1. STAR WARS (1977) Motion-control photography, in which a computer is used to control a long, complex series of camera movements, made possible the spaceship battles in Star Wars. It would have taken too long to film the scenes manually, says Anne Thompson, deputy film editor at The Hollywood Reporter.   2. TRON (1982) It wasn't the first film to use computer-generated (CG) graphics (and many effects were hand-drawn) but the sci-fi video-game fantasy flick Tron was the first to use computer imagery to create a 3D world, making it one of the pioneering CGI films. "Effects people said, 'Let's see what the computer can do,'" says Harry Knowles, movie critic at Ain't It Cool News.   3. TERMINATOR 2: JUDGMENT DAY (1991) "Morphing" was first used in Willow (1988), but in T2 the effect was "jaw-dropping," Knowles says. The liquid-metal robot's humanoid texture, which was layered onto a CG model, looked frighteningly real.   4. CLIFFHANGER (1993) Faux alpinist Sly Stallone was held up by wires that were later digitally removed. The ability to erase wires changed how stunts are done: Now stars and stuntmen can be put in real-world environments as well as in front of green screens.   5. JURASSIC PARK (1993) Although they enjoyed only about 6 minutes of screen time, Jurassic Park's digital dinos were a revelation: They introduced CGI live animals with realistic movements, and believably textured muscles and skin. The photorealisitic digital elements were intercut with animatronic dinosaurs.   6. FORREST GUMP (1994) While most filmmakers in the early '90s used digital effects to create fantasy, the creators of Forrest Gump altered history. Using Kodak's Cineon system, they digitized archival footage, and composited Tom Hanks's character into historical clips.   7. THE PERFECT STORM (2000) Although much previous work had been done to make CGI water look real, The Perfect Storm's monster wave scene set a new benchmark. "Water is an organic thing that's hard to create in software," says Andy Maltz of the Motion Picture Academy of Arts and Sciences. "To make it look believable was a big thing."   8. LORD OF THE RINGS (2001) For the huge battle scenes in the Lord of the Rings trilogy, the filmmakers created Massive, a computer program that generates crowds of artificially intelligent individuals "who make their own decisions based on behavior patterns," Knowles says. This makes for more realistic battles.   9. THE POLAR EXPRESS (2004) Director Robert Zemeckis used a large motion-capture stage and up to 200 cameras to gather data from the performance of Tom Hanks and other actors. This data was used to help animators create digital versions of the actors while maintaining their performances.   10. THE DAY AFTER TOMORROW (2004) The creators of the film about worldwide climatic disaster took more than 50,000 photos of New York City and scanned them into a computer, providing "a 3D, photorealistic model of the city," Thompson says. After that, destroying the metropolis with a giant digital wave was a piece of cake.