'Super' Underwater Effects
Christine Bunish
February 21, 2019

'Super' Underwater Effects

A big story demands big visual effects. So when Warner Bros. Pictures and director James Wan brought the origin story of DC Comics’ Aquaman to life, it was a given that Arthur Curry’s journey of discovery around the world and under the seven seas would be packed with breathtaking VFX. 

As half-surface dweller and half-Atlantean, Arthur (played by Jason Momoa) accepts his destiny to be king of Atlantis as he faces myriad existential challenges. With his staunch and beautiful ally Mera (Amber Heard), princess of Xebel, Arthur battles his younger half-brother and current king of Atlantis, Orm (Patrick Wilson), and legions of other villains and deadly sea creatures as he fights to unite Atlantis and the surface world.

“Aquaman was by far the biggest undertaking of my career,” says visual effects supervisor Kelvin McIlwain. “Creatively and quantitatively, it was a massive project. Aquaman features a lot of world building and creatures. It touches on all aspects of visual effects; it brings everything to the table. It was an exciting proposition in its sheer scope and scale.”

McIlwain worked closely with VFX producer Kim LoCascio, whom he calls “a wonderful partner in this effort. She was instrumental in helping me get workflows set up, teams built and processes implemented so we could get through tasks on a daily basis. She really allowed me to focus on the creative and technical aspects while she took care of the rest.”

LoCascio says Aquaman was “one of the most amazing experiences of my career, incredibly collaborative and open.” With just under 2,300 VFX shots in the film, she marshaled a wide array of VFX vendors worldwide. ILM, MPC, Scanline and Method were the lead studios; Digital Domain, Luma and Exceptional Minds Studio also contributed significant amounts of VFX, with Weta Digital performing character de-aging and sequence design for certain story points. Prime Focus did the 3D conversion as well as more than 100 VFX shots.

One of the main challenges was creating an underwater world that equaled Wan’s vision of the subterranean kingdoms, LoCascio says. “The cities, plant life, marine life, the visual cues that remind you subliminally that you’re underwater — all of that had to be uniquely combined in every shot. Quite a bit of exquisite artwork inspired the 3D environments, and James’s vision was very clear. The VFX studios kept true to his vision while embellishing it beyond expectations.”

With such an epic canvas for VFX, previs was essential. “The dry-for-wet [live-action plate] photography for the aquatic environments was completely dependent on previs,” McIlwain points out. “Previs was the blueprint that allowed the different departments to understand what was happening in a shot.  

“We relied on mocap cameras and virtual production, which allowed us to look through the camera and see on a monitor the actor against a bluescreen set and against a virtual representation of the world,” he explains. “But none of that would have been possible without the careful planning of previs. The Third Floor did the majority of the initial previs and created all the assets for virtual production.”

The dry-for-wet technique, in which complex rigs were built to essentially puppeteer the actors as they performed in digital underwater environments, was new to McIlwain. “The special effects and stunt team in Justice League came up with rigs for one sequence with Aquaman and Mera, but we needed 60 to 70 percent of Aquaman shot dry-for-wet. So, the rigs were heavily modified and pushed way beyond what they were capable of doing in Justice League.”

The entire shoot took place at Village Roadshow Studios in Australia’s Gold Coast (Queensland) apart from plate unit and 2nd unit photography in Newfoundland, Morocco and Sicily. The ground and aerial Sicilian shoot was especially complex. “We extensively documented the mountaintop village with photography and lidar-scanned it so we could build an Italian village digitally,” says McIlwain. “In Australia, we had one large set of the village square with multiple rooftop-tile sets, but everything below that was digital.”

The production “tried as much as possible to have the VFX vendors’ own data wranglers and supervisors or their representatives on-set so we could consult on set ups and process,” he notes. “That was a key component in effective production.”

ILM (Industrial Light & Magic) offices in Vancouver, San Francisco and Singapore completed 670 VFX shots for the film, the bulk of them underwater sequences. A particularly big task was hair simulations for the actors in dry-for-wet photography whose own pulled back hair had to be replaced with tresses that appeared to float artistically through the water.

“We’ve done a lot of above-water and animal hair in the past, but long, flowing human hair underwater was a challenge and stressed our hair tools a bit,” says Jeff White, ILM’s VFX supervisor. “The hair had to not only be physically accurate but also look cool. There was a lot of back and forth with James to review just the hair — it was so important to help sell the characters.”

With ILM’s Haircraft tool “we traditionally simulate guide hairs and the computer interpolates the millions of other hairs,” White explains. “But with underwater hair, the guides separate in unusual ways. So, we needed more guides and tools to simulate clumping; we had to get the right flow of hair that responded to the body movement of the characters.”

ILM added new capabilities to Haircraft, including the ability “to hand-sculpt the hair after the fact, to shape it and get the beautiful poses that James was looking for,” White explains. ILM also had to connect the hair to the actors’ natural hairlines and pay close attention to continuity. “We were constantly reviewing the simulations in the cut to make sure the hair was all flowing nicely,” he says.

ILM was responsible for the entire underwater city of Atlantis, which Wan described as “an entirely new, magical place that you’d want to go to,” recalls White. “James had references of sea creatures and plant life, beautiful underwater photography, and there was a lot of great production design. We added to the artwork and implemented the shapes in 3D creating 200 very complex buildings based on organic shapes with a lot of translucency and color. James wanted a beautiful, clean, modern Atlantis built on top of an older Atlantis covered with growths so there was a cool contrast.”

Ultimately, those 200 buildings became some 7,000 structures, which were layered and lit to be legible to viewers. “Once the city was laid out, we art directed every shot,” says White. “There were bright buildings here and dark areas there. The audience had to understand what they were looking at with a quick read.”

ILM also had to ensure that the fantasy architecture of Atlantis would be “grounded in the real world,” per Wan’s request. So, the foreground features pockets of kelp, anemones or coral, “something real to latch onto to bring authenticity to the world,” says White. “We combined those elements with bubbles, particulates, accurate light and color and depth diffusion to sell the underwater look. There were no copy-and-paste shots.  Every shot was composed by hand.”

The sheer volume and complexity of rendering Atlantis required both Isotropix’s Clarisse and Pixar’s RenderMan rendering engines. “We had all the most difficult material types to render — translucent, shiny — over so many shots,” says White. “When you cross the bridge to enter Atlantis, there are huge lanes of traffic: 150,000 ships are waiting to get in each, with eight to 10 little glowing lights. And we had to get all that to render.”

By contrast, the final battle sequence on the ocean floor was “an entirely different environment,” White notes. “It wasn’t the typical flat terrain of a big battle scene. It had undulations and huge mesas. It was a challenge to build a shot, put the camera in and see that a mesa was blocking the action. We had to reconfigure everything almost shot by shot.”

ILM’s crowd team populated the battle with “hundreds of thousands of assets, all fighting each other, including the crab-like Brine and Atlanteans with stinger vehicles with gracefully flapping wings,” says White. “It was easy to mix them up in the chaos, so we used a strong color palette to tell who’s who: red for the Brine, blue for the Atlanteans, green and gold for the Xebelians.

“James also asked us to really play up the laser trails and bubble trails behind them, like contrails, which were beautiful and helped orient the audience by defining the space and perspective.”

There were several almost :30 shots in the final battle, White notes. “Those were particularly difficult in terms of getting the choreography right: squid releasing ink as a smokescreen, narwhals spearing Xebelian soldiers. We had storyboards and previs for this third act, but we needed to supplement them quite a bit.”

ILM developed crowd tools, built within SideFX Houdini, for the underwater battle and a plug-in for The Foundry’s Nuke for physically accurate color, depth and attenuation. Modeling and animation were done in Autodesk’s Maya.

“The final battle had amazing and gorgeous choreography,” says LoCascio. “The end result puts you in the center of a huge journey. The attention to detail is exceptional, and people who see the film more than once say they discover new things with each viewing.”

ILM also crafted the Karathen monster, a mythical leviathan and guardian of Atlan’s trident. “It was a fun creature — a massive movie monster that you dream about making,” White laughs. “In wide shots you see the whole Karathen, but in close ups Arthur was standing between its horns. So, the level of detail of the creature had to hold up depending where the camera was. We had to figure out the components of the skin and spent a lot of time on the face since the camera would be around the head a lot.”

Karathen had to have enough mass and move slowly enough to convince audiences of its enormous size. “We were constantly looking at scale within shots and sometimes put a small asset in the foreground so Atlantean stingers, for example, would look diminutive as they approached the giant creature,” White explains.

On the Warner Bros. lot, the production built “a DI-quality screening room from scratch in our post production offices,” says McIlwain. “It was an important tool in the process. I could call James and present full-resolution 2K EXR files using my DaVinci Resolve micro control panel. We had an Avid set up in the room too, so we could project through Resolve or flip over so the editors could project through Avid. It worked so well that I want to do the same thing on my next project.”

LoCascio notes that, “we created postvis shots for 100 percent of the film for the director’s cut screening. Proof, Halon, Day for Night, The Third Floor and Digitial Domain, as well as our own full-time, in-house department, worked tirelessly to deliver on an exceptionally-tight schedule. They all did an incredible job, and this process allowed a glimpse of what the final film would be.

“I feel blessed to have collaborated with such a great group of people,” LoCascio says. Although the film is packed with breathtaking VFX, she emphasizes that Aquaman is “very story-driven and emotionally touching with great characters. It offers something for everyone — I enjoy every second of it no matter how many times I see it.”

“The scope of Aquaman was huge and the visual design and complexity of shots was really exciting and a huge challenge,” says White. “James was just fantastic to work with. He cared so much about how the characters would look and feel heroic, and that’s paid off with the audience and how they’re responding to the movie.”