The Building Coder

Curve.Intersect Return Values

The first day of the Saudi Arabian Revit API training completed yesterday. This training will go on for three days instead of the usual two, so that we have more time to deal with the installation and basics as well as various advanced topics. Yesterday we dealt with installation and setup issues, of Revit, Visual Studio, and the Revit SDK with its tools and utilities. We started looking at Hello World style samples, i.e. the basic skeletal structure and installation... Read more →

Creating a Solid

Here is question that crops up from time to time and requires pretty special treatment in Revit: Question: Is it possible to build 3D solids in Revit like we can in AutoCAD? For instance, when you have a bunch of points and you wish to make a mass object similar to an extrusion? Answer: The very words "as in AutoCAD" are extremely dangerous to utter or even think when using the Revit API, so for your own sake and sanity,... Read more →

Revit API Resource and Getting Started Guide

I was very enthusiastic about Rod Howarth's Autodesk University presentation, and especially the Revit API resource guide and suggestions for getting started with the Revit API that he presented in the second half. Rod has now very friendlily published his Revit API Resource Guide. To whet your appetite for having a closer look at this invaluable information, here is a table of contents I put together: Resource Overview C# / VB.Net Resources Get a good book View information online SDK... Read more →

Material Quantity Extraction

This is the tenth and last part of Scott Conover's Autodesk University 2009 class on analysing building geometry. One common analytical requirement is to extract material quantities of elements in the document. Revit 2010 introduced methods to directly obtain the material volumes and areas computed by Revit for material takeoff schedules: Element.Materials – obtains a list of materials within an element. Element.GetMaterialVolume – obtains the volume of a particular material in an element. Element.GetMaterialArea – obtains the area of a... Read more →

FindReferencesByDirection

This is part 9 of Scott Conover's AU 2009 class on analysing building geometry, dealing with the FindReferencesByDirection method and its use as an applications 'eyes'. We mentioned the method briefly in our discussions on how to find a host or a foundation element, Harry Mattison recently presented a very compelling example using it to simulate a pool table in a Revit model, and Scott himself provided the real-world example for creating spot elevations on the top surface of a... Read more →

Project Location

This is part 8 of Scott Conover's AU 2009 class on analysing building geometry, dealing with the project location and its effect on element transformations. We aready looked at the project location in the discussion on unrotate north. However, as Scott pointed out, the results presented there are somewhat misleading and are subsumed by the following discussion. The project location obviously also affects the azimuth of an element, i.e. the angle between the element and true north, and our previous... Read more →

Transformations

This is part 7 of Scott Conover's AU 2009 class on analysing building geometry, exploring coordinate transformations and the placement and orientation of family instances. For completeness sake, here are some back pointers to previous blog posts dealing with transforms and related issues: The Transform class. Polygon transformation. Instance coordinate transformation. Transforming an element. Scaling a curve. So now I hand the word back to Scott: Coordinate Transformations Revit and the Revit API use coordinate transformations in a variety of... Read more →

Face Edges

This is part 6 of Scott Conover's AU 2009 class on analysing building geometry. Edge and Face Parameterization Edges are boundary curves for a given face. Iterate the edges of a Face using the EdgeLoops property. Each loop represents one closed boundary on the face. Edges are always parameterized from 0 to 1. An edge is usually defined by computing intersection of two faces. But Revit doesn't recompute this intersection when it draws graphics. So the edge stores a list... Read more →

Faces

This is part 5 of Scott Conover's AU 2009 class on analysing building geometry. Faces in the Revit API can be described as mathematical functions of two input parameters 'u' and 'v', where the location of the face at any given point in XYZ space is a function of the parameters. The U and V directions are automatically determined based on the shape of the given face. Lines of constant U or V can be represented as gridlines on the... Read more →

Curves

This is part 4 of Scott Conover's AU 2009 class on analysing building geometry. Curve Types Revit uses a variety of curve types to represent curve geometry in a document. The curve types and corresponding Revit API classes include: Bounded line – Line Unbound line – Line Arc – Arc Circle – Arc Elliptical arc – Ellipse Ellipse – Ellipse NURBS – NurbSpline Hermite – HermiteSpline Here are the definitions and some notes on each of these curve types: Bounded... Read more →

South Facing Walls

This is part 3 of Scott Conover's AU 2009 class on analysing building geometry, demonstrating how to find and highlight south facing exterior walls. The previous post discussed curve parametrisation. In this step, we use the tangent vector to the wall location curve to find all exterior walls in the model facing south: The code we discuss is for demonstration purposes on how to use the curve properties. This sample demonstrates the analysis required to determine the facing direction of... Read more →

Curve Parameterisation

This is part 2 of Scott Conover's AU 2009 class on analysing building geometry. Curves in the Revit API can be described as mathematical functions of an input parameter 'u', where the location of the curve at any given point in XYZ space is a function of 'u'. In Revit, the parameter can be represented in two ways: A 'normalized' parameter. The start value of the parameter is 0.0, and the end value is 1.0. This makes evaluation of the... Read more →

Geometry Options

This is part 1 of Scott Conover's AU 2009 class on analysing building geometry. It all starts with the get_Geometry and its options. What are these options? Geometry is typically extracted from the indexed property Element.Geometry, or Element.get_Geometry in C#. This property accepts an options class which you must supply. The options class customizes the type of output you receive: ComputeReferences – this flag sets Revit to make the GeometryObject.Reference property active for each geometry object extracted. When this is... Read more →

Analyse Building Geometry

In a loose series of upcoming posts, I plan to present the content of Scott Conover's brilliant class held at Autodesk University 2009: CP222-3 Analyze Geometry of Buildings Using the Autodesk Revit API. As stated in the class summary, it provides tips and techniques to extract geometric and measurement data from Revit models using the Revit API and teaches how Revit parameterizes 2D and 3D geometry of various building elements, including walls, floors, roofs and structural framing, including techniques for... Read more →

Vertical Projection of Beam Analytical Model

We tried to fly from Milano to Paris this evening for the last DevDays conference, but unfortunately our flight was cancelled due to snow in Paris. Now we are stuck at the Milano airport and hoping that the first flight in the morning will not be cancelled as well. If it is, we will not be able to make it at all. Otherwise, we will arrive rather late and have to reschedule the agenda, but at least then we will... Read more →

AU is not done yet

Here are some updates on AU and the class materials. Class Materials Several people have inquired where the class materials suddenly disappeared to. The AU 2009 classes will soon be available online. Starting Friday, December 11, AU Online will have all of the class handouts, presentation materials, data sets, and screencasts of more than 500 AU 2009 conference and AU Virtual sessions, so you can access them anytime, anywhere, all year long. All class materials will be available from the... Read more →

Distinguish Different Dimension Types

I am back in Europe again after spending most of the weekend travelling, similarly to Kean but in the opposite direction. In his last post, Kean summarised some interesting views on the evolution of Autodesk University. Returning to the Revit API, here is a nice can-do solution presenting a workaround created by my colleague Joe Ye of Autodesk and Henrik Bengtsson of Lindab on how to distinguish between the different kinds of dimension types. Question: I am creating a drafting... Read more →

AU Winds Down

AU is winding down. The physical conference has closed. AU Virtual is still in full swing today with tons of great on demand content. I just learned that everybody, including you, is invited to engage with AU Virtual via the Free Pass option. You can register and access great content right now. Good Suggestions for Beginners I finished my participation by going to the closing party and visiting the shark aquarium after attending one final class by Rod Howarth: CP322-1... Read more →

AU and Automated Testing

AU has been as exciting as ever, with lots of fascinating news and good meetings and discussions with developers and colleagues that I never get to meet except here. Here are some quick facts and photos. I visited two great classes yesterday on the Revit API by Harry Mattison and Scott Conover, who both work with the internal development of the Revit API and really know what they are talking about: CP214-2 Creating and Analyzing New Conceptual Massing Geometry With... Read more →

AU Begins

I left the desert and the climbing in Red Rock and entered the air conditioned world of conference land. My first task Monday morning was the one I found most challenging, the recording session for my virtual class on the Revit Family API, CP9118-1 The New Autodesk Revit Family API: Everything is Relative It was definitely an interesting experience, with an assistant fussing around to set things up and then sitting in a completely darkened room with several technicians managing... Read more →

AU Virtual free for ADN Members

Kean Walmsley just announced that a free Premier Pass to Autodesk University virtual is available for members of the Autodesk Developer Network. Please join us there. We are presenting at both AUv and the non-virtual AU: Kean's F# sessions. AutoCAD-related AU and AUv sessions. The Revit Family and MEP APIs. I am looking forward to seeing or hearing from you in the next couple of days! Read more →

Visible Elements

I am sitting here cramped up in an economy seat crossing the Atlantic Ocean as I write this. I should urgently be practicing and preparing for my sessions at AU, but somehow it feels as if writing a blog post requires slightly less space, so here goes. I would also like to answer some pending comments, but cannot right now due to lack of Internet access... After revisiting the topic of selecting all model elements in the last post, there... Read more →

Nested Family

Here is another interesting question that came up on the creation of a nested family. Question: Can you help me to create a nested family via the API? I have a column family and a shelf family stored in RFA files, and I would like to implement a command which creates a new family with column and the shelf, and load it into a project. How can this be achieved? Answer: The solution to this task is quite easy. I... Read more →

Autodesk University Extension

As already mentioned, I submitted the material for my AU sessions last week, and one of them is a virtual class which will be broadcast live worldwide for those who cannot attend AU in Las Vegas in person. Another option for people not travelling to Las Vegas besides getting the $99 Premier Pass to AU Virtual is provided by the Autodesk University Extension, which is a collection of over 100 completely free training events, held in 35 countries and hosted... Read more →

Revit Family Creation API Labs

The handouts and presentation for my Autodesk University family API session are finally done, as well they should be, since they are due to be submitted by today. The last part I worked on was to add more documentation on the family API labs to the handout document. I think this overview will be of interest here as well. The family API labs were originally created and documented by Mikako Harada, the ADN AEC workgroup lead, so all of the... Read more →

AU 2009

These days I am pretty occupied with the preparation of my sessions for Autodesk University 2009: CP308-2 All Systems Go in the New Autodesk Revit MEP API CP9118-1 The New Autodesk Revit Family API: Everything is Relative The Family API one is a virtual class which requires special preparation, since it is being recorded and broadcast worldwide for Virtual Autodesk University. As Rick Graham pointed out, virtual AU was created for those who are not able to make it to... Read more →