This month sees the release of the second film in The Hobbit trilogy: The Desolation of Smaug. Perhaps the most well-known of its characters is Gollum, a mysterious cave-dwelling creature corrupted by the power of the ring. His digital character was created by New Zealand-based visual effects company Weta Digital.

In this Nature Video we go behind the scenes with Weta's Senior Visual Effects Supervisor, Joe Letteri, who reveals the technology they used to make Gollum's eyes, skin and movements look believable.

Read the story: Computer animation: Digital heroes and computer-generated worlds