What Is CGI for a Movie? The Magic Behind Your Favorite Films

Few people know that the history of CGI in a movie began with Westworld, Star Wars, and Tron. Without the pioneering experiments of CGI artists back then, we wouldn’t have many of the spectacular movies we enjoy today.

Today, CGI technologies are masterfully woven into films, blurring the line between graphics and reality. For example, after the release of Squid Game, many viewers asked themselves: “Is the baby in Squid Game CGI?”

Such questions prove that modern graphics have reached a level of realism where audiences can no longer distinguish between the real and the artificially created. And that is the ultimate mark of quality CGI in movies.

What Is CGI in a Movie?

CGI in a movie transforms imagination into reality. Thanks to computer graphics, we see dinosaurs brought back to life, fantastic worlds, entire universes, and everything that would be impossible to capture on camera. Directors bring bold ideas to life, films generate billions at the box office, and audiences experience powerful emotions. CGI technologies significantly expand the boundaries of filmmaking.

The Key Directions of CGI in Movies

CGI in movies can serve different purposes. Broadly speaking, there are three main directions:

1. Technical CGI. This is the invisible work the audience never notices. Its purpose is to “clean up” the frame and remove unnecessary elements that distract from the scene. For example, safety wires from stunt performers, reflections of filming equipment, or unwanted objects. This doesn’t affect the artistic intent, but it makes the picture cleaner and more professional.
2. Structural CGI. At this level, CGI directly influences the content of the shot. It expands the possibilities of live-action filming through VFX effects. This could be an ocean stretching beyond the horizon, an unexpected snowfall, explosions, or a magical effect. Computer graphics are integrated into the footage while maintaining a balance between the real and the artificially created.
3. Full CGI. Here, CGI becomes the central element of the film. Entire scenes, characters, and worlds are built digitally. There are plenty of examples: Avatar, Harry Potter, The Lord of the Rings, Minecraft: The Movie, and more. Without CGI, such films simply could not exist in their recognizable form. In these cases, the visual effects play a defining role.

CGI Methods and Technologies in a Movie

Behind the beautiful and breathtaking visuals in movies lies a range of CGI technologies that help create the wow effect. Let’s explore which CGI methods are most commonly used in cinema.

Keying (Green Screen)

You’ve probably seen behind-the-scenes footage where an actor stands in front of a green screen, while in the movie it turns into a stunning landscape. That’s keying. CGI artists can replace the green screen with virtually any image: from a window overlooking a sunny beach to a cosmic galaxy.

However, there’s a catch. It’s not just about setting up the screen. Proper lighting and camera adjustments are crucial to make the background look natural. In the film Minecraft: The Movie, all the locations were digitally created.

Cleanup

The cleanup technique helps “polish” a frame by removing noise or adding extra effects. It can be used to eliminate unwanted objects caught on camera, smooth an actor’s skin, or enhance lines and details. For example, in Marvel movies, cleanup was used to remove safety wires during stunt performances.

Rotoscoping

This method involves “cutting out” a character from the background frame by frame and placing them into another scene. Many scenes in White Plastic Sky were created using rotoscoping.

Motion Capture

Remember the vivid facial expressions and movements of the characters in Avatar? To achieve this effect, actors wore suits with sensors that recorded every movement and emotion. These data were then transferred to digital characters. That allows them to move as realistically as possible. The advantages of motion capture are speed and the preservation of natural movement physics.

Tracking (Match Moving)

For CGI to “live” in a frame and appear natural, it must be anchored to real objects. Special markers are used for this purpose. They help track an object’s position and movement. So they can later be linked to other elements in the scene. In Doctor Strange, tracking was used to precisely attach magical effects to the actors’ hands.

Neural Networks

Artificial intelligence is rapidly entering the field of computer graphics. In Dune: Part Two, AI recognized speech and automatically adjusted a character’s eye color as needed.

We discussed the software used to create CGI in movies in a separate article.

How can CGI in a movie be improved?

Creating CGI that is free from technical and visual flaws doesn’t start in post-production but at the very earliest stages. Achieving high-quality results is impossible without thorough preparation. The belief that “CGI artists will fix everything” is a major misconception. Sometimes, certain material is simply technically impossible to work with.

What to Consider When Preparing a Shot?

1. As soon as it is known that a scene will involve CGI, the supervisor must determine and set all the necessary parameters in advance for the seamless integration of digital elements.
2. Before filming begins, it is important to choose the correct camera angle, determine camera movement, set up lighting, and create an HDR map. After that, tracking points should be set if the CGI scene involves any actor movement. Otherwise, during editing and effect compositing, everything will appear jittery.

When sending materials to a CGI studio, it is best to double-check file names, shot numbers, and all technical parameters.

The quality of CGI in a movie also depends on the expertise of the CGI specialist. Ideally, multiple people should work on a single shot. For example, an animator handles the animation, while a compositor manages the compositing. It’s a mistake to assume that a single CGI artist can perform all tasks at a high level.

How Is It Difficult to Create CGI for Movies?

Producing computer graphics for feature films is significantly different from creating CGI for advertising or show content. This complexity is determined by several factors:

• Multi-tool workflows and a complex pipeline. Studios need to be equipped with specialized software for specific tasks such as fluid simulation, animation, texturing, and more. Their production pipeline must be carefully optimized.
• Production scale. While a small team of specialists may be sufficient for an advertisement, a feature film requires a much larger team. Sometimes, working on just one second of footage can take up to 10 days.
• Level of Detail and Directorial Vision. The visual standard for CGI in a movie is fundamentally different. The detail in a shot cannot simply be “acceptable”. It must be of high quality to impress the audience. Equally important is the director’s vision. In cinema, CGI is a storytelling tool that brings characters and narratives to life. It must align with the director’s artistic intent and enhance the overall atmosphere.

Who Creates CGI for Movies?

Many specialized CGI artists can work on computer graphics for films:

• 2D Storyboard Artist — visualizes the director’s ideas and determines how a scene with CGI elements will look.
• Illustrator — creates detailed drawings of characters and environments, setting the scene’s atmosphere.
• 2D and 3D Animators — handle character movements and facial expressions.
• 3D Compositors — assemble the film by combining live-action footage with computer graphics.
• 3D Generalists — versatile specialists who can model objects, create textures, or animate them.
• 3D Modelers — create 3D models of characters and other objects based on concept art.
• VFX Specialist — produces visual effects for films.
• Art Director — defines the overall artistic direction, approves work, and ensures the final image aligns with the director’s vision.

For more about the profession of a CG artist, read the full article.

What Is the Future of CGI in the Film Industry?

The evolution of computer graphics in cinema has reached a point where the industry’s focus is shifting. Undoubtedly, quality and photorealism are still valued. At the same time, there is a noticeable trend toward mass production. In 2025, the film Minecraft: The Movie was released, sparking debates among viewers about whether Minecraft movie good or bad CGI.

On one hand, the film features bright and colorful CGI that captures the aesthetic of the popular game. Zombies, Creepers, and other characters look realistic. On the other hand, some viewers are unsettled by its artificiality. Many consider the CGI to be poor or insufficiently detailed. The headline “Minecraft movie good or bad CGI” remains up for debate.

Unfortunately, computer graphics have begun to be perceived as a residual part of production rather than an integral part of the filming process. In addition, many CGI techniques now seem commonplace. For example, cleanup—the removal or replacement of objects in a shot—may appear easy. However, it involves extremely meticulous work, often more complex than other computer graphics techniques.

What to Expect?

1. Expansion of stylistic and creative possibilities. More tools will emerge that allow the creation of realistic and picturesque locations. For example, filming a movie in Paris may no longer require traveling there—it could be digitally created on a computer, lifting budget constraints.
2. Impact of neural networks. Artificial intelligence will not replace CGI artists but will become their assistant. AI can handle routine tasks and optimize the CGI production process for film.
3. Increased realism in computer graphics. Realism will continue to improve through three main components: technical methods, level of detail, and the specialist’s expertise.

CGI for Cinema at Acquisition.mobi

At Acquisition.mobi, we create realistic CGI for cinema that makes storytelling exciting and visually striking. We edit and enhance videos, remove and replace backgrounds, animate characters, create VFX effects, and design unique locations. Looking for CGI solutions like the viral squid game CGI baby? We’ve got you covered!

If you are interested in collaborating, email us at cgi@acquisition.mobi.