Meticulous Previs and Seamless Execution at 10 VFX Studios Get Ridley Scott's Vision on Screen in 3D

There are no outright spoilers in this story about the visual effects work in director Ridley Scott’s Prometheus, although there are hints — even one about the scene that Glenn Kenny, chief film critic for MSN Movies, describes this way: “It is insane, one of the most perfectly perverse and beautifully executed pieces of shock cinema I've seen in years, an absolutely breathtaking and staggering and exhilarating set piece that kind of reminds you of every sick thing that cinema is good for.”

The year is 2093 and the crew of the spaceship Prometheus is on a quest for the origin of mankind after discovering what might be a map. After two years onboard in deep sleep while a robot named David (Michael Fassbender) tends the ship, the explorers wake up on an alien planet that supposedly holds the secret — a secret not without peril. And a gooey paranoia sets in. “The paranoia becomes palpable, and a lot of its impact comes from how dramatic and dazzlingly seamless the special effects are,” writes Christy Lemire of the Associated Press.

The comments from Kenny and Lemire might invoke images of Alien, director Ridley Scott’s first sci-fi horror film, released in 1979, and his last until this year’s highly anticipated Prometheus. And, it’s tempting to think of Prometheus as a kind of prequel to Alien or perhaps a side trip, but as critic Bill Goodykoontz of the Arizona Republic puts it: “You're more likely to enjoy Prometheus  if you go in thinking less about Alien and more about Scott, with his emphasis on images, tone and atmosphere.” 

The realization of that emphasis, and the drama and seamlessness of the effects, often rested on the shoulders of visual effects crews. Richard Stammers, visual effects supervisor, took leave from his work at the Moving Picture Company (MPC) to lead the group of 10 vendors, including MPC, that created the film’s 1400 visual effects shots. But the vision was Scott’s. “Most of our previs started with sketches and storyboards that Ridley [Scott] drew,” Stammers says. “He obviously has a fantastic vision for images.”

Extensive Previs

Scott worked with Halon Entertainment in LA for pre-production, and Halon artists previs’d an opening sequence. In addition, a previs team from MPC worked with Scott and Stammers on an action sequence, a crash of the Prometheus and an alien ship, and the Prometheus landing sequence.

“Ridley [Scott] got excited about previs, I think, for the first time,” Stammers says, describing the process of previsualizing the landing site on the alien planet.  “Ridley had a definite idea of what he wanted: A desolate desert with no sense of life or vegetation, and with storms, atmospherics, lightning. The concept art I saw from visual-effects art director Steve Messing was along those lines. When I realized we had to create the landscape in CG, we set up an interactive Maya scene so we could build and adjust the landscapes live with Ridley.”

To create the hero landing site, the team at MPC knew that Scott’s reference was Wadi Rum, a desert location in Jordan with tall, sheer, heavily eroded walls. “It was used in Lawrence of Arabia,” Stammers says. “There’s actually a lot of reference to Lawrence of Arabia in the film. You see David [the robot] watching the film when everyone else is in hyper sleep. Ridley loved the idea that the place the crew was visiting was a huge valley and they’d be dwarfed within.”

So, MPC utilized digital elevation files and Google Earth to generate simple geometry of the Wadi Rum valley. “Then we added the Prometheus ship and other elements based on a series of sketches Ridley did, and adjusted it until we got the look and scale Ridley liked,” Stammers says. “We lined up the cameras based on his sketches. When we worked out what we needed, we went to Jordon and shot the location from a helicopter. We did match moves of those shots to track and build point cloud data that we could mesh into the mountain shapes. And when we went to Iceland, we chose a location that would blend into Wadi Rum. The final shots have the ground of Iceland and the valley walls of Jordan.”

It was up to the crew at MPC to blend the flat grey Icelandic landscape with the red walls of Wadi Rum, adding snow-capped mountains and turbulent skies.

“We gave Ridley printouts of everything,” Stammers says. “He storyboarded on top with descriptions, and we’d redesign shots. He draws pretty much everything, and he sketches quickly. Every day, he’d come to the set with drawings of what he wanted. When we were discussing a VFX shot, he’d look at his monitor, draw what was on the screen, and then draw in the visual-effects element we needed to add. I could pass that on to our visual effects vendors, saying, ‘Here’s your brief.’ It was a great starting point.”

That interaction carried on throughout post-production as well. “It was totally amazing,” Stammers says. “And, a great way to work. We could print out frames from the Avid in sequences that his editor put together. He’d sketch on the top. We’d scan them and send them to the visual effects vendors. We’d show sequences to him, he’d draw, and we’d adjust.”

Shooting Stereo

Location work took the production to Iceland, Jordan, and Scotland, but most of the 90-day shoot happened at Pinewood Studios in London with cinematographer Dariusz Wolski shooting in native stereo with 5K-resolution Red Epic cameras. “We shot with the cameras parallel rather than converged,” Stammers says. “The main reason was to alleviate work and pain in the match-move and compositing processes in the visual-effects pipeline. By removing one of the moving, movable parts of the camera rig, namely the convergence, we could reduce the time spent on the stereo match-move. With the cameras always pointed to infinity, we didn’t have to track cameras with animated convergences.”

But that meant the images had to include extra room for convergence to happen in post-production. “If you looked at the output of a camera you would see the full frame and within that, a framing guide that was 93.5 percent [of the full image], which we could use to reposition the images,” Stammers says.

“Without a convergence pass, the stereo in raw form is uncomfortable,” he adds. “Generally in 3D, you want to converge on a subject so the audiences’ eyes are trained there.So in post we took the left and right images, aligned them, and animated the appearance of convergence by moving the images together or apart. If you watch a 3D film without glasses, the area that looks sharpest with no doubling is the area of convergence.”

While shooting, the onset crew did temporary alignments to check. They gave those temporary alignments to the editorial teams so they could watch the film comfortably and have a rough guide for edits. “Company 3 conformed the final edit in DI,” Stammers says. “Sean Santiago, our post stereographer, set the final convergence with them so everything flowed comfortably.”

“For us, the main issue with [stereo] 3D,” he adds, “is that there are so many digital formats that are always changing, and Red is always updating software, firmware, the camera, the chips. Every time you work on a show with Red cameras, you have to re-evaluate where you are. So I did a lot of investigation before setting up a basic color pipeline that worked specifically with the resolution of the Red Epic. It was the first time I’d worked with source 5K material.”

Calibrating Color

In addition to the additional work necessitated by the dual images and high resolution – double the tracking, double the match-moves, double everything, Stammers needed to tailor the color pipeline to fit Scott and Wolski’s working method. “We worked with what Red recommended,” Stammers says, “and then made some slight adjustments based on what Dariusz [Wolski], the DP, wanted to see and what he wanted to view on set on his color-calibrated monitor. We made sure we set up the color pipeline so we could understand what he was doing, and then sent it to all the VFX vendors.”

Those vendors all worked on ungraded shots that had a full dynamic range. If the DP had applied a grade, the vendors would re-apply that grade before delivering. “The vendors want the cleanest, most unaltered image with the greatest color range without artifacts,” Stammers says. “Color choices made on the day of shooting are rarely adhered to when the scenes are cut together, so we needed to maintain the flexibility to change the color grade right through to the final DI process.”

Who Did What?

Stammers gave most of the visual effects shots to MPC, Weta Digital, and Fuel, with Hammerhead, Rising Sun Pictures, Lola, Luma Pictures, Prologue, and two one-man teams from Pixel Pirates and Invisible Effects working in-house on comps and cleanups.

MPC, led by visual effects supervisor Charley Henley, was the lead vendor with around 450 shots. “Ridley [Scott] felt they could do great environment work, as they had done for his Robin Hood and Kingdom of Heaven,Stammers says. “They did everything on the planet surface that the crew of Prometheus visits. So, rather than sharing work, we had them create the human and alien space ships, and therefore they also did the space travel shots and shots of the planet's atmosphere with cloud formations and electrical storms. Any time you see exterior planetary landscapes, that’s all MPC’s environment work. They also created the epic crash sequence and the alien ship rolling toward Vickers and Shaw, as well as some small creature sequences and prosthetic enhancements when the crew get infected in the film.”

Weta Digital handled the majority of the creature work, though, creating around 250 shots, supervised on set by Everett Burrell and at Weta by Martin Hill. “They created the hero alien known as the Engineer,” Stammers says. “That was a digital representation of the actor they had on set, suited in fantastic prosthetics.” 

Weta also created an opening sequence in which an Engineer sacrifices himself. “We see inside his body, his DNA being pulled apart,” Stammers says. “It’s a beautiful moment. They also created some disgusting, gory moments that will be well remembered for years to come. There’s an automated surgery that’s realized with CG robotic arms, and a great combination of prosthetic and CG body parts – it’s really gross."

Fuel VFX had the next-largest number of shots, supervised by Paul Butterworth. “They created fantastically original designs for the aliens’ holographic effects — pixilated, ghost-like holograms of fleeing figures that play beautifully in 3D,” Stammers says. “Ridley wanted the holograms to look decayed, like they were thousands of years old.”

Hammerhead also created a holographic representation at the beginning of the film to present a message from Peter Weyland, but one of their trickiest sequences was helping one of the characters lose his head. “For the most part, that’s an elaborate split screen using a prosthetic head, but they had to do body removal and track in [the actor's] face onto the prosthetic head in stereo,” Stammers says. “They did a great job of seamlessly blending it.”

Rising Sun dramatically augmented close ups of a partially practical sandstorm that had been established in wide, full CG shots created by MPC, and picked up several monitor comps. Lola augmented the faces of the Engineer characters. “Ridley wanted to shoot as much practically as possible,” Stammers says. “So we bulked out the 7-foot-1 actor's head and body with the prosthetics and makeup to sell him as an 8-foot giant. The slight drawback was that in bulking out his face, his features became disproportionately smaller. So, Lola rebalanced his features to make him look more godlike, more perfect.”

In addition, Luma Pictures created a floating holographic screen, and Prologue put a welcome message into a holographic cube, created a dream sequence, and made the opening titles.

“We definitely had our challenges,” Stammers says of the film. “And the pressure involved … If I had stopped to think that I was working on one of the most highly anticipated sci-fi films in a long time, I would have gone crazy. But everyone jumped to the challenge and did a fantastic job.”

As for working with Ridley Scott? “I learned a huge amount, but if I had to put my finger on one thing, it’s that nothing is set in stone. The thing you think is most precious could go at any point. You have to be prepared to lose your favorite shot for the greatest good.”

Images © 2012 Twentieth Century Fox Film Corporation. All rights reserved.