The Building Coder

Migrating VB to .NET Core 8 and AI News

Revit 2025 API migration of VB.NET add-ins to .NET Core 8 and advances in LLMs and AI, Claude, ChatGPT, Gemini, Meta AI, 3D genAI, web scraping, spatial referring, digital twins... Read more →

Journal Magic, Adjacent Rooms and Room Boundary

Taking a look at journal files, room boundaries, adjacent rooms, a ForgeTypeId question and where AI might lead – Harry's journal file magic – Closed contiguous room boundary loop – Challenges identifying adjacent rooms – ForgeTypeId for 'Other' parameter group – AI may obsolete all apps... Read more →

Geometry Options and Clean Simple Curves

Geometry options and clean simple curves – Curve loop simplify and clean up – Geometry options clarification – JtClicker 2023 – OpenMEP by Chuong Ho – Unintelligible film dialogue... Read more →

Pyramid Builder, CommandLoader, et al

Pyramid Builder, CommandLoader, and more – Dynamic load, compile and run code – DirectShape pyramids – Modify level element X and Y extents – How to filter for subsets of elements – Switch document display units – Material tags displaying '?' – Sublime Text... Read more →

Point Clouds, Coloured Triangles and Faces

Let's look at accessing point cloud points and colouring individual triangles and faces – Assigning material to each face – DirectContext3D colorized triangles – Pick and access point cloud points... Read more →

Add-In Manager, FormulaManager and Tiger Year

Exciting news around debugging and loading add-ins and adding formulas and scripting support to your own apps – Open source Add-In Manager – FormulaManager and scripting support – Happy New Year of the Tiger 虎... Read more →

Detailed 2D Text and Other Element Geometry

The 2D custom exporter provides a basis for a new and much more powerful approach to access detailed 2D geometry – Retrieve dimension text height and width – Determine text font geometry – Retrieve 2D geometry of any element... Read more →

References to Symbol versus Instance Geometry

Sooner or later, every serious Revit add-in developer will be scratching her head a bit over symbol versus instance geometry. Here is a nice juicy challenge... Wrap you head around this one in depth and future challenges in this area will seem trivial. Retrieving references from symbol versus instance geometry when placing an instance on a line throws an ArgumentsInconsistentException... Read more →

Revit 2020 C# and VB Visual Studio Add-in Wizards

Continuing the update of my development environment for Revit 2020, I now turn to the Visual Studio Revit add-in wizards. I'll also highlight a couple of recent interesting AEC related job offers, an AI 101 intro, and some really important suggestions on how to ask a question well – C# and VB Visual Studio add-in wizards for Revit 2020 – How to ask a question well – Open Autodesk AEC related positions – AI for all... Read more →

Revit 2019 Visual Studio .NET Add-in Wizards

I updated the Visual Studio Revit C# and VB add-in templates for Revit 2019. They enable you to create a new C# or VB Revit add-in in Visual Studio with one single click on File > New > Project... > Visual Basic/Visual C# > Revit 2019 Addin and define a complete skeleton Revit add-in, ready to immediately compile and run, including an add-in manifest file, external application and external command. Just hit F5 to start debugging; the add-in manifest is installed, Revit launched and the command is immediately available... Read more →

Purge Unused using Performance Adviser

Matt Taylor of WSP shares a solution to Purge Unused using the Performance Adviser – PurgeTool.vb implements GetPurgeableElements – PurgeUnused.vb external command... Read more →

Using Intersection Filter with Linked File

We recently discussed filtering for intersecting elements. Here is a closely related issue with an additional twist – Determining elements intersecting mass in a linked file – Coding suggestions and transformations – Solution by applying transformations... Read more →

Changing Text Colour

Here are some notes on changing text colour and a nice node.js web scraping tutorial – Changing text colour via the text note type – Web scraping using node.js... Read more →

Disjunct Planar Face Outer Loops

I am attending the Forge DevCon conference in Darmstadt, Germany, right now, and putting the final touches to my presentation on Rational BIM programming using Revit and Forge at the European Autodesk University on Wednesday. We discussed several different approaches to retrieve the outer loop of a planar face. Richard Thomas recently shared a possible solution to determine the outer-most EdgeLoop. He now posted a new approach: I found a more straightforward and likely reliable way of getting outer loops of planar faces. This method also allows for faces made up of disjointed parts... Read more →

Prompt Cancel Throws Exception in Revit 2018

In Revit 2018, cancelling family instance placement during a call to PromptForFamilyInstancePlacement throws an OperationCanceledException exception – Easily fixed, once discovered – Question – Change in Behaviour – Exceptions Should be Exceptional – Answer – The Building Coder samples CmdPlaceFamilyInstance... Read more →

Family Category and Two Energy Model Types

Let's pick up two more topics from the Revit API discussion forum today – Family Category property is not always set – Two different energy analysis model types – gbXML export options – BuildingEnvelopeAnalyzer class – EnergyAnalysisDetailModel creation from building elements and volumes – EnergyAnalysisDetailModelOptions... Read more →

Visual Studio 2015 Revit 2017 Add-in Wizards

I updated the Visual Studio Revit C# and VB add-in wizards for Revit 2017. They enable you to create a new C# or VB Revit add-in in Visual Studio with one single click on File > New > Project... > Installed > Templates > Visual Basic/Visual C# > Revit 2017 Addin. The wizard creates a complete Revit add-in skeleton, ready to immediately compile and run. Just hit F5 to start debugging; the add-in manifest is automatically created, copied to the proper location, Revit launched in the debugger, and your shiny new add-in is available in the external tools menu... Read more →

Family Category, Element Ids, Transaction Undo and Updates

Lots of topics from Revit API discussion forum threads and GitHub updates: Family category; Keeping track of elements; Undoing a transaction; RevitLookup, GetRevisionData and ADN Revit API Training Labs update... Read more →

Revit Add-In Wizard GitHub Installer

I recently mentioned the unrestricted VendorId in Revit 2016, and pointed out that I would like to update the Visual Studio Revit add-in wizards accordingly. I now went ahead and did so, adding a couple of other enhancements as well along the way – oh, and I did some work on putting my personal calendar online, as well: Sharing a calendar via GCal, Google API, and GitHub Pages. Visual Studio Revit add-in wizards on GitHub. Updated VendorId tag value. Wizard... Read more →

FireRating and the Revit Python Shell in the Cloud

In the past few days, The 3D Web Coder documented the first steps of research for a re-implementation of the Revit SDK FireRating sample in the cloud, and Daren Thomas pointed out his new project driving Revit and the Revit Python Shell through a REST API: The FireRating Revit SDK sample FireRating data structure FireRating in the cloud Revit and the Revit Python Shell as a REST API driven web server Summer has arrived in Switzerland! This entire week is... Read more →

ADN Labs Xtra, Multi-Version Add-Ins and CNC Direct

Let's discuss some more Revit add-in migration aspects and yet another completed migration task: ADN Revit API training labs Xtra migration Multi-version add-ins and CNC Direct ADN Revit API Training Labs Xtra Migration I recently mentioned that the official ADN Revit API Labs Training Material for Revit 2016 is available from the Revit Developer Centre and the Revit API Training GitHub repository. They are used for our standard two- or three-day hands-on Revit API introduction training courses. They are also... Read more →

Autodesk University, Q1, ADN Labs and Wizard Update

I submitted my yearly Autodesk University proposal for the Revit API expert panel. Time for you to submit yours as well. The call for proposals closes in one week – the deadline is May 26th. Besides that, here are some other things I want to point out: Titbits from the Q1 report Autodesk University proposals ADN Revit API labs training material for Revit 2016 Updated Visual Studio add-in wizards for Revit 2016 Titbits from the Q1 Report Autodesk posted a... Read more →

Add-in Migration to Revit 2016 and Updated Wizards

I updated my Visual Studio Revit C# and VB add-in wizards for Revit 2016. Before presenting them, a quick important note on how to approach resolving issues that you may encounter migrating your existing add-ins: Please read What's New in the Revit 2016 API! Revit add-in wizards for Revit 2016 Revit add-in wizard customisation Revit add-in wizard usage Download and installation Please Read What's New in the Revit 2016 API! Every major Revit API release so far enhanced the existing... Read more →

FindInserts Retrieves All Openings in All Wall Types

On Tuesday, I presented the new SpatialElementGeometryCalculator sample for calculating gross and net wall areas. It discusses a whole bunch of interesting aspects, e.g.: Use of the SpatialElementGeometryCalculator class. Porting a VB.NET Revit add-in to C#. Use of the temporary transaction trick. Use of filtered element collectors to determine all openings in a wall. Filtered element collector optimisation possibilities, e.g. integer instead of string comparison, use of a parameter filter instead of .NET post-processing. Vilo submitted a very relevant comment... Read more →

Calculating Gross and Net Wall Areas

Determination of gross and net areas and volumes is fundamental to BIM. Here is an interesting solution to determine the gross and net area of a wall, i.e. with and without its openings, making use of the SpatialElementGeometryCalculator and the temporary transaction trick. The question was raised and solved by Phillip Miller of Kiwi Codes Solutions Ltd, starting with the Revit API discussion forum thread on door/window areas: Question: I need to determine the cut areas of windows and doors... Read more →

Opening and Activating Document in an Event Handler

I have been a busy beaver with the Revit API on the discussion forum in the past few days, and on GitHub as well. I want to take a closer look at two related issues that date back a little bit further: Switching active documents is not allowed during API event handling Loading a RVT project file automatically on start-up Let's discuss the first today and save the second for later. Before getting to that, I also want to mention... Read more →

PostRequestForElementTypePlacement Sample

I am back from my vacation in the snow, full of new energy, and up to both ears in hot Revit API cases again instead of that frozen stuff :-) The creation document NewFamilyInstance method provides the traditional way to programmatically create a new family instance within a project, or a nested instance within a family document. It does not support any user interaction whatsoever. A little bit of user interaction is provided by the PromptForFamilyInstancePlacement method introduced in the... Read more →

Revit 2015 R2 and the Read-Write Workset API

Finally, the Revit API provides a complete Workset API including creation and modification capabilities. The one snag is that it is currently limited to the subscription update release Revit 2015 R2. This issue was discussed a while back on the Revit API discussion forum, in the threads on R2 versus UR4 and worksets; I searched and re-searched for them frequently enough now to finally decide to promote the gist to a main blog post topic. Read-Write Workset API The Workset... Read more →

Accessing Discipline and Duplicating View Template

I am back again in the land of the living... working, blogging. I'll jump right ... Read more →

Add-In Wizards for Revit 2015

I updated my Visual Studio Revit add-in wizards for Revit 2015. The 2015 version generates the same boilerplate code as the reliable old Revit 2014 one and its update did, which can be simply deleted if not needed. I selflessly also implemented and tested the Visual Basic version right away. Revit Add-in Wizard Customisation As I keep pointing out, it is important to understand how easy it is to modify the wizards for your own needs, and make copies with... Read more →

Revit 2015 API News – DevDays Online Recording

As the Walrus said, now "the time has come ... to talk of many things", including the highlights of the new Revit API functionality, so here we go! Welcome to my first post on the Revit 2015 API, disregarding the RevitLookup migration to Revit 2015, of course. A couple of posts on upcoming Revit 2015 product functionality were already published in the past week or so, e.g.: Overview of new features by synergiscad Feature list by Revit.King Highlighted features and... Read more →

Set a Suitable View for Family Instance Placement

Matt Taylor of WSP raised an issue related to the use of the PromptForFamilyInstancePlacement method, now that API access is also possible in the project browser view. He also went right ahead to suggest and implement a solution: Question: One of the new features of the Revit 2014 API is the possibility to select elements within the Project Browser view. If the Project Browser view is active, selecting a ribbon control that uses PromptForFamilyInstancePlacement will fail because the user will... Read more →

Determining Absolutely All Visible and Hidden Elements

Yesterday, I discussed the view filter API. One issue mentioned that was not completely answered was the following: Question 3: I would like to export only visible objects. Using the element IsHidden method reports whether it was hidden using the Hide in View > Elements menu option, but ignores Hide in View filters, and so does the IsHiddenElementOrCategory method. How can my application determine exactly what the user actually sees on the screen? Our customers obviously expect this functionality for... Read more →

Sydney Revit API Training and Vacation

My days down under were pretty intense. I left Switzerland Sunday night and arrived safe and sound in Sydney early Tuesday morning. I took the train from the airport into the town centre and back out again to the Autodesk offices at Macquarie Park in North Sydney. Three hours later, I was teaching the two-day Revit API training. At the time of writing this, it is Thursday afternoon and I am sitting on the plane back home again. I am... Read more →

Recursively Disable Architecture Mismatch Warning

I recently explained the cause and resolution of the processor architecture mismatch warning MSB3270. On closer consideration, I decided to fix it for all the ADN training material labs and samples, and actually for the entire collection of Revit SDK samples as well. This is obviously not something you want to do manually, considering that it involves a modification of hundreds of project files. Here are the steps involved in automating and testing this process: Disable mismatch warning utility Project... Read more →

Load Your Own External Command on the Fly

How to reload an external Revit command without having to restart the Revit session has been a subject of discussion many times in the past, e.g. in reloading an add-in for debug without restart, which lists four possibilities: Set up Visual Studio to efficiently load the desired project and the debugee, use the standard cycle hitting F5 to start debugging, and stop debugging when you need to make code changes. Use the RevitRubyShell or RevitPythonShell to work interactively with the... Read more →

Add-In Wizards for Revit 2014

I updated my Visual Studio Revit add-in wizards and am taking the time to publish them today, which is Ascension Day and a holiday in Neuchâtel. That also gives me some extra time to prepare for the June 3-4 Tech Summit presentation of my cloud-based round-trip 2D Revit model editing project. The presentation must be pre-submitted by May 20, and a full recording by May 27, so pressure is rising. I completed the implementation and still want to catch up... 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 →

Do Not Delete During Iteration

Here is a type of question that crops up much too regularly, and that I am hoping this little example will help you avoid. When you are iterating over a collection, deleting the elements in the collection at the same time can wreak havoc in many ways. Here is an example: Question: Since my last plug-in was such a huge success here in the office I have been tasked with writing another. However, I've run into an issue. When I... Read more →

Family Usage Filtered Element Collector Performance

Since all access to the Revit database and its elements takes place through the filtered element collectors, it is extremely important to make efficient use of them. We have not looked at that topic for quite a while now. Here is an issue that recently cropped up which illustrates some interesting points. I presented a filtered element sample for creating an XML family usage report which iterates over all the loaded families and launches a new filter for each of... Read more →

Xtra ADN Revit 2013 API Training Labs

I finished the Munich Revit API training yesterday and celebrated with a picnic and a snooze in the sunshine on the on the bank of the river Isar followed by a wave with Maja Mühlbauer in the evening. Today I am heading back home again. Before leaving, let me post the updated ADN Revit API Training material that I used. Lab Projects Most of it is a copy of the migration of the official ADN Revit 2012 API Labs provided... Read more →

AVF Displays Intersections and Highlights Rooms

We held a DevLab in Gothenburg yesterday with lots of interesting things to discuss with our Scandinavian developer guests. Today we are in Munich, Germany. So is Kean :-) One of the topics that came up yesterday is a thing I have been wanting to write about for over a year now and never gotten around to, the use of the AVF or Analysis Visualisation Framework to display temporary geometry to the user. I used it myself to display a... Read more →

Unit Conversion and Display String Formatting

AU went very well for me, and I think this was the one I liked most of all so far, to my own surprise. Now I am already at the next conference in Moscow, from where I continue to Tel Aviv tomorrow. December is always my monster travelling month, and I never get to prepare for Christmas or enjoy the dark and cosy celebration of Advent. But I really did have fun and enjoy AU in Las Vegas. Sunday morning... Read more →

My First Revit Plug-in in VB

Back in May, we published the wonderful new Revit API training tool, the self-paced My First Revit Plug-in guide, originally based on the C# programming language. Based on popular demand, we have now added new VB.NET samples. So regardless whether you are new to this training or have already gone through it once with the C# code, now is your chance to choose the language you prefer, C# or VB.Net, at www.autodesk.com/myfirstrevitplugin. The explanations in the lessons are still written... Read more →

Planar Face Transform

Here is another contribution by Joe Offord of Enclos, who already shared valuable insights on accessing curtain wall geometry, speeding up the interactive selection process, mirroring in a new family and changing the active view. Above all, he implements all his stuff in VB, so this is also something for you VB aficionados. This time, Joe looks at a command that redraws a planar face's edges in a drafting view. The issue is somewhat related to the discussion of polygon... Read more →

Spiderinnet

Have you ever looked at the Spiderinnet? Neither had I, until now, but the intro sounds really promising, and the list of articles is very impressive: This blog focuses on Revit Addin Wizards, Coders, and API Widgets. Coding languages exercised in the various Wizards/Coders/Widgets include but are not limited to C#, VB.NET and C++/Managed C++/CLI. Different Revit versions, flavors (Revit Architecture, Revit Structure and Revit MEP) and bitnesses (x86 or x64), different Visual Studio versions such as 2008 and 2010... Read more →

Visual Studio, C# and VB Express

Yesterday Kean mentioned that debugging AutoCAD.NET projects using the Visual C# and VB Express editions is now directly supported by the latest version of the AutoCAD .NET Wizard. That prompted me to have a look and see what the current situation is with Revit add-ins. Obviously, we poor Revit developers do not have such a sophisticated wizard available ... or so I thought! I installed Visual C# Express and started my experiment: I launched the new installation and selected New... Read more →

Set Copy Local to False

I cannot count the number of times I have pointed out that the Copy Local flag should be set to false on the Revit API assembly references. Here are some of the numerous previous examples and explanations of this: A C++ Revit add-in Selection watcher using Idling event The DevTV add-in templates Pipe to conduit converter Custom ribbon tab Porting from C# to VB.NET Exporting a family instance to gbXML Application events in VB Debugging a Revit add-in The SDK... Read more →

Retrieve Railing Elements

I already mentioned that API access to stairs and railings is currently still a bit patchy. Still, you can retrieve their geometry, determine the instances on a given level, and list the railing types. As you can see from the comments by Berria and Andrew, it is currently not possible to create railings, even though I did once implement a command named CmdNewRailing in The Building Coder samples to test this which unfortunately does not create a new railing instance.... Read more →

Section View Creation

I mentioned some basics of elevation and section view creation a long time ago, but omitted to publicise the results of the ensuing discussion with Konstanty and similar ones with Jenney and Bhavana. The issue came up in some ADN cases as well, so it really is time to get a bit more information on this out there to you. Question: I see that the CreateViewSection SDK creates a detail view of a wall seen from one side. How can... Read more →