The Building Coder

Room Boundaries to CSV and WPF Template

Happy New Year! I spent some time during the winter break working on CSV export of room boundaries for a Forge BIM surface classification tool. Ali Asad presented a new Visual Studio WPF MVVM Revit add-in template – Export room boundaries to CSV for Forge surface classification – Visual Studio WPF MVVM Revit add-in template... Read more →

Python Rotate Picked Around Bounding Box Centre

Let's highlight a nice interactive didactical Python-based Revit API learning challenge on how to get the bounding box from a Revit element and determine its centre – Cyril's Python HVAC blog – Rotating elements around their centre in Python – Retrieve element and bounding box from picked reference – Use location point instead of bounding box centre – Final working solution... Read more →

Rebars in Host, .NET Framework, Importance of Fuzz

Here are a couple more Revit API discussion forum threads well worth highlighting – Retrieve rebars attached to structural element – Installing the .NET framework 4.7 for Revit 2019.1 add-ins – Importance of fuzz for curtain wall dimensioning... Read more →

Fire Rating Zone Intersection

Let's tackle a 2D fire rating zone intersection task. Actually, it was originally raised a 3D intersection task. Reducing it to 2D makes it much more tractable – 3D solid extrusion creation and intersection task – 2D area intersection task – Jack's sample and description – Soffit subdivision sample code – Cleanup and GitHub repository... Read more →

Using an Intersection Filter for Linked Elements

Intersecting elements has always been a hot topic, cf. various previous discussions on 3D Booleans, cutting and joining elements; intersecting with elements in a linked file is even more challenging. Happily, the Revit API provides tools to support that as well – Intersecting linked elements with current project ones – Retrieving rebars intersecting a structural element... Read more →

Resources, Rotated Rebar Stirrups and Steel Stuff

I'll start this week with several solutions from the Revit API discussion forum and elsewhere, especially two different approaches to create rotated rebar stirrups – Embedded tooltip icon resource – Revit 2019 tooltip videos are MP4 – How to read and write bolt, plate and weld – Creating rotated rebar stirrups... Read more →

Protecting a Family from Tampering

The Forge accelerator in Rome is winding down with the demonstrations of what was achieved being recorded as I write. An interesting conversation I had at the celebratory dinner last night gave me an idea for a solution to a longstanding question on family tampering protection – Roma accelerator group photo – Protecting a family from tampering – Implementing a canonical key for geometrical objects... 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 →

Roadmap, CI for RTF, Geometry Library Limitations

Lots going on, and off to Rome next week for the Forge accelerator. Meanwhile, here three of the many topics recently discussed – Revit Public Roadmap – September 2018](#2) – Configuring CI to use the RevitTestFramework RTF – Revit Geometry library limitations... Read more →

Rebar, Wall Centreline, Core and Grid Dimensioning

My colleague Zhong John Wu just solved a Revit API discussion forum issue on how to create dimension line for rebar. I took this as a prompt to clean out a bunch of other dimensioning related issues lurking in my infinite and growing to-do list – Create dimension line for rebar – Newly created dimensioning not displayed – Dimension leader remains visible after removal – Dimension wall centreline, centre and faces of core – Grid references for dimensioning... Read more →

Icon Access and Reference Plane in Family Instance

Today I highlight two of Fair59's numerous solutions in the Revit API forum, and also mention a joke I picked up in a Swedish cartoon – Fadaesen on racism versus realism – Retrieving a reference plane location in a family instance – Accessing the Revit ribbon icons... Read more →

Reference Intersector and Deleting Reference Planes

We already looked at deleting unnamed non-hosting reference planes back in 2012 and 2014. Some things have changed since then, and the old code requires fixing and updating. Other interesting topics also want to be mentioned – Embodyment workshop – Bös Fulen mountain hike – Using ReferenceIntersector to place lighting fixture on ceiling face – Reformat stable representation string for dimensioning – Deleting unnamed non-hosting reference planes updated... 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 →

Mindful Living and Smiling to Myself

I am back from my July vacation. As planned, I visited the Buddhist monastery Plum Village near Bordeaux. Here are some personal notes from my experiences there, followed by a Revit API related issue that just cropped up – Plum Village and its visitors – Mindfulness and relaxation – My struggle with the smile – Mindful watering of seeds – Line intersection with topography surface... Read more →

Simplifying Nested Family Instances

José Alberto Torres Jaraute implemented an add-in tool to protect the intellectual property built into a complex hierarchy of nested family instances by replacing them with a flatter and simpler hierarchy, yet retaining all the relevant non-confidential custom data. Basically, his tool also enables location of overlapping elements and duplicates elimination. In the course of this work, Alberto raised a number of questions in the Revit API discussion forum – Explode nested families – Insert a curve-based family instance associated to a face – Explode family instance to get all the components of a family in project – Change the host and work plane of a family... Read more →

FilterRule Use and Retrieving Exterior Walls

Today, we revisit the interesting and generic question on retrieving all exterior walls. That may be easy in a perfect and complete model. However, it raises some challenges in an incomplete BIM – Retrieving all exterior walls – Several possible approaches – Using a computational geometry approach – Manually adding the huge surrounding room – Encapsulate transactions and roll back instead of deleting – Determining model extents via wall bounding box – Implementing the huge surrounding room approach – Retrieving family instances satisfying a filter rule... 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 →

Bounding Box Filter is Always Axis Aligned

This is pretty obvious, once you think about it, and apparently worth pointing out anyway: The outline defining a bounding box filter is always aligned with the cardinal axes – Rotating Min and Max distorts the box – Rotate target elements or use a solid filter... 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 →

Create 2D Arc and Filter for Intersecting Elements

Several questions on filtering for intersecting elements came up recently. It is pretty easy as long as a bounding box can be used. However, the bounding box is generally aligned with the cardinal X, Y and Z axes. If the containing volume of interest is not, too many elements may be selected – Family instances in a diagonal room – Conduits intersecting a junction box – Generate 2D arc from radius, start and end points... Read more →

Export Geometry and Snoop Stable Representation

Александр Пекшев aka Modis @Pekshev submitted a very succinct and useful pull request for RevitLookup that I integrated right away, and provides many other valuable inputs as well – Snoop stable representation of References – Project point on plane correction – Revit export geometry to AutoCAD via XML – RevitExportGeometryToAutocad – Description – Versions – Using – Example... Read more →

DirectShape from BrepBuilder and Boolean

Here is an interesting code snippet illustrating the use of BRepBuilder and Boolean operations to generate a DirectShape. It might come in useful somewhere, even though this approach is non-optimal to address the task at hand, as explained below... Read more →

Rotation Adjusts and Fixes Conduit End

I listed several possible approaches to trigger a refresh of an element's graphics display. Here is another one: Applying element rotation to adjust and fix conduit end... Read more →

Create Swept Blend DirectShape in C++

Question: I am trying to create a swept blend geometry and assign it to a DirectShape element. The initial code threw an exception when calling the GeometryCreationUtilities CreateSweptBlendGeometry method. How can I fix this? Answer: The path parameters assume that they should be normalised or that the curve has a range of parameterisation from 0 to 1... Read more →

AreaLoad Force Direction, CMake and SDK Access

Here are some of the topics I dealt with in the last couple of days – CMake and YoAudio – AutoCAD and Revit SDK Access and Content – Determining AreaLoad direction and value from its force vectors – ExportCncFab 2018... Read more →

Transform Utils, DirectShape Builder and DevDays Online Webinars

Revitalizer shared two important hints: a performance issue using ElementTransformUtils and a problem reporting mechanism built into the TessellatedShapeBuilderResult method GetIssuesForFaceSet. First, though, let's highlight an even more important upcoming event, the series of DevDays online webinars – Register now for Autodesk DevDays online webinars – Avoid using ElementTransformUtils for batches – Finding cause of DirectShape generation problem... Read more →

DirectShape Topics and Happy New Year!

I'll begin the new year by discussing a bunch of topics addressing various aspects of DirectShape elements – Updated DirectShapeFromFace – Improve loft form creation speed using DirectShape – Create DirectShape instead of conceptual mass – Create surface from face – Create DirectShape from solid – Control DirectShape colour and material – Improve family performance suppressing DirectShape generation – Create DirectShape from room... Read more →

Project Identifier and Fuzzy Comparison

I bring up two recurring topics, fresh every time around – Project identifier – Fuzzy comparison versus exact arithmetic for curve intersection... 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 →

Curtain Wall Panel Geometry with Basic Wall Panel

A quick geometrical question on retrieving geometry from a basic wall being used as a panel in a curtain wall. I am struggling to retrieve the geometry data from a curtain wall that contains a Basic wall in one of the curtain wall panels. My example curtain wall has two panels. With one of the panels, a basic wall type is associated. I need to get the geometry data (i.e., the faces) for the entire curtain wall. When I reach the second panel in my code, the SymbolGeometry contains zero objects, so my code cannot retrieve any geometry for it... 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 →

ExtentElem and Square Face Dimensioning References

Alexander Ignatovich answered several interesting questions in the Revit API discussion forum – The ExtentElem and duplicating legend components – Obtaining generic model square face references for dimensioning – Preparing family with reference planes for dimensioning – Creating a line perpendicular to another... Read more →

Edge Loop, Point Reference Plane and Column Line

A whole bunch of exciting Revit API topics to start the week – RevitLookup updated to use NuGet Revit API package – Determining the outer-most EdgeLoop – How to determine the location curve for a steel column – Determining a reference plane from a reference point... Read more →

Birthday Post on the XYZ Class

Today is The Building Coder's ninth birthday. We'll celebrate by discussing the pretty fundamental issue of XYZ points versus vectors, and how to distinguish different points – XYZ point versus vector – How to distinguish XYZ points... 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 →

BIM 360 Hackathon and Bounding Boxes

Topics for today – BIM 360 and Forge Hackathon and Webinar Series – IsCreatedLocal versus IsLocal – Getting the building height – FamilyBoundingBox enhanced taking instances into account... Read more →

Picked Instance Face Geometry in LCS Versus WCS

Depending on circumstances, interactively picked family instance geometry may be returned in the global Revit world coordinate system WCS, or in the family instance definition local coordinate system LCS. A family instance may have its own non-empty solid, or use the symbol geometry. The symbol geometry requires keeping track of the instance transform to map it to the actual instance project location – Question on Incorrect Face Normal – Working Plane has no Effect – Non-Picked Face Normals are Correct – Solution – Detecting When to Use LCS versus WCS – Retrieval of Picked Geometry Face from Instance is Untransformed... Read more →

Copy Local False and IFC Utils for Wall Openings

New important issues are researched and brilliant solutions shared daily in the Revit API discussion forum. Here are two from the current crop – IFC helper returns outer CurveLoop of door or window – Setting Copy Local to False resolves AddIn Manager issue... Read more →

FindInserts Determines Void Instances Cutting Floor

Here is another brilliant and super succinct solution provided by Fair59, answering the Revit API discussion forum thread on how to get cutting void instances in the floor using the HostObject FindInserts method – Question: I have a floor on which a family instance is inserted on the face of the floor (the instance host is also the floor). I checked in the family the "Cut with Void When Loaded" parameter, so that the void is created in the floor. Now, I want to retrieve all the instances that create voids in the floor... 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 →

Determining Dimension Segment Endoints

A rather hard struggle led to a rather simple solution for determining the start and end points of dimension segments. In summary, the solution looks like this – A Dimension element is either single- or multi-segment; these two cases need to be handled separately – In case of a single segment, the dimension element itself has a line, an origin and a value; the line is indeed the dimension line. However, it may be unbounded... Read more →

Aligning a Slightly Off-Axis Grid

Here is a follow-up on the recent discussion on how to modify a grid curve end point using Grid.SetCurveInView. In the Revit API discussion forum thread on off-axis grids causing warnings in Revit, an attempt to use the same approach fails. Instead, Fair59 presents a solution using RotateElement to align an almost horizontal or almost vertical grid that is slightly off-axis... Read more →

Hatch Line Dimensioning Voodoo

Reporting on a very exciting topic from the Revit API discussion forum from the Forge accelerator in Barcelona – Barcelona Forge accelerator – Retain the Add-In GUID – Dimension on hatch pattern... Read more →

Sensors, BIM, AI, RevitLookup, Fuzzy Comparison

We continue patrolling the well-trodden paths of BIM, AI, Revit precision and RevitLookup – Connected BIM – Intuitive AI – Fuzzy Comparison – RevitLookup 2018.0.0.1... Read more →

SDK Update, RvtSamples and Setting Grid Endpoint

An updated version of the Revit SDK was published, I set up RvtSamples for Revit 2018, which I use to load The Building Coder samples, and we present a useful employment of the DatumPlane class methods GetCurvesInView and SetCurveInView – Revit 2018 SDK Update – RvtSamples for Revit 2018 – How to Modify Grid Curve End Points... Read more →

API Access to Family Instance References

Here is another Revit 2018 API enhancement that is obviously worth highlighting, since it immediately answers the question on getting a specific reference from a family instance raised in the Revit API discussion forum: Is it possible to get a named reference plane from a family without going into the family editor API? For example, I would like to have users be able to name a reference plane 'my arbitrary location' when they are creating a family... Read more →

Wall and Opening Tessellation

Let's turn to a geometric question on tessellation, expanding on the discussion on TessellateSolidOrShell. I am exporting Revit wall geometry to an external application for comparison of net and gross wall areas. I have a problem with the fact that Face.Triangulate(double levelOfDetail) creates a different tessellation segmentation of neighbouring faces for the wall and its opening, although the underlying intersection curve between them is obviously the same. Why does the tessellation segmentation differ in this manner? The levelOfDetail in unchanged... 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 →

RvtFader, AVF, Ray Tracing and Signal Attenuation

I implemented a neat new little sample add-in, RvtFader, that calculates and displays signal attenuation caused by distance and obstacles, specifically walls. It uses two very interesting pieces of Revit API functionality – AVF, the Analysis Visualisation Framework, for displaying graphical data in a transient manner directly in the BIM – The ReferenceIntersector ray tracing functionality to detect walls and other obstacles between two points. In the course of implementing the AVF part of things, I also resuscitated my trusty old RevitWebcam add-in – RevitWebcam – RvtFader – Task – Implementation – Further Reading... Read more →