What Is CGI? Examples of Computer-Generated Imagery in Film

Computer-generated imagery, or CGI for short, is a term that describes digitally-created images in film and television. CGI is a subcategory of visual effects ( VFX ), imagery filmmakers create or manipulate that does not exist in the physical environment being captured on film or video. CGI is instrumental in the making of movies and television shows and serves as the primary method for creating 3D-computer graphics for video games. Before computer-generated technology, special effects were made with real-life practical effects. Today, CGI is often more cost-effective. Filmmakers use CGI in several ways: 1. __Pre-visualization__: In a practice known as pre-visualization, or pre-viz for short, special effects artists can simulate different live-action shots using 3D computer models. In this way, the cinematographer and director can get a preview of how a particular shot will look. This allows for testing different visual and narrative ideas, particularly ones that might be highly complex or difficult to accomplish in real life. 2. __3D modeling__: Artists can use CGI to create a 3D representation of any object, surface, or living creature, like dragons or monsters. [Visual effects](https://www.masterclass.com/articles/how-visual-effects-work-in-film) artists can also use CGI to add images to a shot, like filling a baseball stadium scene with a crowd of cheering fans or adding historic buildings to period pieces. 3. __3D animation__: In 3D animation, the entire world of the film and the characters who inhabit it are computer-generated to create a virtual reality. 4. __Special effects__: CGI can alter the color and intensity of light, changing the appearance of an actor’s face or body in a shot. It can also simulate environmental effects, like rain storms or cloudy skies. CGI can also age or de-age an actor in post-production. With the advancement of technology, CGI has become commonplace in everything from mid-budget comedies to blockbuster hits. These three films are particularly noteworthy for their use of CGI: 1. __*Jurassic Park* (1993)__: The release of *Jurassic Park*, directed by Steven Spielberg, was in many ways a watershed moment of CGI. In this film, many crucial shots of the dinosaurs—particularly the velociraptors and the tyrannosaurus—were accomplished exclusively with CGI. Their realistic movements, skin texture, and scale amazed and terrified viewers all around the world. 2. __*Avatar* (2009)__: James Cameron’s *Avatar* used cutting-edge 3D technology and made extensive use of CGI. Artists crafted an entire world from scratch, as well as the creatures who inhabited it, using complex 3D models, compositing, and environmental detailing. 3. __*Toy Story* (1995)__: *Toy Story*, directed by John Lasseter, was the first feature-length film made entirely with CGI animation. It inaugurated what is today the industry standard for animated films: 3D computer-animated characters and stories. Become a better filmmaker with the [MasterClass Annual Membership](https://www.masterclass.com). Gain access to exclusive video lessons taught by the world’s best, including James Cameron, Spike Lee, David Lynch, Shonda Rhimes, Jodie Foster, Martin Scorsese, and more. Special effects artists can use computer-generated imagery to create animation, composite images, and even de-age actors in films.