The Building Coder

Invitation to Autodesk DevDays 2013

While I am beavering away at my Autodesk University material, or at least should be, instead of answering developer cases and blogging, my colleagues are equally busy preparing the upcoming Autodesk Developer Days. As you can see from the DevDays schedule, there is only a week to go before it starts off in Asia and Australia. This time around, for the first time ever, we are also actively looking to engage with non-ADN members who would like to attend. If... Read more →

Wall Compound Layer, Other Geometry and Licenses

Below, we take another quick look at the issue of licenses. First, here is a pretty basic question that keeps reappearing, so I summarise some existing results for everybody's convenience: Question: How can I programmatically retrieve the coordinates of a wall boundary, especially the geometry of the finished interior and exterior layers? I wish to export the building blueprint to GML. I would also like to know how to achieve the same for the geometry of doors and windows. Some... Read more →

Determining Room Boundary Segment Generating Element

Today we look at how to determine the neighbouring BIM element of a room boundary segment using the ReferenceIntersector to shoot a ray from the room interior into the bounding element. There should not really be any need to implement such functionality ourselves, because the BoundarySegment class already provides an Element property that should return the BIM element generating the given boundary segment. However, unfortunately, the BoundarySegment.Element may erroneously return null under certain specific conditions, and we present a nice... Read more →

RoomEditorApp for Revit 2014 on GitHub

I discussed my Revit add-in for my cloud-based, real-time, round-trip, 2D Revit model editing application on any mobile device in depth last spring, with the last update on its implementation status published back in May. Even at that time, since I was mainly concentrating on the exciting cloud aspects of the application, I had added quite a bit of functionality to the Revit add-in that I never got around to documenting, such as External application Automatic immediate BIM update from... Read more →

ExportCncFab on GitHub and RevitLookup Update

I am in a hurry, still not finding time to prepare my AU classes, and lots going on. I published an add-in named ExportWallboard to automatically isolate and export wall parts individually to DXF for CNC fabrication back in March, still for Revit 2013, at the time. That utility is in use, was renamed to ExportCncFab and has enjoyed some further enhancement since, such as: Support for export to SAT as well as DXF A beautiful little external application to... Read more →

Move Tag to Host Location

After a number of pretty lengthy heavy-duty discussions in the past few days, here is a short and quick summary of a useful result from the discussion forum thread on moving a tag to its host location point: Question: I'm trying to move a tag to the host location point. Can anyone show me what the syntax is to do this? I already have 'tag' and 'hostLocation' assigned. I've tried this but get an error: tag.Location = new LocationPoint( hostLocation.Point... Read more →

RevitLookup on GitHub and Invitation to Collaborate

I sincerely hope that everybody reading this is aware of the power and importance of RevitLookup, has already installed it, and is an avid user. If you do not know what I am talking about, please read these previous posts on the topic, noting that it was previously named RvtMgdDbg, short for 'Revit managed debugging tool': RvtMgdDbg Fixing RvtMgdDbg for MEP Connectors RvtMgdDbg for Revit 2010 RevitLookup Update Units and RevitLookup Getting Started with the Revit API RevitLookup is currently... Read more →

The Dynamo Revit Unit Test Framework

I have repeatedly underlined the importance of unit testing, and recently presented the RvtUnit project enabling the use of the NUnit unit testing tool for Revit add-ins. The Dynamo team now presents another one; in case you have not already heard of and explored it, Dynamo is an exciting visual programming tool on top of Revit. The best explanation of Dynamo is provided in the Dynamo GitHub repository. Much of the discussion and suggestions for new features etc., is happening... Read more →

Programmatic Custom Add-In External Command Launch

One of the highlights of the Revit 2014 API is the new PostCommand functionality enabling programmatic launching of built-in Revit commands. The Revit SDK includes a new sample demonstrating its use, PostCommandWorkflow. However, that programmatically launches an existing built-in Revit command, not an external command added by a custom application. Furthermore, there was a problem launching custom external commands in the initial release of Revit 2014. Happily, it was fixed by the update release 1, UR1, a fact listed among... Read more →

Using the Built-In Revit AcGe Functionality

Anyone who ever used the AutoCAD API for geometrical purposes must be enamoured with AcGe. On the other hand, the Revit geometry library is pretty meagre in comparison. Wouldn't it be nice to be able to use all that powerful AcGe functionality in Revit as well? Actually, if you take a look at the support DLLs included in the Revit main executable directory, AcGe is obviously present: C:\Program Files\Autodesk\Revit 2014 > dir *acge* Directory of C:\Program Files\Autodesk\Revit 2014 02/05/2013 12:52... Read more →

Text File Driven Automatic Placement of Family Instances

My colleague Emmanuel Di Giacomo recently asked me for an application to automatically place Revit family instances in a project at a list of X, Y, Z coordinates read from a text file. A similar add-in was already published for Revit 2011 at Revit Today. The user interface is minimal: This form enables the following simple and effective workflow to achieve a lot of functionality in very few lines of code, significantly aided and abetted by the combo box DataSource... Read more →

Move Duct Join Add-In with Video and GitHub Support

I am always happy to take a look at a real MEP issue, so this case caught my eye and prompted me to sit down and do some actual coding again for a change: Question: How can I programmatically move the join of two ducts, effectively changing their end points? I do not want to delete and re-enter them because they will normally be connected at the other end as well. Answer: In general, when working on programmatic manipulation of... Read more →

The Building Coder Samples on GitHub

After several prompts from various quarters, I finally got around to publishing The Building Coder samples on GitHub. To access them from there, you can either open the repository or grab the code through the direct zip file download. As discussed below in the section on branching and tagging, these links refer to the master branch. For a specific version of the samples, e.g. from today, please see below. Another important aspect that I discovered in the process and always... Read more →

LINQ DIY Transformed Geometry Bounding Box

We looked at a couple of transformation issues in the past, e.g.: Polygon Transformation Transform Transform Instance Coordinates Transform an Element Transformations Get Transformed Family Instance Geometry Planar Face Transform Now Jon Smith of Construction Industry Solutions Ltd raised another issue related to transformations. Unlike the ones listed above, however, this one deals with the transformation and bounding box of the in-memory geometry objects, as opposed to database elements: Question: We need to transform some elements into a different coordinate... Read more →

Handle Your Own Exceptions and Edit Slab Boundaries

Today, we continue yesterday's discussion on the need to handle your own exceptions and mention Joe Ye's solution to edit an existing slab boundary. How to Handle Your Own Exceptions Yesterday we explained why Revit cannot gracefully handle all your exceptions for you and the need to do so yourself in all parts of your Revit add-in, especially the modeless ones that Revit is not even aware of. Better still, of course, is to avoid all modeless activity completely, if... Read more →

Handle Your Own Exceptions

I was under the impression that it should be hard for an add-in to crash Revit. Therefore, it was a surprise yesterday to receive an add-in displaying a form and instructions to reliably cause Revit to terminate unexpectedly with just two or three clicks. The reason is simple, however, as we shall see below, and underlines once again how hard it is to properly implement and handle any modeless activity within a Revit add-in. Important aspects were discussed in the... Read more →

Programmatic Access to Duct Sizes

Here is a nice little MEP related blog post on accessing duct sizes through the API to round off the week. It was provided by our MEP expert Martin Schmid, who says: I recently heard from a couple of developers that they had difficulties accessing the Duct Size settings in Revit. In the user interface, you can see them by selecting Manage > MEP Settings > Mechanical Settings > Duct Settings > Round/Oval/Rectangular. I threw together a macro to check... Read more →

Viewport Positioning and Conceptual Design Automation

Not all location relevant properties of viewports are currently accessible through the Revit API, which makes it slightly challenging to precisely define their position. Let us look at a clever trick to align viewports exactly that works around that limitation, sheds some light on their location calculation and the modification of it that was made between Revit 2013 and 2014. After that, I would like to briefly present a non-Revit-API BIM topic, a single-page MSc thesis overview on completely conceptual... Read more →

Set View Section Box to Match Scope Box for Revit 2014

A year ago, we looked at setting the view section box to match its scope box, in particular: How to retrieve the exact geometric location, size and orientation of the scope box. How to set the exact geometric location, size and orientation of the 3D view section box. Dan Rumery of BVN Donovan Hill recently submitted a comment to point out an error in the code presented there: I think you'll find there's a bug in both versions of your... Read more →

AppHack 2, Training Material and the Developer Guide

Let me talk today about the second edition of the AppHack contest, ADN Revit API training material and developer guide. Revit 2013 API Developer Guide PDF As you know, the Revit API Developer Guide is online only and has been so since the Revit 2013 timeframe. I am a great fan of quick ubiquitous immediate access to information, including offline, so I would love a PDF version of it as well. Nor am I alone in this, as you can... Read more →