The Building Coder

Create Dimension between Two Lines

Another one of those recurring questions: how to create dimensioning. I took the opportunity to highlight how to search the samples, find a solution, and apply a correction to RevitLookup yourself. You have the code. May the Force be with you. Question: I tried to create detail drawings programmatically using the ItemFactoryBase NewDimension method. I am creating detail lines in the drafting view based the on the geometry wall elements and would like to use Revit dimensioning to insert measurements... Read more →

IFC Export Area Calculation and Other Enhancements

Here is a typical question that may arise when working with IFC export and shows the importance of the extension possibilities provided by the IFC export open source project: Question: How are the areas and volumes of walls, rooms, floors, etc. calculated for the IFC export? Are any standards being used? Some examples of values and parameters in question when we export IFC files from Revit: For rooms IfcSpace under BaseQuantities: GrossFloorArea, NetFloorArea; these values are the same in my... Read more →

FindElement and Collector Optimisation

As I recently mentioned, Mikako Harada published a very nice article on programmatically adjusting beam cutback. It was followed it up by a description of some commonly used helper methods to find certain named elements and family symbols in a project. One of them is FindElement, implemented as follows in that post: public static Element FindElement( Document doc, Type targetType, string targetName ) { // Get the elements of the given class FilteredElementCollector collector = new FilteredElementCollector( doc ); collector.WherePasses(... Read more →

Disposal of Revit API Objects

KR raised a very valid and important question in the discussion of exporting parameters to Excel: Question: It would be great if you could clarify in broad terms when to dispose of Revit API objects. You underline the importance of disposing of Transaction objects. Many objects in the Revit API implement IDisposable, for example FilteredElementCollector, DB.Document, etc. If I create a new FilteredElementCollector within the confines of Revit API, e.g. in an external command, Idling event handler, external event etc.,... Read more →

Mobile Device Room Location

I had a so-called education day last Friday, and one of our current goals for these days is to learn about mobile and cloud computing. Here is my account of activities and research that day. Please excuse me for exposing my fallibility in this rambling account of a spontaneous unstructured single-person work-in-progress project. The task I set myself was to query the location of a mobile device and determine the room it is located in in the Revit model. That... Read more →

FamilyParameter IsShared Property

A long time ago, we discussed a workaround to access the shared family parameter GUID using reflection, more specifically (and obviously) .NET Reflection. If you are new to this, here is an in-depth Code Project article on Reflection in .NET. Now Victor Chekalin, or Виктор Чекалин, ran into this issue as well and presents a much improved solution. Here is the background and our discussion on this: Question: Why does the FamilyParameter class have no IsShared Property, like the Parameter... Read more →

Exporting Parameter Data to Excel, and Re-importing

Did you observe the international talk like a pirate holiday yesterday? I did not, I'm sorry to say. I only became aware of it this morning trying to find some reason why it was so quiet yesterday. Aaarrr! Anyway, here is an update of an age-old sample application, originally created by Miroslav Schonauer for the very first Revit API training classes after the first introduction of the Revit API back in the Revit 2008 timeframe. Miro put together a whole... Read more →

Picking Two Points Consecutively

Here is a question on picking points while interacting with a modeless dialogue: Question: I want to pick two points consecutively using PickPoint. I am using a modeless dialog, and have a section of code that is called when a button is pressed. However, after picking the first point, an exception is thrown saying "The user aborted the pick operation". Do you have a solution for this? Answer: I implemented a sample application providing an external command PickTwoPoints for you... Read more →

DivideParts in F# and Line Styles

My internet connection died last night. After worrying and testing quite a bit last night and this morning, I laid a temporary cable from my neighbour's router. Shortly after I finished, my own connection came back up again, after about 14 hours downtime. Murphy's law remains valid, as always. Very reassuring :-) There is lots of building work going on nearby, so probably they broke it and fixed it with no explanations given. Anyway, I am back to normal now... Read more →

Apollonian Sphere Packing via Web Service and AVF

Spheres are not as common as planar faceted objects in the architectural domain. In spite of that, this week has been the week of the spheres, after looking at how to generate spherical solids, display them using AVF, and use them for geometrical proximity filtering. We'll round this off now by displaying lots of spheres. A convenient and interesting way to generate a large number of them is to use Kean Walmsley's Apollonian gasket and sphere packing web service to... Read more →

Categories Collection Item Accessor Fails

The document settings categories collection Item property returns null for certain built-in categories, and even throws an exception for certain others. You should be aware of this. I mentioned a related issue back in the Revit 2011 timeframe, describing The Building Coder CmdCategories sample command. Still, this is a bit unexpected and has caused issues for several developers. Here are some examples: Question 1: For some reason I cannot obtain the category for stacked walls, e.g. using Dim cat As... Read more →

Filter for Touching Beams Using Solid Intersection

I discussed how I created my first sphere in the Revit API and displayed it using the analysis visualisation framework AVF. Now let's make more serious use of it. As I mentioned, the transient solids created by the geometry creation utility class can be used to set up geometrical proximity filters. This exploration was prompted by the following query: Question: I would like to programmatically retrieve all touching beams, regardless of whether they are officially connected or not. The user... Read more →

Sphere Creation for AVF and Filtering

I created my first sphere in the Revit API :-) I was slightly surprised that it was harder than expected. The Revit 2012 API introduced the GeometryCreationUtilities class for creating solids. It provides no simple sphere primitive, however. It does provide the following five methods, as described in the What's New listing for the Revit 2012 API: GeometryCreationUtilities The new utility class GeometryCreationUtilities offers the ability to create solid geometry from input curves: CreateBlendGeometry CreateExtrusionGeometry CreateRevolvedGeometry CreateSweptGeometry CreateSweptBlendGeometry The resulting... Read more →

Parts, Assemblies, PartUtils and DivideParts

Let's end this eventful week with another big and imporant topic that we've neglected for much too long. So far, I presented just one single example of using the PartUtils class, and other information provided on it by a Google search is also awfully scarce. Piotr Zurek of CADPRO Systems Ltd improved the situation by raising and promptly answering the following question: Question: I wonder whether you have any sample code showing how to use the PartUtils.DivideParts method. I'm trying... Read more →

Updating Properties and Announcing Revit LT

Today, exceptionally, a second post, partly to highlight an interesting comment submitted by Jinshou on how to programmatically trigger a refresh of the Revit element properties window, and partly to announce a non-API issue, totally non-API, the imminent arrival of Autodesk Revit LT. Refreshing Revit Element Properties If I first invoke the UIApplication OpenAndActivateDocument method, then highlight elements as described in a previous post, the 'properties' window is updated. The trick is that in order to call OpenAndActivateDocument on the... Read more →

IFC GUID Generation and Uniqueness

We looked at IFC GUIDs a couple of times already, e.g. to discuss the relationship between UniqueId, DWF and IFC GUID, the ExportUtils.GetExportId method, and the IFC GUID representation algorithm. The Revit 2012 API introduced the ExporterIFCUtils class for customizing IFC export, and the IFC exporter was released as open source. In Revit 2013, the IFC export implementation switched to a more generic toolkit, many of the APIs introduced in Revit 2012 were removed and replaced, and new interfaces introduced... Read more →

Group My Own Commands in the Ribbon

Here is an issue that has been presented numerous times in the past, and apparently needs to be highlighted again for newbies. Question: I have implemented a Revit add-in which implements several commands. Currently, I have added all my commands to the add-in manifest file, as recommended by various examples I found on the Internet. It works and they do indeed appear in the Add-Ins ribbon tab under the 'External Tools' pull-down menu. The problem with this is that other... Read more →

Video Animated Ribbon Item Tooltip

We already discussed a number of interesting things you can do with the Revit ribbon and user interface, many inspired by Rudolf Honke's exploration of uses of the .NET UI Automation functionality. Here is a related contribution by Victor Chekalin, or Виктор Чекалин, fleshed out from his answer to Rudolf's question on animating a ribbon item tooltip, discussing the retrieval of embedded resource images: It is possible to add your own video to a Revit ribbon button tool tip, and... Read more →