Effects guru talks 'Watchmen'

A special effects expert working on the movie Watchmen has revealed one of the most taxing aspects of adapting the comic book.

Alan McFarland, who previously worked on Spider-Man and Iron Man, commented that filming the character Dr Manhattan was particularly difficult and often required multiple actors playing the role.

Billy Crudup is cast as the superhero, who gains superhuman strength, clairvoyancy skills and the ability to manipulate subatomic matter after a nuclear physics experiment.

McFarland told UGO that one part of the film, in which Dr. Manhattan splits into four identical versions of himself, was "the most technically difficult scene to pull off".

"We had to have Billy plus three other body doubles in identical [motion capture] suits to pull that off, and it was very early in shooting Dr. Manhattan, so we were new to the process. It was a real trial-by-fire on that day," he said.

The movie adaptation of Watchmen has not been well-received by comic book creator Alan Moore.

Earlier this year, the writer told Entertainment Weekly that neither movie studio bosses or DC Comics, who own the rights to Watchmen, have been in touch regarding the project.

"I don't want anyone who works for DC comic books to contact me ever again, or I'll change my number," he said.