CGI animation explained: definition, history and examples

CGI (computer generated imagery) changed the game in animated film making in the 1990s — but the CGI origin story started decades before Toy Story.

In this guide, we’ll talk about what CGI animation is and how it works. We’ll show you how to create your own computer-generated animations — and revisit some iconic moments in CGI history.

What you’ll learn:

What is CGI animation and how does it work?
CGI v animation: key differences
History of CGI in animation
Examples of CGI animation
How to make a CGI animation
CGI animation FAQs

What is CGI animation?

CGI (computer generated imagery) is a sub-category of VFX (visual effects). It refers to scenes, effects and images created with computer software. CGI can be static or dynamic, 2D or 3D and used in either subtle or obvious ways.

In live action filming, CGI is often used to insert animated elements into raw footage — think the T-Rex chasing Jeff Goldblum in Jurassic Park. Similarly, it might be used to create elaborate scenes that would be too expensive or difficult to build in real life (see Game of Thrones’ epic battles). It can even be used to make actors appear decades younger, as in Netflix’s The Irishman or to insert actors into fantastical backdrops using green screen.

How does CGI animation work?

In animations, CGI can be used to create entirely new worlds — like we see in Pixar’s Toy Story or Disney’s Frozen. Here, CGI removes the need for complex, expensive and time-consuming manual animation and allows artists far greater freedom to work outside the confines of 2D.

CGI animation is just one element of a wider sphere of animation techniques such as:

2D, vector-based animation
Stop motion
Motion graphics
Cel (celluloid) animation

Outside of the world of TV and filmmaking, you can find CGI animation techniques in diverse settings — including medicine, science, engineering, real estate, architecture, astrology, art and advertising.

CGI v animation: key differences.

Prior to the mid-1990s, most animated films relied on traditional cel drawings. Classic Disney titles like The Jungle Book required meticulous, hand-drawn artistry. Stop-motion films like Jason and the Argonauts were similarly painstaking, requiring tiny incremental movements of clay models. But why is CGI different?

CGI animation

Traditional animation

Perhaps the most obvious difference between CGI and animation is the use of computer software. For example, 3D animators create virtual skeletons (rigs) that have a set of key movements. The software handles the transitions between these key movements, saving time, effort and resources.

Traditional animation involves creating sequences of unique drawings or movements to create a fluid motion. For cel animation, this can be up to 24 individual drawings per second of film.

Computer software makes it relatively easy to combine CGI animation with real-world elements. This could involve placing fantastical beings like dragons or monsters into a real shot of a cityscape. It could also incorporate real-world models made from clay or other materials into computer-generated scenes.

Live action and animations have been combined for decades, but it’s an arduous process. In Disney’s 1988 classic Who Framed Roger Rabbit, the crew filmed live scenes before working with animators to manually incorporate cel animations later. VFX studio Industrial Light and Magic ran over 10,000 feet of composite film for the film’s visual effects.

CGI animations use less budget and resource. This is part of the reason for the popularity of the technique. Toy Story employed 110 animators and cost $30 million to create — far less than its contemporary The Lion King.

By contrast, traditional animations require more resource and budget. The Lion King used 800 animators to Toy Story’s 110. It also cost $45 million to create.

History of CGI in animation.

The history of CGI in animation can be traced to Alfred Hitchcock’s seminal 1958 thriller Vertigo.

For the film’s lurid and disorientating opening sequence, Hitchcock hired animator John Whitney and graphic designer Saul Bass to create a series of continuously rotating spiral — evoking the spiral staircases that trigger vertigo in James Stewart’s beleaguered detective.

At the time, animation stands could only rotate so far before they became tangled in wire. To overcome this, Whitney and Bass placed their animation cels on a rotating component from a Second World War anti-aircraft computer. The effect was an endlessly circulating, geometrically perfect pattern, which couldn’t be matched by freehand equivalents. This complex but effective idea was one of the first examples of 2D CGI animation.

In 1972, computer science students Edwin Catmull and Fred Parke digitised a human hand for their short film A Computer Generated Hand. They drew 350 polygons and triangles onto a model hand, before inputting the data into a computer to build a realistic moving hand for the first time ever. The result was one of the earliest examples of computer animation.

Catmull would go on to co-found Pixar. His early short film Luxo Jr., created alongside John Lasseter, broke further boundaries in CGI animation — depicting a heart-warming father-son scene played out between two lamps. It was the first CGI film to be nominated for an Oscar.

Luxo Jr. paved the way for the first ever fully animated CGI feature film — Toy Story. This catalyzed a new era of CGI animated feature films.

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Examples of CGI animation.

Tin Toy (1988).

This John Lasseter short film laid much of the thematic and visual groundwork for Toy Story. It features Tinny, a one-man band toy and his efforts to escape his infant tormenter, Billy.

The film’s animation isn’t as smooth or realistic as later films — Pixar’s proprietary PhotoRealistic RenderMan software was yet to match the ambition of the animators. Nonetheless, the film was enough to gain the interest of Disney, who later agreed to finance Toy Story.

Toy Story (1995).

Toy Story finally brought Pixar to the mainstream and established them as the dominant force of CGI animations for decades to come. Entertaining and hugely innovative, Toy Story was a deserved smash hit and created icons from its lead toys Woody and Buzz Lightyear. It is considered one of the greatest films of all time — a true crossover from the once niche field of CGI animation.

Antz (1998).

This was the moment when battle lines were drawn between CGI animation studios. In 1998, Dreamworks disrupted the release of Pixar’s second feature, A Bug’s Life, with their own insect-centred CGI animation, Antz. For the first time, CGI no longer felt like a novel innovation, but as a new standard for animated filmmaking.

The Lion King (2019).

Like the 2016 remake of The Jungle Book, The Lion King reached new heights in CGI in its creation of a totally photorealistic African savannah. It was a controversial move for fans of Disney’s 1994 hand-drawn classic, but the results are spellbinding. Every shot of this remake — from watering holes and plains to the characters of Simba, Timon and Pumbaa — was rendered digitally, but appeared totally real. CGI animation had come a long way since A Computer Generated Hand.

How to make a CGI animation.

Professional CGI animations often require a team of VFX, pre-visualisation, lighting, animation, rotoscoping and compositing artists — among others. But you can create CGI animations from home too. Check out these steps to get started.

Read up on CGI. Before you start, read books, tutorials and resources on CGI animation. You’ll need a basic knowledge of different terms and techniques before you begin.
Get your set-up straight. To run CGI software, you’ll need some decent firepower in your home hardware set-up. You’ll need at least 3 GB of RAM, decent processing speeds and a graphics card to start working your magic.
Learn how to use CGI software. CGI animation requires specialist software. Some is free, while others require a subscription. Adobe Animate animation software is available as a free trial.
Build a model. Building a model is the first step towards bringing your creation to life. Play around with polygons and shapes to create your 3D or 2D CGI animation.
Add texture. Texture is where your model starts feeling warm and realistic.
Rig your model. For your animation to move, you’ll need to create a rig. If you’re using Adobe Animate, use the Asset Warp tool to create bones and joints for your design. You can then create key movements and tween the rig to help create transitions between each movement. Learn more about character rigging.
Animate. Now to put your creation into action — test your rig to make sure it’s moving how you want it. If not, return to your rig and make alterations to the key movements.
Light, render and add effects. Finally, add the backgrounds, lighting and other visual effects you’re looking for in your CGI animation. Remember, your animation might not be perfect at first. Keep testing and practising to get your animation right.

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Fascinated by the world of animation?

Keep learning by reading our beginner's guide to animation.

Learn more

CGI animation FAQs.

Is 3D animation CGI?

3D animation is just one part of CGI. CGI can encompass visual effects, 2D animation techniques and more. 3D animation is concerned only with the modelling and animating of 3D figures.

How much does CGI cost?

As of 2018, CGI, 3D animation and other visual effects cost an average of $33.7 million per film. For amateur CGI artists, you’ll only need the price of a software subscription and computer hardware. Adobe Animate and After Effects are available on a free trial.

How do I become a CGI animator?

You can learn CGI animation from your own home - but you may need specialist training to go pro. A bachelor’s degree in computer graphics, computer science or a subject related to art, design or film is useful. Whether or not you choose to go down the college route, you’ll need a solid portfolio of work and experience to impress an animation or film studio.

What was the first CGI animation?

CGI animation has been featured in live action films since the 1950s. But the first full CGI animation was arguably 1972’s A Computer Generated Hand. This groundbreaking short film featured a moving hand rendered completely from computer graphics. One of its creators went on to co-found CGI animation studio Pixar.