From Hogwarts’s sorting hat to Buzz Lightyear’s spacesuit, Theodore Kim ’01 has helped bring iconic creations to life on the big screen. A former computer science undergraduate and postdoctoral associate at Cornell, Kim received his second Technical Achievement award from the Academy of Motion Picture Arts and Sciences at the Feb. 24 Sci-Tech award ceremony in Los Angeles.
Kim, now an associate professor of computer science at Yale University, was awarded alongside former Pixar Animated Studios collaborators David Eberle, Fernando de Goes and Audrey Wong for designing and developing the Fizt2 elastic simulation system.
Fizt2 — which stands for “physics tool version 2.0,” according to Kim — is an improved iteration of an earlier Pixar program called Fizt, a physics-based cloth simulator co-developed by David Baraff Ph.D. ’92. Fizt2 was developed to model the dynamics of clothing and other soft materials with more complexity, making animations believable in situations that deviate from reality.
“If you only simulate the clothing of characters [with Fizt], and the animator is given control of the body, the animator can do all sorts of things with the body that actually can’t happen in real life,” Kim said.
Defying the laws of physics in a physics-based simulator, however, causes some undesired outcomes.
“[Animators] would then try to push those animated characters through the cloth simulator, and a lot of times it would just explode. The physics simulator starts to work against you,” Kim said.
Among various improvements, Kim specifically helped incorporate volume simulation capabilities into Fizt2. According to Kim, volume simulation helps Fizt2 realistically model complex interactions between objects like fingers and cloth, especially in difficult situations where parts of animated characters self-intersect.
This technology assists animators like Wong, one of Kim’s fellow honorees and Fizt2 co-developers, in more efficiently exercising creativity and physical realism. According to Kim, before Fizt2, Wong would have to go back to her animation and fix the cloth by hand.
“Right when I moved back to Ithaca [in 2008], the first thing that I did was submit a paper the first few weeks I was there,” Kim said.
This paper earned Kim his first Technical Achievement award in 2013 for Wavelet Turbulence for Fluid Simulation software, which he developed with former Cornell computer science professor Doug James. The program produces realistic simulations of fire, smoke and explosions and was used in films such as “Avatar” and “The Amazing Spider-Man.”
Kim said that as an undergraduate in the College of Engineering, he was eager to take computer graphics courses and completed a graduate-level class on advanced image synthesis. When he was a senior, Kim worked as a teaching assistant for a computer graphics course taught by Prof. Kavita Bala, computer science, who is the current dean of Cornell Ann S. Bowers College of Computing and Information Science.
When not in high-level computer science courses, Kim also spent time pursuing an English literature concentration at Cornell, which he described as critical to his professional development.
“The fact that I took a postmodern literature class with Prof. Molly Hite, or deconstruction with Prof. Jonathan Culler — these really shaped the way that I think and [are] the reason that I see certain things that maybe other people might have missed,” Kim said. “Understanding the different ways that words work when different people say them has been extremely important in what I do.”
Beyond his industry work, Kim has also conducted research on racial biases in computer graphics research, penning numerous op-ed articles on tech-related ethical concerns including the dangers of deepfakes and algorithmic bias. Kim also voiced the importance of representation in technology and computer animation, hoping to increase diversity in graphics research.
“We think we’re building tools so that everyone can tell all of their stories. And it’s not true. It’s not taken into account in these algorithms yet,” Kim — who is currently researching the simulation of more diverse, textured hair — said. “As a community, we should be the ones to make it true.”
Out of the dozens of movie scenes featuring his technology, Kim said his favorite is the train crash scene in J.J. Abram’s blockbuster film “Super 8.” His work will continue to grace the screen in Hollywood films to come — Fizt2 belongs to Pixar, who will use the technology when necessary for future projects.
Journeying from Cornell to Pixar to Yale, Kim currently co-leads the Yale Computer Graphics group, where he will continue to dive into research questions regarding physics-based simulation that people need.
“You go out, talk to people and see what the pain points are,” Kim said. “Eventually it comes back around to ‘what are you working on now?’ ‘How can I help?’”