What makes a face fall into the ‘uncanny valley’?
When the movie trailer for Sonic the Hedgehog arrived, audiences were distraught. Adapting the blue cartoon rodent of video game fame for a film had resulted in what many felt was a disturbing creature with unaligned eyes and ‘terrifyingly human’ teeth. So, where’s the line between a loveable superpowered hedgehog and a creepy blue alien? “Animations must strike a balance between looking real, but not too real,” says Blat, a professor of Computer Science at Pompeu Fabra University Barcelona(opens in new window). There lies the so-called uncanny valley – the unnerving aspect of a face that is almost human, but noticeably isn’t.
Perplexity, uneasiness – even revulsion
According to the uncanny valley theory, faces that don’t perfectly resemble actual humans will provoke an uncanny feeling or a sense of perplexity, uneasiness or even revulsion in viewers. “The goal for animators is to avoid venturing into this valley, and that means creating believable characters,” explains Blat, who has years of experience designing computer graphics and animations with the film and gaming industries.
An unbelievable mismatch
According to Blat, believability doesn’t always mean advanced animations or special effects. In fact, the more complex a graphic, the higher the risk of unbelievability. It’s why old Saturday morning cartoons featuring speaking animals are believable, but a live-action musical with human-like cats(opens in new window) proves to be a flop. “Unbelievability is often the result of a mismatch in the animation’s various elements,” notes Blat. “If everything about a character – its movements, intelligence, appearance, expression, experience, emotions – doesn’t match, viewers will likely reject the animation.” A good example of such a mismatch is Paramount’s attempt at bringing Sonic to the big screen, with a star whose human-like eyes and teeth didn’t match up with its cartoonish face and body.
Striking the right balance
But avoiding the uncanny valley involves more than just matching facial features. The animation’s features must also match the emotions and feelings we associate with such features. “When a face becomes animated, those facial animations must convey the correct emotions in order to be believable,” adds Blat. Needless to say, striking this balance is no easy task, and one that has implications beyond movies and video games. “The experiences of the film and gaming industries can provide important lessons that the AI, robotics and virtual assistant sectors would be wise to follow,” concludes Blat. Read more about Blat’s work designing realistic elements for these emerging technologies: Virtual companions that look and behave like humans