The Science Behind Pixar

The lively actions of toys when humans are not around, the realistic fur and hair of a blue bear-like monster, the graceful and beautiful look of the sea and fishes in an underwater environment, the glamorous shading and reflective paints on the shiny car surface. I believe most of you have seen some of these effects before. They are all created by Pixar.

Pixar is a CGI film production company. The word, CGI, stands for “Computer-generated imagery”. It refers to the technology that three-dimensional computer graphics are used for creating characters, scenes and special effects in films, television programs or video games.

Last month, I paid a visit to the Hong Kong Science Museum to see the “The Science Behind Pixar” exhibition. This exhibition offers visitors an unparalleled insight into how science, technology, engineering, art and maths (STEAM) concepts are merged together to create the lively characters and realistic scenes you see on screen.

Among all the exhibition contents, the one that I enjoyed most is the “Rendering” process. After the virtual scene is set, the characters are shaded and posed, the lights and camera are in position, the computer will start the rendering process. No one knows what the CGI animation looks like until the rendering process turns all the data and programming into an image we can see.

Let’s use “Toy Story” as an example. The movie is about 77 minutes long. There are 60 seconds in one minute’s time. A smooth video usually has about 30 frames per second. So the computers have to render a total of about 138,600 frames in order to create the whole movie. In 1995, when Pixar tried to create the “Toy Story”. Each individual frame could take from 45 minutes to 30 hours to render, depending on how complex it is. So I did a little bit of research and calculations. If you tried to use 100 computers to render the “Toy Story”, each computer is running 24 hours a day non-stop, you need to use about 230 days to complete the rendering process.

Luckily, the computer technology is also evolving at a very high speed. To accelerate the production of computer-animated films, Pixar works with NVIDIA to improve the image rendering process. NVIDIA is a technology company that designs graphics processing units, also known as GPUs. These GPUs are usually used in rendering computer games and animation graphics. NVIDIA has developed a parallel processing system that makes rendering more efficient. The parallel processing system allows many GPUs to cooperate and work together so that it takes less time to finish the whole rendering process.

The solidarity and bonding of all the GPUs makes the dream comes true. Without the advanced computer technology, we may not be able to watch “Toy Story”, “Inside Out” or “Luca” today.

Mr. B. Sham
24 September 2021