The Building Coder

Back from The Conference Tour and Wrapping Up

Things have been a bit hectic the last couple of weeks, just like every December, what with Autodesk University and the DevDays Conferences.

I am still cleaning up various open issues and looking forward to settling down into Christmas real soon now.

Here are a couple of items to share from the last few days:

• AU 2014 classes online
• Family type preview images
• InfraWorks 360 REST API
• Moscow DevDays, Meetups and Hackathon
• Milano JavaScript Meetup
• I Love 3D
• More Wrapping Up to Come

AU 2014 Classes Online

The classes from Autodesk University 2014 are now accessible online.

Here are links to the classes on demand and the search entry point.

Family Type Preview Images

Question: I am writing a Revit add-in app. Part of its functionality is to display images of families, furniture, windows, etc.

Can you point me to some code examples for this functionality?

Answer: You can simply call the Revit API ElementType.GetPreviewImage method.

Here is a really old example from May 2010 of reading a preview image.

It introduced a new external command CmdPreviewImage in The Building Coder samples, which nowadays live in the The Building Coder samples GitHub repository and therefore have been continually updated for the current versions of Revit.

InfraWorks 360 REST API

I don't normally deal much with InfraWorks.

However, it was on my plate during the DevDays conferences as part of the AEC and infrastructure sessions, so here is a query on it that I happened to be involved in:

Question: We have been using InfraWorks since the first release and see a lot of potential in the product. We are very curious about the REST API and have a couple of questions about it:

• Is the REST API read-only or can the users edit data through the REST API? For example, what if a municipality has a model for a city plan and wants to gather comments about the plan from the citizens. It would then be great if we could, through the REST API, grab an object from the model, for example a surface, publish it, and make the attributes on the object editable to the user. We have been working with mapguide-rest and the GeoREST API for this type of editing and publishing.
• Will we be able to publish the model through a server or is it limited to Autodesk 360?

Answer: Thanks for reaching out. We are indeed releasing an InfraWorks 360 REST API, which is currently available as part of our Beta program. The API is used to read model data, such as lists and detailed element information. The models are published using the desktop client of InfraWorks 360, like any other model, by syncing it to the cloud, from where it becomes accessible through the API.

Here are some links with more information:

• The InfraWorks 360 REST API at Autodesk University
• Importing alignments from InfraWorks 360 to Civil 3D
• InfraWorks 360 REST API Tech Preview

Please get in touch with Augusto if you would like to use the InfraWorks 360 API so we can discuss and ensure we provide all you need.

Moscow DevDays, Meetups and Hackathon

In between wrapping up the past, I am also looking toward the future, planning the beginning of next year.

I will be going to Moscow for the Russian DevDays conference and meetup on January 29 next year. In a way, that is wrapping up as well, isn't it? That will be the last conference in the worldwide series.

If you happen to be around during that period, I would love to see you there!

I Love 3D at the Next Milano JavaScript Meetup

I had a great time at the Milano DevDays conference and meetup event last week.

The other meetup participants were pretty thrilled as well, so we went right ahead and organized another meetup there at Milano JS – il DOM di Milan! on February 10 next year.

Here is the latest version of my blurb for that:

I Love 3D

For web designers and software developers, we will show how to make 3D models on the web much more immersive and engaging. We'll also check out 'VR on the cheap', real virtual reality using Google Cardboard.

You may have created fantastic 3D designs. Isn't it frustrating that your website is all in 2D? Now you can also easily embed interactive, intelligent, truly stunning 3D models into your web page, web application, or desktop application.

WebGL is a powerful technology for enriching the web with interactive 3D graphics. How do we get it into the hands of the people, provide easy general access to everyone? I'll walk through all aspects of publishing and delivering 3D models on the web through a simple easy pipeline, providing a powerful 3D web graphics tool for programmers, designers and artists alike. Based on WebGL and three.js, it enables you, your friends and your customers to interact with the 3D model and query all the element metadata.

I also demonstrate how this engine can be elevated to the next level by delivering a stereoscopic interface to 3D models through a simple web page and Google Cardboard VR with no need to invest lots of money in complex equipment or hours of time preparing and publishing your model.

For an entry point to get started and learn more about the Autodesk 3D web technology, check out developer.autodesk.com.

See a full demo app at autode.sk/m3w.

For more details on this topic, please refer to the Autodesk View and Data API topic group.

By the way, if you are not aware of Kean's series of posts on the Google Cardboard stereoscopic 3D interface, you should definitely take a look right now:

• Gearing up
• Part 1
• Part 2
• Part 3
• Speech recognition

More Wrapping Up to Come

Tomorrow is my last day for wrapping up before the break. Still lots to do...

Oh yes, and after wrapping up the work related items, I have to get going on Christmas presents, too!

The Revit API Panel at Autodesk University

The Revit API expert panel session took place directly after the keynote sessions and lunch yesterday.

Before getting to that, let me mention that for the first time after half a decade or more of working closely together in the ADN DevTech AEC team, I was finally able to shake hands with my ex-colleague Ye Xiong Jin (叶雄进), better know to us as Joe Ye.

Joe is now independently active with his own company www.gisbim.com or Mount of Olives, pronounced Gan Lan Shan (橄榄山).

It was a great pleasure to finally meet face to face.

Thank you, Joe, for the good times and fruitful projects we shared.

Revit API Expert Panel

So, now, here are notes from the AU session SD5156 – Revit API Expert Panel – Open House on the Factory Floor:

• Summary
• Panellists
• Participating Companies
• Notes on the Q & A

Summary

SD5156   Interact with a panel of Revit API experts from Autodesk to answer your questions and discuss all relevant topics of your choice. If you are writing add-ins for Revit, then this is the perfect forum to get to know the people who shape the APIs you work with better and explain your views, ideas and needs directly face to face. Please note that prior .NET programming and Revit programming experience is required and that this class is not suitable for beginners.

Panellists

• Adam Nagy, ADN
• Andrzej Trelinski, Revit Development
• Angel Velez, Revit Development
• Jeremy Tammik, ADN
• Mikako Harada, ADN
• Miroslav Schonauer, Autodesk Consulting
• Saikat Bhattacharya, Autodesk Consulting

Participating Companies

AE7, aec factory, AECOM, Acco Engineered Systems, Andekan LLC, Ankrom Moisan Architects, Autodesk, BMMPM, Betech Data A/S, Boulder Associates Architect, Building Data LLC, CADtoWIN, CASE Design Inc., CH2M Hill, Cansel, Daiwa House Industry, Design Automation Systems Ltd, dRofus, Dørteknikk AS, E+M Consulting Engineers, EIC Engineers Inc., Environmental Systems Design Inc, Excitech Ltd, First Solar, Gensler, Goettsch Partners, H.H. Angus & Associates Ltd., HDR Engineering Inc., HOK, Halvorson and Partners Structural Engineers, Hankins & Anderson Architects & Engineers Inc., Harley Ellis Devereaux, Henderson Engineers, hsbCAD, Hydratec Inc, ICA BIM, Inviewlabs Ltd, Ideate, Jacobs, KCL, Kozo Keikaku Engineering Inc., KTGY Group Inc, kubit GmbH, L.A. Fuess Partners, LBBAE, Leviton Network Solutions, Lighting Analysts, MARTA, MWH Global, MacDonald-Miller Facility Solutions, Magnusson Klemencic Associates, NBBJ, NetOnApp LLC, Nucor-Vulcraft/Verco, PTAC Consulting Engineers, Permasteelisa Group, Project Frog, Prota Computers Inc., Quickpen, RTKL Associates Inc, RTV Tools, Revolution Design Inc., Rosendin, SGA Design Group, SOFiSTiK AG, STV Inc., Skidmore Owings & Merrill, SmithGroupJJR, Southland Ind., SrinSoft, Stantec, Sumex Design, TLC Engineering for Architecture, Taisei Corporation, Target, Tekfen Engineering, ThyssenKrupp Elevator Americas, URS, Victaulic, Vinci construction france, Weaver Custom Homes, Wegmans Food Markets, Weidlinger Associates, White, Woods Bagot, Wye River Technologies.

Notes on the Questions and Answers

After the fact, I also added two comments from Arnošt Löbel, who was not able to attend in person.

Q: Performance enhancements, selection sets, deselecting just a few items is very slow, because we seem to be re-selecting all the rest of them. How can we deselect just a couple from hundreds or thousands? It seems to be re-rendering the whole screen.

A: We are not aware of this. Please submit a reproducible case for us to explore and fix. We are working hard at improving all aspects of performance, so stay tuned.

Q: Read the materials, rendering, texture?

A: We have much too limited access to that and are aware of the issue. One hack is through the custom exporter API. You can read the texture image. Read-only, obviously. Background info: this is due to a common Autodesk component used across all products, no API available, we are pushing for more material library access. Arnošt adds: It is not accurate to claim that you can access visual material images via the custom export. The image available in the MaterialNode is an image of the material tile, intended to be used in the Material dialogue. Even if it is available at all, it can hardly be used to display the material as rendered.

Q: Ceiling parameter and elements, trying to find surface loop. I have edges of the 3D solid.

A: We can look at your code in the DevHack in a moment, directly after this session. You are looking at the sketch, like for a floor. Here is a workaround to access the sketch model lines: delete this ceiling, monitor the deleted elements, grab their ids, roll back, and use the element ids to access the model curves. You know the solid and have its edges. This gives you the ids of the edges of the sketch. Assuming the ceiling is flat, not wavy, you can use the ExtrusionAnalyzer class to determine the closed loop.

Q: A philosophical, future directed question: third party developers can develop and add behaviour to the drawings. You seem to be moving towards the cloud. Where do you see third party developers contributing? Current APIs seem focused on distributing content. We want to add behaviour and logic into the model. Where is the support for that?

A: This is the exact optimal point in time to make your suggestion and you will certainly be heard with great interest. There is lots of scope for logic and behaviour in all areas, including cloud and mobile. You need to tell us what you need. Autodesk as a whole is looking for innovative ideas and we are certain that API centric platforms are better than dumb products. Revit is still evolving further in that direction. We cannot imagine all the things you need and are thinking. Let's talk! All our cloud stuff is still very much in an experimental stage, and how to hook up the products with each other. Cloud does not mean desktop is going away. We just have more opportunities to hook up components and do additional stuff. Whether Revit is in the cloud or on the desktop is irrelevant. Same program, no difference, same functionality. Add-ins will have to be supported there too.

Q: I find the Revit API very restrictive. That is frustrating.

A: This is due to the BIM parametric requirements. Revit requires strong control. History: when Revit started in 1988, there was zero API and the founders were opposed to the whole idea. That changed. We had an initial first stage of hard-wired API development. We have now moved to a second stage where API is automatically generated for all new functionality. Some of us experienced a similar shock moving from e.g. the AutoCAD API to the restrictive Revit one. Revit comes with a quite immense set of rules. You have to accept and get used to this. It has certain advantages. There is no way around it. Can be painful. It will get better, in the end.

Q: Regarding cloud: it is not irrelevant whether Revit is in the cloud or not. On my desktop I can install anything I like. If it is on the cloud I can install nothing. How can a developer publish apps on Revit cloud services? Are there plans for that?

A: We are pushing for this. We looked at something like this for AppStore published apps. Could we automatically cloud-install such apps? We have not forgotten about this, we are working at it. Big mission to make sure this happens.

Q: I am an API novice and I worked with Dynamo. The documentation is in C# and VB. Will there be more in Python?

A: No plans that I am aware of. You can compile to IL, .NET intermediate language, and decompile to any other language you please, e.g. using Reflector. Documentation alone is a big thing. Look at the IronPython Revit Python Shell, also Ruby.

Q: Does the current API support copy/monitor? I have an architectural model and want to copy/monitor. I can programmatically go in and copy objects, but have not found a way for copy/monitor. I want to copy elements out of a model into another one and monitor them. This is available as a Revit command. We want to drive copy/monitor fully programmatically without the user having to manually select the elements.

A: You can copy the elements and add a DMU updater to monitor them. This is a lot of work. Or use the built-in Revit command as is? Hard to drive the Revit built-in command fully automatically, PostCommand switches to the standard user interface and prompts for input, e.g. selection. Maybe you can preselect the elements and then call PostCommand? Nope, apparently not. If not, this might be added as a wish list item. Please submit a reproducible case and a wish list item.

Q: We also need copy/monitor. Linked monitor to control visibility of linked model. I have lots of towers, e.g. 20-30. I need to set the visibility of linked structural models. Maybe we have 20 small Revit models. We also need API to select elements in the linked models.

A: I want that too in linked IFC files. There is no API for that. Better view visibility control for linked objects is needed. We are expanding the linked API. Linked documents are listed in the application Documents collection. Workaround: You need to unload the link before making modifications to the linked document. We ended up setting up an interface to select elements in a linked model by grabbing the GUID and, behind the scenes, in a new session, bring those GUIDs back in and hide each one individually, then reload. This requires two Revit sessions. I had the same issue of controlling visibility in linked model and the critical issue in my case was we had to wrap individual models and linked views; it was a kind of painful nightmare. The API does in fact provide a method to get the monitored element of another element: Element.GetMonitoredLinkElementIds. However, is there a way to set this? (Thank you, Eric!)

Q: How to store changes in the model? Store the changes in a separate external database? Store in Revit parameters?

A: I have done this utilising the DocumentChanged event. You can grab the modified element ids and their data. It is just tricky for delete. You would have to cache data for deleted elements before they are deleted. I set up a check box in Revit to let the user control this. There may be an exchange app store add-in already provides this functionality. Joel Spahn can provide info as well :-)

Q: Issues getting access to work lanes. Face based families hosted on the wall. How to find which face of the wall the instance was hosted on?

A: Send us a case; we'll take a look.

Q: Many pain points are with existing Revit commands lacking an API. Is there an active effort to make absolutely all commands accessible programmatically? I need access to absolutely everything. Can we handle wishes such as this in a public forum, e.g. 'user voice'?

A: PostCommand was a big step forward. Request anything you need. Every little thing you need. We cannot know what you need. We just do what we think is important, unless you ask us specifically. Another hard decision: should we rework old API, or just abandon it? Either way somebody will be unhappy. Old things break, or new things are hampered. It is OK to say you want everything missing, but important is also to list the top ten. What will you really use? This is what the yearly API wish list survey is for. We take this very seriously and prioritize based on this input. You can also submit wish list items via the Revit API forum. Mikako will look into this. Andrzej gets wishes from ADN, then if more input is needed looks at the Revit API forum and tries to track the problems there based on frequency and rates their importance accordingly. Arnošt adds: I kind of do not like this answer (or the question, as a matter of fact :-). This is not what the API is for, and it is very hard to bend it that way. The Revit UI was not laid out to be invoked by external applications ad hoc. It was designed to work with the end-user only, and certain workflows are expected (and indeed enforced). In my opinion, if the user wants full-blown script-ability, they can a) use the journal, or b) we would have to develop a completely new scripting platform. I am not saying I do not understand the request and the desire for it – I just state the facts as they are. Boy I wish I had been there! ;-)

Q: Is it possible for the Revit API to expose element relationships? Revit know everything. How can I get access to that information? For example, to re-host a door, to access sketch lines of the floor, a central API to expose all these relationships. If you pick into a system of pipes, you can tab through the selection to get various levels of connectedness.

A: Simply let us know what connections and relationships you are looking for. The host property of a door specifies its host. If we find something that you need, we will happily expose it, of course. Or ask for specific needs. It looks as if we are exposing some of this and not all.

Thank you for participating!

Keep in touch!

Autodesk University Keynotes

Here are some notes I took this morning at the keynote presentations by Jeff Kowalski, Carl Bass and Emily Pilloton:

• Jeff Kowalski
• Carl Bass
• Emily Pilloton
• Jeff and Carl expanded

Jeff Kowalski

Machine learning and generative design.

Identify existing components and their relationships.

Tell the computer not what to do and how to design, but give it the goal we want to achieve.

Computationally grow structures.

Two new kinds of technology: intelligent taxonomies: build new work on all the best existing.

Explore further; don't reinvent the wheel every time by starting every project from scratch.

Bring life to the design process.

Overcome planned obsolescence by designing products that sense, respond and collaborate.

Replace Internet of things, which is often just an Internet of one single isolated thing trying to talk with its owner, by a community of designed collaborative objects.

Take nature's strengths and technology and intertwine them to transcend both.

Carl Bass

Capturing reality, point clouds.

Infraworks builds a complete model from all available data.

A360 for collaboration: a free one-year subscription is available to all AU participants.

Fusion 360, the world's first cloud based mechanical CAD product with all the tools required to design and engineer projects plus, more importantly, the tools to understand and collaborate integrated right in.

Branch and merge designs, collaborate, use any device or platform.

TinkerCAD: cloud based design tool for kids.

Getting involved in the real world. Keyboard and mouse were insufficient for input, so is paper insufficient for output.

Enter the 3D printer – still in its beginnings, like the first version PC or first cell phones.

Spark, a free open platform for 3D printing.

$100 million Spark investment fund to support innovation.

Resolution is down to tens of microns.

Open software, open hardware, open materials: spark.autodesk.com/ember-explorer.

Future of making not just 3D printing: also robotics.

3D printing of stainless steel, use in architectural projects, etc.

Unique objects, not just batches of thousands, e.g., panels in a new SF house.

BIM 360 fastest growing product we ever had.

Point layout to query the BIM model and correlate with field reality.

Subscribe to Autodesk: access to any and all tools for a single price, for use on any platform anywhere in the world.

Emily Pilloton

Emily Pilloton of @ProjectHDesign is an architect who gave up her previous career to reconnect to her love of creating, teaching and building, academia and transformation for students and communities.

Why: One kid said, "I want to return to this town and say 'I built this'."

What: A school class said, "We needed a library, so we built it ourselves."

Who: young people, 8, 9, 15, etc., e.g., "I'm a ten-year old girl and I know how to weld. What can't I do?"

We as adults have a responsibility to share what we do.

I, Jeremy, fully agree with that wonderful inspiring statement; it matches exactly what I think and invest energy in through The Building Coder.

This was a really moving presentation for me and I was deeply touched.

Back to Carl: young people are our most important resource and greatest hope.

All Autodesk software is now freely available to any student anywhere in the world.

Addendum

For a much more complete summary of Jeff's and Carl's keynote remarks, please refer to Scott Sheppard's #AU2014 keynote summary part 1 and part 2.

DevDays Conference at Autodesk University

Today we held the DevDay Conference at AU. Exciting stuff.

Before getting to that, let me add one little Revit API exploration that I performed much later in the day, getting closer to midnight, after the ADN party; prompted by my colleague Katsuaki Takamizawa in Japan, I migrated the old Revit 2012 GeometryPartsAnalyzer add-in analysing detailed part layer geometry by splitting selected walls into parts in a temporary transaction using PartUtils.CreateParts to Revit 2015.

• GeometryPartsAnalyzer retrieving detailed wall layer geometry migrated
• The DevDays 10x theme
• Autodesk Exchange
• Fusion 360
• The A360 platform – from beta to production
• Virtual reality for the masses – and you too!
• Afternoon breakout sessions for desktop platforms
• Still a chance to join!

GeometryPartsAnalyzer Retrieving Detailed Wall Layer Geometry Migrated

Back in the Revit 2012 time frame, Marcelo Quevedo implemented the GeometryPartsAnalyzer add-in for retrieving detailed wall layer geometry.

That is an interesting tool and demonstrates interesting technology that is still useful and important today, touching on the topics of retrieving detailed wall layer geometry, splitting an element into parts and making use of the temporary transaction trick.

To migrate to the current version and keep clear track of the exact steps taken, I published it in its own new GeometryPartsAnalyzer GitHub repository and created a release before and after each migration step, so you can now easily see the exact differences caused by moving from Revit 2012 to Revit 2014 and from Revit 2014 to Revit 2015.

OK, so much for that. Back to the main event of the day:

The DevDays 10x Theme

This year's DevDays conference theme is 10x

A fundamental disruption of the software industry is happening right now, and there is no way for anyone to avoid it.

Let's examine this opportunity for Autodesk and all partners to take advantage of it to grow our customer base by 10x and revenue by 2x – an opportunity like this only comes by once in twenty years – seize it now or risk becoming irrelevant in the next couple of years.

Our tour of DevDays 2014 developer conferences completed in Asia and Australia in November.

I am attending it here at Autodesk University in Las Vegas today and in the Western European venues in the coming two weeks: Paris, London, Gothenburg, Munich and Milano.

There is still time to apply to join us there (cf. below) – come and learn how you can take advantage of new technologies to grow your business reach by a factor of ten.

The DevDays events have always been the best way for Autodesk Developer Network partners keep up to date with new and upcoming technology and features. Now let's leverage what we are doing to expand with new technology and to new customers.

We cover the Autodesk cloud and mobile APIs and, of course, new features and APIs for the desktop products too.

Autodesk Exchange

Jim discussed improvements made to the Autodesk Exchange AppStore, current trends, how to grow towards more sales.

Philippe demonstrated real code showing how to maximise sales by taking advantage of the term based sales and entitlement REST API (2, 3) and how to sell web services on the store.

Fusion 360

Jim demonstrated Fusion 360 as an example of powerful 3D design in a browser and as a web platform.

It supports mixed direct and parametric modelling with tightly integrated advanced T-spline based surfacing.

Using Fusion 360 and a desktop 3D printer, Jim shows how 'rapid' rapid prototyping really can be today.

The platform supports JavaScript and Python scripting (cf. Fusion 360 Learning and Resources > Programming Interface) based on the open source Brackets IDE.

Back to the Autodesk View and Data API, Jim demonstrated live publishing of 3D models in both a blog hosted by Typepad and his personal Facebook page. Less than 60 seconds each.

As Jim keeps saying, "Easy – why would anyone nowadays want to publish any model in anything but 3D?"

The A360 Platform – from Beta to Production

The Autodesk A360 platform includes web services for Identity, View and Data, Create, Simulate, Collaborate and Business.

The Identity and View & Data web services are now going into production, so we looked at code samples for that.

Virtual Reality for the Masses – and You Too!

DIY virtual reality is easily achievable today using the View and Data web service API in conjunction with the low or zero cost Google Cardboard system.

Surprise and impress your friends, colleagues and – above all – customers by delivering your models in stereographic 3D virtual reality with just a few hours or less of work.

Afternoon Breakout Sessions for Desktop Platforms

In the afternoon, we split into three separate parallel tracks: desktop, cloud and mobile and the 'programmers corner'.

The desktop track focuses on news concerning the AutoCAD, Civil 3D, Inventor, Revit, Vault desktop products and their API enhancements.

In cloud and mobile, we take an in-depth look at BIM 360, Field, Glue, Fusion 360, and View & Data future directions and yet more code samples.

The programmers corner is for anyone who wants to chat with ADN and other engineers and is momentarily not interested in the other sessions.

I can't say much more about these here and now in public, obviously... if you have not been to DevDays yet and there is still one coming somewhere close to you in the next few weeks, i.e., if you are located in Europe, grab the chance to come and see for yourself – and say hello:

Still a Chance to Join!

Look for more information, locations and schedule at www.autodeskdevdays.com. ADN members, register via that website. Non-ADN members, please contact us at devdaysinfo@autodesk.com. Material demonstrated and discussed at DevDays is confidential and under Non-Disclosure Agreement.

The DevDays 2014 Conferences Have Started

Our tour of DevDays 2014 developer conferences in 16 cities around the world from November through January has started.

Our indefatigable leader Jim Quanci is already on the road, this time accompanied by Philippe Leefsma, attending all of the venues world-wide.

I will 'just' be attending the DevDay conference at Autodesk University in Las Vegas and all the Western European venues: Paris, London, Gothenburg, Munich and Milano.

Here is Daniel Du presenting the zero client WebGL based Autodesk View and Data web service API at DevDays Beijing:

The theme this time is 10x

Join us at DevDays 2014 to learn how you can take advantage of new technologies to grow your business reach by a factor of ten.

Got great ideas for cloud and mobile apps? Want to know where Autodesk is going with cloud, mobile, desktop and other innovative technologies to grow its business in the near and longer term?

Our annual DevDays events have always been the best way that our Autodesk Developer Network partners keep up to date with new and upcoming technology and features. This time we're showing you how to leverage what Autodesk is doing so that you can expand your customer base with new technology and new customers.

If you are serious about developing on Autodesk platform technologies and have not yet attended an Autodesk Developer Network Conference, join us for a deep dive into a whole range of products and services. We'll be covering Autodesk Cloud and Mobile APIs, including quick reviews of the View and Data API, Fusion 360, BIM 360, Infraworks 360, AutoCAD 360, and AutoCAD Core Engine Services APIs. Of course, we will be covering new features and APIs for our upcoming desktop products too.

DevDays is a traditional road show to 16 cities worldwide for the benefit of members of the Autodesk Developer Network. However, we're happy to hear from – and help – innovators, forward thinkers and companies just getting started, so even if you are not an ADN member and are interested in this event, we invite you view the information, locations and schedule at www.autodeskdevdays.com. ADN members can register via that website. Non-ADN members can contact us at devdaysinfo@autodesk.com. Material demonstrated and discussed at DevDays is highly confidential and under Non-disclosure Agreement.

Autodesk Open Source All Over – Germany and Japan

Here are some notes on Autodesk Open Source involvement from AU Germany, the Japan hackathon, and two other nice topics for today:

• Autodesk University Germany
• Japanese View and Data API hackathon projects
• CAD Term Translation
• Cool presentation gimmick

Autodesk University Germany

In the keynote session, Carl Bass introduced Spark, Autodesk's new 3D printer and total commitment to open source:

• Connected – Spark connects digital information to 3D printers in a new and streamlined way, making it easier to visualize and optimize prints without trial and error, while broadening the range of materials used for printing.
• Open – Because the Spark platform is open, everyone – from hardware manufacturers, to app developers, to product designers – can use its building blocks to further push the limits of 3D printing and drive fresh innovation.
• Free – To encourage any and all members of the 3D printing industry to not only participate in Spark, but also to fuel it forward, Spark will be free to license. Together, we can accelerate the new industrial revolution.

All plans and details of the mechanical construction, electronics, materials, everything about the printer is open source and can be freely reused by anybody.

You can buy the Autodesk printer or use the freely available plans to build every single piece of it yourself.

Obviously, this also enables the entire open source community to participate and improve these plans.

Special invitation to students, universities and research institutes of all kinds.

Where is the development heading? Commercial versus open source?

Another interesting indication of Autodesk's involvement in open source can be had by taking a look at the threejs.org open source project web site, where Autodesk figures quite prominently:

The third from the left in the top line is autodesk360.com, and the Udacity entry in the bottom left is from Autodesk as well:

Eric Haines, Instructor, is a Senior Principal Engineer at Autodesk, Inc., working on a next-generation interactive rendering system for computer-aided design applications. He is a coauthor of the book “Real-Time Rendering”, a founder and editor of the Journal of Computer Graphics Techniques, and maintainer of the Graphics Gems code repository, among other activities. He received an MS from the Program of Computer Graphics at Cornell in 1985.

Very cool, isn't it?

Returning to the AU Germany keynotes, Prof. Dr. Günther Schuh talked about the future of factories.

Be aware of the fourth industrial revolution:

1. Power – steam engine etc.
2. Workflow – Taylor, Ford, etc.
3. IT – computation
4. Collaboration productivity, evolving from human/human > human/machine > machine/machine

Computers and machines are starting to assist the design process in significant ways. Where will automated machine collaboration lead?

My session on the Autodesk View and Data API went very well and was great fun, with standing room only:

Japanese View and Data API Hackathon Projects

Here is a report by my colleague Toshiaki Isezaki on the four hackathon projects that show what can be achieved in a weekend using the Autodesk View and Data API and other open source components.

Toshiaki already published this overview on the Japanese DevBlog in his report on Autodesk 3D Hackathon – Day2.

There were four teams at the hackathon:

• Castle 360
• Okamoto
• Hackshion
• Use of ReCap

Here is an overview of their projects and results with a short video on each:

Castle 360 Team

Ogasawara-san joined to this team.

The concept of web app they created is to provide user experience with much presence. They suppose there are many cameras in soccer stadium including wearable camera putting on soccer players. This app has views from each camera at the right side of screen. When user chooses a single view among them that displayed on the main screen. The main screen is created by the Autodesk viewer LVM and it actually shows movie. In order to display movie on LMV, Ogasawara-san put a planar surface in the space. And he applies movie to planar surface as a material using Three.js. This is unique technique. This app also has '3D Capture' button to capture pictures from all cameras at a time. The captured pictures are processed by ReCap Photo API to generate 3D model. As a result, customer who uses this web app can feel presence with 3D model even if he is in his house. They couldn't implement ReCap Photo API portion actually due to timeout.

You can watch the short demo video:

Team Okamoto

Saitou-san and Takamizawasa-san joined this team.

Japan is the society that is concerned with its decreasing birth rate and aging population. The created web app reflects it. They suppose an administrator's work for villas in resort area. He has to manage many villas alone. He has a convenient web to control facilities in each villa. He can select a villa he wants to manage on Google Map and can show 3D state of villa in LMV. 3D model has switches to turn on and off within LMV for example. He can turn off a light with it.

One of team member has designed lot of apartments using Revit, and he knows that BIM world also has lot of file formats. So he thinks LMV is best solution to show 3D models came from various file format as a front end interface for Home Automation. Home Automation is a recent trend on housing industry. Unfortunately, it seemed they cannot find a way to change light state in current LMV API.

You can watch the short demo video:

Hackshion Team

This team was organized with interesting members. One person came from 3D printer service bureau. Other one is the president of start-up company. He has development skills for mobile but his company is to create and sell custom suit. The problem he is having is that it is difficult to sell suits on e-commerce system, because customer doesn't know whether jackets and pants that have been sold on internet will be fit to his/her body. So this team intended to develop a mobile app which uses ReCap Photo to measure sizes around human body by simply taking pictures. However, ReCap Photo API has not exposed taking survey point features, and it is sometimes slow response depending on internet connection when they operate it interactively. So they cancelled development work for that portion and tried to use Memento instead. As a result, app doesn't work along to single story. But business model to resolve current problem is clear comparing to other teams. Also this team intended to deliver API for other apparel industry that has an e-commerce system.

You can watch the short demo video:

Use of ReCap Team

Original number of this team was 3. But one person could not participate in Day 2. So that they could not complete their entire project. Their idea is to realize food samples (fake foods) that are shown at almost restaurant in Japan. If you don't know about it, refer to fake food.

Second idea this team brings is to share 3D model captured from children to grand father/mother in far place using social media such as Facebook. Both ideas are considered LMV and ReCap Photo API. But they are only two. So they connected our github samples to realize that story, using the workflow-wpf-view.and.data.api-master and Autodesk-ReCap-Samples-master projects.

You can watch the short demo video:

CAD Terminology Translation

Talking about all this international stuff raises the question CAD terminology translation:

Question: I am working on translations for my apps but running into difficulties when it comes to technical CAD terms in other languages. These are important for writing the app descriptions. Are there any resources available that list the proper translations for CAD Lingo? For example, what is a 'spline-fit vertex' in Japanese?

I came across this AutoCAD command dictionary, but it only lists AutoCAD command translations and does not support all languages.

Answer: The Autodesk localisation team uses a cross product corpus database NeXLT for terminology and message translation.

This link is accessible from outside the company and translation companies working with the localisation team around the world make use it, so let's assume this resource is available to anyone working on translating products for Autodesk platforms.

Another option is to reference the CAD platform online help. For instance, AutoCAD provides an end user online document per language. You can read and analyse the various language versions of this document through these links:

• English
• Japanese
• French
• Korean
• Russian
• ...

You can obviously also use the language packs, e.g. the AutoCAD 2015 language packs.

Cool Presentation Gimmick

My son Christopher, composer and sound professional, pointed out this short video demonstrating a funny and enticing presentation gimmick that I thought you might enjoy as well, by Sam Tarakajian, having the happiest day of his life, presenting an update to the Max visual programming of music, sound, video, and interactive media applications.

Max supports audio and video manipulation, similar to Dynamo for 3D modelling, extending building information modelling with the data and logic environment of a graphical algorithm editor.

Max does the same for audio and video. You arrange boxes on a canvas and connect them together to create, experiment, and play.

One new feature is crash recovery. How to best demonstrate that? Simulate a crash, and bring in emotions.

So, enjoy this 3.5-minute video on Max 7 Sneak Preview Episode 3:

Worksharing and Duplicating Element Geometry

I had two more interesting email conversations on Revit API questions, on add-ins in a worksharing environment and duplicating element geometry for detailing and fabrication.

Actually, both of these topics have been discussed in the past, so a lot of the work I did was to dig out the existing material again to make these developer partners happy.

Today I therefore have an opportunity to talk about the Revit API and nothing but the Revit API again for a change, after all the web related stuff in the past few posts.

We will probably return to more web related stuff in the next few ones as well, since I am in Darmstadt right now, getting ready for my presentation on the Autodesk View and Data API, Interaktives 3D Modell in beliebige Webseiten einbetten, at Autodesk University Germany here tomorrow.

Following that, next weekend, I will be attending the third and final hackathon this month in Berlin, after spending the past two weekends at the hackathons in Zurich and Brussels.

Finally, to wrap up for today, my son Christopher, sound recording professional, also pointed out a funny video demonstrating a truly inimitable presentation style that I definitely find worth taking a look at.

Add-ins in a Worksharing Environment

Scott Conover presented an absolutely invaluable class at Autodesk University 2013, DV1888, on Making Revit Add-ins That Cooperate with Worksharing, followed by a lively and highly competent roundtable discussion DV3464-R:

Are you having issues supporting your add-ins in a workshared environment? Have you hit situations where elements can’t be edited or updated due to conflicts? As a follow-up discussion to DV1888, join this roundtable session to further discuss the techniques that are available to developers to operate on workshared models.

I mentioned these sessions before and after the event and promised to publish the full material and roundtable notes sometime.

Apparently, that time has now come, and the long-awaited roundtable session notes are included below.

This information is too important to ignore, and too complex to understand without some expert guidance.

I was prompted to return to this material by the following questions:

Question: I have a question about worksharing.

I need to store global document settings for several different users.

How can I achieve this effectively in a worksharing environment?

I first tried to use the ProjectInfo approach.

That is problematic in a workshared environment, since this element is shared between all users.

Using a DataStorage element is not an immediate solution, since it can cause into similar issues, as discussed in the thread on tips for extensible storage in a worksharing environment.

I am a bit unclear about the whole topic, to tell the truth.

• When am I an owner, and when a borrower of an element?
• Who has write permission?
• How do I request access to an element?
• In another scenario, I can be the owner of an element, but it is out of date.
• All of this also applies to data storage elements.

This all seems rather complex.

Now I would like to explore the API possibilities, e.g. those implemented in WorksharingUtils, etc.

Oops... Unfortunately, the Revit API does not even appear to provide any such class...

The end user tutorial offers enough information on this to get started, so I have lots to read about to understand the product workflow better...

Answer: You should take a look at Scott Conover's Autodesk University 2013 class and roundtable on this topic presented in AU day two with worksharing and API roundtables.

Response: "Sorry, this session is no longer available"...

I was only able to download the audio recording and am listening to that now.

Answer: For your convenience, I uploaded my local copy of Scott's material:

• Handout
• Slide deck
• Sample code

Scott later pointed out that it is in fact also still available online from the AU web site via:

• Autodesk University
• Classes on demand
• Search for 'dv1888'
• DV1888: Facing the Elephant in the Room: Making Revit Add-ins That Cooperate with Worksharing

The roundtable recording DV3464-R: Making Revit Add-ins That Cooperate with Worksharing: A Roundtable Session is also still posted.

The AU site highlights the upcoming conference and new classes, and yet all the old ones are still available by searching the online course catalog for the presenter name or class number.

Response: That is exactly what I need!

Very detailed and down to earth.

Answer: As a follow-up, here are the long-awaited notes from the roundtable session:

Add-ins in a Worksharing Environment – Roundtable Session Notes

Notes from the Roundtable Session DV3464-R on Making Revit Add-ins That Cooperate with Worksharing on December 4, 2013, with Sasha Crotty, Scott Conover, Jeremy Tammik and a dozen expert Revit API and product user participants.

Worksets are used differently in every company, too many variables.

Example usage: Extract sheet parameters for drawing lists, 5-7 buildings in a campus, ca. 60 models, need consolidated drawing list. Open models view journal script, open without worksets. Batch process PDF, open with all worksets. Close Revit using UI automation code and handle dialogues. Open detached is slower than closing in the journal.

Caching element information use unique id. Store document identifier, e.g. path or link instance id. Tracking elements for lighting. If too many elements change, the results are invalidated.

Autoinsertion with families? Autocreate workset for a given object? The API can currently not create new worksets. Some people moved away from this approach. I have seven worksets and want no more.

Have to check in all changes at once, not just selected elements.

Restricting User Access: For us the best answer is not to have worksets. Most uses of multiple worksets are misuses, e.g. for visibility. We set up visibility right in the template and need no worksets.

Elements are still loaded (at least partially) with worksets, just not displayed.

Discipline specific models? We put different disciplines into a single workset and in a single model.

We used to have 30 worksets. We ran into problems. Mix of dumb and smart users. We use worksets to restrict access, e.g. prohibit plumber from moving a duct. We may have 7-8 worksets per trade. We have model managers.

All of our views have view templates assigned that drive the display, separate for display and design.

Two completely different approaches.

Add-in Editing Conflicts and Data Storage: Error messages a re self-explanatory to our users, so we see no need to hide those. Might be more elegant moving to separate DataStorage elements. The DataStorage element ends up in a special workset, named Data Storage Elements. It does matter what workset it is in, because it will not be accessible otherwise depending on what worksets are open. Closed versus locked workset? Use the standard workset or a hidden one. I cannot create new worksets programmatically. It would be nice to specify the workset. I wish that default behaviour for DataStorage elements would be to go someplace that is independent of this whole thing, and as a developer you have an option to specify something different. Issue resolved.

Add-in Misbehaviour Handling and Loading: As an in-house developer, I can just display exceptions to the user and they will bring them to us; it cuts debugging time way down.

Deployment is a challenge, even for AppStore add-ins.

When Revit shuts down, my add-in opens and external application, waits for Revit to shut down, and then copies the add-ins to a local file.

You can load add-ins dynamically, but not unload. You can load an add-in from a byte stream to avoid file issues.

Updater: There are different flavours of things being updated, and via updater is different from other updates. Idling event is still user changes, so only updaters is different. An updater is like a regeneration, in that it triggers regeneration of other elements. System change, e.g. regeneration and updater, versus user change.

File Operations: We have no files at all that are owned by single users, except families, but they are handled differently anyway. Maintaining and controlling standards, ensuring everything is in the right workset, worksets are locked out, eliminate boring stuff and focus on design.

Working with Revit Server? Yes, since 2012. We had disasters and abandoned it. We love it. Server 2012 did not play nicely for us. We are the most up-to-date and running on virtual machines. Our save times went down to almost nothing. Network speed? Ca. 100 Mbit. We have not had any crashes in 2.5 years. Riverbed. 2008 technology to 2013. Yes, expensive. We did run without, and it was a bit slower. We tweaked our settings and worked with Michael Brandy, and it flies. We even put a Revit Server in our single user offices. We would love to learn all the details of your solution. Automate saving a new central to server? How about an updater that can run on the central model?

Exporting Individual Element Geometry

I put together a new topic collection for The Building Coder on exporting individual element geometry, prompted by the following conversation:

Question: We need to duplicate the exact geometry of a Revit Architecture element, e.g. a wall, including its openings, to a new frozen element. The purpose is to have the exact geometry of the wall without the windows or doors.

We tried to use the Get_geometry method but found no way to re-create a new element from it.

We are a fan of your blog, and any help is appreciated.

Answer: You cannot recreate all of the exact geometry in a new element.

Revit geometry is basically read-only.

This is obvious and unavoidable.

Revit is parametric.

The geometry is not.

Still, the new DirectShape provides and easy way to duplicate at least some of the geometry, as long as it is not curved or complicated.

On the other hand, I do not think you should be doing this at all.

You will mess up your BIM.

Remember, the BIM is an exact representation of reality.

In reality, you cannot simply duplicate a wall.

If you want another wall, you have to build a new one.

Response: Thank you for the quick answer. I agree with you on the fact that it’ll mess up the BIM, but the use case is to extract an independent sub-set of the geometry and send it to a drafting supplier without the context.

So, the purpose is to extract the exact Wall geometry with opening and save it in a dead geometry as RVT, IFC, DWG, or something.

Answer: That is a totally different way of putting things.

I provided several different pretty full-fledged solutions for similar tasks on The Building Coder, and now defined this as a new topic group for you, on exporting individual element geometry:

• Exporting walls and floors to SAT:
• Export Walls and Floors to SAT
• Exporting wall parts to DXF for CNC fabrication:
• Export Wall Parts Individually to DXF
• ExportCncFab on GitHub and RevitLookup Update
• AU 2013 Class FB2938 – Design to Fabrication
• Driving CNC Fabrication and Shared Parameters
• Saving a solid to a SAT file:
• How to Save a Solid to a File
• Saving a Solid to a SAT File Implementation

Response: Thanks a lot Jeremy for the answer. This is exactly what we are looking for.

Autodesk View and Data API Notes and Samples

Here is a summary of my notes from three presentations on the Autodesk View and Data API given by Cyrille Fauvel and Philippe Leefsma, in the two introductory workshops at HackZurich on Friday evening, October 10 and at HackaBxl in Brussels on October 17.

Philippe also presented a very nice and absolutely minimal basic viewer sample in node.js demonstrating how to implement a private web service to obtain the authorisation token without exposing your key and secret in your JavaScript source.

I will be making use of this material again in the coming days, for my Autodesk View and Data API class on Thursday at AU Germany in Darmstadt and at the Berlin Hackathon next weekend.

Autodesk View and Data API Presentation Notes

I already presented a bunch of stuff on the Autodesk View and Data API.

Here is an executive summary of the most important information to get started with it. We used this for the recent hackathons in Zurich, Brussels, and the upcoming one in Berlin.

The presentation is quick and efficient; the slides are discussed in just a couple of minutes, before diving into live source code demonstrations.

Please read the following notes in the context of the accompanying slide deck. By the way, this is the version I will be using for my presentation Autodesk View and Data API – Interaktives 3D Modell in beliebige Webseiten einbetten at Autodesk University Germany in Darmstadt on Thursday October 23.

• Introduction
• Samples
• Main highlights
• More Features
• Resources
• Two separate APIs
• Server API – REST
• Client API – JavaScript
• Questions and Answers

Introduction

• We are from Autodesk.
• Traditionally, we have implemented model authoring tools.
• Now we are looking at optimal way to share models with others and use the rich data they contain.
• Complexity is growing, we have a huge number of components addressing all imaginable requirements, many of them open source – how to put all the puzzle pieces together optimally?
• We can use WebGL and Three.js to present any graphical data, either 2D or 3D.
• What is WebGL? – Three.js simplifies it.

Samples

• Look at the mechanical tractor sample, an Inventor model.
• Rotate, pan, zoom, easy intuitive manipulation with zero footprint.
• This is a pretty big CAD model consisting of numerous files,   > 1 GB.
• It is shrunk and streamlined to be viewed interactively in the browser.
• All the CAD model structure and properties are preserved.
• We understand the internal model structure, metadata, properties, how the model was built.
• The pane on the left side shows the engineering structure, e.g. parts, assemblies and subassemblies.
• A hierarchical tree, objects selectable either on screen or in the tree view.
• The selected element is highlighted and its properties are displayed.
• The smart explode engine understands and dissects subassemblies step by step, e.g. the cabin initially remains intact.
• All interaction performed here in the browser is coded in JavaScript.
• An architectural model, the Autodesk Waltham office.
• We understand and can use the internal model structure to select only a specific level or only HVAC MEP data, i.e. ducts and pipes.
• We can pick an individual element, e.g. a window, isolate it, examine its properties.
• The Morgan steampunk sample shows how other JavaScript UI libraries can be integrated.
• The Morgan model was created by the Morgan car company. We worked with them for the Geneva car expo and they let us have it.
• It also shows how to drive the navigation programmatically, e.g., highlight just the engine or other significant aspects.
• All JavaScript libraries can be used.
• Infraworks model representing infrastructure from GIS data.
• Car seat model demonstrating real time price update from a linked external SAP database.
• Multiple user interaction to share remote control over view and camera in real time. Simulate two users in two separate parallel Firefox windows. Based on a node.js implementation using socket io.

Main Highlights

• Zero install.
• Not only geometry, many other data, metadata.
• Public API, open source, based on three.js.

More Features

• Translate heavy CAD model to lightweight JSON streamable web objects.
• Streamed to the browser, you see initial geometry immediately, them metadata, then textures.
• The tractor model was 1 GB and consisted of many files, not useful for web.
• Take all of this, upload to a server, translate to JSON and stream it in little objects.
• Many file formats are supported.
• Long-term objective: support any 3D file format.
• You can still access and manipulate geometry in the viewer.
• You cannot modify original model, just the view.
• Rendering on client side using WebGL.
• Everything is happening through Chrome and JavaScript.
• Everything done interactively can also be driven programmatically.

Resources

• Getting started and documentation.
• Programming examples on GitHub in all kinds of different programming languages.
• An API console for testing.
• The cloud and mobile DevBlog for questions and more info.

Two Separate APIs

1. Server side, to upload and translate.
2. Web client, a normal HTML5 web page using CSS and JavaScript.

Server API – REST

• The server API requires a few initial one-time steps to upload and translate the model:
• Authorisation
• Upload
• Translation
• You get a secret key pair to protect your data.
• The translation gives you the file id or URN.
• From then on all is on the client side.
• This is well illustrated by the documentation and the curl shell scripts available from GitHub.

Client API – JavaScript

• The client side JavaScript API is most likely to be customised, e.g. in hackathon projects.
• It can be used to query model data, examine the model hierarchy, properties, handle model, camera, events, access underlying geometry and textures insert other transient objects, and much more.
• For instance, we can grab the internal id of a model element and use that to attach, display and modify other information coming for separate databases, like in the car seat model displaying prices defined in SAP.
• You can just embed viewer in your web page.
• That is all you need, just an iframe.
• Example on Kean's blog, also Facebook, etc.
• If you have your own website: create HTML5 page, add CSS and JavaScript, create div, initialise, must be div, not canvas.
• The viewer creates the canvas itself internally.
• Show the initialisation function, replace the XXX by your credentials.
• This function can be defined in a plugin, of course.
• Client side API enables all extensions, e.g. to take control of geometry, change properties, get unique id from elements to add more data from external db, etc.

Questions and Answers

• Cost, pricing, business model?
  – The viewer is and will remain free forever; the pricing for translation and storage is undefined. There may one day be a charge for translation, storage or both. If so, however, it will be in the range of cents.
• Access?
  – Viewer is totally open source and JavaScript. You have access to all the code. Only the translation part is Autodesk private. You upload the model to an Autodesk server to convert it to streamable JSON.
• Can I add my own data, metadata?
  – Yes, absolutely. It is not saved, this is a viewer only. You can add both geometry and properties.
• What is driving the backend server?
  – Background is AWS, C++.
• Is the JSON format published?
  – JSON format is not yet published because still in flux. Once it is finished, sometime next year, we might publish the JSON object format. It does not really matter.
• Offline access?
  – If you put all JSON on the local hard drive, you can load and view the models, but you lose the streaming aspects. If you load a file without streaming it, you have to wait until it completes.
• Notification and interaction?
  – You can get callbacks on selection, explode, camera change, property change, everything. All behaviour can be completely customised.
• Is the JSON format published?
  – JSON format is not published. It is still in flux. Maybe once it is finished, sometime next year. It does not really matter.

Philippe's Basic Viewer Sample

Philippe Leefsma presented a sweet client-server sample to demonstrate an easy solution to manage the credentials in a JavaScript viewer application.

The problem is that you do not wish to expose your secret consumer key and consumer secret.

On the other hand, the viewer client needs to use them to access your stored models.

The solution for this is to define a minimal server that provides the required credentials.

The server is called by the client via REST and returns a token without exposing the credentials.

The server can only be called by the client due to the same-origin security policy.

The whole application just consists of four files implementing a node.js application:

• package.json
• server.js
• routes/api.js
• views/index.html

Some points of interest:

• Node.js server app.
• Minimum server.js.
• Generate auth token on server side.
• Serve a static web page.
• Using express and request modules for node.js.
• Code for a super simple REST API called /api.
• Credentials from registering web page.
• Show token – http://localhost:3001/api/token.
• Show model – http://localhost:3001.

The contents of the node.js application package are defined by package.json:

  {
    "name": "AdnViewerBasic",
    "version": "0.0.0",
    "private": true,
    "scripts": {
      "start": "node ./bin/www"
    },
    "dependencies": {
      "express": "~4.8.6",
      "body-parser": "~1.6.6",
      "cookie-parser": "~1.3.2",
      "morgan": "~1.2.3",
      "serve-favicon": "~2.0.1",
      "debug": "~1.0.4",
      "jade": "~1.5.0",
      "request": "*"
    }
  }

The server provides one single REST entry point, /api/token, to return an authoristion token, and implementes one view, views/index.html, setting up and displaying the viewer canvas:

  var api = require('./routes/api');
  var express = require('express');

  var app = express();

  app.use(express.static(__dirname + '/views'));
  app.use('/api', api);

  app.set('port', process.env.PORT || 3000);

  var server = app.listen(app.get('port'), function() {
    console.log('Server listening on port ' + server.address().port);
  });

The REST API call is implemented like this by routes/api.js:

  var express = require('express');
  var request = require('request');

  var router = express.Router();

  router.get('/token', function (req, res) {

    var params = {
      client_id: '********',
      client_secret: '********',
      grant_type: 'client_credentials'
    }

    request.post(
      'https://developer.api.autodesk.com' +
        '/authentication/v1/authenticate',

      { form: params },

      function (error, response, body) {
        if (!error && response.statusCode == 200) {
          var authResponse = JSON.parse(body);
          res.send(authResponse.access_token);
        }
      });
  });

  module.exports = router;

Cyrille Fauvel used a similar technique to implement the PoiPointer node.js REST server.

The client view is defined by index.html, a minimal sample of setting up and displaying the viewer:

<html>
  <head>
    <title>ADN Viewer Basic</title>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
    <link type="text/css" rel="stylesheet" href="https://viewing.api.autodesk.com/viewingservice/v1/viewers/style.css"/>
    <script src="https://developer.api.autodesk.com/viewingservice/v1/viewers/viewer3D.min.js"></script>
    <script src="https://rawgit.com/Developer-Autodesk/library-javascript-view.and.data.api/master/js/Autodesk.ADN.Toolkit.Viewer.js"></script>
    <script>
      $(document).ready(function () {

        var adnViewerMng = new Autodesk.ADN.Toolkit.Viewer.AdnViewerManager(
          'http://' + window.location.host + '/api/token',
          document.getElementById('ViewerDiv'));

        adnViewerMng.loadDocument(
          "*X*u*m*k*2*u*2*q*W*0*z*v*y*v*m*l*3*6*W*u*T*w*j*3*j*w*T*t*T*u*D*u*z*v*2*h*C*k*2*=");
      });
    </script>
  </head>

  <body style="margin:0">
    <div id="ViewerDiv">
    </div>
  </body>
</html>

You can start it up on the command line and then check the results in the browser via your localhost at the specified port:

  $ node server.js
  Server listening on port 3000

ADVA Webinar, Free Student Software and AU

Here are pointers to some relevant non-API news items of interest:

• Free webinar introducing the new Autodesk View and Data API
• Free Autodesk software for all students everywhere
• AU class enrolment

Free Webinar – Introducing the new Autodesk View and Data API

We already held a webinar on the new Autodesk View and Data API in September.

Here are the old description and full details of that, and, for the first time, we proudly present the detailed notes of the September presentations by Stephen Preston and Cyrille Fauvel.

In case you missed it, another chance is coming up again soon: the next free webinar Introducing the new Autodesk View and Data API will be held on Thursday October 23^rd, 2014.

Free Autodesk Software for All Students Everywhere

Autodesk now provides free software for students, teachers, and schools around the world.

Inspiring creativity and a love for science, engineering, and math in young students is more important today than ever. So I'm very happy to announce that Autodesk has opened up FREE access to its desktop software to ALL students, teachers, and schools everywhere in the world.

In the past, access was free in some countries, but not others. Today there are no restrictions. However, all too often students and teachers are unaware that they can have their own copy and use our software in their classroom for free. The simplest way to help a student or teacher is to direct them to students.autodesk.com where they can download as much as they want and find curriculum and learning materials.

AU Class Enrolment

I mentioned the Revit API expert panel SD5156 – Open House on the Factory Floor taking place at Autodesk University.

A few of my fellow ADN colleagues' class enrolments are currently below the attendee threshold, however:

• SD6310 – Bring on the Cloud and Mobilize Your Media & Entertainment Workflows Through Programming – Kevin Vandecar
• SD6432 – Are You Having a Pythonic 3ds Max Experience? No? Come Join the Revolution! – Kevin Vandecar
• SD5752 – OAuth 1.0 Versus OAuth 2.0 and Use Case – Cyrille Fauvel
• SD6230 – Add 3D Photogrammetry to Your Desktop and Mobile Apps using ReCap Photo API – Philippe Leefsma
• SD5931 – Creating Commercial Applications for Mobile Devices Using AutoCAD OEM – David Grieve

If these classes are of interest to you, please register for them to ensure they really take place.

You can check the AU 2014 class catalogue for the complete list of classes.

Events, Again, and Creating an Extrusion Roof

Jon and Scott Wilson discussed some issues creating extrusion roofs on arbitrary planes in the Revit API discussion forum in the past couple of days.

One neat spin-off is a simple little external command that shows the basic use of the NewExtrusionRoof method, so I took the opportunity of adding that to The Building Coder samples.

Before getting to the details of that, here is a little update on the upcoming events:

• October hackathons and AU Germany
• Autodesk University in Las Vegas
• DevDays registration and motto
• DevDay meetups
• Presentation best practices
• Creating an extrusion roof

October Hackathons and AU Germany

October will be a busy travelling month for me, participating in hackathons in Zurich, Brussels and Berlin, with the German Autodesk University in Darmstadt taking place in between as well.

The DevDay, meetup and hackathon event calendar I published a month ago remains valid.

Autodesk University in Las Vegas

As planned and announced, I am participating at Autodesk University in Las Vegas and the ADN DevDay and DevHack events preceding it.

My class proposals were not accepted, so my main responsibility besides the DevDay and DevHack will be to lead the Revit API expert panel SD5156 – Open House on the Factory Floor.

You can check the AU 2014 class catalogue for the complete list of classes.

DevDays Registration and Motto

The DevDays registration is now open to ADN members. The participation is free of charge.

At several sites worldwide, you can stay on for a DevHack or an evening meetup.

The meetups are open for non-ADN members as well.

The list of sites I published a month ago remains valid.

This year's DevDays theme is 10x, sharing how Autodesk is expanding its business and how you can join in on this 10x journey by using Cloud, Mobile and Desktop technologies to expand your user base by 10x while growing your revenue and profits.

DevDay Meetups

The associated meetups offer an opportunity to gather with ADN partners, Autodesk and other local technologists in your community for a social and educational evening. The focus will be on bringing 3D to the web and mobile devices. Autodesk is investing in technology to make it easy for people to bring 3D content to the web across a whole range of industries and applications in addition to design and engineering. We'll have lively discussions and sharing on where broader technologies are heading as well as how to make the web an engaging 3D experience for your customers and target users.

These meetups are open to non-ADN members, so feel free to invite your technology friends and join us for some food, beverages and engaging conversation!

You can check the locations at which evening meetups will be held by visiting autodeskdevdays.com/meetups.

Presentation Best Practices

With all these events and conferences coming up, we will be doing a lot of presenting.

Here is a list of 33 presentation tips and tricks, pointed out by Jim Quanci, courtesy of Geoffrey James, plus another nine important suggestions specific to discussing API and source code contributed by Stephen Preston:

1. Build your presentation around the decision you want made.
2. Structure the presentation as a journey through a series of emotions.
3. Keep it simple. Your audience doesn't want or need more complexity.
4. Cut your intro down to a maximum of two sentences.
5. Cut your presentations to half as long as you originally thought they should be.
6. Include only simple graphics and highlight important data points.
7. Use a slide background that's simple with a neutral color.
8. Eliminate slides that you might need to skip due to time constraints.
9. Expunge business buzzwords from your slides (and your vocabulary).
10. Use large fonts in simple faces, like Arial.
11. Limit the distracting use of special effects and visual gimcracks.
12. Customize every presentation because every audience is different.
13. Unless it's a keynote, cut your presentation down to 20 minutes or less.
14. No matter what, rehearse your presentation at least 20 times.
15. Schedule presentations when audiences can give you their full attention.
16. Check your equipment setup well in advance.
17. Have somebody else introduce you; it creates anticipation.
18. Don't start with an apology lest you seem like a victim.
19. Don't review your company's history because nobody cares.
20. Kick off with a shocking fact, surprising insight, or unique perspective.
21. Keep your front to your audience; don't look back at the screen.
22. Be yourself; audiences immediately sense if you're not being genuine.
23. Don't fidget with papers, jewelry, glasses, or clothing.
24. Speak directly to individuals in the audience, moving from person to person.
25. Tell a story that casts your audience as the hero and you as the sidekick.
26. Use facts that are quantifiable, verifiable, memorable, and dramatic.
27. Slow down. Slow down. Slow down.
28. Never read from your slides. It irritates everyone. Never ever.
29. Be upbeat and positive but don't tell jokes unless you're a comedian.
30. Avoid hot buttons (e.g., politics) that will distract from your message.
31. Identify and emphasize the next step you want the audience to take.
32. Don't ask for extra time because you're late; instead end on schedule.
33. Have a question or two up your sleeve in case nobody has one.
34. Use a mouse if you're demoing something that requires zoom, pan and rotate (e.g. the viewer).
35. Showing function signatures or very small snippets of code on your slides is OK; don't copy large code snippets into slides – switch to the IDE instead.
36. Adjust the IDE font to be large enough to be seen from the back of the room.
37. If you're live coding, make sure you have backup code in case you make a mistake – it's really hard to spot typos in your code when 500 people are staring at you – and don't spend more than one minute trying to fix your code before going to your backup.
38. Live coding is cool, but not if its long or repetitive. Have code snippets available to copy and paste so you don't have to type everything.
39. If you're talking through the code – run it in the debugger and step through it – don't just point at static lines of code and explain what would have happened if it was running.
40. It's often a good idea to demonstrate what your finished code does before going back and showing how to write it.
41. When you're sitting at your laptop debugging code, your head tends to drop down and you voice becomes quieter. Fight this tendency by sticking a post-it note at the top of your screen that says ‘speak up' or similar.
42. Only sit behind your computer for as long as it takes to demo the code – then stand up again and move out from behind the table.

Sounds too good to be true, doesn't it? Let's see how well we can abide by them all :-)

Creating an Extrusion Roof

Back to some hard-core Revit API usage.

In their discussion on extrusion roof failure on arbitrary planes in the Revit API discussion forum, Jon and Scott Wilson are looking at more subtle issues.

Ignoring those for the moment, I just grabbed Jon's example code to demonstrate the basic use of the NewExtrusionRoof method, using it to add a new external command named CmdNewExtrusionRoof to The Building Coder samples.

It generates this stair-shaped element, which in actual fact really is a roof:

The completely self-contained external command Execute method mainline looks like this:

  UIApplication uiapp = commandData.Application;
  UIDocument uidoc = uiapp.ActiveUIDocument;
  Document doc = uidoc.Document;
 
  using( Transaction tx = new Transaction( doc ) )
  {
    tx.Start( "NewExtrusionRoof" );
 
    RoofType fs
      = new FilteredElementCollector( doc )
        .OfClass( typeof( RoofType ) )
        .Cast<RoofType>()
        .FirstOrDefault<RoofType>( a => null != a );
 
    Level lvl
      = new FilteredElementCollector( doc )
        .OfClass( typeof( Level ) )
        .Cast<Level>()
        .FirstOrDefault<Level>( a => null != a );
 
    double x = 1;
 
    XYZ origin = new XYZ( x, 0, 0 );
    XYZ vx = XYZ.BasisY;
    XYZ vy = XYZ.BasisZ;
 
    SketchPlane sp = SketchPlane.Create( doc,
      new Autodesk.Revit.DB.Plane( vx, vy,
        origin ) );
 
    CurveArray ca = new CurveArray();
 
    XYZ[] pts = new XYZ[] {
      new XYZ( x, 1, 0 ),
      new XYZ( x, 1, 1 ),
      new XYZ( x, 2, 1 ),
      new XYZ( x, 2, 2 ),
      new XYZ( x, 3, 2 ),
      new XYZ( x, 3, 3 ),
      new XYZ( x, 4, 3 ),
      new XYZ( x, 4, 4 ) };
 
    int n = pts.Length;
 
    for( int i = 1; i < n; ++i )
    {
      ca.Append( Line.CreateBound(
        pts[i - 1], pts[i] ) );
    }
 
    doc.Create.NewModelCurveArray( ca, sp );
 
    View v = doc.ActiveView;
 
    ReferencePlane rp
      = doc.Create.NewReferencePlane2(
        origin, origin + vx, origin + vy, v );
 
    rp.Name = "MyRoofPlane";
 
    ExtrusionRoof er
      = doc.Create.NewExtrusionRoof(
        ca, rp, lvl, fs, 0, 3 );
 
    Debug.Print( "Extrusion roof element id: "
      + er.Id.ToString() );
 
    tx.Commit();
  }
  return Result.Succeeded;

You can download the most up-to-date version from The Building Coder samples GitHub repository.

The version discussed above is 2015.0.112.0.

DevDay, Meetup and Hackathon Event Calendar

Here is a list of upcoming events, most of which I will be involved in in one way or another:

• DevDays 2014
• DevDay & DevHack in Las Vegas
• Meetups and Hackathons

DevDays 2014

Here is the list of cities and dates where our DevDays events 2014 will be held around the world later this year.

These events are accessible to ADN members. If you are not an ADN member and still would be interested in learning more about application development related to Autodesk products and technology, please contact us and let's discuss.

The DevDays conferences are the best way to learn about Autodesk's newest technologies and future products. To get a feel for what goes on at these events, ADN members can check out the presentations from last year on the ADN extranet at Events.

A complete DevDays 2014 agenda will be posted soon, and online registration will go live in late September. Note that the registration for the ADN Conference at AU in Las Vegas will go live on August 27, 2014. See below for more information on that.

New for 2014: We will be hosting Meetup events in most locations. These events are open to everyone, not just ADN partners. So, invite your technology friends along for an evening of learning and sharing in a casual environment.

DevDays 2014 Locations and Dates

• North America
• 2014-12-01 – ADN Conference at AU, Las Vegas, USA
• 2014-12-02 – DevHack at AU, Las Vegas, USA
• North Asia
• 2014-11-06 – Beijing, China, with evening Meetup
• 2014-11-07 – Beijing, China, DevHack at AU China
• 2014-11-10 – Shanghai, China, with evening Meetup
• 2014-11-11 – Shanghai, China DevHack
• 2014-11-17 – Seoul, South Korea
• 2014-11-19 – Tokyo, Japan
• 2014-11-20 – Tokyo, Japan, DevHack
• 2014-11-28 – Osaka, Japan
• South Asia
• 2014-11-11 – Sydney, Australia, DevHack at AUx Sydney
• 2014-11-12 – Sydney, Australia
• 2014-11-14 – Singapore, Singapore
• 2014-11-21 – Bangalore, India, with evening Meetup
• Western Europe
• 2014-12-08 – Paris, France, with evening Meetup
• 2014-12-09 – London, United Kingdom, evening Meetup
• 2014-12-10 – Farnborough, United Kingdom
• 2014-12-11 – Gothenburg, Sweden, with evening Meetup
• 2014-12-15 – Munich, Germany, with evening Meetup
• 2014-12-16 – Milan, Italy, evening Meetup
• 2014-12-17 – Milan, Italy
• Eastern Europe
• January 2015 – Moscow, Russia (exact date to be confirmed)
• Latin America
• 2015-01-14 – São Paulo, Brazil

DevDay & DevHack in Las Vegas

The ADN Conference at Autodesk University in Las Vegas, Nevada, USA, is taking place on December 1, with two separate DevHack events on December 2, for Design & Engineering and Media & Entertainment, respectively.

Registration will open today, on August 27, 2014. Visit the registration website at http://au.autodesk.com/plan/pre-conference/adn-conference-devdays.

Note:

• Sign in with your Autodesk ID or create one when prompted (this is not your ADN number).
• Make sure you check the ADN box and enter your ADN number. If you don't, you will not see the registration option for the ADN Conference and DevHack.
• Select your ADN Conference classes from the class catalogue.

Meetups and Hackathons

Over the coming months we DevTech engineers and ADN evangelists will be attending a number of different meetup and hackathon events. Here's a list of some of them:

• August 22 – September 5, 2014
  China Roadshow + DevLab + Meetup + Classroom Training in Beijing, Wuhan, Chengdu, and Xian, China
  In attendance: Xianhua Tang, Xiaodong Liang, Daniel Du, Joe Ye
• September 6-7, 2014
  TechCrunch Hackathon – San Francisco, CA
  In attendance: Jim Quanci, Stephen Preston, Cyrille Fauvel, Philippe Leefsma
• September 8-10, 2014
  I♥3 APIs Conference, San Francisco, CA
  In attendance: Jim Quanci, Stephen Preston, Cyrille Fauvel, Philippe Leefsma
• September 9, 2014
  HTML5 Meetup Group, San Francisco, CA (Autodesk sponsoring the event)
  In attendance: Jim Quanci, Stephen Preston, Cyrille Fauvel, Philippe Leefsma
• September 10, 2014
  Tokyo 2nd Meet Up, Tokyo, Japan
  In attendance: Toshiaki Isezaki
• September 12-14, 2014
  AEC Hackathon, Seattle, WA
  In attendance: Augusto Goncalves
• October 10-12, 2014
  hackzurich Hackathon, Zurich, Switzerland
  In attendance: Philippe Leefsma, Jeremy Tammik
• October 17-18, 2014
  Open Data Hackathon, Brussels, Belgium
  In attendance: Cyrille Fauvel, Philippe Leefsma, Jeremy Tammik
• October 23-24, 2014
  Autodesk University Germany, Darmstadt, Germany
  In attendance: Jeremy Tammik
• October 25-26, 2014
  #TMUhack TechMeetups Hackathon, Berlin, Germany
  In attendance: Adam Nagy, Cyrille Fauvel

Toggling Annotation Categories per View

One little pure Revit API issue before closing...

Question: Is it possible to programmatically control the toggle determining whether to 'Show annotation categories in this view' in the Visibility/Graphics Overrides dialogue, marked in red below?

Answer: Please try the read-write View.AreAnnotationCategoriesHidden property.

Autodesk View and Data API

I was away for a few days last week in the beautiful Italian speaking southern part of Switzerland.

Back again, as usual, I am confronted with a host of Revit API issues.

The most important event last week for me by far, though, was the release of the Autodesk View and Data API.

Some of my Autodesk University related tasks and upcoming meetup events are also related to that:

• Autodesk View and Data API
• View and Data API presentations
• Autodesk University advance passes
• Retrieving support information for an element
• Inserting a family symbol from a type catalogue
• API access to revision information
• Installing a Revit add-in

Autodesk View and Data API

As said, Autodesk released its new web based View and Data API.

I will not go into any details, because full documentation and samples are provided:

Full API documentation and access to request an API key is provided by the Autodesk Developer Portal.

Support is available through the Autodesk Community > Web Services API > View and Data API discussion group.

Samples are provided in the GitHub View and Data API sample repositories.

The best way to get started is by hitting the appropriately named 'Get Started' button on developer.autodesk.com and working through the seven simple steps in the Quick Start document:

1. Register for an API key and create an application
2. Get your access token
3. Create a bucket
4. Upload a file
5. Set up References Between Multiple Files
6. Register Your Data with the Viewing Services
7. Load the URN in the JavaScript viewer

Oops.

I said 'released'. Reading Stephen Preston's welcome message to the forum, I note that "we expect the API to become 'public' very soon". If you'd like to be informed when that happens, then please reply to the Tell me when this API is public thread, making sure to include your name, company and contact details. API keys are currently only provided to pilot program participants.

View and Data API Presentation at Basel.js Meetup and Autodesk University

I'll discuss and demonstrate the new View and Data API at the next Basel.js meetup with the title New 3D Geometry Viewer for Web:

"You may have created fantastic 3D designs. Isn't it frustrating that your website is all in 2D? Now you can very easily embed stunning, interactive, intelligent 3D models into your web page, web application, or desktop application. We'll look at some demos showing what is possible, and cover the simple steps to create a 3D-enabled website."

Stephen Preston is presenting on this topic at Autodesk University 2014 in Las Vegas, and I will do the same at the German-speaking event in Darmstadt.

Autodesk University Advance Passes

By the way, AU attendees can buy Advance Passes before the normal AU registration opens. That gives you the following important benefits:

• Save $600 off full price of AU Advance Pass: $1,575, AU full price: $2,175)
• Choose classes and hotel a week before general registration opens, giving the attendee a better chance at getting into the classes and hotel he or she wants

Advance Pass holders can register starting on August 20, 2014, one week before Open Registration starts on August 27, 2014.

Retrieving Support Information for an Element

Question: I would like to know which element sits on top of the other.

For example, I have a floor element sitting on top of 10 columns. I would like to know which columns support the floor.

Alternatively, if I have 10 columns on top of a floor 'X', I would like to know how to extract the information for each column to know that a floor supports this column and the floor is 'X'.

Please let me know if this is possible in Revit.

Answer: Of course, this is definitely possible in Revit.

In a properly designed structural model, you would simply make use of the analytical model to determine this information, e.g. via the AnalyticalModel.GetAnalyticalModelSupports method.

Each AnalyticalModelSupport class instance represents one support for a structural element in the realm of the Analytical Model.

If your model is not structural or has been incompletely specified, there are a number of different approaches available to determine the neighbouring elements below a given element via ray casting or geometrical analysis.

An overview and examples of several different approaches is provided by the analysis of how to determine supporting columns.

Inserting a Family Symbol from a Type Catalogue

Question: Is there any API support for loading a family and creating a symbol from a type catalogue?

If not, I assume that I can write my own code for parsing the catalogue and create the symbol myself. Can you see a problem with that?

Answer: That sounds perfectly sensible. I see no problem with that whatsoever.

You can load a family, either entirely with all its symbols or just one specific type, using the LoadFamily and LoadFamilySymbol methods. Here are some thoughts and background information on loading selected family types.

By type catalogue, I assume you mean the text file specifying a list of possible dimension combinations?

I do not believe the Revit API provides support for that, so it might indeed be best to parse the file yourself and extract the desired dimensions from it.

You can then load one specific family symbol into the project, duplicate it using the Duplicate method, and set the desired dimensions to the required values.

API Access to Revision Information

Question: I am trying to obtain data relating to the revisions present on a ViewSheet.

I can successfully retrieve what looks like the correct information via GetAllProjectRevisionIds, but the PROJECT_REVISION_REVISION_NUM parameter contains no information, and PROJECT_REVISION_REVISION_ENUMERATION always appears to contain '0' (zero) regardless of the Numeric or Alphabetic selection in Sheet Issues/Revisions.

I used a modified version of Max' revision wrapper class for my tests.

The test sheet in question contains 4 revisions, two of which are alphabetic, and two numeric. The output when I retrieve data using the sample code is:

  Number: Numbering: 0 Description: My description 1, Date: 4/1/14 Sequence: 4
  Number: Numbering: 0 Description: My description 2, Date: 5/1/14 Sequence: 5
  Number: Numbering: 0 Description: My description 3, Date: 6/1/14 Sequence: 6
  Number: Numbering: 0 Description: My description 4, Date: 7/1/14 Sequence: 7

Should I expect to see anything in Number, or do I need to calculate this using the Numbering option and the sequence number? Should I expect to see a different value for Numbering if alpha or numeric values are chosen?

Answer: In versions prior to Revit 2015, the API provided hardly any access at all to revision data.

One of the major Revit 2015 API additions is access to revision information.

I recently implemented a sample application showing how to use this access to read revision data and display it in a dynamically generated Windows form on the fly.

Installing a Revit Add-in

The best way to understand how to install a Revit add-in is to read the Revit API getting started material.

However, this material is targeted at developers.

I wrote a shorter and simpler answer addressing the minimal basics answering a comment by Frédéric on the AutoPDF print utility:

All Revit add-ins are installed in the same way.

They consist of an add-in manifest with the filename extension *.addin.

It is an XML file that you can edit and contains a tag pointing to the .NET add-in assembly DLL.

The add-in manifest must be located in a folder that Revit searches, e.g. the one you mention.

The add-in assembly can be placed anywhere you like.

I place small simple add-ins in the same folder as the add-in manifest.

Then there is no need to specify the full DLL pathname.

I hope this succinct summary is useful for non-developers.

Well, I am back in the rut again now...

RevitLookup for UR1, ADN, AEC and AU News

Here are some of the non-confidential items from the new confidential April 17 Autodesk Developer News newsletter, plus one or two additional items of interest from myself and elsewhere:

• AEC Technology Symposium
• Migrate Autodesk Exchange Apps and publish 2015 versions
• Proposals for Autodesk University 2014
• Proposals for Autodesk University Germany 2014
• Autodesk ReCap Connect Partnership Program
• RevitLookup for Revit 2015 UR1
• Happy Easter!

AEC Technology Symposium

I already pointed out the upcoming AEC Technology Symposium in New York City on May 16-18.

I mentioned the bad news, the absence of our bi-annual AEC DevCamp this year, and the good news, namely our participation in this event.

The best news of all is that I will be able to participate myself, so I hope to see you in New York a month from now.

The symposium itself is held on Friday the 16th, followed by a Hackathon over the weekend.

You can learn more and register for the event at http://core.thorntontomasetti.com/aec-technology-symposium-2014.

I hope to meet many of you that attended the AEC DevCamp in the past, and also get to know many new developers interested in cutting edge AEC technology, BIM 360, Dynamo, Revit, and non-Autodesk AEC technologies too.

Migrate your Autodesk Exchange Apps and Publish 2015 Versions

Customers are actively looking for 2015 versions of their favourite add-on tools, so make sure your apps are ready and available. Don't miss out on the opportunity to be found by all the new customers moving to Autodesk's 2015 solutions.

Please direct any questions on migrating your existing apps to appsubmissions@autodesk.com.

If you are submitting new apps, review the information at www.autodesk.com/developapps.

Autodesk University 2014 Call for Proposals Coming Up

You certainly know about AU, Autodesk University, Autodesk's largest annual user conference, with hundreds of classes and labs taught by top-notch instructors and industry professionals.

If you're interested in becoming a speaker at Autodesk University this year, you can now sign up to be notified when the AU 2014 Call for Proposals opens.

Speaker benefits include enhancing your reputation and increasing your networking opportunities, as well as speaker honoraria.

For further details visit http://au.autodesk.com/speaker-resource-center/overview.

Obviously, as always, I plan to submit a couple of proposals myself.

Autodesk University Germany 2014 Call for Proposals

Besides the main Autodesk University event in Las Vegas, I am also hoping to attend the German venue in Darmstadt this year, October 23-24.

The call for proposals for Autodesk University Germany 2014 is already open, and I plan to submit some here as well.

Autodesk ReCap Connect Partnership Program

You certainly know about ReCap, the reality capture functionality producing 3D point clouds and models from a series of 2D pixel images, e.g. normal camera snapshot photos.

Autodesk now announced the ReCap Connect Partnership Program covering several different methods to programmatically connect to and make use of this service:

• Capture Codec Kit
• Embedded ReCap OEM program
• ReCap Photo Web API

RevitLookup for Revit 2015 UR1

I published RevitLookup for the Revit 2015 Meridian pre-release PR10 before the final customer release, which ended up being UR1.

The complete source code, Visual Studio solution and add-in manifest, is provided in the RevitLookup GitHub repository, and the new UR1 version is stored there as release 2015.0.0.1.

I changed nothing from the PR10 version, except updating the Revit API references, so the compilation obviously still generates the same 19 warnings as before.

Happy Easter

I am visiting my sister Helene in the Provence in southern France for a few days, enjoying spring and the Easter holiday.

Happy Easter to you too!

Lots of Clouds

Let me recapitulate my cloud related explorations for my simplified 2D BIM editor, since I will be discussing it again at a web-based BIM workshop later this week.

Before getting to that, though, talking about cloud related topics reminds me of some others of completely different nature that are near and dear to me:

Clouds in La Palma

Cloud Atlas

Cloud-based simplified BIM editor

Autodesk cloud service overview

Updated RevitLookup on GitHub

Above, in and under the Clouds of la Palma

My hiking trip on La Palma was definitely on interesting study of clouds, from close and afar, inside and out.

Happily, I was mostly above them, e.g. wandering the sunny ridge around the Caldera de Taburiente National Park, reaching its highest point at the Roque de los Muchachos, looking back over the roiling clouds and the ridge in the east that we walked along for three days, with the Mount Teide of Teneriffa in the background far behind it, 90 km distant:

From there we descended into the depths of the Caldera itself and admired the same ridge from below, assailed by clouds as ever:

We emerged from the Caldera to cross the impressive volcanoes in the Parque Natural de Cumbre Vieja in the south, again above the clouds, looking back northwards at the ever cloud-filled and overspilling Caldera:

After spending the night up on the volcanoes, we were decisively chased away by more aggressive clouds backed up by strong and cold storm winds:

Happily, we made it down to a warm and sunny beach to dry off and recuperate a bit before starting the long journey back home again.

Cloud Atlas by David Mitchell

Another highly recommended cloud related topic is the extremely impressive and wonderful book Cloud Atlas by David Mitchell, recently and almost equally impressively converted to a film by Lana Wachowski, Andrew Wachowski and Tom Tykwer. I absolutely loved them both. I found the book revolutionary. I never read anything like it. The film is revolutionary as well, and an unbelievable feat. Tykwer and the Wachowskis met for a week in isolation to hatch ideas, then visited the book author Mitchell to hear what he thought of them. It helps to read the book first, though, to understand anything at all about what is going on in there.

Cloud-based Real-time Round-trip Simplified 2D BIM Model Editor

I'm attending a cloud workshop in the next few days, so I dug out the recordings from my Autodesk Tech Summit and Autodesk University presentation DV1736 – Cloud-Based, Real-Time, Round-Trip, 2D Revit Model Editing on Any Mobile Device. Here is the class summary:

This class demonstrates real-time, round-trip editing of a simplified 2D rendering of an Autodesk Revit intelligent model on any mobile device with no need to install any additional software whatsoever beyond a web browser. How can this be achieved? A Revit software add-in exports polygon renderings of room boundaries and other elements such as furniture and equipment to a cloud-based repository that is implemented using an Apache CouchDB NoSQL database. On the mobile device, the repository is queried and the data rendered in a standard browser using server-side generated JavaScript and SVG. The rendering supports graphical editing, specifically translation and rotation of the furniture and equipment. Modified transformations are saved back to the cloud database. The Revit add-in picks up these changes and updates the Revit intelligent model in real-time. All of the components used are completely open source, except for Revit itself.

Here are direct download links to all the class materials:

• Handout
• Slide deck
• AU recording
• Live recording
• Preview recording
• RoomEditorApp – Revit add-in desktop component
• roomedit – CouchDB cloud database source code

I already discussed all the details of all the different components here on The Building Coder, and that just about covers what I personally have to contribute right now to cloud and mobile applications interacting directly with Revit.

Autodesk Cloud Service Overview

Obviously, Revit itself is making more and more use of cloud-based services, and the offerings provided by Autodesk are growing in all directions as well; here is a good overview website for all currently available Autodesk services: autodesk.com/360-cloud.

For a quick text-based overview, here is my list from the cloud & mobile platform web service API presentation given at AU:

• Identity
• Autodesk Single Sign-On Services
• OAuth – i
• Federated Sign-On
• Viewing
• Viewing Services
• Translation Services
• Creation
• AutoCAD 360 Services
• Fusion 360 Services
• InfraWorks Services
• ReCap Photo Services – ii
• AutoCAD Core Engine Services (ACES)
• Simulation
• Render Services
• Building Performance, Green Building Studio Services
• Collaboration (Social)
• Autodesk 360 (Pro) Services
• BIM 360 (Glue + Field) Services – ii
• PLM 360 Services
• Business
• Licensing Services
• Exchange

As always, Autodesk is interested in making APIs available for these services, just like all other products, to provide a strong platform for automation of the related tasks. I added an 'i' to the ones already providing a deep and broad API, and an 'ii' to the ones already equipped with a maturing API. The rest are still under consideration.

The existing APIs are not accessible yet, though, either, since we are still working on pilot programs to get them ready for public consumption.

Updated RevitLookup on GitHub

Finally, as you hopefully already know, RevitLookup now lives on GitHub, also up in the cloud somewhere, so to speak, accessible to all.

This vastly simplifies collaboration, and you are heartily invited to participate in improving it.

One friendly supporter is Florian Schmid of SOFiSTiK AG.

He future-proofed RevitLookup by removing compiler warnings, and significantly extended the functionality for snooping of geometry, FormatOptions and RevitLinkInstances.

Another step of future-proofing that I performed was to bump the years listed in the copyright notices from 2013 to 2014, and, for the first time, incrementing the build version number.

The current version right now is thus release 2014.0.1.0.

You should probably always go for the most up-to-date master branch when downloading.

Calculating a Rolling Offset Between Two Pipes

Here is a nice little MEP related external command that I implemented to calculate a rolling offset for pipes at the CASE BIM Hackathon at AU, prompted by a suggestion by Harry Mattison and Matthew Nelson.

It calculates the rolling offset between two selected pipes and generates a model line in the Revit model to display the result.

In brief, a rolling offset is an angled pipe segment that connects two pipes with each other.

For instance, imagine a situation with two parallel horizontal pipes, offset from each other in all three directions, X, Y and Z.

The task consists in calculating the appropriate angled segment to connect the two.

Maybe the best way to explain the task is to show the solution in action before looking at the detailed implementation.

Given the two parallel offset pipes, one needs to decide how far along the axis defined by their common direction to place the angled segment.

I decided to choose the midpoint defined by the the two pipes' endpoints that are farthest apart, and place the angled segment so that its midpoint coincides with that.

Here is a 52-second video of the rolling offset add-in recorded live in situ at the CASE BIM Hackathon:

In case you prefer stills, here are six screen snapshots highlighting the situation, three before and three after executing the command:

3D view before

East view before

North view before

3D view after

East view after

North view after

If you look carefully, you will notice that both selected pipes are shortened by the external command. A model line is drawn at a 45-degree angle to the existing pipes to connect the two correspondingly adjusted endpoints.

The algorithm supports any other angle as well, of course, e.g. 30 or 60 degrees; it is currently hard coded.

Rolling Offset Calculation Implementation

I implemented the external code calculating the rolling offset and generating a model line to represent the result as a new external command CmdRollingOffset in The Building Coder samples.

For a maximum of flexibility, comfort and efficiency in testing it, it supports three different possibilities for selecting the two pipes:

• Run in a model containing exactly two parallel offset pipe elements, they will be automatically selected.
• Pre-select two pipes before launching the command.
• Post-select them when prompted.

Here is the entire command implementation:

[Transaction( TransactionMode.Manual )]
class CmdRollingOffset : IExternalCommand
{
  const string _prompt
    = "Please run this in a model containing "
    + "exactly two parallel offset pipe elements, "
    + "and they will be "
    + "automatically selected. Alternatively, pre-"
    + "select two pipe elements before launching "
    + "this command, or post-select them when "
    + "prompted.";
 
  /// <summary>
  /// Allow selection of curve elements only.
  /// </summary>
  class PipeElementSelectionFilter : ISelectionFilter
  {
    public bool AllowElement( Element e )
    {
      return e is Pipe;
    }
 
    public bool AllowReference( Reference r, XYZ p )
    {
      return true;
    }
  }
 
  public Result Execute(
    ExternalCommandData commandData,
    ref string message,
    ElementSet elements )
  {
    UIApplication uiapp = commandData.Application;
    UIDocument uidoc = uiapp.ActiveUIDocument;
    Application app = uiapp.Application;
    Document doc = uidoc.Document;
 
    // Select all pipes in the entire model.
 
    List<Pipe> pipes = new List<Pipe>(
      new FilteredElementCollector( doc )
        .OfClass( typeof( Pipe ) )
        .ToElements()
        .Cast<Pipe>() );
 
    int n = pipes.Count;
 
    // If there are less than two, 
    // there is nothing we can do.
 
    if( 2 > n )
    {
      message = _prompt;
      return Result.Failed;
    }
 
    // If there are exactly two, pick those.
 
    if( 2 < n )
    {
      // Else, check for a pre-selection.
 
      pipes.Clear();
 
      Selection sel = uidoc.Selection;
 
      n = sel.Elements.Size;
 
      Debug.Print( "{0} pre-selected elements.",
        n );
 
      // If two or more model pipes were pre-
      // selected, use the first two encountered.
 
      if( 1 < n )
      {
        foreach( Element e in sel.Elements )
        {
          Pipe c = e as Pipe;
 
          if( null != c )
          {
            pipes.Add( c );
 
            if( 2 == pipes.Count )
            {
              Debug.Print( "Found two model pipes, "
                + "ignoring everything else." );
 
              break;
            }
          }
        }
      }
 
      // Else, prompt for an 
      // interactive post-selection.
 
      if( 2 != pipes.Count )
      {
        pipes.Clear();
 
        try
        {
          Reference r = sel.PickObject(
            ObjectType.Element,
            new PipeElementSelectionFilter(),
            "Please pick first pipe." );
 
          pipes.Add( doc.GetElement( r.ElementId )
            as Pipe );
        }
        catch( Autodesk.Revit.Exceptions
          .OperationCanceledException )
        {
          return Result.Cancelled;
        }
 
        try
        {
          Reference r = sel.PickObject(
            ObjectType.Element,
            new PipeElementSelectionFilter(),
            "Please pick second pipe." );
 
          pipes.Add( doc.GetElement( r.ElementId )
            as Pipe );
        }
        catch( Autodesk.Revit.Exceptions
          .OperationCanceledException )
        {
          return Result.Cancelled;
        }
      }
    }
 
    // Extract data from the two selected pipes.
 
    Curve c0 = (pipes[0].Location as LocationCurve).Curve;
    Curve c1 = (pipes[1].Location as LocationCurve).Curve;
 
    if( !(c0 is Line) || !(c1 is Line) )
    {
      message = _prompt
        + " Expected straight pipes.";
 
      return Result.Failed;
    }
 
    XYZ p00 = c0.GetEndPoint( 0 );
    XYZ p01 = c0.GetEndPoint( 1 );
 
    XYZ p10 = c1.GetEndPoint( 0 );
    XYZ p11 = c1.GetEndPoint( 1 );
 
    XYZ v0 = p01 - p00;
    XYZ v1 = p11 - p10;
 
    if( !Util.IsParallel( v0, v1 ) )
    {
      message = _prompt
        + " Expected parallel pipes.";
 
      return Result.Failed;
    }
 
    // Select the two pipe endpoints that are 
    // farthest apart.
 
    XYZ p0 = p00.DistanceTo( p10 ) > p01.DistanceTo( p10 )
      ? p00
      : p01;
 
    XYZ p1 = p10.DistanceTo( p0 ) > p11.DistanceTo( p0 )
      ? p10
      : p11;
 
    XYZ pm = 0.5 * ( p0 + p1 );
 
    XYZ v = p1 - p0;
 
    if( Util.IsParallel( v, v0 ) )
    {
      message = "The selected pipes are colinear.";
      return Result.Failed;
    }
 
    XYZ z = v.CrossProduct( v1 );
    XYZ w = z.CrossProduct( v1 ).Normalize();
 
    // Offset distance perpendicular to pipe direction
 
    double distanceAcross = Math.Abs(
      v.DotProduct( w ) );
 
    // Distance between endpoints parallel 
    // to pipe direction
 
    double distanceAlong = Math.Abs(
      v.DotProduct( v1.Normalize() ) );
 
    Debug.Assert( Util.IsEqual( v.GetLength(),
      Math.Sqrt( distanceAcross * distanceAcross
        + distanceAlong * distanceAlong ) ),
      "expected Pythagorean equality here" );
 
    // The required offset pipe angle.
 
    double angle = 45 * Math.PI / 180.0;
 
    // The angle on the other side.
 
    double angle2 = 0.5 * Math.PI - angle;
 
    double length = distanceAcross * Math.Tan( angle2 );
 
    double halfLength = 0.5 * length;
 
    // How long should the pipe stubs become?
 
    double remainingPipeLength
      = 0.5 * (distanceAlong - length);
 
    if( 0 > v1.DotProduct( v ) )
    {
      v1.Negate();
    }
 
    v1 = v1.Normalize();
 
    XYZ q0 = p0 + remainingPipeLength * v1;
 
    XYZ q1 = p1 - remainingPipeLength * v1;
 
    using( Transaction tx = new Transaction( doc ) )
    {
      tx.Start( "Rolling Offset" );
 
      // Trim or extend existing pipes
 
      (pipes[0].Location as LocationCurve).Curve
        = Line.CreateBound( p0, q0 );
 
      (pipes[1].Location as LocationCurve).Curve
        = Line.CreateBound( p1, q1 );
 
      // Add a model line for the rolling offset pipe
 
      Creator creator = new Creator( doc );
 
      Line line = Line.CreateBound( q0, q1 );
 
      creator.CreateModelCurve( line );
 
      tx.Commit();
    }
    return Result.Succeeded;
  }
}

I hope you find this interesting and useful.

Here are two comments I received on this from Harry and Matt:

• I'm pretty sure this is the most bad-ass thing anyone did at the Hackathon. Nice work Jeremy!
• I second that! I wasn't there but I will pretend I was!

The code presented above is available from The Building Coder samples GitHub repository, and the version discussed here is release 2014.0.106.1.

Tere hommikust!

Sustainably Chugging Along

I continue chugging along here, mainly just answering cases.

January and February tend to be peaceful for me after the extreme travelling and conferencing in December.

I will also be reducing my overdue vacation time in the next couple of months, so expect another break or two in the flow.

Here are today's topics I find interesting or have been looking into myself:

• Autodesk corporate sustainability
• AU 2013 classes available on demand
• AllViews Revit SDK sample enhancement
• Revit API methods that regenerate
• Programmatic Element cutting

Autodesk Corporate Sustainability

Matching the great work done by the Building Performance Analysis team, making strong use of Revit and BIM technologies, Autodesk as a company has committed to reducing its carbon emissions per dollar contribution to GDP by over 9% year over year through 2020, an incredibly long-range goal for a technology company. A review of corporate emissions performance recognized Autodesk and its Sustainability Solutions team as absolute leaders in this area, demonstrating 'tremendous leadership in shaping corporate sustainability metrics to be more grounded in science.'

AU 2013 Classes Available on Demand

What skills could advance your career? Recordings of over 200 classes have been posted online, along with presentations and handouts for the rest of the more 600 classes presented at Autodesk University 2013 in Las Vegas. You can easily get advanced training, explore a new topic, or peer into the future of design software by signing up for a free Autodesk account and starting to learn right away. Here is the AU online overview and a short URL for it.

AllViews Revit SDK Sample Enhancement

Dale Bartlett very kindly provided an enhancement to the AllViews Revit SDK sample. Says he:

The RvtSamples > Views > All Views command retrieves all of the loaded Title Blocks for user selection in the creation of a series of sheets. The code actually builds a collection of Type names using the GetTitleBlocks method, rather than Family:Type names. If each Title Block has a default Type of 'Type 1' (recommended), the following is the result:

Selecting one will result in the first found Type (ChooseTitleBlock) rather than the specific Family:Type.

The above test project contains the following Title Block Families:

If a Family has no Types defined, then the default Type name is always listed the same as the Family name, so in most cases the code would work. I guess that is why it hasn’t been picked up previously.

I fixed this by adding a concatenated FamilyName:FamilyTypeName to the list, and searching for the same to return the appropriate FamilySymbol.Id in the following two methods:

• ChooseTitleBlock
• GetTitleBlocks

Here is the resulting modified and tested code:

  /// <summary>
  /// Retrieve the title block to be generated by its name.
  /// </summary>
  /// <param name="name">The title block name</param>
  public void ChooseTitleBlock( string name )
  {
    if( string.IsNullOrEmpty( name ) )
    {
      throw new ArgumentNullException( "name" );
    }
 
    foreach( FamilySymbol f in m_allTitleBlocks )
    {
      // Original SDK code returns first family 
      // symbol found, e.g. "Type 1" etc.
 
      //if( name.Equals( f.Name ) )
 
      // Replacement by DJB checks for concatenated 
      // family name and type name
 
      if( name.Equals( f.Family.Name
        + ":" + f.Name ) )
      {
        m_titleBlock = f;
        return;
      }
    }
  }
 
  /// <summary>
  /// Retrieve all available title blocks in 
  /// the currently active document.
  /// </summary>
  /// <param name="doc">The currently active document</param>
  private void GetTitleBlocks( Document doc )
  {
    FilteredElementCollector filteredElementCollector
      = new FilteredElementCollector( doc );
 
    filteredElementCollector.OfClass(
      typeof( FamilySymbol ) );
 
    filteredElementCollector.OfCategory(
      BuiltInCategory.OST_TitleBlocks );
 
    m_allTitleBlocks = filteredElementCollector
      .ToElements();
 
    if( 0 == m_allTitleBlocks.Count )
    {
      throw new InvalidOperationException(
        "There is no title block to generate sheet." );
    }
 
    foreach( Element element in m_allTitleBlocks )
    {
      FamilySymbol f = element as FamilySymbol;
 
      // Original SDK code saves only symbol name.
 
      //AllTitleBlocksNames.Add( f.Name );
 
      // Replacement by DJB saves concatenated 
      // family name and type name to ensure 
      // uniqueness in list.
 
      AllTitleBlocksNames.Add( f.Family.Name
        + ":" + f.Name );
 
      if( null == m_titleBlock )
      {
        m_titleBlock = f;
      }
    }
  }

Did I win a t-shirt?

Many thanks for all your help over the year via your Building Coder blog. A lot of people appreciate your efforts I know.

Many thanks to you, Dale, for discovering, fixing and sharing the solution for this issue!

Revit API Methods that Regenerate

A recent ADN case concerns a performance issue creating a large number of roofs, and why each one of them triggers a regeneration of the model:

Question: I have a program that uses a temporary transaction inside a transaction group to make changes to the model. It creates a large number of footprint roofs to represent rooms in a 3D view and shows the user the result in a preview control. However, this is taking a long time in a large model. In the debugger, I can see that each call to Document.Create.NewFootPrintRoof is taking up to 10 seconds. The user interface displays the 'Regenerating' message in the status bar several times before my call returns, so it appears that the model is being regenerated at least once for each call.

How can that be?

I am specifying manual regeneration mode. Revit is not supposed to regenerate the model until a transaction is closed, isn't it? How can I generate all the roofs without triggering a regeneration for each one?

Answer: Sorry, this is working as expected. Unfortunately, setting up the roof properly and ensuring consistency requires an internal regeneration.

This is pointed out explicitly in the Revit API documentation in RevitAPI.chm, which says the following about this method: "This method will regenerate the document even in manual regeneration mode."

There are a number of other Revit API methods that regenerate the model internally as well.

You can find them by searching the help file for the string above, which returns the following:

To see yet a couple of entries more, just search for "regenerate manual regeneration mode":

Response: In the case above, switching to using floors instead of roofs speeded the process up by a factor of more than ten.

Out of curiosity: is there a reason that roof creation regenerates and floor creation does not?

Answer: Sure: a floor is generally flat, whereas a roof with angles can generate an extremely complex shape.

Programmatic Element Cutting

A frequent question is how to cut Revit elements with each other, both in the family and project contexts.

Here is a recent incarnation of the topic that reached me both as an ADN case and a Revit API forum discussion thread on cutting elements:

Question: I'm trying to write a tool that will cut a beam to a reference plane and I'm not sure if it's possible in the API with SolidSolidCutUtils because of the element type that is a beam or reference plane. Here's my code so far:

  TaskDialog.Show( "Step 1",
    "Choose an element as a reference to cut to." );
 
  Reference eRef = m_document.Selection.PickObject(
    ObjectType.Element, "Please reference line." );
 
  TaskDialog.Show( "Step 2", "Choose an element to cut." );
  Reference eCut = m_document.Selection.PickObject(
    ObjectType.Element, "Please pick an element." );
 
  if( eRef != null
    && eRef.ElementId != ElementId.InvalidElementId
    && eCut != null
    && eCut.ElementId != ElementId.InvalidElementId )
  {
    CutElement( eRef, eCut, m_document, doc, activeDoc );
  }
 
  void CutElement( Reference eRef, Reference eCut,
    UIDocument m_document, Document doc,
    Document activeDoc)
  {
    //TaskDialog.Show("Step 2", "Here");
 
    int CutElement = m_document.Document
      .GetElement(eCut).Id.IntegerValue;
    int ReferenceLine = m_document.Document
      .GetElement(eRef).Id.IntegerValue;
 
    Element solidToBeCut = activeDoc.GetElement(
      new ElementId(CutElement));
 
    Element cuttingSolid = activeDoc.GetElement(
      new ElementId(ReferenceLine));
 
    Transaction transaction = new Transaction(activeDoc);
    transaction.Start("AddCutBetweenSolids");
    SolidSolidCutUtils.AddCutBetweenSolids(
      activeDoc, solidToBeCut, cuttingSolid);
    transaction.Commit();
  }

The problem is I get an error at AddCutBetweenSolids that the parameter solidToBeCut isn't of the right type. Is there another method that would accomplish what I'm trying to do or is there a way to fix this method to do what I want?

Answer: There are several different possible ways to perform Boolean operations between Revit elements.

I put together a collection of pointers to various discussions on The Building Coder concerning 3D Booleans and Cutting Elements to help answer your question.

In many cases, within the family environment, the approach you are attempting using SolidSolidCutUtils is one of the best and most effective options.

However, just as you have discovered, it places certain requirements on the input solids.

Just as its name implies, the cutting solid must be a solid.

A reference line definitely does not fulfil this requirement.

You will have to create a solid somehow.

Here is one suggestion of how to achieve this:

Use the reference line you already have and another one perpendicular to it to define a plane, define a large extruded cube based on that plane, and subtract that from your main body.

Starting to Clean Up For the Break

I am starting to clear up some open issues before the break. Here are a few that I can handle right here and now:

• Autodesk University classes ready for viewing and download
• Building Performance Analysis update
• Daylighting Analysis Tool for Revit update

I will obviously not be able to magically transform the entire backlog of interesting topics I still wish to share and discuss.

Still, I am continuously learning to be active and still take things easy, do what I do, not think too much, just act.

Here is a nice little anecdote to illustrate the principle:

A new Zen monk has just been admitted to the monastery.

He pays his respects to the master and says: "I'm new to the monastery, please show me the way."

The master asks, "Have you had breakfast?"

The novice replies, "Yes, just a moment ago."

"Then go and wash your eating bowl."

By the way, I wondered whether to use commas or colons in the lines above, and found a conclusive answer in the Grammar Monster discussion of quotation marks for quotes: "use commas for quotations that comprise fewer than 7 words and use colons for longer quotations". I did not know that before. Thank you, Grammar Monster.

Autodesk University Classes Ready for Viewing and Download

The AU class materials and recordings are now available for viewing and download from au.autodesk.com.

The search tool returns this year's classes as well as previous ones from 2011 and 2012.

Here are the results of searching for my classes:

• 2011 – CP4451 : Extensible Storage in the Revit 2012 API
• 2011 – CP6760-L : Revit 2012 API Extensible Storage Lab
• 2011 – CP4453 : Everything in Place with Revit MEP Programming
• 2012 – CP4107 : Let's Face It: New Revit 2013 User Interface API Functionality
• 2012 – CP4108 : Revit MEP Programming: All Systems Go
• 2012 – CP4109 : Revit API Roundtable: Meet the Champions
• 2013 – DV2010 : Advanced Revit 2014 API Features and Samples
• 2013 – DV1736 : Cloud-Based, Real-Time, Round-Trip, 2D Revit Model Editing on Any Mobile Device
• 2013 – DV1914 : Revit API Expert Roundtable: Open House on the Factory Floor

By the way, talking about AU, and what with the festive season and all, here is a picture of me at AU with a pretty big and festive bird:

Building Performance Analysis Update

I mentioned the Building Performance Analysis blog at autodesk.typepad.com/bpa last year.

The BPA team have completed a number of exciting projects since then.

Thanks to them, Revit 2014 now offers an entirely new way to create an Energy Analysis Model or EAM automatically from Revit building elements, as explained in their following discussions:

• Revit 2014 release news
• Energy analysis using Revit building elements
• Revit 2014 update release 1

If you are already working with the Revit Energy Analysis model or are interested in determination of realistic volumes of rooms and spaces for any purpose whatsoever, this is a topic you absolutely must dive into.

For starters, read the detailed explanation From BIM to BPA: What is an Energy Analysis Model (EAM)?

Expect more in this area!

Daylighting Analysis Tool for Revit Update

One of the BPA tools is the recently announced Daylighting Analysis Tool for Revit, which was just now updated and released for global distribution.

The Revit 2014 Daylighting Analysis plug-in uses the Autodesk 360 Rendering cloud service to perform very fast and physically accurate daylighting analyses from within Revit. In the current first release of the plug-in, it provides LEED IEQc8.1 2009 results for most models in less than 15 minutes.

Here is the detailed BPA presentation of daylighting as a service.

The features provided by the new update include:

• New localized EULA and installer allow global distribution.
• If no Rooms are defined in the model when Run Analysis is selected, the user is given a warning, but analysis will continue.
• A unit option has been added to the AVF results view so lux or foot-candles can be selected.
• The LEED Room parameters now show up as editable in the Room Properties panel when a Room is selected.
• The AVF legend has been improved by clipping the values shown in the AVF to 6000 lux to make the scale visible in the lower ranges. The full raw values are still stored in the Revit Extensible Storage for export.
• User can hide and unhide AVF grids by level to make viewing and navigation easier in 3d section cuts.
• If the user has modified the "LEED 2009…" 3d view, the view is reset to defaults for the analysis run. Best practice is for user to make a copy of that view to create a custom view style.
• The plug-in can now handle multiple projects and multiple concurrent analyses in Revit. It is still required to keep a project open until the analysis is complete and data is downloaded from the cloud service.
• The user will now receive a message if a job fails for any reason, and the successful results will be downloaded.

You can download the technology preview from Autodesk Labs: Download Daylighting Analysis Tool for Revit.

AU Day 3, ReCap & Cloud-based Round-trip Model Editing

When you get to read this, I will be sitting in a plane at 30'000 feet over the middle of the Atlantic Ocean... or somewhere over Greenland, whatever.

Thursday was the third and last day of Autodesk University.

I went out for a quick beer with some of my ex-Autodesk-colleagues from decades ago on Wednesday evening, and a very nice time was had by all.

It turned out to be not quite so quick, however, and not just one beer, and I woke up next morning suffering dire consequences.

I would strongly sustain that they were due to the fact that the brews I sampled to not adhere to the strict and sensible purity rules. I would never have expected such a huge difference in after effects.

Luckily, though, I did wake up, initially thinking that my cloud-based round-trip 2D Revit model editing class would be later in the day. Even more luckily, I decided to switch on the computer and look at the schedule.

Imagine my shock to discover that it was scheduled for 8:00 am.

Anyway, I made it, and everything went really well, and now I am sitting at the airport and the plane is delayed.

These are my main activities of the day:

• Cloud-based round-trip 2D Revit model editing
• Replace Idling by an External Event
• ReCap reality capture and its REST API

Cloud-based Round-trip 2D Revit Model Editing

I presented my class DV1736 – Cloud-Based, Real-Time, Round-Trip, 2D Revit Model Editing on Any Mobile Device.

This is the second time I present my super simple solution open source based solution for this task.

The first was at the Autodesk internal Tech Summit in June (overview, 30-minute pre-recorded video and live recording).

This time around, I had 90 minutes – instead of 30 – to discuss the topic in much more completeness and detail, which felt very good.

Here is the class handout and slide deck.

A recording will come later, once the AU technical staff have completed and made it available.

Replace Idling by an External Event

During the Revit API roundtable on Wednesday, I finally realised what I should have been doing all along instead of fiddling with the Idling event.

I wish someone else would have noticed, thought of this, told me much earlier, and we would not all have had to wait until I finally thought of it myself.

This planet sure can feel like a lonely place sometimes.

Anyway, I now realised that I can significantly reduce the overhead and sluggishness of the Idling event by using an external event instead that I define myself.

An external event would allow me to vary the number of checks I make per second freely, relinquishing control in between, and only bother Revit when there really is something for it to do, i.e. a pending database update to be integrated into the BIM.

I can't wait to implement and test this!

ReCap reality capture and its REST API

At the last moment before leaving for the return flight, I discovered the class by Stephane Negri, Software Development Manager, Autodesk, RC3176 – Put Your Mind at REST: Extend Your Application to Reality Capture:

The reality capture group at Autodesk is working on ways to acquire, manipulate, or analyse real scene data using laser scans or photos through Autodesk ReCap products. While several AU classes demonstrate ReCap use and workflows associated with these products, this class focuses on how to programmatically access the reality capture web API to create or extend an application. We start with a quick overview of basic photogrammetry concepts and image parameters, then approach the reality capture REST API and discuss how to define a photo scene from multiple photos and create a dense 3D mesh, also covering some of the advanced features that are available to customize and refine the process. The class concludes with a complete example written in PHP.

I already mentioned this topic in my overview of the cloud & mobile platform web service APIs provided during the ADN DevDay conference on Monday.

Here are my notes from Stephane's class, with absolutely no guarantee for correctness:

Autodesk offers several different browser-based user interfaces for different reality capture scenarios.

They all use the same underlying ReCap REST API.

You need a special developer key to make use of the API. To obtain one, please contact ADN and ask to become a pilot partner.

Stephane presented a manual demo to clarify the user interface, available functionality and usage workflow.

You sign in with the standard Autodesk single sign-in.

The project gallery presents impressive examples of the kind of models that can be achieved.

He created a new project using only three photos.

Very simple workflow: create a new project, upload photos, wait and retrieve the result.

Photos must be of high quality, good lighting and equipment and overlapping, e.g. with each point visible in at least three pictures.

Quality is more important than quantity.

ReCap is built on Amazon web services, using queues to manage jobs.

The basic API workflow matches the manual approach: create photoscene, upload files, progress check, retrieve results.

Authentication using Oxygen, and Autodesk service based on OAuth 1.0, a three-legged authentication based on HTTP header data.

Documentation is public and embedded in the service, generated by the Swagger framework for describing, producing, consuming, and visualizing RESTful web services.

You can easily try out the UI workflow via the API using manual REST calls.

The results of each REST call are returned in either JSON or XML.

For more information, please contact recap.api@autodesk.com.

Stephane also presented some of the current pilot partners and their work, some of which was also being shown in the AU exhibition:

• SoundFit custom fit ear gear, creating a precise model of the inner space within the ear for prosthetics, a fully automated complete custom application.
• Kubit, dealing with AutoCAD applications for real-world as-built capturing.
• Skycatch, providing a low cost, highly flexible, intelligent & scalable aerial robotics platform.

Tilo Pfliegner of Kubit demonstrated easy integration of calibrated photos, point clouds and ReCap models into AutoCAD.

Point clouds are sometimes too imprecise for modelling needs. Using photos directly instead is better, because they are often more precise, and the photo quality is often better than the generated point cloud. He listed the following applications:

• Photo modelling
• Phototracing
• Monoplotting
• Creation of image plans
• Orthophotos
• Unwinding

Chris Bumgardner of SkyCatch presented their Recap API integration for fully autonomous unmanned flying vehicles.

A typical use case might be the generation of daily 3D models for construction customers.

They have implemented a server-to-server integration using Recap 3.1 API, Node.js server-side JavaScript, OAuth, request etc.

You can use a viewer such as Sketchfab to view the resulting OBJ model. Sketchfab is a web service to publish and display interactive 3D models. No plugin required: upload your model, embed it, share it, done.

This makes it extremely easy to embed the resulting model into web browser, for example.

Again, high quality images are more important than quantity, e.g., four images may be perfectly sufficient.

Use high-resolution images. The resulting accuracy may reach down to one single pixel level. Go closer if you use low resolution.

How to scale the resulting model properly to the real world? You can use a template file, have known camera positions, set GPS coordinates, measure the real-world sample, etc.

GoPro has a fisheye distortion; switch it off with StitchingCreateInputFile = 1.

The Exif data within each image tells you the source of it, e.g. to recognize GoPro images.

You don't have to add any marker points, just make sure the surfaces are not too bland and uniform.

Many thanks to Stephane, Tilo and Chris for the interesting presentation.

AU Day 2, Worksharing and Revit 2014 API Roundtables

Here is my report on Wednesday at Autodesk University, following the DevDay pre-event conference on Monday and the first real day at AU on Tuesday.

These are my main activities of the day in chronological order, plus pointers to a fantastic class or two that I missed and want to highlight anyway:

• Virtually human – modelling the human body using BIM
• Design to fabrication
• Revit add-ins that cooperate with worksharing
• Worksharing roundtable
• Revit API roundtable

Virtually human – modelling the human body using BIM

This is an utterly fantastic presentation on highly professional worldwide BIM collaboration for fun by Mike Slessor, Jonathan Lock, Ken Enright and Casey Rutland of ARUP. I was unfortunately unable to attend, since it took place at the exact same time as my first class on advanced Revit 2014 API features and samples early Tuesday morning: MP2845 – Virtually Human: Modelling the Human Body Inside and Out Using BIM Platforms. They say:

The study of human anatomy has traditionally been the domain of physicians, dentists, physiotherapists, nurses, paramedics, and other health professionals. What happens when you let building designers have a crack at replicating it? This class provides you with the opportunity to meet Project OVE, Arup’s virtual human. OVE has a full structural skeleton and respiratory system. OVE sweats, gets hungry, and even has a heart. We are still working on the operating system but OVE has a huge brain that will act as the main control centre when finished. However, OVE is also more than just an artificial replication of the human body. Creating an intelligent version of OVE required us to exploit the full potential of Revit as a state-of-the-art BIM (Body Information Modelling) tool.

Here is the 161-page class handout PDF, which I find absolutely fascinating.

Design to Fabrication

Another class that I was unfortunately unable to attend yet take a special interest in is William Spier's FB2938 – Design to Fabrication: Design, Validate, and Fabricate Anything Between Revit and Inventor.

William asked me to implement the ExportCncFab add-in, originally published in March under the name ExportWallboard to automatically isolate and export wall parts individually to DXF for CNC fabrication.

Now, after a minute last-minute hiccup that we solved end of last week and over the weekend, the add-in is up and running as expected, including the external application driving the user interface and the new shared parameter generation command.

The updated version is available from the ExportCncFab GitHub repository, and the current version is release 2014.0.0.11.

This is only one of the many powerful fabrication solutions and paths that William developed and presents, though.

Here is current version of his complete handout and slide deck.

Revit Add-ins that Cooperate with Worksharing

The one and only class that I was able to participate in so far without carrying any responsibility whatsoever for myself was Scott Conover's DV1888 – Facing the Elephant in the Room: Making Revit Add-ins That Cooperate with Worksharing.

I am so glad that I did, because the information presented there is absolutely invaluable.

At the moment, it is available only from the Autodesk University site.

We will certainly return to this topic and publish all the material as soon as it is finalised.

This is too important to ignore, and too complex to understand without some expert guidance.

Worksharing Roundtable

The worksharing class was followed by the roundtable session DV3464-R – Making Revit Add-ins That Cooperate with Worksharing with a dozen expert Revit API and product users plus Sasha, Scott and Jeremy.

I took some notes, and so did Sasha and Scott, so we will wait with publishing those until they have been consolidated.

Revit API Roundtable

The next class that I took responsibility for myself is the DV1914 Revit API roundtable inviting the participants to interact with a panel of Revit API experts from Autodesk to get answers to their questions and discuss all relevant customisation topics of their choice. This is the perfect forum to get to know better some of the people who shape the APIs you work with and to explain your views, ideas, and problems directly face-to-face.

Many thanks to all the more than 50 participants of this session, and especially to the following panellists who collectively answered the many interesting questions that were raised:

• Angel Velez, Revit Development
• Augusto Gonçalves, ADN
• Jeremy Tammik, ADN
• Miroslav Schonauer, Autodesk Consulting
• Scott Conover, Revit Development
• Sasha Crotty, Revit Development

This session was recorded. I uploaded a rather low quality version of the 60-minute recording. Luckily, a better quality one was made in parallel by the AU technical staff, and we will have to wait a while for that to become available.

Here are the questions and answers brought up during this roundtable session, almost unchanged from the original form they were jotted down in, and also added to the updated handout:

[q] modify visibility of linked files per view?
[a] currently no API access.

[q] modify selection from a modeless context, how to update view?
[a] check it out in UR2, it should be fixed.

[q] Revit materials. when i try to read bitmap from asset, the bitmap path in the asset property is not consistent. for some materials you can access the full bitmap path, but sometimes there is no entry for the bitmap itself. is there a better way to get the bitmap from materials?
[a] going forward, we definitely are looking at better access to material asset info.

[q] Revit API preview window to display sheets will not dynamically update when we change sheet name or number, so we have to create a new sheet in order to force it to update. part 2: preview window. will it be made more dynamic?
[a] i am not aware of any such issue, please report to ADN, we want to hear about this. post it on the forum so we can track it. we will research and submit an issue if needed. part 2, improvements: we can discuss a little more what you are looking for. some of our exports use the preview window, you can toggle things on and off, we need to hear what you need.

[q] acad has COM + .NET interface to access from outside, open and close documents and start up and shut down autocad. is this possible in Revit?
[a] we do not currently have that. use the external event mechanism instead.

[q] i have an app that opens Revit and configures worksets. it crashes now and again and the problem is reproducible. response: it only happens when you are using Revit server, and the API is not fully supported for that.
[a] the API should support that, there are no limitations for Revit server.

[q] working with schedules and accessing a parameter from schedule or from an element there is a difference. the id is the same. wanted to distinguish between a project and a shared param with the same name.
[a] element ids are used to represent elements, parameters and categories. for params, the id may be negative, e.g. bip, or non-negative, custom or shared. when you call get element on that id, it returns the parameter definition. probably that object does not have an exposed subclass in that context. there is difference between newer and older environments, and the schedule API is newer.

[q] use cut and paste API to import new sheets. the DuplicateViews SDK sample does drafting views and schedules. any advice for sheets?
[a] the mechanics for sheets would be the same. probably best to copy them together, because then Revit can do an optimal job of maintaining relationships. bring in the empty drafting views and settings all together. DuplicateViews demonstrates these two steps.

[q] any plans for enhancing this?
[a] it is already perfect. Revit uses it internally also.

[q] non-technical: collaboration between dynamo and API team?
[a] there is a group of dynamo guys all around us, they are in the same office. we try to expand Revit development in all directions.

[q] purge all. any chance of exposing that, purge unused?
[a] who needs a purge API? lots.

[q] convert an element from linked file and put them into the host document. can i do that?
[a] copy monitor approach lets them remain in the link, and the copy paste API can bring them in properly. use copy paste and then delete the linked element. that will require unloading it. depending on what element you ant to bring over, it may run into problems trying to separate it from its relationships. it might bring it in with the right shape. otherwise you might need to read boundaries and recreate it. if you bring it in as is it will be looking for sketch curves in the wrong place.

[q] macro ide. structural company, little API programs passed out to customers, using macro to transfer to customer, but it is not so simple. to transfer macros to customer it is a bit more complicated.
[a] you could use the python shell. why not make it an external command and send the dll? then the user does not have to touch anything. you can embed the macro in the model, and then there is no code to transfer. the macro does actually generate a mini little hidden DLL that you can transfer to the customer.

[q] add-in existing with a project. can they be bundled?
[a] only macros and dynamo scripts. the exchange store is actually the most official avenue. we are interested in people sharing code, but it also worries some. you have many options.

[q] furniture in Revit families including 150 types. easy way to create blocks of every time. create a symbol library. can that be dome programmatically?
[a] yes, simple to solve, has been published.

[q] reload the keynote file?
[a] yes, we are looking at that for the future. right now it can be solved using an autohotkey script. in 2014 you can also post the command.

[q] can i access the Revit line pattern from a Revit style? line weight is available.
[a] augusto wrote a code about that a few weeks ago. you have to search the assets.

[q] create or control underlays in a section view, like the ones you have in plan view? structural engineering in chile requires you to show the projected elements in front and behind. underlays in the views would solve this.
[a] probably not exposed. that si a good request to make. we have 11500methods and classes, we do not always know. augosto saw a solution involving moving the selection a bit. this is not API functionality, but basic Revit platform functionality expansion request, been requested for ten years.

[q] extensible storage available in families?
[a] yes. there is a sample that demonstrates this in the original estorage au materials.

[q] basic file info, transmission data. can a few more areas be opened up, e.g. view sheet list? now i have to open the file, export the view list, close the file.
[a] yes, that is the current approach. file a request, please.

[q] furniture geometry has a huge amount of unique vertices. how can i reduce that? i need it for a webgl viewer.
[a] Revit is good at optimising. something is curved. Revit likes to triangulate things. there are some knobs that you can use to turn down the triangulation. ifc uses the solid tessellation routine added in 2014. if you are exporting solids, take a look at that. the normal tessellation routines do not line up adjacent faces. doing the whole solid in one go is better. another approach is the custom exporter. then you do not need to think about each element.

[q] document changed event tracks changes. how do i know exactly what changed, and what the old value was?
[a] you have to cache all the values of interest beforehand. we have a similar request around what was deleted.

[q] dual monitor support, how can i take some things outside of the Revit window? it seems to work on autocad.
[a] you can create a modeless dialogue, attach it to the Revit parent window and drag it off the screen.

[q] single core. multicore machine. how can i know what thread Revit is using?
[a] the windows processes can be queried. look for the revit.exe process and the .NET Process library. this is Windows API, not Revit API.

[q] some params have type of colour and bring up a dialogue when the user edits them. can i create a shared param to store a colour as well?
[a] Revit implements some parameters that map to custom behaviour and launch dialogue. this is not accessible programmatically.

[q] can i raycast onto a non-planar surface?
[a] the ReferenceIntersector ray cast utility can be used, but only ray by ray. the extrusion analyser only goes onto a flat plane. you could make repeated calls to the extrusion analyser call for each facet of the tessellated surface.

Many thanks to all who joined in here!

AU Day 1, Revit 2014 API Class and Bounding Box Rotation

Tuesday was the first real day at AU after the DevDay pre-event conference yesterday.

Here are my main activities of the day in chronological order:

• Advanced Revit 2014 API features and samples
• AU Keynote by Jeff and Carl
• DevLab and bounding box rotation
• Adding a marker at the Revit project origin
• Download

Advanced Revit 2014 API Features and Samples

I presented my first class DV2010 – Advanced Revit 2014 API Features and Samples right away starting at the very first moment of AU, at eight in the morning.

Here is the most up-to-date handout and slide deck.

Keynote

As usual, the keynote presentation was given by Jeff Kowalski and Carl Bass, with Jeff focusing on ideas and long-term vision and Carl presenting real live usage examples of existing products.

Jeff expounded on the power and advantages of collaboration and open source, and how the Autodesk 360 platform supports that. He suggested picking a class by chance, to learn something completely new, mentioned reverse mentoring, where young people mentor older experienced folk, pointed out how much there is to learn from each other, e.g. using reverse innovation, consciously looking outside, beyond what you and everybody else thinks is possible, to learn, unlearn and relearn.

Carl highlighted a number of different original and creative companies making use of new technologies to save huge amounts of time and effort, e.g.:

• Orphanage guitars via fusion 360 to create custom made guitars involving the customer directly in the process.
• Aston Martin creating a new car, concept sketches, Sketchbook, Alias, CNC-generated clay model, post processed including hand sculpting, laser scanned to bring it back into Alias, completing the cycle to market in record time.
• PLM 360 cloud-based example with a four month adoption period, to search for data and create documentation
• Prosthetic leg collaboration project using A360 and CAM 360.
• Airport project complexity BIM developer share coordinate using BIM 360 Glue thousands of hours saved BIM 360 Field solve problems in real-time, Infraworks 360, ReCap point cloud image based 3D modelling, the only input you can really trust, saving thousands of hours of modelling work.
• BioLite building a stove scaled up by a factor of 500 from the normal design on short notice using SIM 360.
• Bot & Dolly film and robots Maya animate robots in real life the way you would normally animate virtual characters. Complete control of robot motion in time and space. Robot "Iris" danced for us. For a sample, look at Box on YouTube.

According to Carl, the most important things to look at in the coming days are Autodesk 360 and computational design, e.g. Dynamo. It currently drives Revit. Being open source, it can be adapted by anyone for other products as well, and an implementation driving Inventor has already been unveiled.

Lots of great new technology to discover, and more than 500 classes to choose from.

DevLab and Bounding Box Rotation

DevLab was active, lots of questions addressed.

One little issue I was able to capture was this snippet of code to calculate the max and min of a rotated bounding box, initially inspired by Angel Velez, Revit developer, and heavily edited by your humble scribe:

Angel pointed out that if you wish to calculate the result of rotating a bounding box representing a rectangle around the origin in the XY plane, you cannot simply rotate the min and max points, because the rotated max point may easily end up being 'smaller' in some coordinate than the rotated min.

One way to work around that is to extract all four bounding box corners, rotate each of them and determine new min and max values from those.

I implemented this little helper method to generate the four XY corner points of a bounding box, flattened onto its minimum Z elevation:

  /// <summary>
  /// Return the four XYZ corners of the given 
  /// bounding box in the XY plane at the minimum 
  /// Z elevation in the order lower left, lower 
  /// right, upper right, upper left:
  /// </summary>
  public static XYZ[] GetCorners( BoundingBoxXYZ b )
  {
    double z = b.Min.Z;
 
    return new XYZ[] {
      new XYZ( b.Min.X, b.Min.Y, z ),
      new XYZ( b.Max.X, b.Min.Y, z ),
      new XYZ( b.Max.X, b.Max.Y, z ),
      new XYZ( b.Min.X, b.Max.Y, z )
    };
  }

In order to be able to use the standard .NET Min and Max methods to extract the min and max points from the rotated corners, I need to use a flavour of the XYZ point and vector class which implements the IComparable interface.

To obtain that, I implemented this little XyzComparable wrapper class:

  /// <summary> 
  /// XYZ wrapper class implementing IComparable. 
  /// </summary> 
  class XyzComparable : XYZ, IComparable<XYZ>
  {
    public XyzComparable( XYZ a )
      : base( a.X, a.Y, a.Z )
    {
    }
 
    int IComparable<XYZ>.CompareTo( XYZ a )
    {
      return Util.Compare( this, a );
    }
  }

It makes use of my pre-existing XYZ Compare utility method:

  public static int Compare( XYZ p, XYZ q )
  {
    int d = Compare( p.X, q.X );
 
    if( 0 == d )
    {
      d = Compare( p.Y, q.Y );
 
      if( 0 == d )
      {
        d = Compare( p.Z, q.Z );
      }
    }
    return d;
  }

With all of that in place, the bounding box rotation ends up quite simple and readable:

  /// <summary>
  /// Return a rotated bounding box around 
  /// the origin in the XY plane.
  /// We cannot just rotate the min and max points, 
  /// because the rotated max point may easily end
  /// up being 'smaller' in some coordinate than the 
  /// min. To work around that, we extract all four 
  /// bounding box corners, rotate each of them and
  /// determine new min and max values from those.
  /// </summary>
  private static BoundingBoxXYZ RotateBoundingBox(
    BoundingBoxXYZ b,
    Transform t )
  {
    double height = b.Max.Z - b.Min.Z;
 
    // Four corners: lower left, lower right, 
    // upper right, upper left:
 
    XYZ[] corners = Util.GetCorners( b );
 
    XyzComparable[] cornersTransformed
      = corners.Select<XYZ, XyzComparable>(
        p => new XyzComparable( t.OfPoint( p ) ) )
          .ToArray();
 
    b.Min = cornersTransformed.Min();
    b.Max = cornersTransformed.Max();
    b.Max += height * XYZ.BasisZ;
 
    return b;
  }

In order to test this new functionality, I dug up the old CmdBoundingBox implementation from The Building Coder samples, from one of the very first posts back in the year 2008.

It prompts you to select an element and used to just report its bounding box coordinates in a message box.

I modified that to draw model lines for the box instead, again making use of the GetCorners method defined above to extract the four vertices required. This also obviously requires changing the command's transaction mode from read-only to manual and adding a transaction, since the model line creation modifies the database.

To test the rotation functionality, I call the RotateBoundingBox method with a 60 degree rotation transformation and print and display the result like this:

public Result Execute(
  ExternalCommandData commandData,
  ref string message,
  ElementSet elements )
{
  UIApplication app = commandData.Application;
  UIDocument uidoc = app.ActiveUIDocument;
  Document doc = uidoc.Document;
 
  Element e = Util.SelectSingleElement(
    uidoc, "an element" );
 
  if( null == e )
  {
    message = "No element selected";
    return Result.Failed;
  }
 
  // Trying to call this property returns the
  // compile time error: Property, indexer, or
  // event 'BoundingBox' is not supported by
  // the language; try directly calling
  // accessor method 'get_BoundingBox( View )'
 
  //BoundingBoxXYZ b = e.BoundingBox[null];
 
  View v = null;
 
  BoundingBoxXYZ b = e.get_BoundingBox( v );
 
  if( null == b )
  {
    v = commandData.View;
    b = e.get_BoundingBox( v );
  }
 
  if( null == b )
  {
    Util.InfoMsg(
      Util.ElementDescription( e )
      + " has no bounding box." );
  }
  else
  {
    using( Transaction tx = new Transaction( doc ) )
    {
      tx.Start( "Draw Model Line Bounding Box Outline" );
 
      Debug.Assert( b.Transform.IsIdentity,
        "expected identity bounding box transform" );
 
      string in_view = ( null == v )
        ? "model space"
        : "view " + v.Name;
 
      Util.InfoMsg( string.Format(
        "Element bounding box of {0} in "
        + "{1} extends from {2} to {3}.",
        Util.ElementDescription( e ),
        in_view,
        Util.PointString( b.Min ),
        Util.PointString( b.Max ) ) );
 
      Creator creator = new Creator( doc );
 
      creator.DrawPolygon( new List<XYZ>(
        Util.GetCorners( b ) ) );
 
      Transform rotation = Transform.CreateRotation(
        XYZ.BasisZ, 60 * Math.PI / 180.0 );
 
      b = RotateBoundingBox( b, rotation );
 
      Util.InfoMsg( string.Format(
        "Bounding box rotated by 60 degrees "
        + "extends from {0} to {1}.",
        Util.PointString( b.Min ),
        Util.PointString( b.Max ) ) );
 
      creator.DrawPolygon( new List<XYZ>(
        Util.GetCorners( b ) ) );
 
      tx.Commit();
    }
  }
  return Result.Succeeded;
}

I tested that on a single wall element, with the following resulting model lines displaying the original and rotated bounding boxes:

See how skewed it gets?

Addemdum by Angel Velez: this code assumes that the rotation is in XY only, hence the 'flattening' of the bounding box cube to 4 points. If you wanted to make it applicable to a truly arbitrary rotation, you would take the 8 points of the cube – so factor Min.Z and Max.Z into it – then you wouldn’t have to do any 'add Z back in at the end' hacks. Of course, you also have to do an extra 4 transforms.

That would add a significant amount of complexity, however, and the above should cover the most common cases by far.

Adding a Marker at the Revit Project Origin

In order to understand properly and analyse the rotation results, we obviously need to know around which point it is taking place.

It would be handy to add a marker at a specific point in the Revit model, in this case at the origin.

One way to achieve this, was described by the Revit Clinic discussing the two mile barrier: "If you want to be sure, the easiest method is to import a DWG file that contains a circle or X at AutoCAD's 0,0 and make sure to select the option origin-to-origin while importing the DWG file. This will show you exactly where the Revit origin is located (centre of the circle or x). Here is an AutoCAD DWG file with a symbol at the origin."

When importing the DWG into my model using Insert > Import CAD, I left all the default setting values except the following:

• Import units: Custom factor: 0.5
• Positioning: Auto - Origin to Origin

You can admire the resulting origin marker in the screen snapshot above, along with model lines displaying the positions of the original and rotated bounding box.

Download

The updated version of this command is available from The Building Coder samples GitHub repository and the version discussed above is release 2014.0.106.0.

Have fun, and wish me a good quick sleep, since there are only a very few hours left before my next meeting...