EMOTIONS OF THE FACE
Now we get to explore a little bit about the face
Animating The Face
2. Animation Demo Spline Keys
3. Continue on you Animation
Facial Recognition as Hardwired
Faces are hard wired into our brains they are paramount to our survival. Paul Eckman was one of the first scientist to prove that facial expressions are universal and not learned. He did this by trekking into the remote areas of Papua New Guinea filming the people who had never had outside contact before.
Facial expressions can be very subtle.
A leading scientist in the research into faces Paul Eckman
Paul has become famous through television as seen in the show Lie To Me where Tim Roth Plays Paul Eckman. Pauls books are very interesting and whilst they’re not exactly made for animators there’s a bunch of interesting insights into how the face works.
Here is another promo with an educational bent…
Weta have used the Pauls FACS (Facial Action Coding System) as an integral part of their facial rigging since Gollum on Lord of The Rings. On Avatar for example all the sliders on the face correspond to facial muscles not phonemes (word sounds). This is great for realistic characters which must behave well, realistically. For more cartoony characters we can get away with a lot more simplicity and phonemes are still a large part of a facial library. There’ are many different types of rigging when it comes to faces and many different styles. A good rig will give the animator a wide variety of shapes to work with.
The difficulty of facial animation comes from the fact that every person is a facial expressions expert, but unlike Paul Eckman it’s mostly from unconscious knowledge, we can often tell when something is off but we won’t know why!
The Facial Expressions
Facial Expressions are pretty well known. But the details of how the face works is actually pretty amazing. A great book for facial expressions is The Artists Guide to Facial Expressions by Gary Faigin. For serious animators it’s worth reading from cover to cover and explains the way the face works very clearly.
The face is driven by muscles which can only pull. One end of the muscle is attached to bone and the other end is connected to the skin, that’s how the mechanics of the face work. here’s a rather ammeter facial rig driven by muscles, although rather primitive it does give us a good rough idea of how the face works…
Below are some character facial model sheets. Always look at ref, weather it real life or how other animators have achieved emotion in the face. Again Reference Reference Reference! We may think we know how the face works but by really studying good reference we’ll find the details that can really elevate our work.
There’s loads of facial reference guides around on the net, Pinterest is a great place to spot collections for facial reference like this one…
Keeping Facial Simple
Faces needn’t be complicated. Here is a great example of Grommit, from Wallace and Grommit, who communicates very clearly not by talking but by subtle adjustments to his eye brows.
The Facial Expressions of the Iron Giant are worth a study in simplicity too. Such a wonderful design for a character with remarkably few moving parts and yet so much expression!
Posing Facial Expressions
Some facial testing on one of my recent characters, notice these are just blend shapes on the skin, the jaw is not moving and reveals the teeth.
Animating Facial Expressions
While animating facial expressions we can assume a few things.
1. Facial expressions can be very fast, much faster than other parts of the bodies. It is very hard for a facial expression to float over more than 10 – 15 frames try it yourself.
2. Parts of the face move very fast and individual parts move at different speeds and can have slight offsets.
– Eyes are very quick, to the point that eye darts can be over one frame. Eyes will rarely move over more than 4 or 5 frames. They are very quick and often keep to 2-3 frames as a good rule. The muscles of the face are also very quick and are the first to react to thought.
– Brows can be a little slower than the eyes and lag a few frames but they are still very quick and usually animate them over less than 10 frames.
– Mouth can lag a little more from the brows but are still very quick and should be under 10 frame transitions.
4. Eyes lock onto objects and stay aimed at them, they don’t move with the face. This doesn’t necessarily mean keep them on aim constraints but just keep that in mind.
5. Watch the iris/pupil placement, realistic characters will rarely show white above the pupil except in shock or horror. Cartoony characters this is more about ratios of white. Covering this iris will make characters look sleepy.
6. Eye movement/direction can change the shape of the surrounding lids. Animate the lids with the eyes unless automated.
7. Eyes and brows are most important for facial expressions, without the mouth expressions can be clear.
8. Be sure to add arcs and in-betweens in poses, faces rarely have linear transitions, usually they compress or extend on the inbetween, especially in the case of blinks.
9. Blinks can be very quick, almost to the subframe level. Slow blinks like in love scenes usually represent a very dramatic moment. Keep them fast!
10. The face is extremely versatile even in real life, it can be pushed in large variations, the face also has a habbit of maintaining volume, so add squash and stretch.
11. The Jaw is a pivoting bone but it can also move slightly, the lower teeth are welded to it and the upper teeth don’t move as they are welded to the skull. But on stylised characters the teeth can be moved independently from the jaw and skull, though do so sparingly and hiding the transitions with closed mouths. Teeth shouldn’t float around the face, they placement on the teeth in relation to the mouth can signify a lot of different expressions.
12. Don’t forget asymmetry, facial expressions are rarely symmetrical. Counter posture usually works for the brows and mouth, opposites up and down.
Animation Scout has some great short little videos on facial tips…
Other Facial Animation Tips from Animation Mentor
For more go to their vimeo page.
Finally here’s some interesting videos, example of facial capture. Couple of things to watch is the movements of the face because it’s much easier to break them down while watching the fake character. Also you can see how much subtlety is in realistic facial that gets lost. On movies like Avatar the facial mocap artists take great care to animate the face whilst looking closely at the ref provided by the facial cams. Animators will further tweak the animation too, it doesn’t just come out of the box looking all peachy!
For our own purposes it’s important to stylise and caricature our facial when it comes to animation.
And one more this time check out he expression at the end
Great photos of kids crying here