8 minute read
July 6, 2022

What is CGI (Computer-Generated Imagery)?

Computer Generated Imagery (CGI) has revolutionized the movie industry, marking a significant evolution in cinema. The incorporation of CGI has been one of the most important advances that the industry has made, and its impact can be seen in the production of movies in various genres.

CGI has become an indispensable tool for visual effects, allowing filmmakers to create realistic and stunning visuals that were once impossible to achieve. One of the most significant advantages of CGI is its ability to create worlds and characters that are beyond the realm of reality. With CGI, filmmakers can create stunning landscapes, otherworldly creatures, and spectacular effects that transport viewers to new and exciting worlds. It has been used extensively in science fiction and fantasy movies where the use of practical effects is limited.

What Is CGI?

You might be wondering, what does CGI stand for? Well, it stands for Computer-Generated Imagery which, basically, is the creation of animated visual content using computer software. In some cases, it may be referred to as 3D imaging. CGI is usually used to create 2D or 3D characters, and all sorts of special effects in films, television and video games. You can also find CGI in visual arts, advertising, architecture, engineering, and so many other fields. CGI can be in your favorite science fiction movie as well as a dramatic movie, making it a widely used visual medium around the world.

CGI comes in handy when you need to create visuals that are not humanly possible, and it is more accessible than you think. It can save you the cost of hiring extras or creating sequences using miniature figures. And believe it or not, CGI has been around about 70 years. 

When Was CGI Invented?

This technique was invented around the 1950s. At that time, analog computers were used to create patterns onto animations, which were then included in featured films. And you might be wondering, which was the first film that used CGI? Well, we have an answer for that! The first film to ever used it was Alfred Hitchcock’s classic Vertigo made in 1958. This was the first computer animation used in film. Most animations during that era were very basic 2D compositions.

What is CGI vertigo
Vertigo (1958) by Alfred Hitchcock.

3D computer graphics were introduced in 1972 when Edwin Catmull and Fred Parke made a short film titled A Computer Animated Hand. The film was fully computer-animated, a feat made possible by Edwin drawing 350 triangles and polygons in ink on his hand and then digitizing and animating that data on a 3D program that he wrote. 

What is CGI animated handA Computer Animated Hand (1972) by Edwin Catmull and Fred Parke.

When Hollywood came into the picture, CGI took a leap forward and in 1973, Westworld by Michael Crichton, featured the first 2D CGI scene depicting a robot’s ability to perceive vision. After this successful implementation, CGI started appearing more and more. Some movies from that era that featured Computer Generated Imagery are Alien (1979), Star Wars (1977), and Tron (1982). 

What is CGI Westworld
Robot’s ability to perceive vision. Westworld (1973) by Michael Crichton.

By 1990, new techniques emerged, and great ideas were ¡produced using CGI. Some amazing movies in the 90s that adopted computer aided imagery include Terminator 2 (1991), Titanic (1997), The Matrix (1999). However, the movie with the best CGI of that period is unquestionably Jurassic Park (1993), which achieved incredible visual effects thanks to a mix of real characters, animatronics and CGI bringing dinosaurs back to life amazingly.

What is CGI JP
Jurassic Park (1993) by Steven Spielberg.

Another movie that was a real success, was Toy Story (1995) which was entirely directed with CGI which had never been done before. Later, Pixar produced more CGI movies like Monsters, Inc. (2001) and Finding Nemo (2003). 

Toy Story (1995) by John Lasseter.

From 2000 and onwards, CGI was taken to a whole new level. With new technologies emerging in the film industry, CGI was able to grow and improve. Nowadays, it is a fundamental part of films. The movie Guardians of the Galaxy (2014) heavily relied on this technique, since 90 percent of the movie features it in some capacity. Filmmakers in various genres now continue applying computer generated effects, even though it was initially used in fantasy movies. 

How Does CGI Work?

CGI is created by algorithms that make complex fractal patterns mixed with 2D pixel-based image editors creating vector shapes and animation softwares. 

The process consists of 8 parts:

  • Modelling: This is defined as the process of building 3D objects that feature in animations, it’s called computer for 3d modelling. This process can be carried out in different ways, for instance, 3D digital sculpting or laser scanning.
  • Texturing: The next step of the process is texturing. Here, materials are added to the 3D objects to make them look real. Often, the 3D objects have a default gray color and sometimes you need to put 2D images with the desired texture.
  • Lighting: This part of the process is fundamental for great results. To achieve the perception of reality, just like in a real film set, you’ll need to adjust the size, number, and direction of cinematic lights you use. This step is super important, so don’t forget about it!
  • Camera: You’ll definitely need a camera in your 3D scene, You can choose a regular camera which moves freely or a target camera that is locked and aimed at a particular point.
  • Animation: So now let’s get some movement! This is where all the fun is. You can make your 3D objects move, usually with a timeline that allows you to adjust some settings. Take note that animating the camera is indispensable.
  • Simulations: This is not an essential step, but keep in mind that simulations are crucial when you want to create realistic images of liquids, fire, smoke and other effects.
  • Rendering: This is the process where everything is put into files that you can later be seen in a visual format. Rendering requires a lot of knowledge and even though most CGI animation softwares include their own rendering applications, most animators decide to use external rendering platforms for their final product.
  • Composting: Okay, so this is the final step of the process. It involves refining the look of the rendered content, for example, shadows, lighting, reflections, colors, etc. 

This is basically the process of CGI and most animations follow all (or most) of these steps in a similar order. When it comes to movies, various units like the Art Department, the Asset Department, the Research and Development Department, the Animation Team and many others are involved in the creation of computer generated visuals.  

CGI Past & Present Examples

CGI can make impressive visual effects that leave an audience amazed. This technology has advanced so much that in this section, we will see some CGI past and present examples. 

The iconic Star Wars (1977) movie by George Lucas, used CGI on their visual effects. Here is an interesting video which explores the making of the computer graphics for Star Wars.

Another movie that used CGI, in the 70s, was Alien (1979). This landing sequence uses this new technology to make it realistic. Look at the video below:

The Irishman (2019) by Martin Scorsese is a movie that made a very good use of CGI. They managed to make Robert De Niro, Joe Pesci and Al Pacino look way younger on screen. We see the transition of these characters from their 20s to their 60s and in order to do this, they used de-aging technology. Most of Robert De Niro’s on-screen time in this movie is computer-generated. They needed at least 3 different cameras on the actor’s face and a software which detects the differences between light and shadow. This software, then, uses each pixel as a marker to render a computer-generated version of De Niro’s face. Incredible, right?

What is CGI DeNiro
The Irishman (2019) by Martin Scorsese.

Avatar (2009) from director James Cameron, is another movie that used CGI in a way that has never been seen before. It was not only filmed in 3D, but also 70 percent of the film content is computer generated. It is one of the most expensive movies ever made and arguably the best use of CGI in history. 

What is CGI avatar
Avatar (2009) by James Cameron. 

The movie Matrix (1999) enters this list as an honorable mention based on the brilliant execution of a visual effect known as “bullet time”. The scene where Keanu Reeves dodges a hail of bullets in slow motion as the camera runs at normal speed is the highlight of the blockbuster, and the visual technique was pioneered in that sequence.

What is CGI matrix
Matrix (1999) by Lana Wachowski & Lilly Wachowski.

CGI in Animation

As we’ve mentioned, CGI is also widely used in animation. Toy Story (1995) and Avatar (2009) are two examples of it. CGI works so well with animation in general, that even Disney decided to move exclusively to 3D animation because it lowered labor costs by making less work for the artists. So, all animation is done digitally with the use of CGI. In fact, CGI was a lot cheaper and quicker to do than the traditional animation. So nowadays, advertisers, the gaming industry, and other professionals prefer it.

CGI in Movies

As we’ve also mentioned, movies widely use CGI. This visual effect has the advantage of looking so real that the amateur eye can’t notice the difference. Of course, CGI should be done right. There are many films that have been criticized for featuring really “bad” CGI. We have some realistic CGI such as Avatar (2009) and The Hobbit (2012), and some unrealistic CGI such as King Kong (2005) or Sharknado (2013).

We hope you have gained some insight on the importance of this groundbreaking industry technique and how it has taken its effect on today’s movies. If you want to add music to your projects, consider HookSounds! Our exclusive royalty-free tracks and sound effects could be the perfect addition to your project. Check out our licenses