Northern
Exposure PROLOGUE: Don Burgess, ASC has two holiday gifts for children and the young-at-heart. In The Polar Express he mastered a different type of motion capture technology designed to give computer animation a human touch. Christmas with the Kranks is a live-action film that explores the premise that there is drama in comedy. Both are entertaining, feel-good movies that probe the meaning of the Christmas spirit. Both were imbued with extraordinary production values by the master cinematographer and his crew. A young boy is lying in his moonlit bedroom on Christmas Eve. He is breathing silently, hardly moving, straining to hear Santa's sleigh bells. Just before midnight, a thunderous roar startles him. He gets out of bed and peers out the window. There he sees a magnificent steam train waiting to take him to meet Santa Claus at the North Pole. The Polar Express is the cinematic interpretation of a classic story written by Chris Van Allsburg. Writer/ director Robert Zemeckis and writer William Broyles, Jr. crafted the screenplay in a world that the director describes as "waking space." "It was an annual tradition to read the book to my son while he was growing up, and it never failed to fascinate him," Zemeckis says. "The imagery (in the movie) has an otherworldly quality, existing somewhere between dreams and reality." The Polar Express is a computer-animated film featuring Tom Hanks as the conductor of a train that takes children on a magical journey. Hanks is more than a voice for an animated character. He is the heart and soul of the character, whose movements, body language and facial expressions are based on his live-action performances. It was the first use of a new technology called Performance Capture, which blends traditional motion picture production techniques and aesthetics with computer animation. The performances of flesh and blood actors were photographed by Don Burgess, ASC with the aid of the new motion capture system designed to provide a roadmap for creating virtual characters with visceral, human-like qualities. Burgess' connection to the project began with a phone call from Zemeckis, who asked if he was interested in working with him on a different type of film. Their previous collaborations included Forrest Gump, Contact, What Lies Beneath and Cast Away. "Everything that Bob Zemeckis gets involved with is going to be original, different and challenging," Burgess says. "The idea of working with him on a film that is an interpretation of a Chris Van Allsburg children's book was irresistible. I was also intrigued by the motion capture system and figuring out how to make it work. That's part of the fun of filmmaking. It was a chance to solve problems and experiment with a new way of telling stories in order to get an interesting movie on the screen." The Performance Capture system was conjured up at Sony Pictures Imageworks by visual effects experts Ken Ralston and Jerome Chen. Their goal was to use motion capture technology as a technique for recording performances by actors in a computer-readable format. Burgess and his crew used multiple video cameras to record the performances of actors from different angles and perspectives. The action was also covered by infrared cameras surrounding the stages. "I had my regular grip crew, part of my lighting crew, two camera operators, Robert Presley, SOC and Patrick O'Brien, and assistant cameraman Steve Cueva working with the video cameras to capture nuances in body language and expressions," he says. The actors wore form-fitting motion capture suits with 60 "markers" made of light-reflective material to provide points of reference for building three-dimensional CG images. They also had markers on their faces that were used to record subtleties in expressions. The infrared cameras recorded the frame-by-frame positions of the markers. They were set up and operated by a company that specializes in that type of data collection. Ralston explains that the system is designed to capture every discernable movement and nuance in performances, including the fluttering of eyebrows. The positions of the markers on clothing and faces were used by the animators to plot movements and shape expressions of the virtual characters on virtual sets. "They had done some tests with the system before I came on board," Burgess says. "There were storyboards, and some scenes had been pre-visualized with low resolution images. The production designer, Rick Carter, and I had previously done several films together. In fact, almost everyone on the crew had worked together on other films. "It was like taking a giant puzzle that had been poured on the floor and putting all the pieces together," he continues. "This type of motion capture has been used to create characters in video games, but never with the details in facial expressions like we did on this movie. The technology was being designed and created as we were using it." Burgess had six weeks for preproduction planning with Zemeckis, Carter and his co-production designer Doug Chiang, costume designer Joanna Johnston, Ralston and the motion capture technology team. Three stages at Culver City Studios were set up for motion capture cinematography. One stage included a 10X10-foot area reserved for shooting close-ups. The tracking markers on the actors' faces were used to plot expressions in the CG world. The other stages were used to capture other movements and body language during performances. Burgess watched the actors rehearse and blocked coverage just like he would on a live-action movie. Before shooting the scene where the first boy gets on the train, they plotted grids and planned the actor's movements from one place to another. One big question was whether they needed to build a set for a train car, or just the steps leading up to it and something for the actor to sit on. They decided to make the steps and seat out of chicken wire sprayed with a gray, non-reflective paint. "We avoided using solid objects that would have obscured points of view from different camera angles," Burgess says. "Before we shot a scene in a bedroom, we marked the positions of walls and places occupied by furniture with tape on the floor. That told everyone where all the objects in the room were and where you couldn't walk." Burgess also discussed focal lengths with Zemeckis. The computer software used to create the virtual world enabled them to emulate the characteristics of different lenses. They decided to mimic Super 35 lenses, mainly in focal lenses ranging from 20 to 35 mm. Burgess used as many as twelve video cameras to cover the action, including Canon XLs and GL2s. Most were locked down and a few had operators. The flat fluorescent lighting had to be set at a low level to allow the infrared cameras to track movements. There was a video village with a monitor for each camera. "We would watch the cameras catching the performances and make sure we had all the information Bob (Zemeckis) needed in post," Burgess says. Zemeckis began each day staging scenes with the actors while Burgess planned his blocking. One camera was always on a facial close-up that Zemeckis used to judge performances, and another was always on a master shot. The video cameras recorded time code, which enabled the director and editor to synchronize dialogue with the images. "When we shot a performance that Bob liked, we could move on without retakes, because the actual shots were created in postproduction," Burgess says. "We'd wait about two weeks for the images to come back in a virtual environment." While Burgess was on the set with Zemeckis, Presley was at a computer console finessing the virtual images and beginning to translate the raw data recorded during motion capture shots. The control module for a Libra head was adapted to interface with the computer, which enabled Presley to give the images a human touch by panning-and-tilting and moving a virtual camera through low-resolution virtual sets. There were no facial expressions at this point. The characters were referred to as Michelin Men. "We'd show Bob (Zemeckis) those shots the next day," Burgess says. "Sometimes he was satisfied with what he saw, and other times he would ask for a refinement, like 'Can we make that move a little longer, with a close-up at the end?' After we made those fixes, he would do a rough cut of the scene with the editor to make sure it was working. The process was evolving all the while we were shooting." Burgess shot 13 Going On 30, Radio and Christmas with the Kranks after completing production of The Polar Express. Presley stayed with the film for about another year through postproduction, finessing the images with Zemeckis. "It took a lot longer than everyone anticipated," says Presley, "partially because of the time it took to process all the motion capture data. One of the great things about this process is the flexibility it gives you. I'm sure Stanley Kubrick would have loved it, because it is incredibly easy to reshoot a scene over and over again. Bob (Zemeckis) would look at a shot, get a new idea and ask me to shoot it again. This way we could really perfect how the story would be told in camera. "After they finally put expressions on the faces, we saw things that would work for the story if we did a little additional tweaking," Presley adds. "I'm computer literate and into PhotoShop, but probably the best preparation I had for this project was the work I've done with Don (Burgess) and other cinematographers, getting the feeling of working with cameras on remote heads. I'm used to looking at a monitor and feeling the pacing of shots through the wheels. I think that's what prepared me to evaluate and improve shots. The camera is an active participant in all of Bob's (Zemeckis) movies. He didn't want to sacrifice that perspective or aesthetic just because it's an animated movie." The Polar Express was completed during digital intermediate timing sessions at Imageworks, where it was timed for continuity and recorded onto intermediate film used as a master for release printing in both IMAX 3-D and 2.4:1 cinema formats. About two months into a schedule that went for a total of 18 months, Zemeckis and the studio decided it was appropriate for Presley to share a cinematography credit with Burgess. He has worked on some twenty narrative projects as a camera and Steadicam operator, including four with Burgess with the latest being Radio. The Polar Express is his first credit as a cinematographer The Polar Express was produced by Castle Rock Entertainment and distributed by Warner Bros. "It's all about storytelling," Burgess concludes. "You've got to be open to different ways of telling stories and be willing to try new ways of doing things. It looks and feels different than a normal animated movie. I believe you can tell that it was Tom Hanks who was driving the character of the conductor. This is just the beginning. I assume the next movie shot this way will be light years ahead of what we did." |
