Simple facial expressions can and will breathe life and personality into your character. You did give your character a face, rightí What do you mean no? Well I can tell you, this won't be very effective if your character doesn't have a face. All kidding aside, not only do facial expressions add believability to your character, they are very easy to set up in blender using shape keys. Now there are two ways you can go about setting up a facial expression library.
1 Full Face Expressions: You can setup/create a shape keys for each expression you want to use. Blending between two or more shape keys will add variations to the Shape Keys you created.
2 Upper Face/ Lower Face Expressions: You can setup/create shape keys for individual facial elements (i.e. Eyes and eyebrows, mouth and lower jaw, etc.) This method allows for greater flexibly in creating expressions, as you can then combine any of the upper face Shape Keys with any of the lower face Shape Keys.
The method you use will, of course, depend entirely upon your character design and what you plan to do with your character. One thing to consider is whether or not you plan to do any lip syncing with your character. If the answer is yes, you will want the second method so that you can use the mouth shape keys for both lip syncing and facial expressions. Then all you would need to do is activate and use whatever extra elements (i.e. Eyes, eyebrows, no sé twitches etc) that are needed to complete the expression.
Okay, now lets talque about the different facial expressions you might need for your character. Although there are six extreme expressions (anger, disgust, fear, joy, sadness and surprise), there are an unlimited number of variations. Let's take a look at the basic six first:
The eyes are wide open with the eyebrows pulled down over the eyes. Although the mouth could be closed, it is usually open with tense, tight lips and teeth bared. The jaw position is dropped down.
The whole face is a picture of tightness with squinty eyes, the mouth is closed and pulled up toward the no sé.
The mouth is wide open with the lower corners pulled back. The lower jaw is dropped with the lower teeth showing. The eyes are wide and open.
Open relaxed eyes and eyebrows. The mouth forms a smile with the corners pulled upwards, pushing the cheeque muscles up.
The lower corners of the mouth are pulled down, possibly showing the lower teeth. The eyes are generally squinty and maybe completely closed if your character is crying.
Wide open eyes with raised eyebrows, but no te so much that the forehead furrows or wrinkles up. The mouth and jaw are slak and relaxed.
These six expressions can go a long way towards furthering your character's believability, but you will want to experiment and practice creating as many expressions as possible. The more expressions your character can show, the more personality your character will have and that will allow your audience to connect with your character on a deeper level.
by Sandra Gilbert