From Script to Previs and, Sometimes, Vice Versa

By IAN FAILES

A previs’d moment in Logan’s limousine chase scene by HALON.

THE PLANT GATE BLOCKED BY THE ARMADA OF VEHICLES, Logan drives straight at the chainlink fence – and we prepare for a classic action movie fence smash.

LOGAN

Hold on!

BUT THE LIMO HITS THE FENCE, BENDS THE SUPPORTS AND GRINDS TO A PATHETIC HALT, TANGLED IN MESH. As it would in real life.

That’s an excerpt from the screenplay for Logan (story by James Mangold, screenplay by Scott Frank, James Mangold, and Michael Green). It’s a moment in the story that was fine-tuned with the help of previs. Getting the director’s vision on screen is always the goal for the actors and crew on a feature film, but it’s often the previsualization, or previs, team who gets a crack at it first.

Previs artists tend to take a script or an outline and turn it into story beats, preview imagery and breakdowns for how shots can be filmed. Occasionally, their work also informs scripted moments or generates further ideas for the director during filming (and often extends to postvis after principal photography).

Either way, the previs department has become crucial in the age of complicated visual effects and action filmmaking. VFX Voice asked three previs studios – HALON Entertainment, The Third Floor and Proof – how their artists worked at the earliest stages of production to flesh out story ideas and key moments for the films Logan, Ant-Man and the Wasp and A Wrinkle in Time.

The limo reverses after attempting to burst through a fence, only to have part of the fence stick to the vehicle. This was a moment ‘found’ through the previs process.

A FENCE STORY

In Logan, director James Mangold depicted the X-Men character Wolverine (played by Hugh Jackman) with much-applauded grittiness. Helping him on that character journey from early on was HALON Entertainment. One sequence in particular summed up the previs studio’s work – Logan, driving a limousine, escapes a group of adversaries with fellow mutants Charles Xavier (Patrick Stewart) and Laura (Dafne Keen). A key moment in the final film has the limo get stuck on a piece of fencing but continues to drive, something that actually came about as the previs was explored.

“In the beginning of the previs work, when interpreting the script pages, Jim asked me to showcase how un-heroic the life of Logan was,” recalls HALON Previsualization Supervisor Clint Reagan. “The script I started with had the limo driving around in circles avoiding capture, but upon seeing it play out it was not believable for Jim. He wanted something more realistic and difficult for Logan to manage. Nothing goes right for him, everything is hard and not fair. Right about this time we had lost the original location for the shoot that we had previs’d the entire sequence to. Now a new location was being sought.”

HALON also delivered postvis for the sequence where the limo is forced to slow down, and gets wrapped up in the metal and barbed wire.

So Reagan oversaw previs that could explore more options for the director, such as arranging the car so that Logan could just back out of the compound he was trapped in. This was deemed too ‘slick’ and convenient by Mangold. “In giving notes,” says Reagan, “Jim ranted about the Hollywood trope that so many conflict resolutions aren’t real enough. He said, ‘Like, when cars burst out of fences on cue as if they were not there. If you or I drove out of a fence right now outside you’d probably get caught up in it.’ Everyone listening laughed as he described the list of absurdities we all see in action movies. I liked how plainly this idea rebuffed  convention, and I decided to previs it exactly as he had mocked. Jim was intrigued by the first pass and a bit surprised we took him so literally, but in the end it did exactly what we hoped it would.”

Meanwhile, the production searched for a suitable location, with the fence-crash shot now in the mind of the director. Even the script was updated to include it. “The stunt evolved in previs as we designed outward from the fence beat to account for how the rest of the scene would be affected,” describes Reagan. “At this point we didn’t have a location so we adjusted the old location by moving buildings to allow for the creative needs I had in previs.”

Eventually a new location was found, and HALON adjusted its previs shots to a matching digital version of the location. Says Reagan: “My team of animators and I went through the entire sequence again. We solved camera blocking problems, adjusted animation and added new beats to connect the scenes together. I’m told that irony reared its ugly head on the day of the shoot, and the fence fell right over. So they had to cable the car to stop it from blasting right through!”

WHEN PREVIS BECOMES TECHVIS

Sometimes previs is used just for working out story beats, but very often it is taken one step further, to ‘techvis.’ It’s at this stage that set diagrams, camera positions and rigging locations, for example, can become part of the previs delivery to see if the planned shots are actually achievable. Proof delivered a combination of previs and postvis in this way for Ava DuVernay’s A Wrinkle in Time, including for a scene of the green flying creature, Mrs. Whatsit (Reese Witherspoon), taking a group of children into the skies.

“The flying sequence was the first thing we worked on,” says Proof Previs Supervisor Christopher Batty. “It started with some initial discussions with Ava along with a few keyframes from storyboard artist John Fox. We did a short concept animation that was presented to the studio early on. It explored how the movement of the kids would look over the top of ‘Creature’ Whatsit. It was very important for Ava to have the kids do something different than the typical riding or sitting on top of the creature. She wanted to see the kids truly flying and for the characters to experience that freedom and exhilaration.

A still from Proof’s previs for the Mrs. Whatsit flight sequence in A Wrinkle in Time.

Proof used a toon shader effect on the final previs to give a sense of ‘work in progress.’

Techvis for the Mrs. Whatsit shots involved coordinating how the flying could be achieved with Robomoco’s robot arms.

“Once we had the basic concept, we moved onto exploring how the kids moved across the creature’s back. We explored how they would lift off and how far they moved along the back and from each other. We looked at footage of sky divers for reference and, specifically, indoor skydiving. Once up in the air we developed this action of her fully spreading out her wings so that the kids had more room to fly around on her back. It solved a few logistical as well as aesthetic issues.”

The major step forward on this sequence for Proof was a further collaboration with motion-control camera-system makers Robomoco, which would be operating their robotic arms on set and providing the illusion of the children being mid-air. Proof came in to ensure that the operation of the robotic arms could achieve the planned shots.

“We received accurate models of Robomoco’s robotic arms and worked on scripts together in order for our systems to communicate with each other,” outlines Batty. “Once we had a previs of the flying actions that Ava had approved, we got to work on translating those animations into movements that the robotic arms could achieve. We had special scripts that basically translated our animated robotic arms into a file that would drive the machines. So after a few tests it was relatively easy to go back and forth from our Maya scenes into the Robomoco arms.”

Proof provided previs with a unique toon shader look, something requested by the director and that signaled previs was part of the continual evolution of shot and story design. “She liked that it had a ‘work in progress’ visual connotation.” says Batty. “Since the beginning of the process was a creative exploration, we didn’t  want anything to look too ‘finished’ or locked in. The toon shader helped to communicate that we were still open to changes up until the shoot. It can also be quicker to set up characters and other previs assets. With the toon shader’s more abstract, stylized look, we can worry less about the materials and lighting and concentrate more on action and composition.”

A scene from The Third Floor’s previs for the car chase sequence in Ant-Man and the Wasp.

COLLABORATION IS KEY

Marvel films are, of course, big users of previs, often for brainstorming, and with the strong notion that things will change along the way – or even be abandoned as the story and edit continue to develop. On Peyton Reed’s Ant-Man and the Wasp, for example, The Third Floor contributed previs while the script was still being worked on and as different crew members for the film came on board.

In terms of day-to-day collaboration, previs studios tend to work with many department heads. For Ant-Man and the Wasp, The Third Floor Visualization Supervisor Jim Baker says they regularly talked to the director [Reed], producer Stephen Broussard, Visual Effects Supervisor Stephane Ceretti, Stunt Coordinator George Cottle and second-unit director Jeff Habberstad. The film’s San Francisco miniature car chase involved contact with just about all of these crew members as the sequence itself evolved.

Ant-Man’s ‘Giant Man’ interacts with a ferry in this previs shot. The Third Floor would also deliver postvis for the scene once the live-action ferry scene was filmed.

Wasp looks on from hiding in her miniature form in this previs shot from the film.

“The scene was initially a much smaller sequence and earlier in the script than appears in the final film,” notes Baker. “Early on, Peyton and Stephen had us trying out different scenarios with the chase. They would review these and pick the ones they liked, which ended up informing the script. We would meet with Peyton two or three times a week. In a typical week, we would have a kickoff on Monday using, say, a beat sheet. We would then get to work immediately blocking in previs. As part of the visualization, we also cut together shots from other movies to give a flavor of what the sequence could be like. The car chase grew so much that it moved to the third act and became a central structure for the climax.”

“The nature of previs,” adds Baker, “is such that we may visualize even more than is used in the film and, while some of the ideas may end up on the cutting room floor, other aspects that have been previs’d can end up informing the feel of the film or may inspire something for a completely different part of it than originally intended. On some projects, there are storyboards throughout, but on this one we went directly from the script and from pitches for our action sequences. Peyton was extremely enthusiastic about exploration and was always welcoming to ideas.”

Baker identifies the film’s kitchen fight as a good example of this exploration. “Peyton kicked it off to our team, the visuals effects team and the stunt team. As we all brainstormed ideas, it led to concepts like Wasp running along the knife and the goons smashing all of the vegetables while trying to get her to come out. These types of creative outcomes happen when the whole team is open to collaboration, and it starts at the top with the leadership of the director and producer.”