Megan Facial Expressions
Megan is a character I was asked to design and create for Emotion FX as a demo character. She was sculpted in ZBrush, Modeled in 3ds Max, textured in xNormal, Zbrush and Photoshop. These screenshots from ZBrush illustrate a few of the expressions that have been built into the facial rig for Megan. The expressions are built using the Facial Action Coding System, developed by Paul Ekman, as a knowledge base . This means these targets are based on muscle shapes or muscle group shapes that when blended together, create a comprehensive expression.
A Short Tutorial
One thing I have learned in my work on facial expressions for characters is that the appearance of lines in expressions is crucial as a character exresses emotion. The lines are what make an expression readable and realistic. There are challenges for doing this in CG, but the more wrinkles and lines appear and disappear when they should, the better the expressions will read.
Have you ever watched your grandmother talk to a baby? Grandmothers LOVE talking to babies. Part of why it's so fun for them is that babies respond very positively to older people in general. What does everyone, especially older folks do when they talk to a baby? They make faces. All kinds of pleasant happy faces, and babies respond very well to the stimuli. Especially so with older people who have lots more wrinkles in their faces. All those lines give away what they are feeling and the babies pick up on all those good vibes in those readable faces.
Babies have limited vision in the earlier months. It's a pretty safe bet to assume they can read read the expressions of older faces a little easier than others because of the additional lines and wrinkles. This example helps illustrate how lines are so important in reading and making expressions of emotion – and not for just babies, but everyone.
This is also why we get an off-putting feeling when we see the signs of deception in the face, like the effects of botox injections or other plastic surgeries and procedures designed to remove wrinkles. The areas of the face treated by botox look "dead" to us. They are a deviation from the natural state which we are programmed in our subconcious to recognize as deceptive and even dangerous.
Fear & Surprise
This first image is a look at two similar emotions. Fear and Surprise. They both include raised eyebrows, a mouth drop, but they are different in the extra tension in the brow for Fear, which entirely changes how the expression is read. We are very tuned to recognize signs of tension in the face and this is one great example of how this tension makes a huge difference in the character's expression.
This next image is a look at two versions of pain. Both feature an extreme and tight brow crunch, with extreme tightening around the eyes, pulling the cheeks up and pulling down the brows. Stress wrinkles appear around the brow above and below. One is a contained and silent pain with the lips rolled in and tight with the mouth pulled tight. The second is a more vocally expressive pose in the lower face which implies a release instead of containment, though tension remains in the lower face, shown via the lower lip depressor and platysma muscles. Yup... platysma, not platypus. :D
Pout & Shrug
This image is a look at two more similar expressions with entirely distinct meanings. Pout and shrug both feature a protruded lower lip at varied intensity. Pout is full-on intensity. Shrug is less so. In the upper face, both have brows raised, but the pout features an elevated inner brow to add some sad emotion, a characteristic of pouting.
Smooch, Disgust & Suspicion
This next image features the common "smooch" pose, which of course is a mostly relaxed expression other than an elevated brow, and constricted and protruded lips. The disgust of smelling something bad or reacting negatively to something is done by crunching the nose and mouth upward, constricting the lips tighter and pulling the lips to one side or the other.
Anger & Holding Breath or Blow
This image features the also common anger pose. Anger can be epxressed in several ways, but mainly is done with the brow down, the nose crunched, and the mouth either open or closed but also with the upper teeth exposed by a snarl in the upper lips. The blow or puff pose is done by tightening and constricting the lips and filling the cheeks with air.
Vocal Anger & Wink
This image features another anger pose. This one is a more vocal pose that is appropriate for a battle cry or a yell. A wink is a one sided eye contraction with brow down, nose crunched and cheek raised on just one side of the face. The only differences between a wink and a wince is the intensity of the wince is much greater, with the wink being done more relaxed and with the mouth open. Wince usually has the mouth closed with the teeth exposed.
These feature two versions of the smirk that are, again, similar, but have a different effect. The first is a self assured or confident smirk. The next is an inquisitive smirk. It seems to ask: "Really? Are you sure?".
These are two versions of a smile. The first is a basic, natural smile. This smile is the common everyday smile that you experience casually between friends. The second is a more intense smile that is used in more formal social situations where we want to appear more posed and camera ready. There can be tension underneath this smile which a formal situation would create. The differences are again in the intensity, but also the first relaxed smile does not expose the upper and lower teeth as much. The second one does and that is why it reads with a bit more tension than the first. The sincerity of smiles is read in the eyes. If the smile raises the cheeks into the eye area, pushing up the lower eyelids, the smile is read as sincere. a menacing smile or fake smile is mostly relaxed around the eyes.
Laughs and Chuckles
These laugh poses are almost identical but one has the added surprise element of expression by raising the inner brow that alters the message even though it varies only slightly from the other. The one on the right is also reading more as a chuckle or giggle than a belly laugh by merely removing the inner brow raise and closing the mouth slightly.