What is CGI in Films How is it done

What is CGI in Films? How is it done?

CGI or Computer Generated Graphics is an advanced technology that has brought a revolution in audio-visual art creations. Not only in films, but CGI is also a prime phenomenon in the gaming and animation industry. If you dig deep about CGI, you will know that CGI is actually a part of the animation.

The stunning unearthly visuals on a film screen might have definitely appealed to while watching a film such as Avatar, Life of Pi, or Jurassic Park. But, all of the dinosaurs, tigers, or any other dangerous creature on the screen are made using CGI. But, CGI in films is found in various other places that swiftly pass your vision, but the human eyes fail to dissect the computer-generated images from the real images.

What is CGI in films?

CGI in films has tremendously increased since its first encounter in 1958. Today, CGI plays a crucial role in almost every film made. What creates the difference is that some films heavily use CGI, whereas some films subtly use CGI to carry forward the narrative in the film.

With the rise of CGI in films, a filmmaker has the liberty to bring the accurate version of their vision into a movie screen in front of the viewers. As already said, creativity has no limits; CGI in the contemporary world has ensured that the bar of creativity is set high and no vision ever goes off without speaking to the world.

Some of the common use of CGI in films, apart from creating unrealistic visuals includes, age-manipulation, physical feature resemblance, graphic construction, etc. In this article, we will understand the comprehensive use of CGI in films and how it is actually visualized and brought into action.

How is CGI actually done?

The highly complex process of CGI is done using a step-by-step team integrated method. It is not easy, but with expert understanding, creativity, and a strong executive mindset, CGI in films can be made possible in the seven-step process.

Step 1: Initial Visualisation

Before any film production begins, the director visualizes his perspective into the narrative. Visualization helps the entire team to understand what the storyteller wants to portray through the film—understanding that a team of artists indulges in creating the first draft of visuals which is later converted into computer graphics.

The art team works closely with the director to storyboard and create sketches that clearly depict what the film will look like. Then, the pre-visualization artist creates the first draft of 3D models upon the director’s approval. This is done to give an idea about the final setup of a particular scene. One of the most fundamental reasons to create a low-quality 3D model is to define the final set in terms of camera movement and key narrative styles. 

Following the approval and technical decisions of the director and creative head, the CGI artists put real-world effects into the 3D model. The effects we are talking about include lighting, detailing, logical placements of props, etc. At this stage of pre-visualization, one can see a blueprint of the final film, in a way low quality.

Step 2: Animation

Once the pre-visualization stage is successfully achieved, the real or final process of creating computer graphics begins. The first step toward creating awestruck computer graphics is animation. Everything that is in motion on the screen must be animated. Animations are done over the sketches of subjects in a shot. Every subject is animated carefully. 

Step 3: Matchmove

The most important aspect of 3D filmmaking is the feel of reality for the audience. The audience looks at the screen and gets a holistic experience of cinema. Perhaps, this is one of the best technological advancements in theatre screens. The sense of 3D films draws in a large number of the audience because cinemagoers love the feeling of witnessing the events of the movie rather than just watching it.

Matchmove is the technique that brings life to a 3D film. By this method, a computer graphic generator develops a virtual camera for the entire team to work upon. The virtual camera later becomes the eye of the viewer after wearing a 3D glass. 

Matchmove is one of the most challenging tasks. Matchmove experts use live footage to determine a virtual angle and develop virtual cameras for every scene. This is a time-taking as well as difficult process. However, this is a step that is limited to 3D filmmaking. In addition, not all types of computer-generated images need the adaption of a virtual camera.

Step 4:FX Simulation

FX Sminulation is the process of recreating real-world elements into a computer-generated scene. The real-world elements we are talking about here are light, rays, waves, fire, smoke, clothes, hair, explosions, etc. These elements are a necessity in any video production because it is impossible to tell a humanly possible story without them.

FX simulation is used to create the FX animation, dynamic and procedural simulation, and particle-fluid systems. This is a time taking and challenging process. An FX artist works closely with the creative director to generate these graphics. One of the most important notes that FX artists keep in mind is logic. The illustrations created for a particular scene must adhere to logical rules. Such as the direction of sun rays, shadows of subjects, etc.

Step 5: Lighting

An expert in the CGI department is responsible for creating the lighting in the scene. For a given scene, the lighting expert determines the input of lights, working closely with the cinematographer to make real-world conditions through technology. 

The artist understands the light sources and creates the lights from them in the scene, acknowledging the real-world rules.

Step 6: Rhotoscopy

Rhotoscopy offers different values for different types of computer-generated images. Primarily, it is the process of creating a matte by tracking live-action or subject movement using specific tools so that it can be composited over a different background. 

For creating stunning visual effects, rotoscopy is essential to trace subjects in motions frame by frame to produce realistic actions on the screen. Films widely use this technique to add realistic visuals such as explosions. 

To understand rotoscoping, one must be aware of the concept used for the basic background removal of a picture. Following that, rotoscopy is the background removal of live-action, moving elements such as a man running, the intense smoke caused due to explosion, etc.

Step 7: Composting

The final step to successfully creating a computer-generated graphic is composting. It is the process of assembling the products obtained from all the above processes and making the final intended visual.

All the graphic elements, such as matte paints, animations, 3D lighting, live actions, etc., are combined together during composting, and the final version of the graphic is obtained. 

The director monitors the process to ensure the correct layout of the story; however, after reading through the process of creating stunning computer graphics, we know that it is a lengthy and challenging process. Not only challenging but also expensive.

How expensive is CGI?

After understanding the highly laborious and time-consuming process of bringing a computer-generated image into the final big screen, you must have had a clear idea that it is an expensive process. Definitely, it is a process much easier and more cost-effective method than building live sets; however, it is not a game of cents.

CGI can be very expensive, depending upon the scope of the project. However, the prime factors that contribute to the high cost of CGI are:

  • Complexity– The entire process of generating computer graphics is very complex. This complicated process is carried out by expert professionals who seamlessly perform the technical functions with minimum flaws. Unfortunately, such experts come at a huge price, thus, hiking up the maximum part of the budget.
  • Team– A film assignment demands a well-skilled team who can divide into departments and carry forward the process of computer-generated images one step at a time. To afford a great team that offers flawless creations and fast results requires a massive amount of money.
  • Systems– Although the skillset of the CGI professionals is of utmost value, we cannot deny the high-tech system requirement for a film project. Now a film production usually hands over the CGI creation to the professional team, but the cost of systems used is definitely added on to the final cost.

How do I start learning CGI?

Standing in 2022, diving into the vast world of CGI is not difficult. Today, almost everything is easily accessible via the internet. One can easily take up an online course or even try their hands at generating computer graphics by watching an online tutorial.

Everything is just some clicks away. However, if you want to dedicatedly learn the skills of CGI, getting into a good animation school is highly appreciated. Moreover, a school not only makes an aspiring student industry ready but also provides a certification making your skills and learnings valid.

However, no certificate proves quality. The skills lie within oneself, and thus, not being able to access high-quality certification courses shouldn’t be a reason to get demotivated when there are plenty of online tutorials available.

Apart from the passion for learning, the only requirement is a capable system to handle significant software needed for generating computer graphics. Once you ensure that you meet these criteria, nothing must stop you from visualizing the next big computer-generated imagery project.


Filmmakers are going to a large extent so that their vision can be accurately portrayed to the audience. In addition, the development of CGI techniques has made it more accessible. Hence, the scope of CGI remains high because films are always made and will never cease to be made. Future might await an evolution of the technology, but we know that the decline of CGI is far away. 

Similar Posts