Chapter 14 Facial Animation Expressing Emotion Copyright 1999 Peter Ratner (Excerpt from Mastering 3D Animation) Blending Expressions After you finish creating all the basic facial expressions, then it is time to load them into your shape shifting editor. Blended shapes are then created by combining various mouth, nose, eyes, eyebrows, and so on targets. By altering the percentage of each, one can achieve countless facial expressions of varying subtlety. Figures 14-39 to 14-45 illustrate some of the expressions one can attain by blending the base objects. Figure 14-39 The original shapes are blended in different percentages. Even though they are not shown here, both the left and the right sides are used. Figure 14-40 A look of disgust is the result of blending varying percentages of the above base expressions. Figure 14-41 The subsequent shy look comes from combining the above target shapes. Figure 14-42 A sad expression is achieved by combining the above base objects. Some targets like the eye wink have a left and right side that is utilized. Figure 14-43 Sometimes unexpected expressions can be formed by the most unlikely combinations. In this case a tired look is the result of the above implausible mouth shapes. Figure 14-44 A few target shapes can create a very expressive look such as this one of craziness. Figure 14-45 A coy aspect. The examples are only meant as a rough guide. Each person will get different results depending on the shape of their original targets and the capabilities of their software.   Direction of the Muscular Pull A muscle is composed of a bundle of fibers that work in a mutual consortium to perform common duties. Muscles never act alone. When one muscle or set of muscles contract, other opposing muscles become active to regulate or change the behavior of the contracting ones. It this combination of movements that results in the complicated harmony of the facial muscles. Figure 14-46 illustrates the directional pull of the various muscle groups to achieve specific expressions. Figure 14-46 The muscles combine to create aspects of anger, hysteria, fear, surprise and suspicion. 1 2 3 4 This tutorial is an excerpt from Mastering 3D Animation Peter Ratner is the author of 3-D Human Modeling and Animation. He is the founder of the Computer Animation program at James Madison University where he is currently teaching.