Editing Utah teapot (section)

==History==
[[File:Original Utah Teapot.jpg|thumb|The actual [[Melitta]] teapot that [[Martin Newell (computer graphics)|Martin Newell]] modelled, displayed at the [[Computer History Museum]] in [[Mountain View, California]] (1990–present)]]
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| image1 = [http://www.computerhistory.org/revolution/computer-graphics-music-and-art/15/206/556 A scan of the original diagram Martin Newell drew up, to plan the Utah Teapot before inputing it digitally.]<br />Image courtesy of Computer History Museum.
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For his work, Newell needed a simple mathematical model of a familiar object. His wife, Sandra Newell, suggested modelling their [[tea set]] since they were sitting down for tea at the time. He sketched the teapot free-hand using graph paper and a pencil.<ref>{{cite web|title=The Utah Teapot - CHM Revolution|url=http://www.computerhistory.org/revolution/computer-graphics-music-and-art/15/206|website=Computer History Museum|access-date=20 March 2016}}</ref> Following that, he went back to the computer laboratory and edited [[bézier curve|bézier]] control points on a [[Tektronix]] [[storage tube]], again by hand. {{Citation needed|date=December 2008}}

The teapot shape contained a number of elements that made it ideal for the graphics experiments of the time: it was round, contained [[saddle point]]s, had a [[Genus (mathematics)|genus]] greater than zero because of the hole in the handle, could project a shadow on itself, and could be displayed accurately without a surface texture.

Newell made the mathematical data that described the teapot's geometry (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 did not have to laboriously enter geometric data for some other object. Although technical progress has meant that the act of rendering the teapot is no longer the challenge it was in 1975, the teapot continued to be used as a reference object for increasingly advanced graphics techniques.

Over the following decades, editions of computer graphics journals (such as the [[Association for Computing Machinery|ACM]] [[SIGGRAPH]]'s quarterly) regularly featured versions of the teapot: faceted or smooth-shaded, wireframe, bumpy, translucent, refractive, even leopard-skin and furry teapots were created.

Having no surface to represent its base, the original teapot model was not intended to be seen from below. Later versions of the [[data set]] fixed this.

The real teapot is 33% taller (ratio 4:3)<ref>{{Cite web|title=The Utah Teapot|url=http://www.holmes3d.net/graphics/teapot/?graphics/teapot|access-date=2021-07-10|website=www.holmes3d.net}}</ref> than the computer model. [[Jim Blinn]] stated that he scaled the model on the vertical axis during a demo in the lab to demonstrate that they could manipulate it. They preferred the appearance of this new version and decided to save the file out of that preference.<ref>{{cite web|last1=Seymour|first1=Mike|title=Founders Series: Industry Legend Jim Blinn |url=http://www.fxguide.com/featured/founders-series-industry-legend-jim-blinn/|website=fxguide.com|access-date=15 April 2015|archive-url=https://web.archive.org/web/20120729175832/http://www.fxguide.com/featured/founders-series-industry-legend-jim-blinn|archive-date=2012-07-29|date=2012-07-25}}</ref>

Versions of the teapot model — or sample scenes containing it — are distributed with or freely available for nearly every current rendering and modelling program and even many graphic [[API]]s, including [[AutoCAD]], [[Houdini (software)|Houdini]], [[Lightwave 3D]], [[Modo (software)|MODO]], [[POV-Ray]], [[3ds Max]], and the [[OpenGL]] and [[Direct3D]] helper libraries. Some [[RenderMan Interface Specification|RenderMan]]-compliant [[rendering (computer graphics)|renderers]] support the teapot as a built-in geometry by calling <code>RiGeometry("teapot", RI_NULL)</code>. Along with the expected cubes and spheres, the [[OpenGL Utility Toolkit|GLUT]] library even provides the function <code>glutSolidTeapot()</code> as a graphics primitive, as does its [[Direct3D]] counterpart [[D3DX]] (<code>D3DXCreateTeapot()</code>). While D3DX for Direct3D 11 does not provide this functionality anymore, it is supported in the DirectX Tool Kit.<ref name=DirectXTK>{{cite web |url=https://github.com/microsoft/DirectXTK/ |title=DirectX Tool Kit|date=November 29, 2022 | publisher=GitHub}}</ref> Mac OS X Tiger and Leopard also include the teapot as part of [[Quartz Composer]]; Leopard's teapot supports [[bump mapping]]. [[BeOS]] and [[Haiku (operating system)|Haiku]] include a small demo of a rotating 3D teapot, intended to show off the platform's multimedia facilities.
 
Teapot scenes are commonly used for renderer self-tests and benchmarks.<ref>{{cite journal |last1=Wald |first1=Ingo |first2=Carsten |last2=Benthin |first3=Philipp |last3=Slusallek |title=A Simple and Practical Method for Interactive Ray Tracing of Dynamic Scenes |journal=Technical Report, Computer Graphics Group |year=2002 |url=http://graphics.cg.uni-saarland.de/fileadmin/cguds/papers/2002/DynRT/DynamicRayTracing.pdf |publisher=Saarland University |archive-url=https://web.archive.org/web/20120323191204/http://graphics.cg.uni-saarland.de/fileadmin/cguds/papers/2002/DynRT/DynamicRayTracing.pdf |archive-date=2012-03-23}}</ref><ref>{{cite journal |last1=Klimaszewski |first1=K. |last2=Sederberg |first2=T.W. |title=Faster ray tracing using adaptive grids |journal=IEEE Computer Graphics and Applications |year=1997 |volume=17 |issue=1 |pages=42–51 |doi=10.1109/38.576857 |s2cid=29664150 |url=https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=1669&context=facpub }}</ref>

===Original teapot model===
The original, physical Melitta teapot was purchased from [[Zions Co-operative Mercantile Institution|ZCMI]] (a department store in [[Salt Lake City]]) in 1974. It was donated to the [[The Computer Museum, Boston|Boston Computer Museum]] in 1984, where it was on display until 1990. It now resides in the ephemera collection at the [[Computer History Museum]] in [[Mountain View, California]] where it is catalogued as "Teapot used for Computer Graphics rendering" and bears the catalogue number X00398.1984.<ref>{{cite book |title=Original Utah Teapot at the Computer History Museum |url=http://www.computerhistory.org/collections/accession/X398.84 |website=Computer History Museum |date=2001-09-28}}</ref> The original teapot the Utah teapot was based on was available from [[Porzellanfabrik Friesland]], once part of the German Melitta group.<ref name="Siems_2015"/><ref name=FrieslandPorzel>{{cite tweet |user=FrieslandPorzel |author=Friesland Porzellan |author-link=Friesland Porzellan |number=845221850900762625 |date=2017-03-24 |title=The original Utah Teapot was always produced by Friesland. We were part of the Melitta Group once, thats right. Got yours already?}}</ref> Originally it was given the rather plain name {{lang|de|Haushaltsteekanne}} ('household teapot');<ref name=RadioBremen>{{cite web|language=de|title=Eine Teekanne als Filmstar|url=https://www.radiobremen.de/bremenzwei/rubriken/reportagen/utah-teapot100.html|publisher=Radio Bremen|access-date=March 1, 2019|archive-date=April 1, 2019|archive-url=https://web.archive.org/web/20190401175656/https://www.radiobremen.de/bremenzwei/rubriken/reportagen/utah-teapot100.html|url-status=dead}}</ref> the company only found out about their product's reputation in 2017, whereupon they officially renamed it "Utah Teapot". It was available in three different sizes and various colors; the one Martin Newell had used is the white "1.4&nbsp;l Utah Teapot".<ref name=Teekanne>{{cite web |language=de |title=Teekanne 1,4l Weiß Utah Teapot |url=https://frieslandversand.de/teekanne-1-4l-weiss-utah-teapot?number=1209034011 |publisher=[[Friesland Versand GmbH]] |access-date=November 15, 2023|archive-url=https://web.archive.org/web/20230329105432/https://frieslandversand.de/teekanne-1-4l-weiss-utah-teapot|archive-date=March 29, 2023}}</ref>

The original teapot is no longer in production, following a fire at [[Friesland Porzellan]].<ref>{{cite news |title=Großbrand zerstört Porzellanfabrik in Varel |language=de |trans-title=Large fire destroys porcelain factory in Varel |author=Der Landesdienst Niedersachsen/Bremen (dpa/lni) |location=Varel, Germany |date=2023-06-30 |work=[[Deutsche Presse-Agentur]] |department=Brände [Fires] |via=[[Süddeutsche Zeitung]] |url=https://www.sueddeutsche.de/panorama/braende-varel-grossbrand-zerstoert-porzellanfabrik-in-varel-dpa.urn-newsml-dpa-com-20090101-230630-99-238140 |access-date=2023-12-25 |url-status=live |archive-url=https://web.archive.org/web/20231225194841/https://www.sueddeutsche.de/panorama/braende-varel-grossbrand-zerstoert-porzellanfabrik-in-varel-dpa.urn-newsml-dpa-com-20090101-230630-99-238140 |archive-date=2023-12-25}}</ref>