Visual effects
Two thousand three hundred visual effects shots (VFX) appear in the movie, completed by Industrial Light & Magic (ILM), Base FX, Rodeo FX, Scanline VFX, DNEG, Luma Pictures, Weta Digital, Moving Picture Company (MPC), Method Studios, Digital Domain and Clear Angle Studios. The visual effects for the director's cut were created at the same time as the theatrical cut.
ILM was the main VFX company and worked on creating Atlantis and all its CGI animals, the Karathen, and the final battle. Jeff White served as the VFX supervisor for ILM. For the underwater sequences, the actors were shot dry-for-wet on special tuning fork rigs designed by the VFX team, and later the bodies of the actors were replaced with digital doubles in post-production. For creating Atlantis, the team relied on the designs provided by the art department. ILM's environment team created over 200 buildings, including the signature jellyfish buildings, and laid over 7,000 buildings in districts covering almost 600 square miles for the action to travel through. The underwater ships were modeled after organic creatures and designed to move that way. For the entrance to the Atlantis sequence, the team built over 150,000 ships to fill the traffic lanes leading into Atlantis. All the animals, including the Karathen, were built by ILM and animated using keyframe animation.
Approximately 700 shots in the film required high-detail hair simulations. ILM had to significantly improve its hair simulation software due to the unique aspects of hair flowing underwater. Normally, hair simulations use guide strands to define or influence the movement of groups of hair strands. This did not provide a satisfying look, so ultimately, ILM simulated strands individually, which required heavy computations. Additionally, Wan wanted to be able to direct the hair when the physically accurate simulation resulted in undesirable results. ILM delivered 670 shots.
Weta Digital handled most of the digital de-aging involved in the film. They digitally de-aged Kidman and Morrison for flashback sequences. DNEG digitally de-aged Dafoe for the scene where his character Nuidis Vulko trains the young Arthur.
Jay Barton served as the VFX supervisor for Digital Domain. They worked on creating the Dead King's Island environment. For the sequence, the actors were shot in a pool of water against blue screen backgrounds with Digital Domain adding CGI extensions, waterfalls, mountains, and dinosaurs in post-production. Most of the waterfalls in the scene were created using Houdini, while some were created using practical elements of things such as pouring salt and glass beads. They also built an extensive library of shot VFX elements. The dinosaurs were animated using keyframe animation. Digital Domain delivered 19–20 shots.
David Nelson and Craig Wentworth served as VFX supervisors for Method Studios. Method handled the Sicily fight sequence between Arthur, Mera, and Black Manta; Arthur's encounter with the Karathen in the Well of the Souls; and his acquisition of Atlan's trident. For the Sicily fight sequence, the team built the main square of the Italian village and terracotta-tiled roof set pieces that were backed with a blue screen. A completely CGI village was also created based on scans and documentation of the real village. For the Well of the Souls sequence, Momoa was filmed dry-for-wet and captured on set in rigs that simulated underwater movements, but they ultimately felt restrictive, so artists replaced the majority of his performance with a digital body double and added the CGI environment, Karathen and Arthur's free-flowing locks. A specially designed 700fps shot was used in the scene where the camera travels through Arthur's eyes.
Rodeo FX worked on two key sequences, with Sebastien Moreau as VFX Supervisor. For the aquarium that young Arthur visits near the beginning, Rodeo FX used simulations as well as algorithms for the fish behavior. They created hard and soft corals by developing a colonization growth system, along with procedural stem and tentacle generation tools. They also created the environments for the Atlantis ruins below the desert. Artists used a Lego-type approach to layer the environment with a large amount of sand, dust, and rocks, all of which would realistically give way to the characters' interactions. From there, they sculpted ruined buildings, bridges, towers, statues, and temples, which were textured and shaded to add depth to the ruined city.
Scanline VFX delivered 450 shots. Bryan Hirota served as VFX supervisor. The main sequences produced by them were the lighthouse and its surrounding environment; the "Aquaman" title card that follows the Boston aquarium; Aquaman pushing the submarine to the surface and rescuing the sailors inside; Orm's tidal wave that sweeps away Arthur and Tom, including the rescue and aftermath; Black Manta being paid by Orm for the submarine's delivery; and Arthur and Mera's visit to the Kingdom of the Trench. For the title card, the team relied on Rodeo's work on the aquarium sequence and simulated up to 60,000 fish. The tidal wave sequence was realized with a large-scale simulated wave, which was integrated with a combination of day-for-night footage, blue screenshots for the actors in truck interiors, a truck on a rotisserie rig, an interior cabin in a water tank, and VFX simulations for debris. For creating the lighthouse, a full-size house with the base of the lighthouse tower was constructed by the VFX team. Additional house and dock sets were built on sound stages. A digital build-out was done to complete the lighthouse tower and extend the dock fully out into the sea. For the sequence where the camera pushes into a toy snow globe with a tiny lighthouse inside, a CGI transition was created from the lighthouse's living room set to a fully CGI winter coastline. For creating the Trench creatures, motion capture was done on set by stunt performers.