentioned the issue of converting Revit SDK samples from C# to VB in one post, and Adam Nagy later presented a more complete port. Question: I am making an application to export Revit views to DWG files. I used the ImportExport sample converted to VB.NET as a basis. I am having... Read more →

DWG and DWF Family Creation

Here is another question on family creation, this time not regarding parameters, but the geometrical content and reuse of existing geometry. Revit is a strongly parametric system, and the Revit family management obviously also. However, if one happens to have important predefined static geometry for certain components, that can be reused as well. It is of course a shame to be using static, non-parametric geometry in an environment with such powerful support for parameterisation. In some cases, however, reusing pre-existing... Read more →

Imports in Families

I will have left on vacation once again by the time this is posted. In case you wonder why I am on vacation so much, the trip to Italy in March and the wonderful experiences I had there were actually to use up last year's contingent. Now I am getting started on this years', going off on a climbing and driving trip to southern France with my two sons Christopher and Cornelius, especially to the Provence and Avignon to visit... Read more →

Access to Linked File Geometry

Here are some notes on accessing the geometry of imported or linked files from a case handled by my colleague Joe Ye: Question: How can I access the geometry of imported or linked Revit RVT, AutoCAD DWG, and SketchUp SKP files? For instance, I have created a file Wall.rvt containing a wall and use Import/Link to insert it into LinkWall.rvt. Now, when traversing the entities of LinkWall.rvt, I see an Autodesk.Revit.Element.Instance using a Symbol which seems to be the imported... Read more →

Hiding Linked Files

Rod Howarth raised a question in the discussion on linked files: Question: I'm trying to make a command to turn off the visibility of linked Revit and DWG models in the current view. The intent is to turn off the visibility for all imported categories in the drawing, i.e. all imported CAD files. This would be like going to Visibility/Graphics > Imported Categories > Show imported categories in this view. Is there an easy way to do this, or am... Read more →

Linked Files

Here is pretty thorough exploration by Joe Ye on how to retrieve linked Revit files in a project. The built-in category of a linked Revit file is BuiltInCategory.OST_RvtLinks, and the class storing it in the Revit database is Instance. Therefore, we can retrieve all linked Revit files in a document like this: Autodesk.Revit.Creation.Filter cf = app.Create.Filter; BuiltInCategory bic = BuiltInCategory.OST_RvtLinks; Filter f1 = cf.NewCategoryFilter( bic ); Filter f2 = cf.NewTypeFilter( typeof( Instance ) ); Filter f3 = cf.NewLogicAndFilter( f1, f2... Read more →

Running AutoCAD inside Revit

The preceding post on RealDWG and object enablers discussed one potential method for making use of AcDb functionality to read and write AutoCAD DWG files inside of Revit. Assuming that you have a license for a full version of AutoCAD in addition to your Revit one, there is another easy method to achieve this which has been implemented and tested. It is possible to run AutoCAD as a full-blown process in the background inside Revit. This functionality is new in... Read more →

RealDWG and Object Enablers

Revit uses the RealDWG toolkit to implement the DWG file export and import functionality. A frequent question is whether there is any way to hook into this functionality, and how this relates to custom objects and DBX object enablers, like for instance: Is there a way to load a DBX application into Revit as a RealDWG extension? It would be handy to be able to reuse the functionality of some custom ObjectDBX classes. First of all, let us clarify some... Read more →

Adding a Shared Parameter to a DWG File

I was recently asked whether it is possible to attach a shared parameter to a DWG drawing file imported into a Revit model. The exploration of this issue was interesting enough for me to like to share it. First of all, if you are interested in attaching a shared parameter to Revit elements, there are some pretty clear examples available demonstrating how to achieve this. One is the FireRating sample in the Revit SDK, the other is the Revit API... Read more →