I’m well known for enjoying tea in superhuman quantities. When working at home I often nip to the kitchen and make a pot of tea, then add milk and sugar directly to the pot, before snugly refitting the tea-cosy and resuming work: this gives me approximately 120 minutes of mind-focusing brain juice. This is one of the reasons for the inclusion of a picture of a teapot on this site, the other reason is more technical.

When I was an undergraduate in Plymouth, back in 1991, the course members were asked to present posters on any aspect of computing that interested them, but which they’d not had a chance to study in detail before that point. It was a rather good first assignment because it got everybody using the university’s research facilities on a personal-interest topic. My three A1 posters were an overview of the maths behind photo-realistic computer graphics, and specifically an introduction to a technique called ray-tracing.

This is where the teapot comes in. The teapot that adorns every page of this site is a photograph of a real teapot that was part of a tea service that was bought from a Utah department store in the mid 70′s. At that time computer generated imaging was in it’s infancy and the majority of pictures demonstrated either simple surfaces or the five platonic solids.

This “Utah Teapot”, as it is most commonly known, was digitally modelled by Martin Newell circa 1974 and was the first model to use bezier curves to form sculptured surfaces rather than being composed of a set of interlocking polygons. In the picture here, the teapot can be seen suspended within it’s bezier control frame.

A curiosity of the teapot is that the digital model is most commonly rendered at two thirds of it’s real height because when it was originally modelled computer monitor pixels were rectangular, not square – so digital versions appear more squat than the original teapot.

The digital model, which is affectionately and humourously considered to be the sixth platonic solid (and often referred to as the Teapotahedron) has become one of the most rendered objects in history. The original teapot now lives in Silicon Valley and is on display in the Computer History Museum in Mountain View, though I question the wisdom of storing such a historical piece of crockery so close to the San Andreas fault.

Rendering the Utah Teapot

If you’d like to render this scene for yourself; here it is.