【正文】 w that increases gradually over time. You are now at the phase where you bee both the actor and the director of a movie or play. Although animation appears to be a more spontaneous act, it is nevertheless just as challenging, if not more so, than all the previous steps that led up to it. Your animations will look pitiful if you do not understand some basic fundamentals and principles. The following pointers are meant to give you some direction. Feel free to experiment with them. Bend and break the rules whenever you think it will improve the animation. SOME ANIMATION POINTERS 1. Try isolating parts. Sometimes this is referred to as animating in stages. Rather than trying to move every part of a body at the same time, concentrate on specific areas. Only one section of the body is moved for the duration of the animation. Then returning to the beginning of the timeline, another section is animated. By successively returning to the beginning and animating a different part each time, the entire process is less confusing. 2. Put in some lag time. Different parts of the body should not start and stop at the same time. When an arm swings, the lower arm should follow a few frames after that. The hand swings after the lower arm. It is like a chain reaction that works its way through the entire length of the limb. 3. Nothing ever es to a total stop. In life, only machines appear to e to a dead stop. Muscles, tendons, force, and gravity all affect the movement of a human. You can prove this to yourself. Try punching the air with a full extension. Notice that your fist has a bounce at the end. If a part es to a stop such as a motion hold, keyframe it once and then again after three to eight or more keyframes. Your motion graph will then have a curve between the two identical keyframes. This will make the part appear to bounce rather than e to a dead stop. 4. Add facial expressions and finger movements. Your digital human should exhibit signs of life by blinking and breathing. A blink will normally occur every 60 seconds. A typical blink might be as follows: Frame 60: Both eyes are open. Frame 61: The right eye closes halfway. Frame 62: The right eye closes all the way and the left eye closes halfway. Frame 63: The right eye opens halfway and the left eye closes all the way. Frame 64: The right eye opens all the way and left eye opens halfway. Frame 65: The left eye opens all the way. 計算機與信息學(xué)院 本科畢業(yè)設(shè) 計（論文） 12 Closing the eyes at slightly different times makes the blink less mechanical. Changing facial expressions could be just using eye movements to indicate thoughts running through your model39?，F(xiàn)在你既是電影和戲劇的演員又是導(dǎo)演。不要試圖同時移動身體的每個部位，應(yīng)集中精力制作具體部位的動畫。整個手臂的活動就像是一邊連串的連鎖反應(yīng)。動作圖形會在兩個相同的關(guān)鍵幀中間產(chǎn)生一條曲線。 第 63 幀：右眼半睜，左眼緊閉。 5. 攝像機沒有拍到的內(nèi)容不用關(guān)注。 劇烈，類似于卡通的動作是使用分布密集的關(guān)鍵幀制作的。處于地面的部分應(yīng)該在好幾幀上保持在同一位置。 三維動畫中最富挑戰(zhàn)性的一項任務(wù)是讓一個數(shù)字演員顯得計算機與信息學(xué)院 本科畢業(yè)設(shè) 計（論文） 19 擁有重量和質(zhì)量。就用前面跳躍的角色例子，角色著地時，腹部可以上下顫動，胳膊可以微微彈起，頭可以向前傾斜等。 我們很容易只是坐在電腦前，努力解決人體動畫的所有問題。 FK能控制不同身體部位的運動。某個特定姿勢會變得難以實現(xiàn)。如果動畫和對話配合良好，比起他們的競爭對手，這些學(xué)生便具有了相當(dāng)大的優(yōu)勢。 一種使用圖形編輯器的好方法是在制作面部動畫后清理 morph Shape。記住，您是在試圖模仿人類的動作，而不是機器人的動作。 連續(xù)地制作各個部位的動畫會簡化該流程。 1. 第 1 輪：移動身體和腿部。運動員總是從撅到極限的骨盆部位開始 結(jié)束動作。 對話基礎(chǔ) 1. 看鏡子。例如，點頭和搖頭分別表示贊成和反對。 音素是我們在對話中聽到的單個聲音。 7. 不要過于夸張。 要使人物顯得生動，一定要添加眼睛動作。 10. 呼吸應(yīng)該是面部動畫的一部分。說話時嘴巴不會張得很大。例如：單詞 puter 根據(jù)音素拼為“ pewtrr”。移動頭部來強調(diào)特定的狀態(tài)。 2. 眼睛、嘴和眉毛是變化最大的部分。有趣的是尚武的人可以發(fā)現(xiàn)他們的大多數(shù)力量來自于下體。 3. 第 3 輪：移動或旋轉(zhuǎn)胳膊和手。 有時動畫從身體某一部位切換會引出另一部位。比如，可以移動的第一個部位是身體和腿。這會造成一些不可預(yù)知的結(jié)果。 在計劃故事時，考慮在角色之間形成交流，這種交流不僅是身體層面的，而且要通過對話來表現(xiàn)。 IK 可以設(shè)置身體的下半部分把腳固定在地上，而上半部分用 FK 使身體移動的自由度和精確度更好。使用 FK 的缺點是當(dāng)你的角色處在一個互動的環(huán)境內(nèi)，簡單的移 動也會變得困難。這會讓角色的動作顯得更為獨特，也可以解決許多時間和位置安排問題。地板可以振動，有人坐進去的椅子通過下陷再稍微彈回也可以顯示出對重量的反應(yīng)。第 12 章中討論的動畫的 12 個原理之一的擠壓與拉伸（或者重量與反彈）是為角色提供重量的好方法。當(dāng)模型移動重量時，落下的腳被鎖定在適當(dāng)?shù)奈恢?。動畫中通常結(jié)合使用二者。如果你希望一只手看上去靠近身體并且攝像機視角看上去也是如此，即使實際并不靠近，也沒必要再做調(diào)整。 第 65 幀：左眼完全睜開。 計算機與信息學(xué)院 本科畢業(yè)設(shè) 計（論文） 18 4. 添 加面部表情和手指動作。 生活中，只有機器會突然停止。然后返回時間軸的起始位置，制作另一部分的動畫。如果你不懂一些基礎(chǔ)知識和基本原理，制作出的動畫會很可笑。s actions more unique and also solve many timing and positioning problems. The best animators are also excellent actors. A mirror is an indispensable tool for the animator. Videotaping yourself can also be a great help. 10. Decide whether to use IK, FK, or a blend of both. Forward kinematics and inverse kinematics have their advantages and disadvantages. FK allows full control over the motions of different body parts. A bone can be rotated and moved to the exact degree and location one desires. The disadvantage to using FK is that when your person has to interact within an environment, simple movements bee difficu