In film and video games, we've already seen what's possible with 'digital humans'. Are we on the brink of the world's first totally virtual acting star?
When you're watching a modern blockbuster such as The Avengers, it's hard to escape the feeling that what you're seeing is almost entirely computer-generated imagery, from the effects to the sets to fantastical creatures. But if there's one thing you can rely on to be 100% real, it's the actors. We might have virtual pop stars like Hatsune Miku, but there has never been a world-famous virtual film star.
Even that link with corporeal reality, though, is no longer absolute. You may have already seen examples of what's possible: Peter Cushing (or his image) appearing in Rogue One: A Star Wars Story more than 20 years after his death, or Tupac Shakur performing from beyond the grave at Coachella in 2012. We've seen the terrifying potential of deepfakes – manipulated footage that could play a dangerous role in the fake news phenomenon. Jordan Peele's remarkable fake Obama video is a key example. Could technology soon make professional actors redundant?
Like most of the examples above, the virtual Tupac is a digital human, and was produced by special effects company Digital Domain. Such technology is becoming more and more advanced. Darren Hendler, the company's digital human group director, explains that it is in effect a "digital prosthetic" – like a suit that a real human has to wear.
"The most important thing in creating any sort of digital human is getting that performance. Somebody needs to be behind it," he explains. "There is generally [someone] playing the part of the deceased person. Somebody that's going to really study their movements, facial tics, their body motions."
'The most important thing in creating a digital human is getting that performance' ... digital Tupac Shakur at Coachella in 2012. Photograph: Christopher Polk/Getty Images
Digital and digitally altered humans are commonplace in modern cinema. Recent examples include de-aging actors such as Samuel L Jackson in Captain Marvel, and Sean Young's image in Blade Runner 2049. And you can almost guarantee the use of digital humans in any modern story-led video game: motion-captured actors give their characters lifelike movement and facial expressions.