A greeble or nurnie is a prominent detailing added to the surface of a larger object that makes it appear more complex, and therefore more visually interesting. It usually gives the audience an impression of increased scale. The detail can be made from simple geometric primitives, or more complex shapes, such as pieces of machinery. Greebles are often present on models or drawings of fictional spacecraft or architectural constructs in science fiction and are used in the movie industry.
Etymology
The earliest recorded use of the term "greeble" found to date was by those working on the special effects for Star Wars, the group that would later become Industrial Light & Magic. They also described this design method as "guts on the outside". Ron Thornton is widely believed to have coined the term "nurnies" referring to CGI technical detail that his company Foundation Imaging produced for the Babylon 5 series.
An early physical example of their application was in the production of the spaceships in ' where they were called wiggets'. In physical models, these greebles could be anything from parts of plastic cut to an interesting shape, or actual elements taken from shop-bought model kits. This method was referred to as "kit-bashing". For instance, in Star Wars the original Imperial Star Destroyer was constructed from a plywood frame and adorned with sheet styrene. Panel lines were cut into the sheet styrene, but this technique left the ship looking bare. Hundreds of model kits were purchased and the model department promptly cut apart pieces of the model kits and stuck them, along with more sheet styrene, to the surfaces of the ship. The ultimate effect was to make the ship appear more believable to the viewer through the addition of these large areas of ancillary details. The greebles themselves served no purpose other than to fill space and individually had no definite function to the design of the ship, although later each greeble was given a specific function by either fans or technical illustrators for fan guides. A plastic soldier was part of the greebling on the Executor. A common model to glean small bits from was WWII submarines. They had great pipes, cranks and knobs that worked perfectly for the outer sides of starships and weapons. When the crew was done they had several submarine "hulls" left over and some were used in the creation of the EF76 Nebulon-B Medical Frigate seen at the end of The Empire Strikes Back. George Lucas is quoted as saying the ship reminded him of an outboard motor. Another example of greeble application was the Battlestar Galactica model for the original 1970s series, which featured on its hull pieces from a wide assortment of kits, including Apollo orbiters, Saturn rocket boosters, F-16fighter jets, and various tanks. As would be expected, given these origins, greebling is most commonly associated with the particular kind of large city-like spaceships made popular in Star Wars, but has been generalized to refer to any dense covering by different components. Similarly, Borg starships in Star Trek appear heavily "greebled" using leftover sprues from previous kitbashing and photoetched bits. An anecdote from the creation of the first Star Wars'' movie involves Tunisian Customs enquiring what a part of C-3PO's costume was. Their response was allegedly "Something that looks cool but doesn't actually do anything."
Used in interiors
Greebles are also used to enhance the interest of interior sets. In Star Trek, walls of the corridors were decorated with bits and pieces of things that looked interesting. Pieces of pipe poked out of walls, usually with several fittings, and a label implying this was an important piece of the infrastructure of the ship. In the movie Alien, the interior of the ship Nostromo was thoroughly greebled. Art directorRoger Christian said, "Let's have a go at it. So we recruited some dressing prop people, got a hold of several tons of scrap, and went to work on the Nostromo's bridge... encrusting the set with pipes and wires and switches and tubing... then we painted it military green and began stenciling labels on everything."
Automated greebling
In 3D computer graphics, greebles can be created by specific software in order to avoid the time-consuming process of manually creating large numbers of precise, custom geometry. This is often tedious, repetitive work, and may be best suited to automatic, software-based procedural generation, particularly if a great degree of control is unnecessary or the greebles will be small on screen. Most greeble-generating software work by subdividing the surface to be greebled into smaller regions, adding some detail to each new surface, and then recursively continuing this process on each new surface to some specified level of detail. Similar algorithms are used in the creation of fractal surfaces.
