Ghosts in the Machine

Article by Jody Duncan

Cinefex, Issue #99, October 2004, exerpt from page 97-99

The years-long conceptual work continued as the project entered official preproduction, which would last ten months. During that time, Proyas continued to develop animatics for virtually every scene in the film, using them to plan the production -- and even using them as a selling tool. "While the studio was still deciding whether or not to proceed this movie," recalled producer John Davis, "Alex used the animatics to cut a trailer, which was very clever of him. He came in and said, 'Here's the trailer for your movie.' And the studio people looked at it and said, 'We are so in.'"

The shoot, like preproduction, was on the long side, consuming nearly six months on locations and stages in Vancouver. Art department and construction crews built partial sets surrounded by massive bluescreens or greenscreens to facilitate the addition of digitally-rendered environments by Digital Domain and Weta Digital, the two primary effects vendors on the show. Senior visual effects supervisor John Nelson, in addition to orchestrating 1,000-plus effects shots in postproduction, was on set throughout the shoot to oversee the many bluescreen/greenscreen setups -- all of which were aided immeasurably by an on-set virtual studio system, 'Encodacam,' devised by Joe Lewis at General Lift. "Encodacam enabled us to start a shot on a partial set," explained Nelson, "and, in real time, do a camera move that moved off the set and into a digital set. On a monitor, we could see the actors in that digital set, see the extension of the camera move -- all in real time. It was one of the many cutting-edge technological advances we used on this picture."

To develop Encodacam, Lewis had combined traditional motion picture camera encoding and recording equipment -- for which his company is known -- with broadcast virtual set technology. Employed for many years in controlled broadcast studio environments, that technology involved mounting targets on the studio's ceiling and walls, which enabled a computer to track, live, a moving camera and make it look as if it was moving within a virtual environment -- creating the illusion of a news anchor's or any other live subject's presence within that environment.

Applying that technology to fast-paced motion picture production had been impractical, due to the lack of time to set up markers and calibrate the computerized camera tracking. With advances in camera recording and encoding technologies, however, Encodacam's time had come. "Encodacam was one of the coolest, most helpful things I've seen in a long time," stated Brian Van't Hul, on-set visual effects supervisor from Weta Digital. "It allowed us to key together low-rez geometry -- which often came from the previz -- and the actor on the bluescreen or greenscreen stage, so we could actually see them together on a separate video assist split. If the camera was moving around, we could record that motion and see the same moves on this keyed-together image of the actor in the low-rez virtual environment. It showed up on a monitor like a rough 3D composite -- but done live, with all the camera moves."

The benefits of the Encodacam system were many. First and foremost, it enabled actors -- often adrift in a sea of green or blue -- to see what the final shot would look like. "More and more these days," Van't Hul commented, "films are being shot on big greenscreen stages with minimal sets and actors who don't have a clue as to what is going on. They are told to look at a cross on a wall or to look at a tennis ball, and that's all they've got to go on. It is not a very inspiring environment. This system was tremendously beneficial to the actors because, between takes, they could see the comped image and get a better sense of the scene, which really helped their performances."

The system also enabled the director and the camera operator to collaborate as if in a real environment. "In a primarily green environment," explained Van't Hul, "the camera operator might do a pan, for example, without knowing exactly what he is panning from or to. It is all a guess, and then it has to be fixed in post. With this system, the camera operator could see what was happening and knew where to point the camera and how fast to pan back and forth. The director could have a relationship with the camera operator, to confer with him in real-world terms. He could say, 'If you pan a little bit over and tilt up, look what we'll see!' It allowed him to direct the camera movement, for real, on a virtual set."

Another benefit of Encodacam was that it created keyed-together footage that editorial could use to cut into the film, giving the director a sense of pacing and timing in a scene many months before final effects shots would be completed. "Without it," said Van't Hul, "the editors get a bunch of material where the camera is panning from green onto this guy and then off of this guy to green -- and they are like, 'Uh…okay…I don't know what is going on.' This gave them a bash comp they could use to do the cut."

The film's opening moments establish a Chicago that is futuristic, and yet familiar, with all of the city's landmarks and iconic buildings still in place. "A lot of futuristic movies have environments that are dazzling, but quite cold and hard to relate to," noted John Davis. "Alex wanted to create a future that was an exciting, technologically-friendly place, rather than the alienating place we so often see in movie future worlds. The architecture is amazing, but also relatable. The cars are fantastical, but understandable. The technology all looks as if it is the next logical leap from where we are now."