The Building Coder

Efficient and Elegant Code

I remain busy, mainly in the Revit API discussion forum. Here are three recent samples dealing with pretty generic questions – Efficiency and elegance in simple code – Pushing wall type to doors... Read more →

Floor Area Above Room and Mysterious Hide

Today, we focus on two pure programming questions from the Revit API discussion forum – Area of an exterior floor above a room – Mysterious element hiding activity... Read more →

Colleagues Deleting Non-Shared Project Parameter

Some happy news about two new Revit API supporter colleagues, Naveen Kumar and Zhong Wu. They already reached second and third place in the list of top solution providers. Here is also a very relevant recent case handled by Zhong – Top solution authors – Naveen on Naveen – Zhong shifts to AEC – Zhong on Zhong – Deleting a non-shared project parameter... Read more →

Revit 2019.1, CEFSharp, Forge Accelerator in Rome

I am back from a multi-day hike of about 70 km along the Swedish Sörmlandsleden wilderness trail. In the meantime, lots of noteworthy things happened – Revit 2019.1 update and features – Revit Add-Ins using the CEFsharp library – BIM 360 Issues API – Forge Accelerator in Rome and elsewhere – Looking for a Forge development partner – New way to retrieve a parameter id... Read more →

Wall Profile Command Update

I returned from my time off in July. I dived in deep into the Revit API again to resolve an issue retrieving wall profile curves. Here are some other noteworthy items to keep company with my debugging report – CmdWallProfile update – Access to the IUpdater original value – Getting element dimensions from IFC files – Creative workaround to rotate elevation marker in chunks... Read more →

Forge Tutorials and Filtering for a Parameter Value

Today, let's revisit the topic of filtering for a parameter value, and mention the updated Forge tutorials – Learning Forge tutorials – Filtering for a specific parameter value – Filtered element collector optimisation... Read more →

Getting All Parameter Values

How to export all the Revit data to an external database? It is very simple to extract all the parameter data. Let's implement a solution to do so – Existing sample implementations – Black box input – Choices for the output and its structure – Retrieve parameter values from an element – FilterCategoryRule versus category filters – Category description extension method – Retrieve parameter data for all elements of given categories – External command Execute mainline – Sample run results – Download... 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 →

Parameters, Walls and Driving Revit via WCF Service

Exciting news from Russia and some mundane updates on other repetitive topics – Driving Revit from a modeless context via a WCF service – Room walls' directions – Retrieving all exterior walls – Getting and setting a shared parameter value... Read more →

Revit 2018.3, SetValueString and External Events

I installed the latest Revit update, and want to highlight two of the numerous interesting ongoing Revit API forum discussions – Revit 2018.3 update – Avoid SetValueString – Passing Data via ExternalEvent.Raise... Read more →

DevDays, Keynote Manager and REX Extensions

Let's highlight a few recent threads from the Revit API discussion forum. Before getting to those, a quick pointer to the DevDays Online recording from last week – DevDays online presentations on Revit API updates – External command with ribbon button sample – RevitAddinKeyNoteSystem keynote manager – REX extensions versus Revit add-ins – Reloading Revit links from user selected folder – Converting all parameter values to metric... Read more →

Autodesk University Past and Future

Quick notes on the best speakers at the last event in Las Vegas, and your chance to become one of them at the next in London – Best AU Speakers in Las Vegas 2017 – CFP for Autodesk University London 2018... Read more →

Setting Parameter Varies Between Groups

Looking at setting the SetAllowVaryBetweenGroups flag on a shared parameter; is there any way to set can vary by group instance (what I need) the default for API-created bindings? ... Read more →

Automatic Wall Creation

Alexander Ignatovich shares an exceedingly elegant solution for automatic wall creation, illustrating a number of important concepts and implementing the following functionality very succinctly indeed – Retrieve all the cube family instances – Retrieve their height parameter value – Retrieve their solids making use of the .NET yield operator – Extract their horizontal outline contours using an ExtrusionAnalyzer – Create walls along each contour curve segment – Place a door family instance at the midpoint of each wall... Read more →

Cloud Model Predicate, and Set Parameter Regenerates

The Revit API discussion forum continues to reach ever new levels of depth and coverage. Here are a couple of recent topics – Welcome to the top solution authors, Jim! – Setting a parameter to regenerate the model – Checking model for C4R versus local file... Read more →

Use Forge or Spreadsheet to Create Shared Parameters

I spent last week working on a new little BIM sample showing a round trip connection between Revit and Forge, and an automated way of generating and populating shared parameters from spreadsheet data – RvtMetaProp – Revit meta property add-in – CSV and JSON input file format – Forge configurator sample – Round-Trip Forge meta property editor – BipGroupList lists built-in parameter group enums and labels – Two options to add custom properties to the Revit BIM – Translation of shared parameters to Forge – Handling BIM floors in Forge... Read more →

Unit Abbreviations

Håvard Dagsvik of Symetri implemented code to automatically generate a dictionary mapping the Revit DisplayUnitType to corresponding UnitSymbolType display strings. The developer guide describes these classes like this – UnitType – type of physical quantity to be measured, for example length or force (UT_Length or UT_Force) – DisplayUnitType – units and display format used to format numbers as strings or convert units (i.e. DUT_METERS) – UnitSymbolType – unit symbol displayed in the formatted string representation of a number to indicate the units of the value (i.e. UST_M)... Read more →

Forge, Installed Version, Move Group, Name Filter

A biggish post rather late in the week... still answering too many cases – Forge for AEC demos and sample code – Determining the starting view – Detecting installed Revit version – Detecting installed C3D version – Moving items inside a detail group – Filtering for family instances and types by family name... Read more →

Finding an Exit Path and ElementId Parameter Values

As usual, lots of exciting discussions are being conducted in the Revit API discussion forum. I'll just highlight two of them going on right now – Finding a path through the BIM – Finding all possible ElementId values for specific Parameter... Read more →

Work Half, AKS Opener, RvtFader and ForgeFader

I completed a first revision of the ForgeFader project, bringing it up to par with RvtFader. It is pretty cool seeing the same functionality implemented in two such different ways, on completely different platforms, using different tools. Alan Seidel shared another exciting Revit add-in. First and not least, another exciting topic for me personally is switching to half-time work – Work half – AKS Opener – Video – GitHub repository – Why? – Specific interest – RvtFader – ForgeFader... Read more →

WTA Mech and TTT for Provision for Voids

Today is the last day of the Forge accelerator, and I am still working on the ForgeFader project. The topics today are mainly related to Revit, though – Google prettifier on GitHub – WTA mechanical family placement add-in – Provision for void – What is a provision for void? – Creating a provision for void... Read more →

WTA Elec, FireP and 3D Aimer Tools

I am traveling to Gothenburg for the Forge accelerator. Meanwhile, Allan Seidel shared his WTA FireP 3D Aimer add-in that creates a custom ribbon tab with discipline related tools for placing specific Revit family types with some families requiring parameter settings made on the fly and the 3D Aimer example that "aims" a special Revit family to a target – WTA FireP 3D Aimer Tools – GitHub Repository and YouTube Video – Source Code Documentation – WTA Elec – Another Family Plunk and Concept Share... Read more →

Elasticsearch-Head, RevitLookup and Area Schemes

I ran the first query on the collection of tbc blog posts imported into Elasticsearch to experiment for the question answering system Q4R4 Question Answering for Revit API and installed the elasticsearch-head web front end to better explore and understand my local Elasticsearch cluster – Elasticsearch text field mapping – Elasticsearch-head web front end – More RevitLookup updates – Get area scheme from an area... Read more →

RVT Properties to XLS and Forge Accelerators

Are you interested in easy access to your Revit model properties? Well, you can have that even without a need to install Revit. The Forge Model Derivative API extracts a streamlined copy of all geometry, BIM element hierarchy and properties from over fifty file formats, and Revit RVT files are just one of them. Augusto Goncalves implemented a Forge sample to read all the properties on all BIM elements in an RVT file and export them to an XLSX spreadsheet – Test run it yourself – Source code on GitHub... Read more →

Schedule Parameters and Shared Parameter GUID

Lots of information on, from and about schedule parameters, and a new elegant solution to a long-standing challenge – Direct access to shared parameter GUID – Getting parameter information from a schedule... Read more →

Parameter Definition Overview

I am happy to present a pretty comprehensive overview and explanation of the process of defining a shared parameter by Scott Conover. Question: What do I need to do to programmatically create a shared parameter? I would like to set the SetAllowVaryBetweenGroups flag on it. Answer: You create the details needed to define a shared parameter from ExternalDefinition. Existing shared parameter file entries can be read to become an ExternalDefinition in your code, or you can create a new entry in the current shared parameter file using the DefinitionGroup.Create method... Read more →

Need for Regen and Duplicate Parameter Access

A Python Revit API question on renumbering viewports helps highlight two separate important programming aspects; I also add some other notes from the Munich Forge accelerator – Question – The need to regenerate – Use built-in parameters to access parameters – Forge accelerator and outage report – Added materials to 210 King model... Read more →

Material Shared Parameters and ADN Xtra Labs

How to attach a shared parameter to Material elements? – Updated ADN Xtra labs to remove all deprecated API usage – A new addin that creates and populates a shared parameter to provide material information for each element – Autodesk University 2016 class materials have now been posted, including the recording of my session on connecting desktop and cloud – Linking Material elements to external database entries – Binding a shared parameter to elements – Attaching a shared parameter to Material elements – Create and populate a shared parameter ForgeMaterial – Cornelius story – cured by natural remedies... Read more →

Forge Formats, Webinars and Fusion 360 Client API

I updated the WebGL and Forge introduction for BIM programming and its GitHub source for the presentations in the coming days at the RTC Revit Technology Conference Europe and the ISEPBIM Forge and BIM workshops at ISEP, in Porto, implemented two little curl wrapper scripts to help me list the supported file formats, explored why they changed and updated the hackathon webinar overview. Before getting to that, I'll also highlight a helpful note by Christian on how to access the 'Symbolic Representation' setting – 'Symbolic Representation' setting parameter – Forge intro for BIM programming – cURL wrapper scripts to list Forge file formats – Updated Forge file formats – Forge hackathon webinar series and Fusion 360 Client API recording... Read more →

UnitUtils Converting Units for Unit Weight

Here comes a quick clarification of the units used for the UnitWeight built-in parameter PHY_MATERIAL_PARAM_UNIT_WEIGHT. One example usage is to calculate the total weight of rebars in a project... Read more →

MEP System Structure in Hierarchical JSON Graph

Yesterday, I presented the new TraverseAllSystems add-in to traverse all MEP system graphs and export their connected hierarchical structure to JSON and XML that I am helping the USC team with here at the San Francisco cloud accelerator. I continued with that today, and also integrated a minor enhancement to RevitLookup – TraverseAllSystems updates – Shared parameter creation – Options – Bottom-up JSON structure – Top-down JSON structure – TraversalTree JSON output generator – TreeNode JSON output generator – Download and to do – RevitLookup updates... Read more →

Reading an RVT File without Revit

A huge number of developers have requested a possibility to read or even write an RVT file without running Revit, similar to the possibility to read and write a DWG file without AutoCAD installed. For the latter, one option that has been around for ages is to make use of the RealDWG library for reading and writing DWG files. A more recent and future oriented option is provided by the cloud-based AutoCAD I/O web service. Here is yet another variation on this query – Question: Is there any way that I can read a Revit model without having Revit installed on the users machine? ... Read more →

Tracking Element Modification

How to determine and track element modification? I implemented a solution! – Two approaches – Task analysis – Modification tracker – Creating an element state snapshot – Determining which elements to track – Implementation – Geometrical comparison – String formatting – Retrieve solid vertices – GetTrackedElements – retrieve elements of interest – GetElementState – store element state – Creating a database state snapshot – Report differences – External command mainline Execute method – Sample runs – Demo recording – Download... Read more →

Loading an IES Photometric Web and Exciting Times

Today, let's look at an MEP related issue, loading the IES photometric web data for a light source, plus all the exciting things happening both for myself in the next weeks and for Autodesk as a company as a whole, reinventing itself for the modern cloud-based collaborative sharing technoculture – The first annual Autodesk X summit – Jeremy's January – DevDay in Munich – Accelerator Workshop – BIM Workshop in Madrid – Loading the IES photometric web data for a light source... Read more →

All Model Text, StringSearch 2016 and New Jobs

I migrated another one of my samples to Revit 2016: StringSearch. That was prompted by a question on extracting all visible text from the Revit model that I will take a closer look at below – ADN Internship and Other Jobs – Extracting all Visible Text from the Revit Model – StringSearch for Revit 2016... Read more →

Shared Project Parameter GUID Reporter

I am still busy on the Revit API discussion forum, when not involved in other important seasonal preparations. Now let's look at the overdue solution to determine the GUID of a shared project parameter – Issue – Implementation – Download – Discussion – Solution. A long discussion between CoderBoy, Scott Wilson and Ning Zhou on reporting on project parameter definitions – need GUIDs was resolved back in 2013 and never published... Read more →

Quick, Slow and LINQ Element Filtering

I arrived back safe and sound in Switzerland after the exciting week at Autodesk University. Another happy arrival is my first grandson: He was preceded by his big sister almost two years ago. Life goes on. I have been wanting to highlight the difference between quick and slow element filters for quite a while, and now a query came in that provides an ideal opportunity – Use of LINQ with filtered element collectors – Revit element filter classification – Filter types – Efficiency guidelines – Logical filters – Quick filters – Slow filters... Read more →

Drop-down Enumerated Parameter Values

I repeatedly hear from developers who wish to define a specific enumerated set of parameter values for their add-ins and limit the selection to these values in the element property palette user interface. Internally, Revit does implement a system to handle this, for instance by using negative element ids for element property drop-down list enumerations. This has also been a long-standing wish list item, and unfortunately still remains in that state, currently incorporated in the issue CF-3498 API wish: drop-down enumeration parameters for combo box... Read more →

Clicks, DMU, Surfaces, FireRating Feedback, Vacation

Let me list some of the topics we discussed today in the Revit API discussion forum before I head off for vacation: Reacting to Windows mouse clicks in Revit. Reacting to changes and setting parameters using DMU or DocumentChanged. Creating a surface in Revit. FireRating in the Cloud feedback. Vacation Time Now. Summer has seriously arrived in Europe, and the weather is really good as well, for a change. I took advantage of it this weekend and climbed the Alphubel... Read more →

Type Catalogues

Let's veer away from the Revit API for a moment and take a look at family type catalogues, since questions on those pop up regularly in connection with programming as well: Programmatic type catalogue creation Tweaking type catalogue behaviour Type catalogue parameters Type catalogue units Programmatic Type Catalogue Creation Question: Is there any API support (function) to create type catalogues? Answer: As far as I know, there are two ways to create type catalogues, and both are programmatically accessible: Create... Read more →

IFC GUID Access, Life Span and Cloning of Geometry

Today, let's talk about the life span of Revit geometry and accessing the IFC GUID of an imported element: Life span and cloning of solids and faces Accessing the IFC GUID of an imported wall First, I'll just mention that I returned safe and sound from the successful fourth and last day of the Milano WebGL workshop, which we concluded with a group session guiding through the View and Data API tutorial. I wrote is a short report on that... Read more →

CNC Direct – Export Wall Parts to DXF and SAT

I implemented the Revit ExportCncFab add-in back in 2013 to export Revit wall parts to DXF or SAT for CNC fabrication. The full source code, Visual Studio solution and add-in manifest lives in the ExportCncFab GitHub repository. The project was prompted by William Spier, who recently published a nice 12-minute YouTube video Revit to CNC Direct describing and demonstrating its practical use and application: In William's words: "Asked Jeremy to write a DLL that allows users to export multiple objects... Read more →

Geometry Creation and Line Intersection Exceptions

Today, let's look at some geometry related questions, a small enhancement of the line intersection we discussed two days ago, NURB spline and solid creation: Creating a NURB spline GeometryCreationUtilities, moving and copying solids Line intersection enhancements Built-in parameter checker for Revit 2016 1001 discussion forum posts Creating a NURB Spline This question was raised by anarchyfree in the Revit API discussion thread on a NurbSpline creation error: Question: I'm working on a Revit plugin that in part accepts curves... Read more →

Re-Researching Lighting Family Instance Placement

The placement of family instances can sometimes be a tricky topic in the Revit API. Programmatically, this is always achieved using the NewFamilyInstance method. However, this method provides 13 different overloads to choose from, which can be a non-trivial task: NewFamilyInstance(Face, Line, FamilySymbol) – Inserts a new instance of a family onto a face of an existing element, using a line on that face for its position, and a type/symbol. NewFamilyInstance(Line, FamilySymbol, View) – Add a line based detail family... Read more →

IFCExportUtils Determine Door and Window Area

Last week we discussed the SpatialElementGeometryCalculator sample for calculating gross and net wall areas that in turn led to the discovery of the FindInserts method to retrieve all openings in a wall. Both of these were prompted by the Revit API discussion forum thread on door/window areas raised by Phillip Miller of Kiwi Codes Solutions Ltd. Another question that arose in that thread regards the meaning of the built-in parameter HOST_AREA_COMPUTED and how to best calculate the area of a... 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 →

Family Instance Area and Auto-Loading a Project File

I have been pretty busy answering queries on the Revit API discussion forum in the last few days. Here are two that I quite like that came up today, on calculating areas occupied by furniture and equipment family instances and loading a project file automatically on Revit start-up. Calculating Areas Occupied by Furniture and Equipment Family Instances This query was raised by Vyom Dixit on how to calculate model group elements area: Question: I am new to the Revit API.... Read more →

The Revit API is Never Ever Thread Safe

Let us summarise and preserve this interesting Revit API forum discussion between Erik Eriksson, Ollikat and Arnošt Löbel on why the Revit API cannot safely be used from multiple threads under any circumstances whatsoever, even for read-only operations: Question: I've been using the Revit API for some years now, but I have never tried multithreaded requests. Basically because Autodesk told me that it will never work. I've now grown a little more confident and started testing a bit. So I... Read more →

DirectShape versus Families, Category and Texture

Let's begin this week with a discussion of several aspects of direct shapes: Direct shapes, part families and application porting DirectShape categories DirectShape texture assignment Direct Shapes, Part Families and Application Porting Question: I am looking for some guidance related to porting my application to Revit. I have a parametric part engine that lives outside of Revit with a large set of existing library content. It would be very costly to rebuild from scratch using the Revit Part Family editor... Read more →

Attached Detail Groups and Inverse Relationships

I am still at the Berlin hackathon, working with the MovieMemory team... In between other tasks, let me mention the interesting discussion and solution by Revitalizer on the Revit API discussion forum to check for attached detail groups: Question: Can someone tell me, please, how I can find out if a Group (Type) has an Attached Detail Group (Type) via the API? Answer: A group of category OST_IOSAttachedDetailGroups has a BuiltInParameter.GROUP_ATTACHED_PARENT_NAME. This way, you will find matching Model groups. Response:... Read more →