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n n n n CG Environments Flynn’s creation, Clu 2.0, took control of the system and trapped him. Te Grid is now even more dangerous than before, and Sam must fight gladiatorial games to survive. All told, TRON: Legacy has close to 1500 A 50-polygon Recognizer in the 1982 TRON became this giant machine in TRON: Legacy that captures Sam when he first arrives in the digital world. All enemy vehicles and Programs have orange glow lines. Back to the Future As TRON: Legacy opens, we learn that Flynn disappeared when his son, Sam, was a child. Now 27 years old, Sam (actor Garrett Hed- lund) finds himself investigating a strange signal apparently sent from his father’s old video-game Track Stars Approximately 25 trackers worked on TRON: Legacy, some as long as a year. “We had the whole film,” says Ross Mac- Kenzie, 3D integration supervisor, “1500 shots, and they were long shots. Most were over 300 frames, and they kept getting longer and longer.” Although trackers at Digital Domain sometimes use com- mercial software, the mainstay at the studio and the workhorse for TRON: Legacy was the studio’s in-house software Track, for which software engineer Doug Roble received an Acad- emy Award in 1998. Simply put, Track calculates the position of the camera used to film a shot as it moves through three- dimensional space, frame by frame. Similarly, the software can also track the path of any objects or characters as they move in the scene. With this information, artists can position a virtual camera in a 3D scene built to match footage shot on set, insert CG objects into the footage, and/or replace something in the scene with a CG object. Once rendered, the inserted objects fit correctly into each frame of the 2D scene, even as the cam- era changes perspective. “I started writing Track in 1973, 17 years ago,” Roble says. “Every once in a while I come back to it, and for TRON, I real- ized, well everybody realized, it needed significant upgrades. The software has 175,000 lines of code. I probably modified about 20 percent of it, and I added things that we needed.” Roble primarily updated the user interface and added math to manage more than one camera and do calculations with enough precision for stereo. “I wrote my tracking camera with a main camera in mind,” Roble says. “With TRON and other 8 December 2010 movies nowadays, people have learned that witness cameras and other cameras on set can really help. So on TRON, a lot of the shots had the two main left- and right-eye cameras, plus multiple witness cameras. I had to add a heck of a lot more data and make it easy for the artists.” The artists begin by lining up one frame and attaching mark- ers to various features in the filmed footage to help the software calculate the camera path. “It’s all about managing errors,” Roble says. “The pipeline was to track the main camera, choosing one eye [camera] as the main eye. Then, if everything was perfect, you would only have to know how far away the other eye was. But nothing is perfect. There might be an error in the left eye that you notice only because the right eye is off.” The mechanical rig might have vibrated one camera more than the other, or one camera might have pointed up a little more than the other, and that would mean the tracked points would be in different positions from one frame to the next. “In the CG world, you assume perfect cameras and perfect lenses, but in the real world, the lenses aren’t even exact,” Roble says. Moreover, simply finding points to track wasn’t always easy. “Lots of sets have brick, corners, and other details the com- puter-vision programs can hang onto,” Roble says. “We had smooth sets. All we had were lines separating one smooth thing from another. Even the corners were nicely rounded and smooth.” “We used pieces of dust,” MacKenzie adds. “We used what we could. We also had a lot of reference photography that we arcade. He discovers his father’s hidden work- room and, while there, the same laser beam dig- itizes and sends him into Kevin Flynn’s digital world. Once there, we discover that when his father revisited and upgraded the digital world he had left, things didn’t work out so well. visual effects shots, of which approximately 170 feature Clu 2.0, the younger version of Bridges. “When Joe asked us to do this job, we knew we’d do the character Clu here based on our work on Button,” Barba says, referring to director Joseph Kosinski. “But we also had to create an entire world in 3D, a world never seen before. We kept the major sequences that establish TRON here at Digital Domain: the disc game battle, the iconic bike sequence, the small, difficult character pieces. And Joe wanted to keep the two big sequences at the end here. We found outsource partners to do the rest.” Tose partners included Mr. X, Ollin Stu- dio, Prana Studios, Prime Focus, Whiskey Tree, and Yannix. Electronic Arts did motion capture in Vancouver, where Kosinski shot the film, and House of Moves assisted in post- production.

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