Animation Guild | We are 839 Digital Magazine
Issue link: https://digital.copcomm.com/i/1500204
F E AT U R E WAVES OF FURY Mermaids are often depicted as temptresses luring doomed sailors with their siren call, and this film taps into the mythological creature's dark side with the return of Nerissa and a plot twist that pits her against the krakens in a Pacific Rim- style, kaiju battle. Water interactions at this large scale are always challenging and expensive, but the filmmakers also envisioned the sequence to be balletic and elegant, adds DeMicco. "We wanted an element of surprise," adds Vincent. Using water as a dramatic statement, he envisioned Nerissa as drawing power from the ocean to create waves of turbulent water hair. "We're helping them conceptually," says Vincent, "but FX is such a powerful department, dealing with all the reality of that element and calibrating it to our needs. It looks a little bit like magic." The FX team faced three main challenges transforming Nerissa into a fighting titan with cascading hair. The character is a 300-foot mermaid half submerged in water that can travel at speeds of over 100 mph, says FX Supervisor Mark Newport of the first challenge to address the scale and the speed. Next, they had to create the appearance of water being sucked up into her hair that is also illuminated from an internal glow. The third challenge was the sheer number of shots, about 71, ranging from close-up headshots to full body fighting interactions. The solution was a multi-technique approach. The modeling department created a tubular structure for the overall shape of the hair, then Character FX ran a soft body simulation to give the hair weight and scale, and a more flowy feel. Next, Newport applied some procedural ridges to the hair to make it appear more like strands. They needed to essentially bundle strands of hair together, and in order to do so, Research and Development developed a new filleting tool that creates a smooth curve shape between two angles to look like "they're joining together rather than being a sharp disconnected angle," says Newport. Once the overall geometry of the hair was finalized, they turned their attention to the material qualities to make it react like water but also reflect the concept of glowing hair. The geometry mesh was transparent; while the internal volume had two fields, a density field that essentially absorbed and scattered the light to make it appear to glow brighter at the scalp and an incandescent field that emitted light. Newport generated a curve through the center of the hair bundles that was used like a suction force in the fluid simulation in order to make it appear as if the energy of the ocean was being sucked into their hair. A churning force was applied to generate more white-water foam around the base of the hair to integrate more seamlessly with the ocean. Other volumetric paths included two different kinds of foam and two different types of spray. The spray needed to both tear away from the body and travel with the character. As the titan mermaid battles, she makes some fast, sweeping motions. In the real world, the spray would fall almost like a curtain of water, but in the film it had to also travel with her. Newport created a local spray that would essentially stay with the character as she moved, while the world spray could tear away from her body. The spray simulation had a corresponding mist element "to basically represent fine water particles that kind of vaporized almost like a waterfall type effect. So, you've got local spray and then you've got a volumetric mist," says Newport. The tools that Newport set up would get the FX artist working on the shot about 75 to 80 percent there, but then controls allowed for customization. For example, at Nerissa's speed and scale in the fighting sequences "she just ends up becoming a big ball of spray," says Newport. The controls made it easier for the FX team to clear out the face so it wouldn't be covered by spray and water that might be accurate to real-world physics but not necessarily aesthetically pleasing. For lighting, the glowing water hair became a key source of light, not only illuminating Nerissa's skin but lighting up the surrounding area, much like Ruby does when she's in the kraken's activated form. The light is brightest at the scalp, illuminating the churning white spray; it then turns into a blue cyan color as it gets closer to the ocean and connects with the water in a continuous stream, says Wu. "Water is interesting because there is that self-illuminating property of the material," she adds. Normally, lighting would create the glow-like appearance, but in this case FX set up the material properties with an internal glow to create the path of illumination. The FX team provided lighting with controls to allow the artists to determine how far up or down the brightness would travel through the hair. This modular approach throughout the film turned kraken-sized challenges into manageable solutions that embodied the vision of the filmmakers. Adds DeMicco: "I'm sure [the FX artists] were worried, but I wasn't worried because I think they're geniuses and they can do anything. It's like wizardry." 40 KEYFRAME this page: Original concept art of Nerissa by Pierre-Olivier Vincent; opposite (top): Storyboard of Nerissa by Story Artist Darren Webb. (bottom, from left): Modeled hair; Local and World spray; Final render of Nerissa.