【文章內(nèi)容簡介】 effort and skill to create animation with dialogue. When you plan your story, think about creating interaction between characters not only on a physical level but through dialogue as well. There are several techniques, discussed in this chapter, that can be used to make dialogue manageable. 12. Use the graph editor to clean up your animations. The graph editor is a useful tool that all 3D animators should bee familiar with. It is basically a representation of all the objects, lights, and cameras in your scene. It keeps track of all their activities and properties. A good use of the graph editor is to clean up morph targets after animating facial expressions. If the default ining curve in your graph editor is set to arcs rather than straight lines, you will most likely find that sometimes splines in the graph editor will curve below a value of zero. This can yield some unpredictable results. The facial morph targets begin to take on negative values that lead to undesirable facial expressions. Whenever you see a curve bend below a value of zero, select the first keyframe point to the right of the arc and set its curve to linear. A more detailed discussion of the graph editor will be found in a later part of this chapter. ANIMATING IN STAGES All the various ponents that can be moved on a human model often bee confusing if you try to change them at the same time. The performance quickly deteriorates into a mechanical routine if you try to alter all these parts at the same keyframes. Remember, you are trying to create human 計算機(jī)與信息學(xué)院 本科畢業(yè)設(shè) 計（論文） 14 qualities, not robotic ones. Isolating areas to be moved means that you can look for the parts of the body that have motion over time and concentrate on just a few of those. For example, the first thing you can move is the body and legs. When you are done moving them around over the entire timeline, then try rotating the spine. You might do this by moving individual spine bones or using an inverse kinematics chain. Now that you have the body moving around and bending, concentrate on the arms. If you are not using an IK chain to move the arms, hands, and fingers, then rotate the bones for the upper and lower arm. Do not fet the wrist. Finger movements can be animated as one of the last parts. Facial expressions can also be animated last. Example movies showing the same character animated in stages can be viewed on the CDROM as CD111 AnimationStagesMovies. Some sample images from the animations can also be seen in Figure 111. The first movie shows movement only in the body and legs. During the second stage, the spine and head were animated. The third time, the arms were moved. Finally, in the fourth and final stage, facial expressions and finger movements were added. Animating in successive passes should simplify the process. Some final stages would be used to clean up or edit the animation. Sometimes the animation switches from one part of the body leading to another. For example, somewhere during the middle of an animation the upper body begins to lead the lower one. In a case like this, you would then switch from animating the lower body first to moving the upper part before the lower one. The order in which one animates can be a matter of personal choice. Some people may prefer to do facial animation first or perhaps they like to move the arms before anything else. Following is a summary of how someone might animate a human. 1. First pass: Move the body and legs. 計算機(jī)與信息學(xué)院 本科畢業(yè)設(shè) 計（論文） 15 2. Second pass: Move or rotate the spinal bones, neck, and head. 3. Third pass: Move or rotate the arms and hands. 4. Fourth pass: Animate the fingers. 5. Fifth pass: Animate the eyes blinking. 6. Sixth pass: Animate eye movements. 7. Seventh pass: Animate the mouth, eyebrows, nose, jaw, and cheeks (you can break these up into separate passes). Most movement starts at the hips. Athletes often begin with a windup action in the pelvic area that works its way outward to the extreme parts of the body. This whiplike activity can even be observed in just about any mundane act. It is interesting to note that people who study martial arts learn that most of their power es from the lower torso. Students are often too lazy to make finger movements a part of their animation. There are several methods that can make the process less time consuming. One way is to create morph targets of the finger positions and then use shape shifting to move the various digits. Each finger is positioned in an open and fistlike closed posture. For example, the sections of the index finger are closed, while the othe