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发表于 2007-2-2 21:21:00
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Re:[转载]CG animation 高级角色动画理论
The 12 Basic Principles of Animation 动画的12条基本原则
The 12 basic principles of animation are listed below. You may see them in a slightly different form or order in other articles, books or magazines. I have listed them here as shown, because I feel this order facilitates learning them more easily. You can learn one first, then go on to the next building up your skills. I also feel they tend to be related, and flow more easily from one to the other in this order.
下面列出了动画的12条基本原则,也许在其他的文章或者书刊中有过不同版本,但内容基本类似。按照这个顺序列出它们,我觉得会更方便大家理解。你们可以从第一个学起,然后逐个学习,加深理解。同时,我也感到它们之间又是交叉联系的。按照这个顺序学习的话,将来运用的会更加自如。
1. Timing
2. Ease In and Out (or Slow In and Out)
3. Arcs
4. Anticipation
5. Exaggeration
6. Squash and Stretch
7. Secondary Action
8. Follow Through and Overlapping Action
9. Straight Ahead Action and Pose-To-Pose Action
10. Staging
11. Appeal
12. Personality
By following and knowing when, where and how to apply these basic ideas, and by understanding them, one should be able to create good animation. It is important to note that simply memorizing these principles isn't the point. No one will care whether or not you know this list. It's whether or not you truly understand and can utilize these ideas that matter. If you do, it will show automatically in your work.
通过学习并理解清楚什么时间,什么地方,和怎样运用这些基本法则后,你应该能够制作出比较优秀的动画出来了。只是简单机械的记忆这些法则不是我们的目的,因为没有人会在意你是否背得出我列出得这些法则。关键是你能否真正的理解它们,了解这些法则的实质。如果做到了,那么就会在你的作品里立杆见影。
1. Timing 节奏
2. Ease In and Out (or Slow In and Out) 渐进和渐出(或慢进慢出)
3. Arcs 运动弧线
4. Anticipation 动作预备
5. Exaggeration夸张
1. Timing 节奏
It may seem kind of silly to even have something as basic as timing on the list. Obviously timing is the essence of animation. The speed at which something moves gives a sense of what the object is and why it is moving. Something like an eye blink can be fast or slow. If it's fast, a character will seem alert and awake. If it's slow the character may seem tired and lethargic.
有些人会觉得把timing(节奏)放在法则列表里似乎很愚蠢,因为这个对动画制作来说实在是太基本了。显而易见,“节奏”是动画的基本要素。物体运动的速度说明了物体物理本质,和运动的成因。仅仅是“眨眼”的动作就可或快或慢。如果眨的快,角色看上去就处在“警觉或者醒着”的状态,如果眨得慢,角色就会显得比较慵懒,疲惫,昏昏欲睡。
John Lasseter gave a good example in his famous Siggraph paper using a character with a head that turns left and right. Essentially, he gives different durations for the exact same head turn motions, and shows how it can be 'read' differently based merely on the timing. If the head turns back and forth really slow, it may seem as if the character is stretching his neck. A bit faster it can be seen as saying "no". Really fast, and the character is reacting to getting hit by a baseball bat.
John Lasseter在他的那篇著名的Siggraph论文里使用了一个关于头部从左向右的转动的范例。虽然是同一个转头的动作,但他按照不同的时间节奏做出来,却表现出不同的意思,而本质上他仅仅是改动了运动的timing“节奏”而已。如果头从后往前转的很慢的话,角色看上去只是在活动颈部而已。加快一点速度,看上去就象是在说:NO! 再快点,角色看上去就很象被物体砸到头部一样。
Having a good sense of timing is critical for good animation. Cartoony motion is usually characterized as fast snappy timing from one pose to another. Realistic tends to have more to do about going between the poses. But both require careful attention to the timing of every action.
对于好的动画来讲,好的“节奏”感非常重要,非常基本。动作的卡通风格一般要求物体从一个pose(姿势)到另外一个pose的变换很灵活简洁。写实风格的则要求在pose之间细节上要有变化。但是无论哪种风格,都要注意每一个动作的timing节奏问题。
I think it was Chuck Jones who said "The difference between the right timing and the almost right timing, is the difference between lightning and a lightning bug."
记得Chuck Jones曾经说过:“好的timing节奏和差强人意的timing节奏之间的差别就有如“光”和发光的萤火虫之间本质的差别”。
范例:请按ctrl+鼠标左键点下面的AVI链接,以下同。
60 Frame Hea把d turn - This looks more like a stretch action 这个版本看上去象是生硬的分解动作(60 fps)
30 Frame Head turn - This is more like a "no no no" action 这个版本象在说“NO NO NO ”(30 fps)
5 Frame Head turn - This is more as if he just got hit 它看上去象是被什么东西给打到。(5 fps)
Note how all of these samples have the same key poses, but simply changing the timing causes the action to be read very differently.
请注意这些例子里的动作pose 都是一样的,只是调整了timing节奏,结果动作就有了不同的含义。
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2. Ease In and Out (or Slow In and Out) 渐进和渐出(或慢进慢出)
Ease in and out has to do with gradually causing an object to accelerate, or come to rest, from a pose. An object or limb may slow down at it approaches a pose (Ease In) or gradually start to move from rest (Ease Out).
渐进和渐出的规律通常是运用在物体pose的加速或减速变化过程中。一个当物体接近某个POSE时,通常是减速变化的(称之为渐进或慢进);相反地当它从一个POSE开始向另外一个POSE变化时,应该是加速的(称之为渐出或慢出)。
For example, a bouncing ball tends to have a lot of ease in and out when at the top of its bounce. As it goes up, gravity affects it and slows down (Ease In), then it starts its downward motion more and more rapidly (Ease Out), until it hits the ground.
比方说,一个弹跳的小球凡是在它达到顶点的时候都会有渐进和渐出。当它起跳时,受重力影响速度应该越来越小(即渐进)。当它向下运动的时候应该逐渐的加速(渐出),直到它触地为止。
It's important to note that "gradually" here doesn't have to mean slow. It just means the object isn't moving 100% and then in one frame coming to a complete stop. For snappy cartoon motion, you may have ease in and out over only a couple of frames. But even 3 frames of ease in and out may help a limb from looking too stiff or mechanical.
需要注意的是这里“通常“并不意味着速度慢。真正的意思是物体运动不必本来是全速前进但只是用一帧就嘎然而止,这是不行的。卡通类型的动作里你只要2帧来做这个渐变过程就可以,但如果是用3帧来做,看上去就会比机械的僵硬的动作好很多。
As applied to character animation, you usually use ease in and out for most movemnts. Even if the character is just turning their head, you will probably want a few frames to soften up the start or end of the motion.
对于角色动画,你总是要在运动中加入渐进或渐出的处理。即便角色只是旋转了一下头部,你也可能需要在动作的起始和结束的地方加一些帧使之更平滑些。
范例:请按ctrl+鼠标左键点下面的AVI链接,以下同。
Bouncing Ball - The ball on the left is linear, which looks abrupt. The one of the right eases in/out at the top and looks smoother and more natural. 左边的球是线性运动,没有渐变处理,看上去很生硬。右边的球则在运动的顶点出有渐进、渐出,看上去就平滑自然的多。
Arm - Bad, No Ease - Very robotic/computery looking 没有渐变处理的胳膊的弯曲动作,看上去非常的僵硬,如同机械一般。
Arm - Good, With Ease - Much more natural and fluid 加入了渐进和渐出,则自然了很多。
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3. Arcs 运动弧线
In the real world almost all action moves in an arc. When creating animation one should try to have motion follow curved paths rather than linear ones. It is very seldom that a character or part of a character moves in a straight line. Even gross body movements when you walk somewhere tend not be perfectly straight. When a hand/arm reaches out to reach something, it tends to move in an arc.
在现实生活中,所有的运动都是有弧线的。当做动画的时候你应该让动作沿着曲线运动而不是线性的直线。很少有角色或者角色身上某个部位的运动是直来直去的。甚至当你整个身体在行走过程中也不是呈一条直线运动的。当手或者胳膊伸出去触摸物体时,都是按照曲线来运动的。
Sticking with the head example, the head rotates in an arc like fashion. That is if a characters head rotates from left to right, at the halfway point, it should actually be dipped or raised slighly depends on where it is looking. This stops the rotation from being perfect linear or mechanical looking.
还是拿头部运动来做范例,头部象扇子一样呈弧线旋转运动。也就是当头部从左象右转动时,在中间位置头部应该根据他视线看的方向加一点低头或者抬头的动作,而不是纯线性的旋转或者机械式的动作。
范例:请按ctrl+鼠标左键点下面的AVI链接,以下同。
Bad, Linear Ball - Linear motion looks rigid and stiff 错误的线性运动的小球??线性的运动,动作看上去非常僵硬
Good, Arc Ball - Smoothly arcing the same motion looks more natural 好的弧线运动的小球 ?? 平滑的弧线运动让一样的运动看起来更自然。
Head Turn, Linear - Stiff and mechanical 线性的转头动作 ??非常机械
Head Turn, Arc - A bit more natural and interesting looking 具有弧线的转头运动?? 非常自然有趣
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4. Anticipation 动作预备
Action in animation usually occurs in three sections. The setup for the motion, the actual action and then follow-through of the action. The first part is known as anticipation.
角色的动作一般分为三个阶段:运动的准备阶段,动作实施阶段,和动作跟随阶段。第一个个阶段就是所说的动作预备。
In some cases anticipation is needed physically. For example, before you can throw a ball you must first swing your arm backwards. The backwards motion is the anticipation, the throw itself is the motion.
有些情况动作预备是根据物理运动规律需要这样做。比如说在你投掷一个球之前必然要先向后弯曲你的手臂获得足够的势能。这个向后的动作就是预备动作,投掷就是动作本身。
Anticipation is used to lead the viewers eye to prepare them for the action that follows. Generally, a longer period of anticipation is needed for faster actions. If you think about cartoons, you've probably seen cases where a character zips off screen leaving a puff of smoke. Usually just before the zip, there is a pose where the characters raises a leg and bends both arms as if he's about to run. That's the anticipation pose for the off screen run.
动作预备一般用来引导观众的视线趋向即将发生的动作。所以常见的一个长时间的预备动作意味着下面的动作速度会非常快。如果你注意观察卡通片,你可能会遇到类似的情况,角色先是预备奔跑的样子,然后一溜烟地急速消失。角色在奔跑前,通常会先抬起一条腿,弯曲他的胳膊即使他马上就开跑了。这就是常见的动作预备。
Generally, for good clear animation, the viewer should know what is about happen (anticipation), what is happening (the actual action itself) and what happened (related to follow through).
总之,一个好的动画应该让观众明白什么是将要发生的(动作预备),什么是正在发生的(动作本身),和已经发生的(类似于动作跟随)。
Most body movements of a character require anticipation in some form, especially from rest. For example, before a character takes a step to walk, they must shift their weight on one leg so they can lift the other, another example of anticipation.
角色身体的绝大多数运动都需要某种形式的动作预备阶段。特别是从静到动的运动状态的转变。比方说,在角色开始走的时候,他们肯定要先转移自身的中心到一条腿上,这样他们才能抬起另外一条腿。
现在看看预备动作的例子:
范例:请按ctrl+鼠标左键点下面的AVI链接,以下同。
Moving Ball - The ball on top simple moves from left to right, but the bottom ball anticipates the motion before moving, broadcasting what is about to happen. 运动的球??屏幕上面的球从左到右做着运动,但屏幕靠下的小球先是做了预备动作,让人能看出即将要发生什么。
Bug Jump, Bad - The bug jumps without any anticipation and looks totally wrong. 糟糕的小虫弹跳??虫子没有做预备动作就跳了起来,看上去明显是错误的。
Bug Jump with Aniticipation - Here the bug character jumps up after first crouching (anticipating) the main action. 有预备动作的小虫弹跳??这个虫子在压缩了整个身体(预备动作)之后才跳起来,是正确的。
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5. Exaggeration 夸张
Exaggeration is used to accent an action. It should be used in a careful and balanced manner, not arbitrarily. Figure out what the desired goal of an action or sequence is and what sections need to be exaggerated. The result will be that the animation will seem more realistic and entertaining.
动作上的夸张处理一般用来强调动作的突然性。这个原则应该根据实际需要适当的运用,不能随便使用,否则会适得其反。制作者应该首先清楚动作的目的性,剧情需要是什么,以及决定哪个阶段需要动作上的夸张处理。适当的夸张会让动画看起来更可信更有趣。
One can exaggerate motions, for example an arm may move just a bit too far briefly in an extreme swing. A pose can be exaggerated, perhaps the characters leans just a bit farther than normal. Generally when animating to dialogue, one listens to the track and picks out areas that sound like they have more stress or importance, and then tends to exaggerate poses and motions that fall at those times.
角色的动作过程是可以夸张的,譬如可以让胳膊摆动过程中抖动的很厉害。某一个POSE也可以夸张,比如让角色比正常情况下倾斜很多。在制作对话过程中,动画师要仔细辨认出音轨里重音强调的地方,然后据此配合一些夸张的动作或者运动来强调这些部分。
The key is to take something and make it more extreme in order to give it more life, but not so much that it destroys believability.
做好“夸张”的处理关键要让被夸张的部分发挥到极致,赋予它们活力,但要适度,否则会让人觉得很假。
范例:请按ctrl+鼠标左键点下面的AVI链接,以下同。
Bug Point, Bad - Pretty subtle not exaggerated motion. 没有做夸张的“指指点点”的动作
Bug Point, Good Exaggerated - Much more exaggerated motion. He is obviously mad here. 加强了夸张效果,很好的体现了虫子角色发狂的状态。
*note that in many cases, subtlety is good. Subtle action mixed with exaggeration here and there can make for some of the best acting and animation. The first sample above is almost scarier because it's so subtle...he seems mad, but somewhat controlled...you're not sure if he is going to explode. However, it could probably use a bit more motion on the spine. The second sample is more exaggerated and might fit within the context of a larger animation, especially if it was more cartoony.
注意:
在很多情况下,正常的动作状态也是必要的。 正常状态下的动作夹杂着一些适当的夸张,是优秀动画必不可少的出彩的部分。上面的第一个例子可以看出角色已经有些愤怒了,看上去角色是发狂了,但在努力的控制情绪,你不清楚他将要什么时候爆发,动作上只是在躯干上做了些弯曲。第二个例子里则夸张的多,根据上下镜头动作的特点决定使用多大的夸张程度,特别是动作类型是不是卡通风格的。
话题列表:请按ctrl+鼠标左键点下面的链接,以下同。
1. Squash and Stretch挤压和拉伸
2. Secondary Action 次要动作
3. Follow Through and Overlapping Action 动作惯性跟随和动作重叠
4. Straight Ahead Action and Pose-To-Pose Action 一气呵成制作动画和按关键帧做动画
5. staging 动作表现力
6. Apeal 动作精彩程度
7. Personality 角色个性
6. Squash and Stretch 挤压和拉伸
Squash and stretch is a way of deforming an object such that it shows how rigid the object is. For example if a rubber ball bounces and hits the ground it will tend to flatten when it hits. This is the squash principle. As it starts to bounce up it will stretch in the direction it is going. Squash and Stretch was also initially done to prevent strobing due to lack of motion blur. However even in cases where motion blur can be used, there may still be reasons to use it.0020
挤压和拉伸是用来表现物体的弹性的。比如一个橡皮球弹跳后落到地面时身体会被压扁。这就时挤压的体现。当小球弹跳起来后它要在它弹跳的方向上拉伸变形。在没有条件做motion blur 运动模糊处理的情况下,有时动作可能会看上去比较糟糕,可以用挤压和拉伸变形来补偿。即便做了motion blur ,我们同样需要做挤压拉伸。
An important note about squash and stretch, is that no matter how an object deforms, it should still appear to retain it's volume. That is, if a ball flattens down 2 times as much as normal, it will have to get 2 times as wide to keep its volume. If a character or part of a character doesn't maintain volume with squash and stretch, believeability will be lost.
关于挤压和拉伸比较重要的一点是无论物体本身怎样形变,它的体积、容积至少要保持不便。也就是说如果它的高度压扁到比平时水平低2倍,那么它的宽度也应该相应的扩大2倍来保证体积不变。如果一个角色或者角色身上的某个部分在变形中不能保持其体积,看上去就会很假。
The most obvious usage in character animation is muscles. When a muscle is contracted it will squash and when extended, it stretches. Not every part of a realistic character should have this principle applied. For example, the skeleton or things like eyeballs etc may not really deform much, though the flesh around them may.
角色动画中动作很大程度上是靠肌肉形变来表现的。肌肉收缩就是挤压,肌肉舒展就是拉伸。当然并不是角色身上所有的组织都是按照这个规律变化的。比如说,骨骼和眼球并不会随着周围很多肌肉组织的形变而变形。
Most people try NOT to simply use scaling for squash and stretch. Real squash and stretch is usually some part of an object deforming differently that just a simple scale up or down. This presents a challenge to get CG squash and stretch looking as nice as drawn poses, since it's usually a bit tougher to easily animate random shape deformation.
但大部分人都不是简单的改变角色的缩放比例来实现挤压拉伸效果。真正的挤压和拉伸应该是角色身上各部分都有变化互相配合的结果,而不是简单的缩放比例。这样想要做出象手绘POSE的那样的完美挤压拉伸效果无形中增加了很多的难度。
Rigid objects can still squash and stretch in a way. Think of the lamps in Luxo Jr. The lamp itself is a rigid metal object. But before it jumps it anticipates the action by crouching down and bending. That bending is basically squash and stretch.
刚性物体一般是按同一方式挤压拉伸的(有别于有机物体)。想象一下Luxo Jr.动画里的台灯。这些台灯本身是刚性的金属物体。当它们准备弹跳的时候,它们首先要作出弯曲的预备动作。这个弯曲就是挤压拉伸的最基本的形式。
范例:请按ctrl+鼠标左键点下面的AVI链接,以下同。
Ball Bounce and Squash - The ball on the left is animated without squash and stretch, while the one on the right deforms. Note too how the one of the right does not use a simple scale for the effect. The result gives a more elastic and loose feel to the ball on the right. 挤压拉伸的小球??左边的小球的弹跳没有挤压拉伸,但右边的有变形。 请注意右侧是怎样变形的,不是简单的缩放比例。我们感觉右边的小球更有弹性。
Bug Squash Tummy - Here the bug pats his stomach and it squashes and stretches. 这个虫子拍打它的肚子,注意肚子上面有挤压拉伸形变。
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7. Secondary Action 次要动作
Secondary action creates interest and realism in animation. It should be staged such that it can be noticed but still not overpower the main action. A good example of this is a character at a table acting and delivering their main acting. A side piece of acting business might be the character thumbing their fingers on the table. This isn't the main action say, perhaps it occurs as the other hand is more largely gesturing and your focus is on the face. But it is something that the character is doing/acting that adds a more realistic and natural feel to the animation. As mentioned, it must be staged so that the main action isn't overpowered. It's the kind of thing that is usually more subtle or can be felt more than noticed immediately.
次要动作是用来增加动画的趣味性和真实性,丰富动作的细节的。它要控制好度,既要能被察觉,又不能超过了主要动作。一个比较好的例子是一个角色坐在桌子旁边,一边表演着什么,一边手指还在敲打着桌子。后者并不是角色的主体动作,也许角色正在一边比划着什么,我们的视线焦点也是在角色的脸上。但重要的是我们应该赋予角色更真实更准确自然的表演,所以我们增加了手指敲打桌子的细节,也就是“次要动作”。
正如前述,次要动作不能超过主体动作的幅度。是一些很细微,轻易不容易被察觉到的动作,但是却很重要,很必要。
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8. Follow Through and Overlapping Action 动作惯性跟随和动作重叠
Follow Through is the same as anticipation, only at the end of an action. It is usually animated as something goes past its resting point and then coming back to where it would normally be.
动作惯性跟随和动作预备类似,只是前者在动作结束前出现,而后者出现在动作发生前。经常在动画中见到这样的情况,物体或者其中一部分的运动或表演动作已经超过了它应该停止的位置,然后折回来返回到那个位置。这就是动作惯性跟随
For example, in throwing a ball, you put your hand back, that's anticipation, it's the preparation for the throwing action itself. Then you throw the arm comes forward for the main action. Follow Through is then the arm continuing past the normal stopping point, overshooting it and then coming back. The arm has continued or "followed through" on the action it was doing before returning back to rest.
比如说做投掷的动作,你首先要把你的手向后摆,这是动作预备。是为了将来做投掷的动作做准备。然后投球出去后胳膊因为惯性没有停下来而是继续向前摆,所谓的动作惯性跟随就是发生在这个时刻,胳膊没有停在本应该停止的位置上而是靠惯性继续摆动一段时间然后反方向摆回来。
Overlapping Action is an action that occurs because of another action. For example if a dog is running and suddenly comes to a stop, its ears will probably still keep moving for a bit. Another example, if an alien is walking and it has an antenna on it, the antenna will probably sway as a result of the main body motion. This is overlapping action. It is caused because of the main motion and overlaps on top of the main motion.
动作重叠本质上是因为其他动作的连带性而产生的跟随动作,而且时间上动作间有互相重叠部分。比方说,如果一只奔跑的小狗突然停下来,她的耳朵可能仍然继续向前因为惯性运动着。另外一个例子,如果alian(范例中虫子角色的名字)在行走着,头上顶着的触角会随着身体的摆动而摇摆不停。这就是所谓的动作重叠,即因为主体动作的连带性而产生的动作,同时叠加在主体动作上的动作。
范例:请按ctrl+鼠标左键点下面的AVI链接,以下同。
Ball Follow Through - The ball on the top simply moves and stops, while the bottom ball continues past the end point and then comes back to rest (follows through). 小球运动的动作惯性跟随 ?? 上面的小球只是简单的由运动变为停止,而下面的那个小球在停止的位置继续向前保持惯性运动了一段距离然后返回到应该停靠的那个位置。
Bug Arm Follow Through - Here the bug arm rotates up with follow through. The arm itself and the hand continues moving past the stop position, then falls back into place. In addition, this shows good timing breakup since the arms comes to rest before the hand. That is the hand takes a little longer than the rest of the parts to stop. This effectively breaks up, or overlaps the action so it doesn't all stop at the same time avoding "twins" in time and not only "pose". Because delaying parts of a hierarchy or chain (like an arm, leg, antenna, etc...) is such a common form of action, and makes things look smooth, it is often given it's own term, "Successive Breaking of Joints". This means that each part of the limb moves and stops one after another, by being offset in time slightly. This gives the action a more natural and whiplike feel as shown here. 小虫手臂动作的惯性跟随??范例中小虫的胳膊向上弯曲,能看到结束的位置有动作惯性跟随。胳膊和手都没有在应该结束的位置立即停下来,而是继续运动一段距离后返回最后结束了动作。而且这个例子也很好的体现出胳膊比手掌更早进入静止的状态的动作先后连带关系。正是因为动作重叠规律的存在导致了胳膊和手不是同时达到静止的状态。类似现象还能在各种铰链系统中有所体现,比如手臂,腿脚,天线等等。。。不同部位的动作重叠让动作本身看上去更柔和。“完美的打断了骨骼之间的联系”意思是说我们让骨节之间的运动有先后连带关系,通过让动作timing彼此之间有一点的延迟而使运动和停止都是一个接一个的完成,如同甩鞭子一样,这样整个角色的动作就看上去自然的多。
Bug Antenna Swing - Here the bug does a take and notices the camera. The antenna motion is overlapping action, it is caused by the head and body motion. 小虫头顶触角的摇摆??这个例子表现的是小虫看到镜头突然转头的情形。它头上的触角的运动就是明显的动作重叠。触角的运动是由身体和头部的运动连带产生的。 |
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