Visual effects winner of Oscar 2021

CGI and Oscar 2021

What is CGI

Movies nowdays generally use lots of CGI: computer-generated imagery or so called virtual reality technology. In this post we introduce some basic aspects how these technologies are working.

CGI is used in lots of different applications: from video games to simulators or movies. It is also used for visualizing complex mathematical models, and it can also be used to create photo-realistic imagery of imaginary worlds.

First important question is when the CGI is looking real? The answer is very simple: as long as the viewer (human eye) does not see any difference between CGI and reality – CGI looks real. However, what if camera angle shows the background? In this case it is necessary to add some occlusion (hiding) so that background objects appear behind CGI objects (because they are behind/beneath).

In some movies CGI was too obvious, and they just forgot to add occlusion. This happened e.g. in Mr. & Mrs. Smith (2005) and 300 (2006).

The second important question is how long will it take to make CGI? The answer is simple: as long as it takes for computer to process this scene (but it must be less than 1 second). Of course, in movie industry there are lots of ways how to accelerate video processing, but at the end the movie has to be shown by the projector and human brain does not accept anything faster than 24 fps (frames per seconds).

The third important question is how to show CGI on the screens? The answer is that there are lots of possible ways, but all have in common that CGI must look like it is really behind the screen. The most popular methods are: refraction (in water), reflection (mirror), and ray-tracing/ray-casting. Of course, for these methods to work there must be several cameras in front of screen – i.e. movie audience sees through several cameras, but they do not see them directly – they see only reflections from these cameras.

Actors interacting with CGI characters

You can see from movies that computer simulation is sometimes better than using real human actors. For example, it would be really difficult to make an accurate CGI character of Arnold Schwarzenegger – for instance, not too long ago studio tried to make a CGI version of Arnold. The result was very bad – even by today’s standards.

We won’t go into details but only mention two main reasons: first, today’s computers have all necessary calculations for all possible motions and expressions, but in order to create an accurate CGI version of Arnold it would take months just to create his facial muscles (although this is not the only problem).

The second reason is even more important: an actor must know exactly how to move face and body in order to show emotions, but computers can’t calculate this precisely. Actors are trained from childhood in order to show emotions, but CGI is still far from human actors.

The only solution is basically to hire lots of professional actors for few days and let them record some basic emotional facial expressions (frowning eyebrows, wincing mouth, etc.) which will be used later by the computer for CGI facial expressions and movements.

Today’s computer graphic methods are so advanced that it would take too long time for us to explain them here. However, there is no perfect computer graphic method which will be able to replace actors in movies.


As we already mentioned, one of the most popular method how to show CGI on a screen behind the physical screen is ray-tracing or ray-casting. But what does this means? The answer is simple: if you want to create an image on computer screen, then first of all convert everything into numbers (binary code).

Then if you want to have this image in front of the screen – you must draw each pixel on your computer screen (there are millions of these pixels on screen) and then convert this pixels into 2 dimensions (X and Y). Then simply add all these pixels together. For this we need lots of calculations – many millions of them. Of course, by drawing all these pixels we cannot see any difference between CGI and reality – after all there is nothing behind the screen, so there is no difference between CGI and real world.

The fictional movie Avatar (2009) uses ray-casting method to show its characters interacting with an alien world. But first of all, to create accurate 3D models is very time-consuming and it also takes a lot of resources (a computer with 64 GB memory and 8 TB HDD may be required).

Second, we must remember that the 3D models have to be used by computer for ray-casting. So if we have to transform these models from one space into another – then it is necessary to calculate all possible movements in both spaces (for e.g. adjusting arms and legs and creating eye movement). In this case it will take many minutes just to create an avatar in real-time video. So why don’t they use CGI? The reason is that the CGI would require even more resources, especially memory since they have to render thousands of different 3D animations, but there is a deeper problem. If we use CGI – then the CGI is not physical and it simply could not exist.

Even by using ray-tracing, it won’t be possible to show CGI characters interacting with physical actors. Why? Because in this case we will need several cameras behind screen to capture every CGI character. And there are lots of problems which must be solved first: How to make actor see through these cameras? How many cameras will be needed? And how to create interaction between CGI and real world actors, without any delay (in real time) – i.e., if CGI character touches a wall or an actor – then the actor must respond immediately?

We still don’t have such technology today although it is a basic technology needed for advanced computer games and movies (even more advanced than the common ray-tracing).

And even if we have such technology, then the CGI would fail to mimic physical objects. Can you imagine that a small leaf will be able to react in a physical way (same way how real leaf reacts) when it touches other movable objects? Of course, it won’t be possible.

So what is the point of using ray-tracing? Well, this method allows to create very complex models which can mimic some physical properties (e.g. wind resistance or acceleration of gravity). But still you can’t show them in real life because they are not physical (they don’t exist).

Popular movies using CGI technology

  1. Avatar
  2. Avengers: Infinity War
  3. Blade Runner 2049
  4. Interstellar
  5. Terminator
  6. Star Wars
  7. 2001 Space Odyssey
  8. Avatar 2 (2022)

TV Series

Lost in Space, Battlestar Galactica, Star Trek Discovery, The Walking Dead, Game of Thrones and others. They used real actors filmed on blue-screen or green-screen and animated the scenes using computer graphics software to create the illusion of CGI characters interacting with real-life actors and scenery (3D models can be seen on environmental backgrounds).

Oscar Nomination

An Oscar nomination is a recognition given out each year to the best of Hollywood’s best. Inclusion on this prestigious list has always led to many awards for different cinema.

The Academy Award of Merit, informally known as the Oscar, is an award presented by the Academy of Motion Picture Arts and Sciences (AMPAS) for excellence in the film industry. The award was first introduced in 1929 for a live-action short film and expanded to include both live-action and animated films in 1934.

Animation was not considered as competitive until after 1945 because most animators previously worked on small productions that were not seen outside their own studio or used animation primarily as a filler medium between sequences or when live action photography wasn’t possible due to wartime restrictions. Feature-length animation also did not receive any form of recognition until the late 1940s.

Saturn Award

The Saturn Award is an award presented annually by the Academy of Science Fiction, Fantasy and Horror Films to honor the top works mainly in science fiction, fantasy, and horror in film, television, and home video. It began in 1973 as the Golden Scroll Awards for 1973 films and was created in 1960 by Dr. Donald A. Reed (president) of San Francisco State College (present day San Francisco State University).

In 1992, it was renamed The Saturn Awards. The current trophy is a stylized representation of the planet Saturn with a ring around it made of film. The Saturn Awards are presented annually by the Academy of Science Fiction, Fantasy and Horror Films.

The award was originally given to genre films long before the Internet became a commercial entity. In many cases, films that are more than 20 years old that were considered to deserve award consideration even if they were not submitted for consideration because they were not released theatrically or made available on home video are now being entered into the Saturn databases and placed into the “Best of” lists for awards consideration. Therefore, many older films have been added to the Saturn databases as well as many newer films.

Oscar 2021

The President of the Academy is revealed little by little.

Each new day, more and more people are going to the polls.
There’s a lot of tension in the air as everyone is starting to realize that it will soon be time for them to vote.
At this point, there’s not much left before we start hearing speeches from nominees and winners on behalf of themselves as well as their films.

In the last few days, the Academy has increased its efforts to have a more diverse list of nominated films as well as nominees.
We’ve seen some upsets and surprises in different categories this year.

And the winner is:

Tenet (Warner Bros) – Andrew Jackson, David Lee, Andrew Lockley, Santiago Colomo Martinez

For more interesting articles, please see our other posts at PC Ocular online magazine.

Benkő Attila is a Hungarian senior software developer, independent researcher and author of many computer science related papers.

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