The Building Coder

Verona Revit API Training

Yesterday was the last day of the advanced Revit Structure API training at Steel & Graphics srl in Verona, Italy, with Gianni, Stefano, Michele, Paolo, and we started diving into deeper topics. But first, here are some of the initial things we discussed in the previous days: Making use of FamilyInstance.AddCoping to implement a Boolean operation between solids, for instance to cut a hole in a steel beam. Computing the volumes of all compound wall layers. Creating new column and... Read more →

Category Comparison

Still giving Revit Structure API training in Verona, Italy, we ran into a problem in one of the Revit SDK samples today. The FrameBuilder sample works with structural beams and framing elements. It implements a FrameData class which defines an Initialize() method to set up internal lists of column, beam and brace symbols. These are sorted into different lists depending on their type, which is determined by comparing the category names. Unfortunately, the original SDK sample compares the category names... Read more →

Mechanical Duct Types

Question: When selecting duct type properties, under the mechanical heading, various fitting property values are specified. How can I find out what property a given fitting belongs to, i.e. is it an elbow, a transition or cross etc.? Obviously, the type of fitting is described in the family name, but is there a more definite way of knowing what kind of fitting it is through the API? Answer: In Revit 2009, you can use the built-in parameter FAMILY_CONTENT_PART_TYPE. You can... Read more →

Room and Wall Adjacent Area

I continued the discussion on the room and wall adjacency with Massimiliano Revelli of Informatica System srl, because he is actually interested in determining the wall area adjacent to the room, and not just the overlapping curve segment length. The overlapping area is obviously easy to determine if the wall has a constant height, as I pointed out in the earlier post, but this is often not the case. For instance, let us look at the upper wall in this... Read more →

Use F# Directly in Revit

Still struggling to load a native F# module directly as a Revit add-in? Ralf Huvendiek had a quick look at this issue and created all three different flavours of external commands implemented in F# that can be called directly as external Revit tools: Defined in a namespace. Defined in a module. Defined in a module within a namespace. The problem I had when calling F# via C# is caused by the line specifying 'module BuildingCoder', which generates the strange class... Read more →

Unit Types and Format Options

Here is a question from Matt Mason and some exhaustive research results by Saikat Bhattacharya of Autodesk on unit types and their format options. To provide some context, UnitType is an enumeration listing all the unit types supported by Revit. The FormatOptions class is used to manage information for the ProjectUnit.FormatOptions property, which returns a FormatOptions instance containing the user's current project unit settings for each UnitType queried. Through the project units and the format options management, each unit type... Read more →

Happy New Year in the East

I am always happy this time of year to hear from my far eastern colleagues about the biggest Chinese festival of the year, the Spring Festival and Chinese New Year. Here is calligraphy on this year's celebration that we received from Joe Ye: Barbara Han and others provided the following explanation and rough translations: Left Field mouse jumps between the branches, and makes the shadow of the moon wobble. Right Spring ... An ox ploughing the field ... Nice smell... Read more →

AutoHotKey

Automate beyond the API ... Some parts of the Revit functionality are not yet accessible through the API, even though are repetitive tasks that are trivial to perform manually and a lot of work could be saved by automating them. One tool that many have found useful for this task and have published a number of working solutions for is AutoHotKey. Here is an AUGI discussion presenting a number of them, such as how to: Define F2 to open the... Read more →

Walls and Doors on Two Levels

Here is a little note to answer a question from Berria on creating walls and doors on two separate levels. This is a slightly edited version of the original query: Question: I need to create a house with two floors. I create a level and then a new wall and a door. It draws the two objects on different levels. When I build the first level, all is OK. An error occurs when I build the second, because the level... Read more →

Element Caching

Here is a question from Julien Duprat of Vertice: Question: I would like to know the best practises for data caching. This topic is mentioned in your tutorial on "Ten Steps for enhancing your Revit add-in". Specifically, I wonder: How to put the elements in a static List of cached elements? How to refresh this list? Answer: We do not have any official recommendations from the API or development team, so it is more a question of finding out what... Read more →

Database Integration

Here is an in-depth analysis of integrating Revit with external databases or other data sources performed end of last year by Miroslav Schonauer of Autodesk Consulting. Miro is a Senior Solution Architect in the AEC Solutions Division of Autodesk Consulting and has a lot of experience in this area. In previous years, he also presented on this topic at Autodesk University. We use the term DB to refer to a generic external source. The main issue with 'integrate Revit with... Read more →

Room and Wall Adjacency

Question: How can I obtain the part of a wall that touches a room, especially its face area? The wall can be adjacent to more than one room. Answer: You will probably find the Room object's Boundary property useful. It returns the boundary of the room in a BoundarySegmentArrayArray object, i.e. an array of boundaries or loops. A room may have more than one boundary loop if its floor surface contains holes, which is why this returns an array of... Read more →

Transaction Responsibility

The last post on transactions explained the need to open a transaction of our own before trying to modify a document during an event. That is actually not all. We also need to remember that starting a transaction is not permitted at all times, and also that starting a new transaction or ending one may fail. This leaves us with a certain amount of responsibility. Therefore, we should add some error handling to ensure that failures are handled gracefully. The... Read more →

Toolbar Image List

Question: How can I define a separate icon for each item in a toolbar? I only see one single property on the Toolbar class, Image, which gets or sets the collection of images available to the toolbar button controls. But how can this help me define the icon for an individual toolbar item? Answer: This is indeed the only way to define toolbar icons. This is demonstrated by the Revit SDK samples. For instance, in the DoorSwing sample, the code... Read more →

Transactions

We recently mentioned the need to open a transaction in an event handler. In that case, the transaction was required in a handler for the document closed and saved events on the application object. Here is another similar case involving the application OnDocumentNewed event. Question: I am trying to set up some shared parameters on OST_Rooms in a ControlledApplication. I can read and bind values from a shared parameter file, and have checked that the binding is set up correctly... Read more →

Hello F# via C#

Still in Barcelona, after a very interesting day spent with Alex Vila Ortega, who gave us on a tour of the Sagrada Familia cathedral by the famous Catalan architect Antoni Gaudi to discuss the interesting mathematical and geometrical aspects of his architecture, and what we can do together to implement some effective support for them in Revit. I plan to write more on that as soon as possible, but I have something more urgent to discuss first. Kean's F# programming... Read more →

Filter for Hosted Elements

Today was the last day of the Revit programming training here in Barcelona. One of the items we examined is yesterday's suggestion to use API filtering and the HOST_ID_PARAM to select the doors and windows hosted by a specific wall. Here is a code snippet that implements this and displays the result in a message box: ElementId id = wall.Id; Type t = typeof( FamilyInstance ); BuiltInCategory bicd = BuiltInCategory.OST_Doors; BuiltInCategory bicw = BuiltInCategory.OST_Windows; BuiltInParameter bip = BuiltInParameter.HOST_ID_PARAM; Autodesk.Revit.Creation.Filter cf... Read more →

Barcelona Questions

Thanks to Alex Vila Ortega of Autodesk Spain, I spent the last couple of days here in Barcelona giving a training class on the Revit API, with lots of professional and enthusiastic participants. Here are some of the questions that we explored. Question: How can I retrieve all the windows hosted by a specific given wall? Answer: Well, one possibility is to make use of the relationship inverter that we already discussed. This will provide a global dictionary mapping each... Read more →

Hiding Linked Files

Rod Howarth raised a question in the discussion on linked files: Question: I'm trying to make a command to turn off the visibility of linked Revit and DWG models in the current view. The intent is to turn off the visibility for all imported categories in the drawing, i.e. all imported CAD files. This would be like going to Visibility/Graphics > Imported Categories > Show imported categories in this view. Is there an easy way to do this, or am... Read more →

PlanTopology Class

Another question raised by Jochen Reichert of the University of Stuttgart last week was the use of the PlanTopology class and its members, which include: Circuits Level Phase Rooms This class represents a plan topology within the Revit project and looks like it might be useful for handling rooms and areas, which could be used for analysis of cost and gross versus net floor area, volume, or facility management. Each of the circuits managed by this class represents an enclosed... Read more →

Viewports and Sheets

Jochen Reichert of the University of Stuttgart asks: How can I determine all the view ports of a drawing sheet and vice versa? To determine the view ports of a drawing sheet, you can simply use the ViewSheet Views property. It returns the set of all views on the sheet. For the inverse relationship, you can create a mapping of your own as described in the discussion on inverting the relationship between hosted und hosting elements such as doors, windows... Read more →

F# Programming Contest

Kean Walmsley just announced a programming contest using the exciting new functional .NET language F#. Since functional programming has many uses in all realms including architecture, there should be lots of scope for making use of it in conjunction with the Revit API as well. I hope to install Visual Studio 2008 real soon now and have a look at setting up a basic F# Revit add-in project. I am very much looking forward to hearing from you about ideas... Read more →

Creating a Viewport

Here is another short and simple question and answer session from a dialogue between Greg Wesner and Harry Mattison, both of Autodesk. Question: I’m wondering if there is a way to create a new viewport on a sheet. I would like to automate the process of updating standard details. I can see where I can create a sheet and I can create a view, but I do not see the ability to create a viewport on a sheet. I need... Read more →

Revit Serial Number

Here is a short and simple question with a simple answer. Question: How can I determine the Revit product's serial number? Answer: The Revit serial number is available in the Licpath.lic file, which is a text file located in the Revit program folder. The content of the file is something similar to the following, where the string after # SN is the serial number: ## Autodesk Revit ## License Information # SN 123-45678910 # NSN 000-00000000 # Standalone Read more →

Family Category and Filtering

So here we are in a brand new year, 2009. Welcome back! Here is an interesting question regarding families, their categories, and filtering, raised last year by Martin Schmid of Autodesk. Question: In the following code, I attempt to use Revit API filtering to select all families with a built-in category value of BuiltInCategory.OST_MechanicalEquipment: Document doc = app.ActiveDocument; List famsInCat = new List(); Autodesk.Revit.Creation.Filter cf = app.Create.Filter; TypeFilter typeFilter = cf.NewTypeFilter( typeof( Family ) ); CategoryFilter catFilter = cf.NewCategoryFilter( bic... Read more →

Happy New Year 2009

This break is great. I am really relaxing, and this machine is taboo ... and yet ... This is just a short note to say that I am having a good time, enjoying life, spending time with my kids and friends, occasionally looking in a mirror to watch at least some of the creases in my face relax a little. On December 26 I went for a brief climbing session just before sunset with my son Cornelius and his friend... Read more →