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Problem Solving With Previs

Previs continues to evolve as a 3D problem-solving tool, and Thomas J. McLean discovers some of the latest examples.

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Nvizage's work is seen in the teaser for 10,000 B.C.. The U.K. studio finds that previs helps to quickly work out mechanical issues for the shoot. © Warner Bros. 

Making movies has always been a complicated endeavor, but as budgets soar, audiences expect greater spectacles and digital tools exponentially increase the number of decisions to be made, it's harder than ever to keep a handle on the process.

That at least in part explains the growing use of previs and postvis techniques in feature films, commercials and videogame cinematics.

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The use of these techniques has grown slowly throughout the past 10 to 15 years, evolving from animated storyboards to an essential quality control process that maximizes creative expression and optimizes the entire production process to save time, money and effort.

"In the early days, it really was very focused. 'Hey, here's the shot. How big a bluescreen do we need?" says Ron Frankel, who is both President of previs house Proof and a previs supervisor. "We couldn't take on entire sequences. It was really about almost creative engineering."

Now, the process has evolved to a complete planning and problem-solving solution that works out every detail of a shot in advance to ensure it works creatively and from a production standpoint.

Generally, it involves quickly creating rough animations of each shot in the computer and using it to determine everything from camera lenses, positions and movement to how and where to set up lighting, rigging, sets and even how much time a shot should take and how long a crew has to work with optimum natural light.

The generation of such data is, however, the second stage of a process that is primarily focused on nailing down the creative elements of each shot.

"For us it's really about honing in on that creative vision and in as few moves as possible getting something in front of the director and prod designer that hits the creative goals and really starts to breakdown what are the technical limits they might encounter, whether it's how big they're building their set, to even limits of daytime," explains Frankel.

Frankel says previs work isn't pretty, but it's more important to be quick and accurate. "We try to work incredibly quickly," he says. "We always aspire to start showing work within the first week."

Chris Edwards of The Third Floor says it's important to hit a project hard and fast. Above is a comparison of images from a Jeep commercial from studio. Courtesy of Brand New School, BBDO, and Jeep. 

Chris Edwards of The Third Floor says it's important to hit a project hard and fast. Above is a comparison of images from a Jeep commercial from studio. Courtesy of Brand New School, BBDO, and Jeep. 

Nic Hatch of U.K. previs house Nvizage says previs helped quickly work out mechanical issues for the shoot of next summer's Batman Begins sequel The Dark Knight. "Solving mechanics in a workshop can take a long time," he says. "It's a lot quicker for us to do something in Maya and we can come up with a concept really quickly and show the director."

Chris Edwards, CEO of The Third Floor, says it's important to hit a project hard and fast. Third Floor uses asset builders early in the project, though that has increasingly come to focus only on a film's custom elements because the firm has developed an extensive library of assets for objects and camera rigs that can be reused.

While some of the previs assets can be exported for vfx houses to use, the process is more concerned with the creative elements. "We're kind of production indifferent," says Frankel, citing Live Free or Die Hard, on which he says they prevised a complex chase sequence without regard to whether CG or miniatures would be used to create the final effect.

The previs also can set parameters for what's needed in a location. Josh Wassung, a senior artist and co-Founder of Third Floor, says previs helped define the location for the final battle in Andrew Adamson's upcoming The Chronicles of Narnia: Prince Caspian (from Walt Disney Pictures in association with Walden Media). "We had some possible locations in mind and we tried them out," Wassung adds. "He wanted larger."

Frankel says previs was essential to planning a set piece in Constantine. © 2005 Warner Bros. Ent. Inc. All rights reserved. Courtesy of Proof.

Frankel says previs was essential to planning a set piece in Constantine. © 2005 Warner Bros. Ent. Inc. All rights reserved. Courtesy of Proof.

Wassung then worked out in previs a location large enough to satisfy Adamson's direction and then a list of parameters was given to location scouts who were able to find a match.

Frankel recently prevised I Am Legend, Sony's upcoming adaptation of the classic Richard Matheson sci-fi novel, directed by Francis Lawrence and starring Will Smith. Frankel worked on location in New York, assisting in shadow studies that were essential to the story, as Smith is pursued by creatures that avoid sunlight.

"Where can they film in Manhattan so they can get this sundial effect of the shadows marching across the street?" he offers. "At the end of the day, a lot of this did boil down to, 'The shadows will fall there at this time,' and getting down to the architecture."

On Lawrence's previous movie, the comic-book adaptation Constantine, Frankel says previs was essential to planning a set piece in which Keanu Reeves' character runs down a derelict freeway in hell. Frankel suggests previs enabled them to map out the action, figure out how many real cars were needed for the set, where the camera platforms had to be to film the scene and how the visual effects would fit into the shot. "We didn't want to have to go to the effort of creating stuff only to have it be on the edge of frame," Frankel continues.

For previs to work, the data must be accurate so that it can actually be done on set, observes Chris Edwards from The Third Floor.

For previs to work, the data must be accurate so that it can actually be done on set, observes Chris Edwards from The Third Floor.

Generating this kind of data is far from glamorous, but it is increasingly valuable on set. "It's all about getting that info out there early enough that people can make decisions and act on it," Frankel adds.

For this to work, the data must be as accurate as possible. "It's easy to create stuff, but it's hard to create stuff that can actually be done on set," says Edwards.

Frankel says everything built in the computer is done to scale, "so when we measure off 10 feet, it's 10 feet." Sets are built to an accuracy of as little as a quarter-inch for small locations, and as much as a foot on bigger locations.

The camera info is similarly detailed, with information on lenses accurate to a high degree in terms of distortion.

As previs grows, more department heads are becoming involved in the process, such as production designers, vfx supervisors and cinematographers. "We're completely capable of being autonomous, but we don't want to be. We need that input," says Edwards.

That's not always easy as key crewmembers may not all be assembled by the time previs needs to start. "We get people coming in and being surprised at how much is already done," Edwards says.

PLF's Colin Green cites I, Robot as an example of where previs and postvis allowed the editorial process to go more quickly. © 2004 Twentieth Century Fox. All rights reserved.

PLF's Colin Green cites I, Robot as an example of where previs and postvis allowed the editorial process to go more quickly. © 2004 Twentieth Century Fox. All rights reserved.

The work done in previs is also useful in what has come to be known as postvis, which quickly checks that live action plates will work out creatively and technically with things like visual effects. If something doesn't work, they know quickly enough to re-shoot before sets have to be struck.

Postvis also is useful in the vfx bidding process, as it gives houses a concrete idea of the number of shots and type of work required to complete a job, resulting in more accurate bids as well as savings in time and money.

"With a lot of visual effects, you have nothing to cut, nothing to work with until you get your shots back finished," says Colin Green, Founder of previs house Pixel Liberation Front. "The editorial process is hindered by the fact that you don't have these important shots until the vendor does them."

Green cites I, Robot as an example of where previs and postvis allowed the editorial process to go more quickly. "It was very difficult for the story to even be told with what was shot. We had to put in a temp version of those shots in so the film could get edited and the shots get counted."

The future looks bright for previs and postvis, with houses looking to make it an even more essential part of the filmmaking process as well as adapt it to new technologies like 3D.

Nic Hatch of Nvizage says tools are getting better and allowing more complex visuals.

Nic Hatch of Nvizage says tools are getting better and allowing more complex visuals.

Hatch, who recently worked on Roland Emmerich's upcoming 10,000 B.C. and Tim Burton's Sweeney Todd, says tools are getting better and allowing more complex visuals. "People want to see more," he suggests. "It's no longer kind of blocky animation and blocky models. We try to make it, not photoreal, but make it look visually interesting, make it look like what you'd see on the real plate."

Third Floor has been doing more work beyond feature films, with commercials being an area where the short shoots make previs especially valuable. The company also has worked on videogame cinematics, architecture visualizations and theme park ride footage.

It's also moving into dramatic films, comedies and project pitches. Wassung says he recently worked on a pitch for a drama that had to convey the emotional arc of the story.

"What's making this more accessible is the fact that we can get more lighting, detail and animation so it's readable to anybody, not just the vfx supervisors," Wassung concludes.

Thomas J. McLean is a freelance journalist whose articles have appeared in Variety, Below the Line, Animation Magazine and Publishers Weekly. He writes a comicbook blog for Variety.com called Bags and Boards, and is the author of Mutant Cinema: The X-Men Trilogy from Comics to Screen, forthcoming from Sequart.com Books.

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