The CGI revolution

Hollywood blockbusters spend millions to get just the right look and that means plenty of action-packed set pieces, stunts - and several hundred gigabytes of computer-generated imagery (CGI). CGI has given directors the chance to create enormously elaborate scenes at a fraction of the cost, and danger, of staging something real.

With Troy, starring Brad Pitt, out this week and featuring some truly spectacular effects created by London-based post-production company Framestore CFC - including digitally rendering an armada of 100 ships and a 50,000-strong Greek army - Metro salutes the key films that marked the CG revolution...

Star Trek II: The Wrath Of Khan (1982)

The much-loathed first big-screen outing for the crew of the USS Enterprise needed a sequel that would pull in the punters. Wrath Of Khan proved that the Star Trek format could adapt to feature-length format spectacularly, as well as introducing the world to the first ever computergenerated graphics in film. The 60-second 'Genesis effect' scene, crafted by Lucasfilms, depicts a warhead hitting a dead planet, causing a chain reaction that restarts life.

Young Sherlock Holmes (1985)

An oft-ignored yet delightful tale charting an early foray into sleuthing by the eponymous schoolboy may not seem a likely landmark for CG effects, but it qualifies on two counts. During a hallucination sequence in a church, one of the characters sees a knight jump from a stained glass window and attack him. This knight was the first ever CGI character to appear in a motion picture.

Not only that, but it was the creation of none other than Pixar, who have become the leading force in CG animation.

Terminator 2: Judgment Day (1991)

The film that really showed what CGI could bring to the film world, especially with morphing - a technique developed by George Lucas's Industrial Light & Magic and used first in 1988's Willow. T2 represented a major shift in the way computers were used in the filmmaking process: instead of CGI being kept sparingly for one or two specific scenes, T2 used it throughout to show off the abilities of the liquid metal assassin T-1000. Audiences marvelled as he turned his arm into a knife, repaired bullet holes and seamlessly reflected the surrounding scenery.

Jurassic Park (1993)

While James Cameron used technology to depict something from the future, Stephen Spielberg chose to use CGI to bring our past back to life. The effects used to create dozens of different dinosaur species were groundbreaking in their anatomical detail and their level of interaction with the human characters. Spielberg initially wanted to use stop-motion techniques for the dinosaurs but, after seeing demo animation from ILM, plotted on an Amiga Toaster, he decided to shoot nearly all the dinosaur scenes using CGI.

Toy Story (1995)

Disney and Pixar got together to make the first fully computergenerated full-length feature film, released almost a decade ago.

Images required around 800,000 hours generation time on Pixar's so-called 'render farm,' which comprised more than 100 separate computers. The film's massive success made Pixar a household name and enabled the studio to go on and create even better animation in several pictures. Its latest, The Incredibles, is released later this year.

The Matrix trilogy (1999-2003)

The stonking original and its sequels - underrated, though not as good - introduced a highly stylised way of integrating cutting-edge CG effects. While 'bullet time' was the signature of the first film, most of the fight scenes in both sequels and the amazing assault on Zion in Revolutions are digitally rendered set pieces. The kung fu fest between Neo and hundreds of Agent Smiths in Reloaded contains four entirely computer-animated sequences.