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Utah teapot

The Utah teapot is a 3D model which has become a standard reference object (and something of an in-joke) in the computer graphics community. It is a simple, round, solid (i.e. not hollow), partially concave mathematical model of an ordinary teapot.

the Utah teapot

The teapot was created in 1975 by early computer graphics researcher Martin Newell, a member of the pioneering graphics programme at the University of Utah. Newell needed a moderately simple mathematical model of a familiar object for his work, and his wife's teapot (a Melitta) provided a convenient solution. The shape contains a number of elements that make it ideal for the graphics experiments of the time - it's round, contains saddle-points, has a concave element (the hole in the handle), and looks reasonable when displayed without a complex surface texture.

Newell made the mathematical data which describes the teapot's geometry (largely a set of three-dimensional coordinates) publicly available, and soon other researchers began to use the same data for their computer graphics experiments. These researchers needed something with roughly the same characteristics that Newell had, and using the teapot data meant they didn't have to labouriously enter geometric data for some other object. Although technical progress meant that the simple act of rendering the teapot was no longer the challenge it was in 1975, the teapot continued to be used as a reference object for increasingly advanced graphics techniques. The common (rather squat) appearance of the teapot differs from the Melita original, reportedly because Newell's colleague Jim Blinn transformed it to compensate for the non-square pixels on his early frame buffer.

Over the following decades, editions of computer graphics journals (such as the IEEE's SIGGRAPH journal) regularly featured versions of the teapot: faceted or smooth-shaded, wireframe, bumpy, translucent, refractive, even leopard-skin and furry teapots were created.

Versions of the teapot model, or sample scenes containing it, are distributed with (or freely available for) nearly every current rendering or 3d-design program, including AutoCAD, POV-Ray, OpenGL, Direct3D, and 3D-Studio. Teapot scenes are commonly used for renderer self-tests and benchmarks. Along with the expected cubes and spheres, the OpenGL library GLUT even provides the command glutSolidTeapot() as a graphics primitive.

With the advent first of computer generated short films, and then of full length feature films, it has become something of an in-joke to hide a Utah teapot somewhere in one of the film's scenes. Classical Utah teapots can be found in Toy Story, Monsters Inc, and Disney's Beauty and the Beast. The teapot also occasionally appears in the Pipes screensaver, shipped with Microsoft Windows.

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