About CGI

Computer-generated imagery which is more commonly known as CGI is the use of computer graphics, more correctly, 3D computer graphics as special effects in films, television programs, commercials, simulators and simulation generally, and printed media. Video games employ the use of real-time computer graphics which is not often considered CGI, however they may also utilize pre-rendered “cut scenes” and intro movies that would be regular CGI applications.
CGI is employed for visual effects because computer generated effects are more easily controlled than other more physically based processes, for example those that may involve constructing miniatures for effects shots or hiring multiple extras for crowd scenes. CGI essentially allows the development of images that would not otherwise be doable using any other currently available technology. It also allows a single artist to create content without the need for actors, expensive set pieces, or props.
Widely available 3D computer graphics software is used to produce computer-generated imagery for a wide range of media. The ever increasing availability of CGI software and much enhanced computer speeds have allowed independent artists and small companies to create professional grade films, games, and fine art from their at home computer work stations. Additionally, simulators, most notably flight simulators, use the CGI techniques to represent different elements of the Outside World.

3D computer animation couples 3D models of objects and programmed movement. Models are developed out of geometrical vertices, faces, and edges in what is known as a 3D coordinate system. Objects are typically sculpted in the same way as real clay or plaster, creating general forms and specific details using a variety of sculpting tools. A bone/joint system is genreated to deform the 3D mesh. Using a rigging process, the virtual marionette is given multiple controllers and handles for controlling movement. Animation data is then created using motion capture, or keyframing by a human animator, or an amalgamation of the two.
The 3D models that are rigged for animation may maintain hundreds of control points for example, the character “Woody” in Pixar’s movie Toy Story, used 700 specialized animation controllers. Rhythm and Hues Studios spent two years creating Aslan in the movie The Chronicles of Narnia: The Lion, the Witch and the Wardrobe which had a total number of 1851 controllers; 742 were used specifically to represent the lions facial movements. In the 2004 film The Day After Tomorrow, designers had to create the forces of extreme weather by using a lot of video references and actual meteorological facts.
In the 2005 remake of King Kong, actor Andy Serkis was employed to help designers identify the gorilla’s prime location in the shots. They also used his expressions to model “human” characteristics onto the fictional creature. Serkis is notable for his earlier work in The Lord of the Rings trilogy in which he provided the voice and performance for the creature Gollum.

There are many websites created specifically to help promote and support CGI artists. Some of these are managed by software developers and content providers. However, there are also standalone websites, inclusive of one of the largest communities on the web, Renderosity. These communities allow members to look up advice, post tutorials, write product reviews or share examples of their own CGI productions.