The Golden Compass and a British adventure in Hollywood

A crew for a flying ship? A giant gorilla towering over Manhattan? A schizophrenic halfling besotted by a golden ring? And a portly 50-year-old British actor suddenly blessed with an Adonis-like six pack?

None of the above would be possible without a new technology favoured by Hollywood luminaries such as Peter Jackson, Robert Zemeckis and George Lucas that allows directors to conjure up fantastical creatures and giant armies.

New Line Cinema, the studio behind the Lord of the Rings trilogy, has drawn heavily on motion capture for The Golden Compass, the film version of Philip Pullman's Northern Lights, which opens this week. The movie, which stars Nicole Kidman and Daniel Craig, uses the technology to create "digi-extras" in a huge battle that pitches Lyra, played by Dakota Blue Richards, against Tartar guards, and to crew the film's Noorderlicht ship.

Motion capture, or performance capture as it is also known, is the film-making sensation of the decade. And it has put a small British technology company on the map in Hollywood. More than half of all the motion-capture cameras used by the big studios are made by Vicon, part of the Oxford-based OMG, including those used to shoot The Golden Compass.

The technology originated from the life sciences industry, where it was developed to measure skeletal movement accurately. Its users include doctors assessing the gait of children with cerebral palsy, coaches analysing the bowling techniques of cricketers, videogame programmers making ever-more realistic software and movie directors creating new worlds and fantasy characters.

From Beowulf to Gollum, King Kong to an emperor penguin called Norma Jean, they all owe their screen presence to the art of motion capture, a technique that translates actors' performances into digital coordinates in space that can later take any form required to fit the plot's storyline.

Britain is home to Europe's biggest motion-capture studio, Audio Motion, also based in Oxford, which shot some of the scenes in The Golden Compass. Mick Morris, who runs Audio Motion, said: "Motion capture is perfect for digital extras and for doing lots of crowd replication."

Andy Serkis, the British actor who played Gollum in Lord of the Rings, believes motion capture is the future of film-making. "It's definitely here to stay. More and more films are using it because it's so creative," he said. Nick Bolton, who runs Vicon's parent company OMG, said: "The film industry is very excited about motion capture right now."

Zemeckis has set up a company to make performance-capture films for Walt Disney. He is the man behind Beowulf, the first full-length adult film to use the technology: it transforms the rotund, 50-year-old, 5ft 10ins Ray Winstone into a 22-year-old, 6ft 6in warrior.

Motion capture is proving controversial in Los Angeles. Two of the three films nominated for best animated feature film at the last Academy Awards were made using motion capture, and some in the film business fear it is threatening the future of traditional animation. Brad Bird, the director of Disney's hit cartoon Ratatouille, is in the anti camp; the end of his film features a cartoon businessman smiling as the text proclaims the movie was made with "100 per cent genuine animation" and "no motion capture or any other performance shortcuts".

Steve Hulett, at the Animation Guild in California, said: "Ultimately, audiences will decide if motion capture is the future. So far it has had a lacklustre, spotty track record at the box office."

How it works: From the lab to the film studio

* Motion capture was developed in the late 1970s to help orthopaedic surgeons treat children with cerebral palsy, a serious condition affecting the movement of one in 400 children.

* Small plastic spheres covered in reflective material are attached to the body of a child, who walks around a lab while special cameras, which can see only the markers, take hundreds of photos very quickly. The software converts these images into three-dimensional measures that help the surgeon precisely diagnose the underlying bone and ligament problems.

* Sports medicine adopted motion capture in the early 1990s to help prevent injuries and improve the technique of runners, golfers and cricket bowlers.

* In 1994 animators started using the technology to make videogames; 'Sinbad: Beyond the Veils' was the first film made using large amounts of motion capture.

Nina Lakhani

Further viewing: 'The Golden Compass' opens nationwide on 5 December