Gollum. Ney’tiri. King Kong. Caesar. Cole Phelps. Nathan Drake.

These life-like, smoothly animated and beautifully realised characters all have one thing in common. Whether a 1940s L.A. detective or a 25 foot tall gorilla, they all started off as an actor in a skintight grey suit.

With James Cameron giving the lowdown on his Avatar sequels this week, I thought it fitting to take a look at the technology that makes these films and games possible: motion capture.

The development of video games and movies has come a long way in the last few years. Although motion capture has been used in video games since Atari’s 1995 game Highlander: The Last of the McLeods, the technology rose to mainstream prominence during the production of Peter Jackson’s film The Lord of the Rings: The Two Towers in 2002. For the creation of Gollum, actor Andy Serkis performed live on set while dressed in a motion capture suit, and his performance was converted real-time into Gollum’s character model. This technique was adopted by other filmmakers and video game designers, and was developed extensively by James Cameron during the production of his mostly motion captured science fiction epic Avatar.

Motion capture requires the actor to wear a specially designed suit covered in tiny markers. The markers are placed at key locations on the body and detect motion as the actor moves around a virtual “set” – a space surrounded by cameras that then recreate the actor in a 3D virtual space. Backgrounds and textures are painted in afterwards, allowing a totally virtual scene that faithfully records the actors’ performances.

Motion capture actors performing in Ubisoft Studios.

The origins of motion capture lie in rotoscoping – the overlaying of live action film with hand-drawn animation. Motion capture provides a faster, more reliable and accurate alternative and is increasingly becoming the norm in video game and film production.

As well as capturing the physical movements of actors, cameras attached to helmets are used to record minute facial movements and expressions to create even more realistic character models. Whereas previously actors’ voices and faces have been recorded independently of their bodies for video games, Ninja Theory’s Heavenly Sword was the first time all these elements were captured at the same time. This was developed extensively for use in Rockstar and Team Bondi’s L.A. Noire and is referred to as performance capture. The game revolved around picking up on character’s facial expressions to tell whether they are lying or not, so it required even the smallest of muscle movements to be identified and translated into the virtual space.

All the actors’ performances in L.A. Noire were performance captured, including Aaron Staton as Cole Phelps.

With motion capture, the line between movie and game production is becoming increasingly blurred. The processes involved with making a game are now very similar to making movies, with actors able to use physical space, sets, props and respond to each other in real time. This technology has allowed a whole new level of realism in gameplay and cutscenes. Whereas in the past developers relied on animators to convey emotion in characters, motion and performance capture has allowed actors to add the emotion and physicality that animators cannot do by themselves. Motion capture is a collaboration between actors and animators to enhance the story and make the game an even more enjoyable experience.

Actor Nolan North provided both his voice and the physical performance for Uncharted’s Nathan Drake.

After the massive success of Avatar and the increasing prevalence of motion capture in other media, there may be a time in the future when live-action actors are a thing of the past. As scenes can all be shot in the studio and the backgrounds painted in digitally afterwards, there is no need to travel between locations and deal with the challenges that this creates. But if there is one place motion capture will always have a true home, it is video games. Whether it is used to animate enemy AI on patrol, Nathan Drake scrambling up a sand dune or riveting, beautiful cinematics in Final Fantasy, motion capture will always lay at the heart of video game visuals. The technology has come a long way in a short amount of time, and as the current generation of consoles nears the end of its life we can only imagine what the next generation has in store for us.

To get a fascinating insight into motion capture, check out this video about the making of upcoming PS3 exclusive Beyond: Two Souls, which will feature Ellen Page as the likeness and voice of the main character.