AECbytes Tips and Tricks Issue #65 (January 31, 2013)
Autodesk Revit Architecture Certified Professional and Author
Have you ever wondered what that little Revit teapot render button signifies? I’m talking about the small icon down below the View Control bar that appears in 3D views.
Clicking on the teapot icon takes you to the Rendering dialog box in Revit.
The first time I used it, I said to myself…"That’s very clever of Autodesk! Of course it’s an appropriate symbol for render options! It’s based on a renderer’s habit of heading out to get coffee or tea the moment he hits the Render button!" You know who you are and you know what I’m talking about. Even with today’s fast computers, there are still rendering times we have to contend with (except if you have a second computer that you can use while waiting!).
After deciding to get to the bottom of this, I did extensive (ahhemm!) research on the internet concerning this teapot icon, whose meaning I couldn’t find anywhere in any of Revit’s manuals! I’ll give you links about this subject, but in a nutshell, here is what I found out.
In 1975, 3D polygon modeling was new. To do simple shaded rendering of curved shapes required approximation of a large number of polygons. Back then, computers had very small memory capacity. At the University of Utah, a British-born computer scientist by the name of Martin Newell presented his Ph.D. dissertation to show how curved shapes could be represented as smooth objects by using bicubic Bezier patches. Beziers are basically mathematical splines defined by a set of control points used in the early stages of computer graphics, computer-aided design, and finite element modeling. Part of Newell’s thesis was to present samples of computer models which he didn't have enough of. At one point in time, while he was having tea with his wife Sandra, she suggested to him that he use their tea set as his models. He immediately got some graph paper and a pencil and sketched the tea set as shown below:
He then went back to the lab and manually edited the Bezier control points on a Tektronix storage tube (a special monochromatic CRT back then whose screen has a kind of 'memory', hence the name). He was then able to digitize the pot, spoon, cup and saucer which he used as part of his dissertation.
Since then, the teapot has become a benchmark model for computer graphics programs in the SIGGRAPH (Special Interest Group on Graphics and Interactive Techniques) research community. Here is an image of an actual photo from the Boston Computer Museum where the teapot was on exhibit:
Along with other computer-generated renderings hanging on the wall, the original teapot (inside a case shown above) was shown side by side with the computer generated version. Martin Newell’s original rendering print can be seen too, third from the left of the top row.
Here is a screen shot of that print:
And here is the original teapot which later came to be known as the Utah teapot:
This was manufactured by Melitta (makers of Melitta coffee, coffee makers, and filters) in 1974 and purchased by Martin and Sandra from ZCMI, a department store in Salt Lake City. It was eventually donated to the Boston Computer Museum, then relocated to the Computer History Museum in Mountain View, California. It is cataloged as “Teapot used for Computer Graphics rendering” (catalog number X00398.1984).
If you notice, the actual teapot is a little taller than the computer model. That’s because Newell’s frame buffer (video output device that drives a video display from a memory buffer containing a complete frame of data) used non-square pixels. Rather than having a distorted image, Newell’s colleague Jim Blinn (known for creating animations) scaled the geometry to cancel out the stretching.
Versions of the teapot model are now being used by nearly every rendering and modeling programs including AutoCAD®, Revit®, Lightwave 3D®, POV-Ray®, OpenGL, Direct3D and Autodesk® 3ds Max®. Teapot views are commonly used for renderer self-tests and benchmarks.
So there you go!
Now the question is: Can this teapot be easily created as a Revit family? Absolutely! The Revit family editor has all the necessary tools to create this seemingly complex model. But first, let me show you a rendering done by a student of University of Auckland back in 2001. His name is Jing Li and while he was taking a course in Advanced Computer Graphics, he recreated a rendering of the tea set from Martin Newell's original computer data set. It is shown below.
And now, ladies and gentlemen, here is my Revit version of the tea set using the teapot I modeled and cups, saucers and spoons from my Kitchen-Dining product line.
If you click on the link below, you can see a short movie clip of the teapot.
Michael has written the following PDF eBooks available for purchase at his website:
A 163-page PDF sampler containing the full table of contents and sample images from these two eBooks can be downloaded from the following link:
These ebooks contain hundreds of tips, tricks and techniques. Each eBook teaches the efficient ways to create families and explains the subtle little details that go with family creation which no other books explain. A major feature is Chapter 16, which reveals the secrets behind the creation of the families at his website.
Michael Anonuevo is a published author, BIM modeler, and musician who owns and runs www.littledetailscount.com. His website specializes in unique and highly detailed Revit families created in native Autodesk Revit Architecture geometry.
Michael is also an Autodesk Revit Architecture Certified Professional. At ClubRevit.com, he regularly writes articles pertaining to Revit families. He also writes product reviews and is a contributing author at AUGIWorld.
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