What is CGI in a Film?

Do you know what is CGI in a film? Are you interested to know about this term? To understand clearly what actually CGI do in a film, keep reading this article. Hope you enjoy!

CGI stands for Computer-generated imagery which is the application of computer graphics to create both stable and dynamic three-dimensional images for the production. CGI is a new component of VFX, the digital creation of visuals in post-production that cannot be captured directly by any live action or shot.

The way digital technology movies are made has completely changed. Filmmakers now have the ability to completely change sets, move locations, and create a whole new outside world by using CGI effects. As a spectator sometimes you can guess the laser explosions and dinosaurs are computer-generated imagery but some movie moments filled with CGI effects look so real that you will never understand.

Evolution of CGI

The evolution of CGI led to the rise of virtual cinematography in the nineties where the approach of simulated cameras was not limited by the laws of physics. The availability of CGI software and increasing computer speeds have allowed individual artists and small companies to create professional-grade films, games, and fine arts from their home computers.


1975 to 1980

The application of CGI in movies began effectively in 1975 when George Lucas created Industrial Light and Magic. A division of Lucas’ production company, Lucasfilm, ILM, was initially charged with developing visual effects for the “Star Wars” film. However, its long-term goal was to develop CGI software and services for the sales to motion picture industry. It will be incorporated into animated filmmaking in 1979 when the CGI animation component of the New York Institute of Technology hired key staff from the Computer Graphics Lab.

1980 to 2000

In 1986, Moore’s law would influence Steve Jobs to buy ILM’s Graphics Group, which would turn into Pixar Animation Studios. Cash flow problems arising from R&D spending, declining Star Wars license revenue, and divorce settlement were among the reasons Lucas Graphics Group sold. Jobs, who had recently been ousted from Apple Computer, would pay $5 million for Pixar and immediately invest another $5 million in the company. Eventually his investment in Pixar would approach $50 million.

Meanwhile, London-based firm Framestore and Double Negative (DNEG) UK filmmakers and Hollywood filmmakers have emerged as major CGI players for filmmaking in the UK. Framestore was launched in 1986 and established its CGI division in 1992 under Mike Mine. In 1997, it acquired the Computer Film Company, one of the first digital film special effects companies to develop technology for digital film scanning, compositing and output. DNEG was founded in 1998 by four visual effects artists formerly with The Moving Picture Company.

2001 to Present

As the new millennium progressed, CGI software programs and organizations became multifaceted and specialized too. Not surprisingly, films of Marvel Studios—specifically “The Avengers” (2012), “Iron Man 3” (2013), “Guardians of the Galaxy” (2014), “Avengers: The Age of Ultron” (2015) and Avengers: Infinity War (2018)—were prime sources of CGI business.

How CGI Technology Works in a Film?

The process begins with the development of mathematical three-dimensional models of living and inanimate surfaces of objects, specifically with the use of graphics software. These models then map out their positions in the field of view of the frame, the positions of the objects relative to each other, the color of the object and, when applicable, geometric patterns mapped to the surface texture.

The most realistic 3D effect and the standard for moviemaking is achieved through a process called “ray tracing.” Here the frame is divided into points commensurate with the frame’s resolution, e.g., 640 by 400 pixels. A line is projected from the eye to each point in the frame, and from there extended to its intersection with the surface of an object.

If a line does not make contact with an object, its pixel assumes a specified background color. When an intersection does occur, the intersection is then projected to the scene’s light source or sources, including sources of reflected and refracted light. The color of each point in the frame is determined by the specified color of the surface as it would appear in its defined location when illuminated by the scene’s light sources.

Ray tracing begins with an eye situated centrally on the screen. Lines are projected from the eye to all pixels in the screen, and from each pixel, a line is projected to the first programmed surface in its path. From this surface point, lines are projected to all light sources able to illuminate the point. This process is then reversed. The effect of the light rays on the surface color is calculated, and the resulting hue is projected back to create the color of the pixel.

CGI development has always been tied to the advancement of computer processing power. This dynamic points to the conclusion that eventually the motion picture star will be replaced by personas visually created by computer.

10 Noteworthy CGI films so far

Hollywood blockbusters have become increasingly reliant on visual effects over the past few decades, and recent advances in technology have made it possible to do almost anything you can possibly imagine! 10 notable film names that used CGI are given below:

  1. “Westworld” – The first film that used CGI.
  2. “Terminator 2: Judgment Day”- CGI has been used in this film to create the most iconic villains ever.
  3. “Toy Story” – Introduced the use of 3D animation, which takes a familiar fact in films now a days.
  4. “Lord of the Rings”- One of the earliest characters created with the use of 3D motion capture in this trilogy.
  5. “Young Sherlock Holmes”- Its contribution to CGI is more important than you think.
  6. “The Matrix”- In this film, use of CGI was so well in the bullet scene that a whole technique was named after it.
  7. “Tron”- It may not be a good film, but it was an important film for the development of CGI.
  8. “Gravity”- pushed the use of CGI to a whole new level.
  9. “Avatar”- Utilize 3D CGI in a way that had never been seen before.
  10. “Jurassic Park” is an example of how just a little CGI can go a long way.

If I want to conclude briefly ‘What is CGI in films’ I must say, CGI is one of the effective tools that help a talented artist or filmmaker to tell their stories more creatively as well as interestingly. CGI is not created with the push of some magic button suddenly. Rather It is the ultimate mixture of careful thinking, design, experimentation and authentic creativity of an artist. The impossible becomes reality when it is done well in a film. If you want to replace boring, overused shots to a new interesting scene then use CGI in your film.