PhD candidate Joel Wretborn and his colleagues Alexey Stomakhin and Steve Lesser at the New Zealand–based visual effects studio WētāDigital x Unity and Douglas McHale at WētāFX have won an Emerging Technology Award at the 21st annual Visual Effects Society Awards for their water simulation toolset used in Avatar: The Way of Water.
Joel Wretborn, who began his doctoral studies under Professor Christopher Batty’s supervision in January, and his colleagues at WētāFX developed a new comprehensive toolset to simulate water realistically, from colossal splashes and cresting waves at the largest of scales to tiny water droplets, thin films and bubbles at the smallest.
As the film’s name suggests, Avatar: The Way of Water features spectacular water scenes, and the visual effects to portray water naturally required development of a variety of solvers running in tandem.
“We knew Avatar would have a lot of challenging scenes, so a Water Task Force was assembled early on with a mix of researchers, developers, and artists,” Joel recounts. “We were given a few characteristic shots, for example a creature creating a huge splash, where we needed to capture both the large- and small-scale details of such a scene. We worked on specific water simulations with the intent to develop tools that could be employed in a variety of simulations. With most movies you have six months or maybe a year to deliver, and when you have such a short timeline research becomes difficult. But the longer lead time we had with Avatar gave us the opportunity to develop high-fidelity effects.”
The water effects team also developed a new tool they call the state machine, which allowed them to transition between solvers at a variety of scales.
“Solvers are usually tailored to create simulations at a certain scale,” Joel said. “You might have a solver that’s particularly adept at creating ocean-sized water simulations and you might have another that’s great at simulating tiny bubbles or thin tendrils of water on a person’s face as they emerge from water. One of the things we developed that was heavily used in Avatar were solvers that could transition between scales — a solver to simulate large, bulky fluids, a solver to simulate water spray or foam, a solver to simulate mist, and so on. Depending on the phase of the water and scale of the scene, we would transition to the most appropriate solver.”
This year is the first that the Visual Effects Society has recognized emerging technology as a category to be acknowledged and celebrated.
“Typically, only the artistic side of a movie is given an award, such as an award for best visual effects,” Joel said. “But this is the first time that VES gave an award to highlight the contributions the technical crew made to support the artists who use the tools to create these amazing scenes. It’s a great honour to be rewarded for creativity in developing the tools and workflows that artists use to create the visual effects in a movie.”