Theodore Kim, an assistant professor in UCSB’s Media Arts and Technology Program, is the first sitting UCSB professor to earn an Academy Award.

Kim is among a group of researchers that created a smoke-and-fire visual effects technique called wavelet turbulence. The award recognizes an innovative software algorithm they developed that has been used in movies such as “Avatar,” “Sherlock Holmes,” and “Hugo,” among others.

This technique allows for fast, art-directable creation of highly detailed fluid simulation. Not only are the details more intricate, they are also easier to control, as well as faster to create than the technology available to movie artists nearly a decade ago.

Mechanically, wavelet turbulence increases the scale on the grid and adds detail that is not distorted over the time domain. Compared to simulation with same grid spacing, the computation is faster and the demands are lower. In addition to small smoke effects, this new wavelet turbulence software also enables digital artists to actually create visuals of massive explosions, violent volcanic eruptions and even faint mist on water.

Kim, along with Nils Thürey, Markus Gross and Doug James, developed this technology to make simulations of large-scale smoke and fire more practical. The algorithm was an addition to the Navier-Stokes equations for incompressible fluids.

Kim explained that the research group added a theory of turbulence developed by mathematician Andrey Kolmogorov to increase the speed of their method.

“Wavelet turbulence takes as input a small-looking cigarette smoke simulation and quickly adds tiny whorls and vortices to make it look bigger. You don’t have to wait days or weeks, just a few minutes or maybe a few hours. The reason our method is faster is that we leveraged a theory known as ‘Kolmogorov’ turbulence, which was developed by a Russian mathematician named Andrey Kolmogorov in 1941,” Kim said in an email. “The previous methods from 1999 used an older theory, known as the Navier-Stokes equations, which were developed back in the 19th century. So, to be technically precise, we found a good way of incorporating Kolmogorov turbulence into a Navier-Stokes simulation.”

The fluid simulations have implications beyond entertainment, including medicine and aerospace design. In medicine, this program could enhance the understanding of blood flow turbulence, and collision of red blood cells with each other and capillary walls. In astrophysics, it can reveal the movement of intergalactic gases, and in aerospace research, it can provide insight into how air flows across an air wing, thus contributing to new airplane designs.

The source code for this technique is available for free, as Kim and his team decided against patenting. Due to the tight budgets of movie studios, royalty-free methods are especially attractive.


A version of this article appeared on page 5 of January 23rd, 2013’s print edition of the Nexus.