The Building Coder

Autodesk University 2010 Classes

Kean's post on AU 2010 classes yesterday reminded me that I might mention my upcoming classes here as well. The catalogues of both physical and virtual classes have been posted to the AU website: My classes are the following: CP228-2: Optimal Use of New Autodesk Revit 2011 Programming Features, a lecture on Revit 2011 API features in general, on Tuesday 2010-11-30 14:00-15:00. CP234-2: Exactly What You Want and Faster: Autodesk Revit 2011 Programming Optimization, a lecture on Revit 2011 API... Read more →

Modeless Form and Shared Parameter Disappearance

I am still acclimatising to Europe after four weeks in Thailand and Cambodia. So many differences: time zone, temperature, food, health, people... Yesterday I was able to join some colleagues in Neuchâtel for a game of hockey, which is generally the most exhausting sportive event I participate in on a regular basis. I managed to keep up in spite of feeling a bit weak, and was saved by the rain which stopped us from going for the full customary hour... Read more →

Suppress Unwanted Dialogue

I am posting this in advance from Pattaya before leaving laptop-less for Cambodia, so that you have a little something for the duration of my absence. Before I left on vacation, we had several queries on suppressing unwanted dialogues, and we also looked at this issue in some depth discussing editing elements inside groups. Here are some further examples of the questions and solutions we found: Question: I am importing a DWG containing AutoCAD solids into a Revit document. The... Read more →

Filtering for a Non-Native Class

I left Ko Tao by boat and night bus to Bangkok and am now heading towards Pattaya, where my brother Marcus currently lives. Mentioning this to a resident of Ko Tao I learned that Pattaya is renowned for foreign old age pensioners and prostitutes, and a saying says that "good boys go to heaven – bad boys go to Pattaya". Marcus has friends there, enjoys the local bridge club, great transport links, a nice apartment at a good price and... Read more →

ElementParameterFilter with a Shared Parameter

I thought I had already covered everything I could on filtered element collectors, but far failed. Here is a pretty obvious question that just came up on using an ElementParameterFilter with a shared parameter: Question: I have successfully used element parameter filter to find elements with a particular parameter value, using 'built-in' parameters, such as BuiltInParameter.ELEM_ROOM_NUMBER. What I want to do now, is to use a similar filter to find all elements that have a value for a shared parameter.... Read more →

Get Element Type

In the Revit 2011 API, the Symbol class was been renamed to ElementType and some other changes were made to clarify the usage of element types in Revit, which were previously referred to as both types and symbols. Some remnants of the previous naming conventions still exists, such as the FamilySymbol class and the FamilyInstance.Symbol property, but the long-term intention is to move toward calling these things element types instead of symbols. This renaming and restructuring has causes some confusion... Read more →

Transaction Migration Errors

Joo Lee just submitted a comment pointing out an error or two in the flat migration of the CmdWallFooting command, which demonstrates an approach to retrieve the host reference using a wall footing: Question: I tested your CmdWallFooting command in Revit Architecture 2011. But it does not work. The transaction is not started. How can I get the transaction to work? Answer: Thank you very much for pointing this out! This command was flat migrated from Revit 2010 and never... Read more →

Structural Dynamic Model Update Sample

I am away again on the next leg of my extensive vacations this summer, travelling a bit further afield this time. After one night in a plane and another night in a bus I find myself on the island of Ko Tao in Thailand, where I completed my first open sea water dive in the Japanese Garden with Boris of Alvaro Diving. Since I will be away for the whole month of August, I decided to take the computer with... Read more →

Debugging in Visual Studio 2010 Express

Yesterday was the first day of the Revit API training in Munich. As usual, I was able to learn something new. Frank Neuberg of MAX BÖGL assembled and tested the following summary of information sources related to using Visual Studio 2010 and its Express version for creating and debugging a Revit add-in. I've summarized some information sources to set up an integrated debugging process for class library projects together with Revit.exe (2011) in C# Visual Studio 2010 Express Edition: Currently... Read more →

Visual Studio 2010 and the .NET Framework

In section 1.6 'Supported Programming Languages', the developer guide "Revit 2011 API Developer Guide.pdf" in the Revit SDK clearly states that "The Revit Platform API is fully accessible by any language compatible with the Microsoft .NET Framework 3.5, such as Visual Basic .NET or Visual C#." In section 1.3 'Requirements', it also mentions that the programming environment recommended for going through the examples is Visual Studio 2008. That is also the environment used to create and compile all the SDK... Read more →

API Training and AEC DevCamp Material

I am back again from a wonderful holiday in Greece! I spent one week in a retreat centre in the village of Kissos, and then a couple of days on the Banika beach north of Agios Ioannis and south of Chorefton. I was there with a friend, we had a little cooking stove and food for a couple of days, slept on our mats in the sand in a little cave, went swimming and played with the stones on the... Read more →

Modeless Loose Connectors

One of the most enthusiastically received samples I presented at the AEC DevCamp conference has also proved a valuable resource since then, in answering various questions on modeless dialogues and ensuring that the Revit application main window becomes the foreground window in certain situations. It demonstrates how we can combine several ubiquitously useful pieces of functionality that we already discussed in the past to implement a homogenous whole. We create an application which collects information from the Revit model and... Read more →

IFC Import and Conversion Journal Script

In the past, people repeatedly asked how to export a Revit model to IFC. The ability to programmatically save to IFC format has been added in the Revit 2011 API, as we can see from the section 'Export model to IFC' in the Revit API help file RevitAPI.chm What's New section, which notes that the new method Document.Export taking an IFCExportOptions argument exports the document to the Industry Standard Classes (IFC) format. The inverse functionality, programmatically importing an IFC file... Read more →

Revit 2011 Web Update 1

Rather belatedly, I note that the first web update of Revit 2011 was released in the beginning of this month and can be downloaded from the public Revit product pages: Revit Architecture > Product Download Revit MEP > Product Download Revit Structure > Product Download Here is the list of the API enhancements, which is the same across all three flavours: Elements will now be properly joined when the ExternalCommand concludes when using automatic regeneration and automatic transaction. ExportImage(ImageExportOptions) no... Read more →

Place Family Instance

The Revit SDK does not include any example of calling the new PromptForFamilyInstancePlacement method, which prompts the user to interactively and graphically place instances of a specified family symbol, so I am creating a new Building Coder sample command to demonstrate its use. At the same time, I can answer an interesting follow-on question: Question: I am starting to use PromptForFamilyInstancePlacement to get the user to place one or more instances of a family symbol. This method returns void. It... Read more →

Retrieve MEP Elements and Connectors

My colleague Martin Schmid recently asked about the feasibility of listing all unconnected connectors in a Revit MEP model. To do so, the first step is to retrieve all the elements that can potentially have connectors, and then examine their connectors to see which of them are not connected to a neighbouring element. We looked at many examples of using the filtered element collectors in the past. A summary of previous posts is given in the discussion on parameter filters,... Read more →

Do Not Filter For All Elements

One question that has come up several times is how to retrieve all elements from the Revit database. This was the default behaviour in previous releases of the Revit API. In the Revit 2011 API, the filtered element collectors have been intentionally designed to warn you if you try to retrieve all elements in a project, since this is not something that the Revit API designers expect a normal application ever to have to do. However, there are some special... Read more →

Revit API Introduction Webcast Recording

The recording and materials of the Revit API Introduction webcast presented on May 20 2010 by Adam Nagy and Saikat Bhattacharya is available from the Autodesk Developer Network (ADN) DevTech API Training & Consulting page, following the webcast archive link and filtering for 'Revit API' and 'English'. Select the download link to obtain the archive file RevitAPI_20May2010.zip containing the following four files: Revit 2011 API - Intro_PPT.zip Revit API Intro Webcast_May 2010_Recording.zip Revit_API_Intro_Webcast_May_2010_QA.docx RevitLabs.zip They obviously contain the presentation, recording,... Read more →

ClientId Versus AddInId

Looking at many other developers' add-in manifest files here at the AEC DevLab in Waltham, I just noticed that the ClientId tag that I have been using in my manifest files has actually been renamed to AddInId to be more consistent. Most other developers are using the AddInId tag instead of the ClientId one. The ClientId tag still works, but maybe I should start using AddInId myself as well in future. I updated my guidize utility to populate and update... Read more →

DevLab and Birthday

It is Saikat's birthday today, and he is far away from home and family. We prepared a small celebration with flags and cake and a birthday song for him last night: Here is the part of the ADN DevTech AEC workgroup that is present to support the DevLab here in Waltham. From the left: Augusto, Partha, Saikat, Michael (Navisworks team), Mikako, Adam, Jeremy: Happy birthday Saikat! Meanwhile, we are back at DevLab again with a host of exciting developers and... Read more →

To Regenerate or Not to Regenerate...

... that is the question. We already discussed some best practices concerning the regeneration option. A related topic is how often and when to make calls to the Document.Regenerate method, and how to eliminate such calls when possible. One of the issues we ran into during today's DevLab had to do with performance and elimination of extraneous calls to this method. We also learned that the location curve of a newly inserted family instance does not reflect the true insertion... Read more →

DevCamp Session on What's New

Yesterday we had a great start to the AEC DevCamp here in Boston with lots of great presentations and meetings, and ending with the traditional beer bust at the Autodesk offices in Waltham half an hour's bus ride away from the convention centre here in Boston. Today is packed with more presentations, obviously, some of which I will hate to miss since there are multiple tracks and I cannot attend all of them simultaneously. Some sessions will be presented by... Read more →

Element Name Parameter Filter Correction

The AEC DevCamp has kicked off here in Boston and it is great to be here with all the fascinating presentations and exciting meetings with colleagues and developers. Somehow, I am also able to keep up with other issues in parallel, and one of them has been a lively discussion with Kevin Vandecar which prompted the presentation of lots of new parameter filter samples this morning. Kevin pointed out that the method I presented in the filtered element collector benchmarking... Read more →

Parameter Filter

AEC DevCamp begins here in Boston today. I started writing this on Sunday evening, before it begins, waiting in the lobby for my colleagues. Later on: finishing it off after a nice dinner with Mikako, Saikat, Partha amd Miro... Later still: posting it first thing in the morning before breakfast... One area that several people have recently been struggling with is the use of parameter filters. As shown by the filtered element collector benchmarking, the use of a parameter filter... Read more →

Display Webcam Image on Building Element Face

We are now ready to implement RevitWebcam, making use of the webcam image grabber that I presented yesterday. As I explained, the idea is to make use of the new Revit API Idling event which allows semi-asynchronous access to the Revit API. In order to display the webcam image updating itself in real-time on a Revit building element face, I implement the following steps: Select a face on a BIM element. Set up a spatial field primitive for it. Set... Read more →

Add-In Applications for Multiple Revit Products

We recently discussed the add-in visibility mode, which only applies to external commands. The Revit API does not provide a similar built-in facility to control the loading and availability of an external application. This turned out to be an issue for Dave Echols of Hankins and Anderson, Inc., who very friendlily is sharing his solution to this lack with us here: Managing Custom Applications for Multiple Revit Products As a follow-up on and complement to the Add-In Visibility Mode posting,... Read more →

Add-In Visibility Mode

This Monday is the Pentecost holiday in Neuchâtel. I used it to make my first experiments using the add-in manifest visibility mode tag. The developer guide has the following to say about it: Provides the ability to specify if the command is visible in project documents, family documents, or no document at all. Also provides the ability to specify the discipline(s) where the command should be visible. Multiple values may be set for this option. Optional; use this tag for... Read more →

Determine Sheet Size

We already discussed some issues related to sheets and title blocks, such as the relationship between viewports and sheets and how to retrieve the title block of a sheet. Here is a question on determining the size of a sheet which provides an opportunity to update these explorations based on the Revit 2011 platform. Question: Using the pre-release 2011 RevitAPI.dll I was able to detect the sheet width/height by iterating the ParameterSet collection for each element in the ViewSheet.ElementSet object.... Read more →

RevitLookup Update

I recently mentioned RevitLookup, the new incarnation of RvtMgdDbg, which is now included in the Revit SDK, and so did Matt Mason. The version provided in the initial release of the Revit 2011 SDK had several pretty fundamental problems. We are in a continuous process of improving it, and now have a version available with the following enhancements: ElementType instances Revit MEP connectors Revit Structure analytical model Retrieving all Revit Database Elements Regarding the ElementType instances, the initial version for... Read more →

RevitAddInUtility for 32 and 64 Bit Systems

We already discussed the RevitAddInUtility, a stand-alone .NET assembly providing its own API for manipulating add-in manifest files and determining Revit installation information. People are starting to make serious use of it now, which led to the following question that popped up several times in the last couple of days, among others in this comment by Joel, saying: Question: I am trying to create a single installer for both 32 bit and 64 bit but it seems that RevitAddInUtility.dll is... Read more →

Cable Tray Orientation and Fittings

In the overview of the Revit MEP 2011 API, I mentioned that new elements have been introduced to represent cable trays and conduits. We already had a look at the creation of new conduit elements in the pipe to conduit converter. The creation of cable tray elements is equally simple, making use of the static Create method on the CableTray class. This is another example of the new element creation paradigm instead of the creation document classAutodesk.Revit.Creation.Document, a second generation... Read more →

Solar Radiation Technology Preview

The solar radiation technology preview for Revit 2011 is now available. It helps understand and quantify solar radiation on the surfaces of a conceptual building model. This can help make informed design decisions about building shape, orientation, and shading strategies early on when changes are least expensive. A new version was just released, including many improvements and closer inntegrated in the Revit user interface: One aspect of interest to application developers is that this plug-in is written entirely using the... Read more →

The Revit Structure 2011 API

Since I talked about the Revit MEP API yesterday, I should be fair and mention the Revit Structure API as well, shouldn't I? Last year, we provided an overview over a number of Revit Structure resources, including pointers to the structure related webcasts, samples, trainings and Autodesk University classes available in the Revit 2010 timeframe. Here is a quick tour by Joe Ye of what has changed in the Revit Structure 2011 API as well as new enhancements. Changes in... Read more →

The Revit MEP 2011 API

Revit 2010 and 2011 both put a strong focus on the development of Revit MEP, both from an end user and a programming point of view. The API features provided with Revit 2011 provide important new functionality for Revit MEP add-in developers. Of course, the entire platform API features such as dynamic update, analysis visualization, user interface integration, selection mechanism, transactions and other enhancements are applicable and extremely useful to MEP add-ins as well. A number of additional MEP specific... Read more →

Pipe to Conduit Converter

I am pretty busy right now, both with day-to-day work answering cases and preparing training material, and also preparing for upcoming events. These include: Revit Programming Webcast on May 20 (register). DevCamp conference on June 7-9. DevLabs in Waltham, USA, on June 10-11 (register). DevLabs in Munich, Germany, on June 21-25 (register). Autodesk University ... still far away in the future, but some preparations already have to be made. Lots and lots of vacation this summer! Due to all that... Read more →

Get Type Id and Preview Image

It seems like there is an infinite amount of new functionality in the Revit 2011 API. Here is another little item that I was not aware of before, even though it is listed clearly in the What's New section of the Revit API help file RevitAPI.chm, which says: Extract image of an ElementType The new method ElementType.GetPreviewImage extracts the preview image of an Element Type. This image is similar to what is seen in the Revit UI when selecting the... Read more →

Detail Curve Must Indeed lie in Plane

The day before yesterday, I mentioned that the geometry curve used to define a detail curve must lie in the plane of the view displaying it. This requirement has always been there, in theory, but it was not strictly enforced in previous versions of the API. As mentioned, the NewDetailCurve method now throws an assertion if the curve passed in to it violates this condition, and so does NewModelCurve. Two other questions arose in this context, and the second one... Read more →

AutoJoinElements

I just heard that there is an issue with the Document.AutoJoinElements method. This gave rise to a discussion which raises some interesting points and is worth sharing. For those of you not familiar with this method, here is the brief description from the Revit API help file: AutoJoinElements forces the elements in the Revit document to automatically join to their neighbours where appropriate. Use this method to force elements in the document to automatically join to their neighbours. Note that... Read more →

Detail Curve Must be in Plane

Here is a recent case concerning some Revit API behaviour that changed in the new release. Question: Were any major changes applied to the NewDetailCurve method? In the Revit2011 API, I am getting an error saying "Curve must be in the plane". Do I now have to project the curve object onto the plane myself, or is it still taken care of automatically like in Revit 2010? The code I am calling looks like this: DetailCurve detailCurve = doc.Create.NewDetailCurve( doc.ActiveView,... Read more →

Filter for Views and the IsTemplate Predicate

Several people encountered issues when retrieving views in Revit 2011. The reason is that the most direct approach to filtering for view elements using the new element filtering also returns view templates, which were not accessible in the Revit 2010 API. Here is the initial issue: Question: I tried to extract all PlanView elements from the model and found something weird: besides the expected and obvious plan views such as Level 1, Level 2 and Site, some other unexpected ones... Read more →

Add-In Manifest and Guidize

Developers have always had a lot of complaints about the Revit.ini add-in registration facility. It was hard to access and modify the file in the Revit installation directory and the same file is shared by all users. Revit 2011 offers a completely new and vastly improved add-in registration facility using add-in manifest files. The new mechanism supports a number of new options and there is no reason to continue using the obsolete Revit.ini mechanism. Let's have a look at this... Read more →

Asynchronous API Calls and Idling

I discussed the Idling event yesterday, and since received a note from the venerable Revit API guru Guy Robinson who finds this new event just as momentous and exciting as I do and therefore promoted it to the Revit 2011 API standout feature. If Guy likes it, it's the real thing, for sure. Since this once again dives full into the topic of controlling Revit from an external application or a modeless dialogue, here is a very apt comprehensive summary... Read more →

Idling Event

One of the most exciting of the many new Revit 2011 API features which opens up completely new possibilities for applications to interact with Revit is the Idling event. The What's New section of the Revit API help file RevitAPI.chm describes it as follows: The new event UIApplication.Idling is raised when it is safe for the API application to access the active document between user interactions. This event is raised only when the Revit UI is in a state where... Read more →

Matt Mason's API News

I just noticed from Matt Mason's comment on the plug-in migration steps that he is running a very interesting series of posts on the new Revit 2011 API as well. Here is his current table of contents: Upgrading Existing Revit API commands/applications New Deployment Methods The New UI vs. Database split. New Ribbon Capabilities Element Iteration Changes Ooh-ooh Pick Me! New Selection Methods Dynamic Model Update Event Model Changes RevitLookup: The New RevitMgdDbg What’s New in Element Creation? What Kinds... Read more →

Failure API

A very frequent question from developers in the past has been about suppressing various warning and error messages in Revit. One of the many new Revit 2011 API features specifically targeted at allowing an add-in to integrate very tightly with Revit and its user interface is the new Failure API, providing the ability for an add-in to react to and suppress failures as well as define its own new ones and post them. This is the description in the What's... Read more →

Plug-In Migration Steps

We discussed the migration of The Building Coder samples from the Revit 2010 to the Revit 2011 API and noted some of the required steps there, but skipped a lot of the obvious and onerous detailed information. Luckily, my colleague Joe Ye was more patient and precise when he migrated our Revit Structure labs and analysis link sample, and kept track of the required steps in great detail. So, without further ado, here are Joe's Revit 2011 plug-in project migration... Read more →

Regeneration Option Best Practices

Our discussion of the risks of using the manual regeneration option triggered several very interesting comments and suggestions. Here are some important fundamental things to note about the regeneration modes: The automatic mode is not new. It is the mode that Revit has been using all along so far. Developers complained that it is too slow, so we introduced the SuspendUpdating mechanism and now the manual option, providing more and more optimisation possibilities. There is no need to overcomplicate things.... Read more →

Revit 2011 API Webcast

Here is a last-minute reminder to register for the Revit 2011 API webcast that we are holding on Wednesday April 21st, in eleven hour's time. To register, you can visit the Autodesk Developer Network (ADN) DevTech API training schedule site, filter for 'Revit 2011 New APIs', and click on the register link. This webcast is open to all developers, regardless of ADN membership. Sorry for the late notice, I was too caught up in the discussion on the regeneration option... Read more →

Retrieve Stairs on Level

As mentioned in the discussion on selecting model elements, stairs are not represented by an own class in the Revit API, but using the generic Revit Element class instead. They do have a valid built-in category assigned to them, however, which makes it easy to retrieve them from the database and use the generic element and parameter access to retrieve and modify a lot of their data. We also discussed other aspects of stairs in the past, such as listing... Read more →

Manual Regeneration Option Danger

Here is a serious issue that several developers have already run into when migrating to the Revit 2011 API, including myself. It sometimes causes pretty obscure errors which are hard to understand and very easy to resolve, once you understand the source. Obviously it is best and most efficient to completely avoid running into the problem at all, which I hope this post will help you do. The issue is the regeneration option, one of the required attributes that must... Read more →