Computer Generated Imagery

Computer Generated Imagery (CGI) involves the use of computers to create visual material for a film or animation. CGI is used to create animations for film, television and other forms of multimedia (Wikipedia, 2007a).

CGI can be broadly divided into two main categories: 2-dimensional animation, and 3-dimensional animation.

Early Applications of CGI

2D CGI techniques are largely based on those used in traditional animation, but using computers to aid or procedurally generate the production of the imagery.

The first use of a 2D CGI effect in a major feature-length film was in the 1973 science-fiction movie Westworld, where the effect was used to give the point-of-view of one of the robotic antagonists.

3D CGI was first applied in the 1976 film Futureworld - the sequel to Westworld. In this film, an animated, computer generated hand and face were created.

The following year, saw CGI being used for a scene in Star Wars, where vector-graphics were used in the Rebel Death Star briefing scene.

Star Trek II, released in 1982, saw the first use of fractal-generated landscapes in a film. These were computer-animated for part of a simulation scene. These terrain effects were generated by mathematical operations, and textures were applied to give it a realistic appearance. This allowed the creation of a complex, 3D planet without requiring every detail to be manually animated.

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However, until the late 1980s, CGI was mainly used to illustrate plot-driven computer generated graphics - simulations, robotic views etc., film-makers at the time did not see the full potential of the technology - despite the rapid development taking place at companies such as Pixar.

The short film Luxo Jr. created by Pixar in 1986 became the first fully 3d animated short-film, the first use of computer-generated shadows and the first CGI film to be nominated for an Academy award. This helped to cement Pixar’s place in the film industry, and opened the eyes of Hollywood directors to the potential of CGI.

The 1989 film, The Abyss, directed by James Cameron extensively used CGI to create an alien water creature, and it is widely regarded as the first film to showcase the capabilities of modern CGI.

James Cameron would continue to make heavy use of CGI in his films, with his next film Terminator 2, introducing the liquid metal terminator - the first CG lead character to be used. It was also notable for the reflectivity of the character and its use of high-quality surface textures.

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