Renaissance Revit - A Partial Review

Some time ago, I purchased Renaissance Revit^® - Creating Classical Architecture with Modern Software, by Paul F. Aubin. Since then, I have been struggling with finding time to work my way through the tutorials in the book. Having finally made it into Chapter 6 (of 14), and completed the Tuscan column, it occurred to me that I should write something about it now, rather than waiting until I had gotten through the entire book (whenever that may be).

The intent of the book is to provide intermediate and advanced lessons in the use of the Revit Family Editor. The vehicle in which these lessons is delivered is classical architecture, but whether or not your design work involves use of the classical orders, all but the most highly experienced Family Editor users will find numerous techniques and tips that will be quite useful in the families that you create for your work. The book assumes a basic understanding of Revit. Chapter 2 provides an overview of basic family editor skills for anyone new to the Family Editor.

The book starts out by laying a foundation of skills needed throughout the rest of the book. A brief discussion of the classical orders and the strategies that will be used is followed by a review of core Family Editor skills. Since the classical orders are all based on scale and proportion, and because the SCALE command in Revit does not work on many elements, including 3D geometry, Chapter 3 introduces methods for enabling scaling and maintaining proportions through parameters. Anyone who has ever struggled with parametrically controlling curves and/or angles in a family (which includes me) will find Chapter 4, which covers constraining curves, well worth the cost of the book.

Chapters 5 and 6 apply the lessons learned to the creation of content for the Tuscan Order. All of the content is tied back to the diameter at the base of the column by formulas, and, for the columns, the base diameter is determined by the column height. One family, with just two types (Without Pedstal and With Pedestal), produces columns of any size, scaled up or down based on the column height.

The Screencast below shows the Tuscan column in action.

I have no hesitation in highly recommending this book to anyone seeking to improve their knowledge of the Revit Family Editor, particularly those who have made some basic families and are looking to learn more advanced techniques. If you can afford the higher cost, the color edition enhances the learning experience. But if cost is an issue, the content in the black and white version is the same. Instructions for downloading a dataset from the author's website are provided. You can download either just the files needed to start each lesson, or a larger package that also includes catch-up and completed files. The catch-up files let you jump in at intermediate points in a lesson, if desired (or can be used to compare against your file, to see if you executed the tutorial up to that point correctly).

FULL DISCLOSURE: I know the author and have worked with him in a paid capacity on other books (the 2010 and 2011 editions of his book for AutoCAD^® Architecture). I did not have anything to do with the production of this book (other than responding to a survey that Mr. Aubin conducted) and paid the full retail price for my copy of the book.

Revit: Restricting a User-Input Value to a Specific Increment

There are times when you are creating a family to represent an object that can have multiple values for a particular parameter, such as a length, that you would prefer not to create a type for each possible length. Using an instance-based parameter allows you to do so, as this allows the end user to set the value as needed on each instance. But what if the object you are modeling only comes in specific increments? How can you prevent the end user from entering a value that is not available? You can add another instance-based parameter and by entering a formula, you can round the user-input value to the desired increment. If the user could enter values that would be invalid, such as zero or negative values for a length parameter, or a value outside of the range available for the object, you can add one or more additional instance parameters and use a formula to assure an invalid value is not used.

As an example, I created an upside-down "T" shaped Generic Model Family, where the length is restricted to 6" increments, while the width can be any value.

The rounding functions in Revit^®, Round, Roundup and Rounddown, require a unit-free number as an argument, so in the formula for the LengthRounded parameter, the user-input value is divided by 6". This value is then rounded (up in this case) and that result is multiplied by 6" to restore the units and get the rounded value. The LengthActual parameter then checks the rounded result and passes that value through if it is greater than 0 feet; otherwise the minimum value of 6" is set. The Length Actual parameter is what drives the family geometry.

Since formula-driven, instance-based length parameters will not generate stretch grips in Revit, I added an additional reference plane, UserInputEnd, and assigned the LengthUser parameter to a dimension between it and the Front reference plane so that stretch grips for the length would appear in a project. None of the family geometry is locked to the UserInputEnd reference plane. You can see the family and the family in a project in the following Chronicle.

Revit Family Editor - Lock Column

While working in the Family Editor, have you wondered what was the purpose of the Lock column in the Family Types dialog? I have often wondered what this column, first introduced in the 2011 release, does, and was never able to find anything about it in the Help. Today, thanks to a link posted by Richard Black in this thread in the AUGI Revit Architecture - Families Forum, I was able to watch this video, which does a good job of explaining what effect locking a dimension parameter has.

Revit - Rectangle Tool in Families

Here is a tip that I picked up watching one of The Revit Kid's videos a while back, and it has proved to be sufficiently useful that I thought I would make note of it here. When drawing linework that you intend to constrain to Reference Planes in a Revit Family, if you are drawing a rectangle, use the Rectangle tool.
Not only does it allow you to draw four lines with two clicks, but it also allows you to draw those lines in place and then activate the constraints. No need to use the Align tool after drawing the linework.(As always, you can click on a reduced-to-fit image to see it full size. Use the Back button in your browser to return to the blog article.)

Revit Praise #1 - Parametric Families

Today was a really, really bad Revit day, but it would be churlish of me to say only bad things about Revit^® Architecture, when that does not reflect my opinion of the software on most days. I realize that much of my struggle can be ascribed to a combination of my inexperience with the software, the overly demanding nature of the geometry of the building for which the fitout is being done and "issues" with the linked Revit files for the building, done by another firm and outside of my ability to control or improve.

So lets focus on a strength of Revit that I find quite fascinating: the ability to create custom components that are driven by parameters. This past August I had the good fortune to be able to take Paul Aubin's on-line Mastering the Family Editor, a series of five one-hour, on-line training sessions covering the use of Revit's Family Editor. (See Paul's website for current offerings. It was my understanding that he plans to make recordings of sessions available, for a fee, to those who did not sign up for the live course, but I did not see a link for this particular course as of tonight.) By setting up parameters, you can get the same graphics to "flex" to multiple sizes ("types", in Revit terminology) without the need to create multiple styles, as you would with a Multi-View Block in AutoCAD^® Architecture.

Armed with that excellent knowledge, I was able to create two families for accessible shower seats (one each for rectangular and L-shaped). Each family currently has two types - one for the maximum seat size allowed under ICC/ANSI A117.1 and one for the minimum size. The images below show the plan views for the two families. The origin point for the component is at the upper left corner. The green dashed lines are "reference planes", and the top and far left ones are designated as defining the component's origin (the corner of a shower). The reference planes do not show when the object is placed in a project, but within the family, provide a framework on which the 2D linework (used here, to keep file size down) or 3D objects can be locked.

Square Shower Seat

L-Shaped Shower Seat
(Click on any image to see a full-size version; use the back button in your browser to return here)

The dimensions with text are the parameters and in this case are all type-based. Each type created can set a different value for each of these dimensions. The dimensions with numbers only are fixed dimensions, which maintain desired distances between two reference planes when one is moved by a change in a parameter value. In this case, I chose to make the maximum allowable distance off the back and side walls fixed dimensions.

The blue double arrow icons are controls that allow the graphics to be "flipped" to cover opposite hand situations. Adding these is as simple as selecting the Control tool on the Design bar, choosing the Control type on the Options Bar and clicking in the plan view window to place the Control. (I am currently using Revit Architecture 2009; the process in 2010 may be slightly different.)

One might argue that with only two types in each family, this is a bit of overkill. Other types, based on specific manufacturer's dimensions, could easily be added. (The elevation views also have a Height and Thickness parameter to drive the location of the top of the seat and the thickness of the seat.) The point here is to show some of the possibilities. Components that have the same basic shape, but many possible sizes - for example, Doors - allow a single piece of content to have many types, representing the range of available sizes. By carefully setting up reference planes and parameters, you can add as much control to your custom content as you need, rather than having to make a custom Profile or View Block for each size or live with having a single Profile or View Block being scaled to the overall width/height, as you would have to do in Architectural Desktop.

Using type parameters allows you to build-in standard sizes, which is appropriate for items that are manufactured to certain, predetermined sizes. Parameters can also be made instance-based, if you want to be able to set the parameter value for each instance, which would be appropriate for content that is built-to-order.

Live On-Line Training

Speaking of Paul Aubin, he is now offering live, on-line training sessions. If you are wondering how to get the most bang for what remains of your recession-reduced training budget, you may want to keep an eye on the classes he is offering. So far, these have all been Revit classes, but he has requested input on future topics for both Revit and AutoCAD Architecture. You can pay for one connection and, if you have a projector or a conference room with a large monitor, as many people as you can get in the room (respecting building code occupancy limitations, of course) can watch the session. The initial presentation of each session is live, using GoToMeeting software, and includes the potential for two-way VOIP communication (plus a Chat feature, if, like me, your computer does not have a microphone hooked up to it). There is an option to call in, if you prefer, as well. The software also allows Paul to post occasional polls (and even a quiz on the previous session). The sessions are recorded, and are posted a few days later for review or to allow later watching of the session should you not be able to attend the live event.

The current class is a five-session series on the Revit family editor. As a "late" registrant, I watched the recorded version of the first session, and attended the live presentation of the second session today. The image below shows a screen capture from today's presentation, in mid-demonstration in Revit, to give you a feel for the look of the presentation. (Click on the image to see a full-size version; use the Back button on your browser to return here.)As a relative newbie with Revit (having just finished three days of "essentials" training last week), I found both to be quite informative, and look forward to the remaining three classes in this series. Paul provides a nicely illustrated PDF that includes tutorials covering the examples he shows during the class along with explanatory material. There is also a ZIP file containing a dataset with files related to the tutorials.

If the Revit family editor is something that you have always wanted to know more about, or if you have some experience with it but are interested in how it is done in the 2010 interface, then you may want to consider signing up for this class, even though two sessions have already been presented. You can watch the recorded version of the first two classes and then catch the live presentation of the following three classes, starting next Thursday (August 13, 2009). Having done a session each way, I can say that other than the polling and the opportunity to ask a question at the end of the live session, there is no substantive difference between the two. (I assume that the polls and parts where Paul asked for a show of hands were edited out of the recorded version.) The fifteen-registrant limit mentioned in Paul's blog article has been increased to 200, so there is plenty of room if you are interested.

Full Disclosure: I have known Paul through the Autodesk Discussion Groups, have met him and attended his classes at AU over the years and recently helped him update his Mastering AutoCAD Architecture book for the 2010 release. Paul provided me with a complementary registration for the Family Editor class.