So close and yet so far... (scene from Final Fantasy: The Spirits Within animated movie)
There are over 50 muscles in the human face. Those muscles that control expression make the face an incredibly mobile part of human anatomy, capable of both extreme and subtle displays of emotion. The skin that lies over those muscles is highly elastic. It stretches and creases, wrinkles, bulges, and puckers. While catching every last subtle motion of the face isn't impossible, it's certainly a herculean task to ask of an animator, much more likely to end in failure than success. Even Squaresoft, who spent nearly enough time, money, and talent to bankrupt itself on an incredibly ambitious movie failed to perfectly cast the illusion of true human expression. Video game budgets are much tighter on all resources, thus, when photorealism is the goal, the end result typically ends up squarely in the Uncanny Valley the moment the camera focuses on a face.
The more realistic a face is drawn, the harder it is to bring it to life. From my experiences in my animation courses at DigiPen, it seems like one of the main reasons is a reluctance to “push the extremes”. Cartoonie characters practically beg to be exaggerated and this goes far to give them a genuine feeling of life.
Edit: I recommend watching these videos with the sound off to get a better feel for what the facial expressions and body gestures are trying to convey.
Daxter is particularly great at demonstrating how lively a cartoonie character can be. Now compare the characters of Jak II to the characters in Castlevania: Lament of Innocence.
When I first watched these cut scenes I immediately thought: “Fantastic Plastic People”. While far from universal, realistic characters tend to have almost mask-like faces, as though the animators were afraid they'd break the character's face if they made it too expressive. The results are, frankly, a bit creepy. Even though the character designs here are anime styled, their body movements are motion captured from live actors. That realistic movement combined with the stiff faces has a pretty strong Uncanny Valley effect.
For a final comparison, we turn to one of my favorite games, Legacy of Kain: Defiance.
Again we have stylized characters that trend towards realism, however the animators were less reluctant to push the extremes of expression. Raziel is a particularly interesting case since all we really see of his face is his eyes, which must carry the weight of his expressions. This is done incredibly well, bringing forth his moods very clearly with the aid of his exaggerated features and facial animations.
It's ironic that it's harder to bring to convincing life realistic characters than cartoonie ones and that photorealistic characters are often the least convincing. Nowhere is this more true than with the face, the part of the human body that we social animals are hardwired to read the expressions of. We spend a lifetime perfecting our abilities to pick up on the subtle cues faces tell us about the people we interact with and the social situations we navigate. While the broad animations of the body may fool us into believing an animated photorealistic character is truly real, this illusion most often comes crashing down the moment the face is focused on. The moment it smiles or speaks the jig is up and the fake revealed.
I hope everyone is finding my Uncanny Valley series interesting. Tomorrow's post will talk a little about techniques that have been used to capture realistic animation and how they don't necessarily work when applied to animated characters.
Related Links:
Crossing the Uncanny Valley: Part 1
Crossing the Uncanny Valley: Part 2
Mother 3 Makes Me Feel Human Again