Denis Villeneuve's latest sci-fi film, based on a Nebula Award-winning short story by Ted Chiang, and praised as one of the smartest films of the year, tells the story of a linguist and a mathematician that are tasked with the mission of figuring out the intentions of 12 alien ships that have landed on Earth. For Arrival, shot entirely in Quebec, VFX Supervisor Louis Morin assembled a stellar group of Montreal-based VFX studios: Hybride, Oblique FX, Framestore, Rodeo FX and Raynault. We spoke to them to gather details on how Arnold helped deliver such high-quality imagery.
The main VFX vendor on the show was Hybride, which worked on 245 shots, including all the alien shots, the creatures, the mist they live in, and the logogram effects when they communicate. The Aliens were rigged in Fabric Engine, animated in Softimage and Maya (depending on the animator) and rendered using Arnold in Softimage.
The mist was simulated in Houdini, and required a special compositing workflow. Four view points were rendered, long sequences at high resolution beauty shots. The renders were very long, which is why only four of them were rendered, to use as reprojections in all shots. The team basically rendered quick cheap deep images in Mantra for each shot and used Nuke to select the best pre-rendered Arnold beauty and re-project them on the plates using the Mantra deep images and a complex Nuke set-up. This mix of Arnold, Mantra and some creative Nuke hacking gave Hybride the best look and the most flexibility in comp.
Hybride also did the hair effects of the main character when she goes into the mist and her hair starts flowing. The R&D department developed a hair simulation tool using Fabric Engine which they ran on Maya with xGen. The hair was then sent to Arnold in Softimage for final rendering. Read more about Hybride's work in CG Society.
Led by VFX supervisor Alexandre Lafortune, Oblique FX did around 130 CG shots for Arrival. This work included both complex full-CG shots as well as set extensions with CG spaceships, helicopters, tanks, boats, cars, soldiers, trees, grass, traffic and crowds. For the best part of the last 5 years, Oblique has relied heavily on Arnold as their main rendering solution, so it's no surprise that every shot used Arnold. Thanks to Arnold's simplicity, and despite the number of assets, never more than two artists were needed for the lookdev and lighting of all the assets and all the shots. Oblique used a workflow based on per-light AOVs, which allowed a great deal of control in compositing without breaking the physical correctness of the shaders.
The Depth of Field was very shallow on this film. Most shots were captured at f/1.9 by the cinematographer, resulting in a very strong blur in the background. DOF information was directly extracted from the footage metadata and wired into the Focus Distance parameter in the SItoA plugin, so that both animated and still DOF could be raytraced directly in-camera, avoiding extra comp and saving precious setup time. For cleaner results, the DOF shots required between 20 and 50 AA samples, with the highest settings used when small, very far away objects were out of focus. But these were exterior shots, lit by only a skydome and a directional light, so they were never too long to render; most shots were under 1.5 hours on 16-core machines. Oblique didn't have any other project that needed rendering at the same time and therefore had the entire farm available for this project for once, so they pushed the sampling up even though it wasn't strictly necessary, as it was not much more effort and the results were good.
As much as the team would like to say how much they worked on the nice flowing clouds in the shot where we first see the alien ship, amazingly, they were in the live action plate.
Framestore's Montreal facility did 10 shots of the complex spaceship dematerialisation effect, including a 30-second shot of the Montana ship. This was inspired by the vapour condensation effect sometimes seen surrounding landing or high-speed aircraft, and was done with a combination of Maya fluid simulations and particles converted to volumes at render time to preserve the intricate look of the wispy vapour filaments. Subtle "Fata Morgana" refractive effects were added on top of the condensation patterns.
You can read more about Framestore's work in an interview with VFX Supervisor Ivan Moran here.
Rodeo FX had previously worked with director Denis Villeneuve on Enemy and Incendies, and with VFX supervisor Louis Morin on Source Code. For Arrival, Rodeo FX completed 60 VFX shots, creating an anti-gravity sequence, multiple aircraft, and digi-doubles of actors. Led by VFX supervisor Arnaud Brisebois, the Rodeo FX team worked on CG aircraft exteriors and interiors, including fighter jets in flight, a helicopter landing and taking off, and a spaceship interior.
The most technically challenging sequence has Banks and Donnelly entering the alien ship for the first time, through a tunnel in which gravity disappears, allowing them to walk vertically up the shaft. Rodeo FX created full digital doubles of the actors, including the challenging fabric texture of their orange hazmat suits. The hazmat suits were created by starting from scans from a live suit; the data was then imported into ZBrush to generate the displacements. Having retrieved all the wrinkles information from the scan data, everything was then brought into Maya and six different versions of the suit were created to fit the different actors' measurement. Rendering was done in Arnold through Solid Angle's MtoA plugin.
See Rodeo's VFX breakdown here.