Embedded with production at Warner Bros. Leavesden Studios and from The Third Floor’s dedicated offices in London’s Soho, The Third Floor worked closely with director Chris McQuarrie, producers, cinematographers, unit directors, stunt and special effects coordinators and the visual effects team to help map out sequences and develop plans for how to shoot and execute them. The previs was also used to communicate the vision as well as the impact and viability of major action moments, which included the opening in-camera stunt by Tom Cruise on the A400 military plane, the high-speed motorbike chase, a virtuoso spy chase set at the Vienna Opera House, and a suspenseful underwater scene involving extremely long takes.
For a look at how the actual visual effects were accomplished, see “Staying Real” in the July/August 2013 issue of CGW.
Given its ambition and scale, the sequence in the water-filled, torus-shaped chamber involved precise coordination and collaboration from every department. “From the underwater DP and camera teams to stunts, special effects and visual effects, the scene needed to be prepped, rehearsed and achieved extremely carefully,” explains Vincent Aupetit, previs supervisor at The Third Floor London, whose team worked on the feature for about eight months. “This is where previs and the techvis derived from the previs were absolutely crucial.
Basing from models provided by production design, Aupetit’s previs artists constructed the whole torus environment to scale with high attention to detail. The sequence was originally prevised as a "classic" cinematic sequence of around 80 shots. After director McQuarrie decided to experiment with a bolder approach using long “oner” camera takes, the team re-worked the previs with a bare minimum of cuts to convey more of the feeling of claustrophobia and suffocation experienced by Cruise’s Ethan Hunt character.
“The key motto for the director, and for our team, was making the scene believable,” Aupetit recalls. “Using the experience I gained working on Alfonso Cuaron's Gravity, and thanks to the talent and dedication of our previs animation team, a sequence was developed that felt fluid and never contrived, where the camera follows Tom in a manner that is natural and tangible, but has all of the cinematic quality in framing and shot composition that is needed to portray such an intense and extraordinary situation.”
As the sequence was taking shape and finding its cinematic rhythm, the previs team collaborated to help explore the ways in which it would be achieved. Artists first deconstructed the long, continuous takes that would appear seamless in the final movie into smaller ones more adapted to live-action shooting. The different junctions — where the camera would subtly drift away from the action or near-invisible camera wipes would happen — were defined with the input of all other departments and the director.
In the sequence, Hunt is sent circling around the underwater chamber at high speeds. To achieve the effect of the current, the actor needed to be strapped to a rig that would move him around and allow him to tumble underwater, but the camera then needed to move at great pace towards and away from him to accentuate the illusion of movement through space.
“To help with this effect, we reverse-engineered our previs, taking into account the precise dimensions of the tank and soundstage, to closely recreate in CG the conditions of the actual shoot,” Aupetit explains. “We integrated the rigs created by the special effects team and had ongoing interactions with the underwater camera crew to provide them with as much technical data as we could — position, angle and speed of the different elements through time, dimensions, position and speed of the camera, depending on the lens.”
The special effects team used the previs to create and refine the rig that would carry Cruise underwater and define the placement of the various turbines that would create underwater current. It was also key for the divers and camera crew to work out the length of each take and how long the actor would need to hold his breath. In a particularly complex beat of action, two actors interact during a very long underwater take, making coordination of rigs, camera movements and choreography even more complex.
As rehearsals and shooting tests progressed, previs and techvis scenes — including The Third Floor’s cameras, props and characters animations and textures, the environment model, and techvis setup for each shot — were provided to Double Negative, who could then use the production-approved assets to kick-start final visual effects work.
During the shoot, the previs was super-imposed on the master monitor, allowing live-action elements to be shot with remarkable prevision to the previs plan.
“From early concept to the final result, this sequence represents a tremendous team effort,” concludes Aupetit. “Carried forward by the vision of director Christopher McQuarrie, the result is some magnificent work and a breath-taking piece of action cinematography, with creative and technical talents coming together to create something that had truly never been attempted before.”