作者：Michael Jungbluth

弧线（Arcs)

动画中的应用

这也许是所有人都知晓的一大原则。任何液体或物体在移动时最快速的移动方法便是沿着直线走。而且当我们想从A点移动到B点时，走直线也是最快捷的方法，但是直线也会让人感到无聊。这是一种直达目的地的路线，而很少会牵扯到过程的乐趣。但是通常这种移动的过程正是显示物体的变化及其意义的过程。（请点击此处阅读本系列第1、第2、第3、第5、第6节内容）

动画的过程则有点像钟摆。它不会直线型地从一个顶点滑落到另一个顶点，而是会划过一个漂亮的弧形并停落在中央，再往另外一个方向摇摆。整个运转的场景非常好看，并且吸引人去探索这种弧线的乐趣。而这种极致的弧线美能够传达出很多内容，或宏伟壮丽，或轻盈精致，很难让人移开眼球。从这种移动的过程中我们可以看出物体的特性，并赏心悦目于这种优美的移动线条。而如果不使用弧线，则会让观众感受到一种冷酷，失重且不自然的感受，所以这却只适用于动画中的机器人描述，或者像Spock（游戏邦注：《星舰迷航记》里的角色）这类型的外星人。

手臂移动(from gamasutra)

如上图，这是Richard Williams的《Animator’s Survival Kit》中关于身体运动的弧线描绘。注意身体每个部分的运动变化，特别是臀部。

游戏设计中的应用

在叙述中，这种原则便更加明显了。我们在小学就学到了传统的叙事弧线。不论是角色弧线还是故事弧线都是创造出强大叙述的基本要素。每一个角色和故事都必须拥有一个循序渐进的发展过程。随着这种过程的发展，它们将能够到达一个最高点，并在后来开始慢慢往下回落。

而在游戏设计中，弧线的使用也是相同道理。即玩家的游戏过程或者游戏机制的变化都是按照弧线而展开。当玩家在游戏中前进时，游戏机制将会一层一层展开，但是在最后，为了让玩家顺利完成游戏，游戏机制也会适时地一层一层合拢起来。一般来说，游戏总会在一开始就往机制中添加更多功能，直到一个饱和点。但是你必须知道应该在何时止住，并往回走，懂得张弛有度，让玩家能够最大限度地吸收自己的所得。当游戏开始回收这种机制弧线时，玩家便会松一口气，且更愿意去尝试并吸收下一个机制弧线。弧线是用于连接起点和终点，同时也能够体现你所创造出的优美而流畅的重叠动作。但是你同时也必须清楚在游戏的最大弧线中哪个点是最重要的，且每一个小弧线之间都不能存在任何矛盾点，且应该与大弧线完美地连接在一起。

注意每条弧线的层级，以及小弧线是如何维持整体的故事弧线(from gamasutra)

如果在游戏中每个敌人，武器以及关卡都拥有属于自己的弧线，那么不管这些内容的分量大不大，都能够与游戏世界更好地连接在一起了。这种小弧线能够更清晰地体现出游戏内容的发展和变化，并在游戏设置中更深刻地展露出它们的功能。其实这已经形成了一种定律。当你在游戏中遇到一个新的敌人时，都会出现关于该敌人的简介，而这就是弧线的起点。然后你开始与敌人战斗，并经历各种程度的攻击与防御，直到最后打败了敌人，而这便是游戏的高潮。后来的结果便是敌人的死亡或者投降。你益智游戏也常使用这种弧线。你在游戏中创建了布局和工具，让玩家在游戏中面对不同难度级别的问题，慢慢提高挑战，直到玩家最终完成游戏。而当玩家最终完成一个较为简单的问题后，游戏弧线便回到了与起点持平的界面。如果游戏弧线的设置足够合理，流畅，玩家定会喜欢游戏。

我们需要记住，如果让玩家沿着直线通过一个目标或关卡可能会很不自然，但是如果能让他们按照弧线移动，也许他们的游戏体验便会更加顺畅了。就像是坐过山车时，我们会在最低处大松一口气，并在最高处屏足呼吸。当你在游戏中使用了弧线，你便能够在游戏中更自由地移动，并且更深刻地感受到游戏体验。而这时候玩家与游戏便能够更紧密地结合在一起了。

副体或副动作(Secondary Action）

动画中的应用

动画中的副体包括了头发，披肩，尾巴，旗帜等。它们也许对核心内容没有任何影响，但是却能够起到额外的视觉效果。举个例子来说，当你看着一个人的时候，他的身体便是主体，而其它部位则是副体。副体是外部内容，但是却牢牢依赖于它所附着的主体。副体是一种外表现象。并且副体能够帮助我们更好地衡量一件物体的重要性，因为副体通常都是一些比较不重要的角色。实际上，很多副体都是通过弧形动作和重叠动作体现出来。

顽皮跳跳灯(from gamasutra)

《顽皮跳跳灯》(游戏邦注：皮克斯1987年制作的短片)的前进动作所体现出的副体是指电源线的晃动，而以此指明跳跳灯来自哪里以及如何移动。

当副体出现在动画中时，它的功能便能够真正体现出来。副体的加入能够增强并推动动画角色的个性。所以，比起通过描绘一个人蹦蹦跳跳去展现他的愉悦，还不如让他哼哼小曲吹吹口哨。角色在吹口哨时不一定要继续往前走，但是如此一个小动作却能够更好地流露出他的喜悦心情，让角色更加生动。

游戏设计中的应用

在游戏中，次要目标和能量也就是副体的存在。它们可以拥有属于自己的实体形象，也可以拥有美丽的外表，但是却必须与主题紧紧连系在一起，并且无需任何细节描述。它们可以是游戏主要目标的扩展，或者至少是一些与游戏主题相关的的内容。就像是一个口哨能够用来表现玩家的情绪，调动游戏气氛，但是却没有任何目标性。就其本身而言，副体在游戏中的分量很轻，甚至可能一点都不重要，就像一块随风飘荡的布匹。但是当副体与一些举足轻重的内容结合在一起时，它便能够用来修饰这个重要的内容，并展示它的重要性。这时候副体便从一块没有作用的布片转变为旗帜，自豪地充当一种有意义的标志性存在。

在主要行动之前或之后使用次要行动也很重要。但是如果你是在主要行动过程中进行次要行动，它们便会被无情地埋没掉。以面部表情为例子进行说明。如果你的表达方式发生了变化，那就说明你的思维过程也发生了变化，而如果这种变化是发生在快速移动的过程中，你便会很容易忽视这种表达。所以表达方式的变化必须发生在移动之前或之后，这也是更好地依附于主要行动的另外一种方式。如果你在主要行动以及重要任务的执行过程中堆积了太多次要目标，有可能会因此给玩家罩上巨大的压力，并让他们混淆了游戏的主要目标。同样地，如果你在各种能力，武器或机制中附加了太多次要功能，或者在关键时刻突出它们，那么玩家很有可能会忽视他们的存在，因为这时候的他们正关注于其它更重要的目标。

所有附件都在盒面上，虽然它们能够给人们留下深刻的印象，但是真正谈及执行力时，它们只能是不依附于主要物件的副体(from gamasutra)

次要行动总能最先吸引玩家的注意，因为它们具有深刻的情感和视觉表现，很容易让观众上瘾。就其本身而言，它们只能是帮助核心内容吸引关注的次要内容，并且在游戏中不能占有太大的分量。要记住，次要行动是一面旗帜。它能够体现许多关于人类，国家以及意识形态的内容，但是如果没有旗杆起支撑作用，并帮助它连接起最重要的部分，它就只能是一块随风飘荡的布片。（本文为游戏邦/gamerboom.com编译，拒绝任何不保留版权的转载，如需转载请联系：游戏邦）

Adding Weight to Your Game Design Part 7: Arcs

by Michael Jungbluth

Arcs

Applied to Animation

This is the principle that probably everyone has some knowledge of.  One of the quickest ways to rob something of feeling fluid, organic or alive is to move it in a straight line.  Sure, straight lines may be the fastest way to get from point A to point B, but they are also the most boring.  They are all about the destination, and care nothing for the journey.  And that journey is where you find growth and meaning in a character.

In animation, think again of the pendulum.  It doesn’t move from apex to apex in a straight linear fashion.  It drops in the middle, creating a beautiful arc that gives it weight, and fluid motion.  Arcs are what animators love more than just about anything else.  It is pure beauty in motion and what makes the movement between key poses fun to watch.  The extreme of the arc conveys so much, be it big and grandiose, or small and contained that is impossible not to enjoy the path that gets you there.  It shows the personality of the character and leads the eye through a smooth ballet of motion.  Likewise, lack of arcs is how you can make something feel cold, weightless and mechanical, which is useful when animating a robot… or Spock.

A page demonstrating arcs during body movement from the Animator’s Survival Kit by Richard Williams. Notice how there are in every part body parts movement, even the hips.

Applied to Game Design

In a narrative sense, this principle is a no brainer.  This is the classic narrative arc that everyone learned in grade school.  A character or story arc is the fundamental of creating a strong narrative.  Every character & story must have progressive challenges that allow them to grow.  And as those challenges increase, they reach an eventual climax, which is then resolved.

And in game design, arcs can work much the same way.  It means you are starting the player on a journey, or growing a game mechanic organically.  As they move forward in the game, it builds, and builds until eventually some sort of resolution is required to make it feel complete.  Often times, this means adding more power or functions to the mechanic until it maxes out.  But at a certain point, you need to know when to pull back on how much is too much, and allow the player to digest everything you have given.  As this mechanics arc is pulling back, the player will feel comfortable, and more than willing and capable of digesting the next mechanic’s arc.  Arcs are what link everything together towards a complete and final point, as well as how you create beautiful and flowing overlapping action.  But be aware of the staging of your arcs to make sure that the one with the biggest arc is the most important at that moment or to the overall game.  Everything else needs to have smaller arcs that will not compete, but flow seamlessly compared to the larger one.

Notice the hierarchy of each arc and how the smaller help to hold up the main story arc.

If every enemy, weapon and level can have an arc, no matter how small, they will feel far more connected to the world they reside in.  And it will give each their own history and experience, making each feel like a fully functioning element of the gameplay experience.  In most cases, this already happens on a regular basis.  When you encounter a new enemy in a game, there is usually a unique intro for them, which is the beginning of the arc.  You then fight them, through different attacks and stages, until finally you defeat them, which is the climax.  At which point, you want a death or surrender that matches the arc leading up to it.  This works exactly the same with puzzles.  You establish the layout and tools.  You allow the player to face each step of the puzzle, growing the challenge, until they complete it.  And just completing a satisfying puzzle is often times the resolution to the arc for the player.  If built up properly, and fluidly, then the resolution will resound strongly for the player.

But remember, when leading a player through an objective or level, that the straight path will always feel the most mechanical.  Let them feel the organic flow of an arc as they go through a level.  Like a roller cost, let the dips take their breath away while the hills make them hold it.  But keep the arcs clean and fluid, so that it feels effortless.  Because the arcs are where the beauty lies and different points in an arc carry different sensations of weight.  The moment you nail the arcs is the moment you can get lost in the motion and just naturally feel it flowing throughout everything you do.  And that is the moment that the player and the game become a seamless unit.（source:gamasutra）

Adding Weight to Your Game Design Part 8: Secondary Action

by Michael Jungbluth

Secondary Action

Applied to Animation

Secondary action in animation is everything from hair, to capes, to tails, to flags.  It is the parts that aren’t necessary to the core action, but add extra visual flare.  When you look at a person, the root of the body is the main action, and everything else is secondary.  It is ambient, but reliant on whatever it is tethered to.  It is the icing.  It is also a great way to see where the weight of something has just come from or where it will be going as secondary actions are often very light and almost weightless.  In fact, a lot of secondary action is shown by using follow through and overlapping action.

The secondary action of Luxo Jr’s forward motion is the rippling of his power cord which shows clearly where he came from and how he moved.

Where secondary action really becomes powerful is when it comes to acting in your animation.  The secondary action is what can be added to help establish and push the personality.  So instead of just adding a bounce to the step of a happy person walking, you can also make them whistle.  That whistle isn’t necessary for the character to continue walking, but it helps to establish their pleasant mood and makes them feel even more alive.

Applied to Game Design

In games, secondary objectives and powers need to work the same way. They can be their own entity, and they can be beautiful, but they must stay tethered to the main objective and not become so elaborate that they distract from it.  They should feel like a natural extension of it, or at least something that is relevant to the main purpose of the game.  They should feel like that whistle, adding to the overall mood, atmosphere or purpose, but not necessary for that purpose to go on.  In and of itself, it is very light, and almost weightless, like a random swatch of cloth blowing through the air.  But, when attached to something more substantial it helps to define the form underneath or trail behind showing off just how much power it is attached to.  It is transformed from being just a random piece of cloth floating in the air into a flag, proudly displaying any number of symbolic and meaningful messages.

Think of any secondary mission or quest that quickly grew repetitious.  More than likely it had you collecting something you didn’t care about and in all honesty the game world itself didn’t care about it either.  That is probably because it didn’t match the main action of the game.  Because without that anchor, secondary actrions are lost to the wind, aimlessly floating in an ocean of meaningless grind fests.

It is also important to use secondary action before or after a major action.  If you try to use them during a large main action, they can get lost.  Take for instance a facial expression.  If you have a change of expression, which is signifying a change in thought process, during a fast action, it will be lost in the motion.  The change in expression should happen before or after a move.  This is just another way to keep it tethered to the important action.  If you layer too many secondary objectives during a major, important quest, you will run the risk of overwhelming the player & having them become lost as to what is really important at that moment.  Likewise, if you give a power, weapon or mechanic too many secondary functions, or introduce them during intense moments, the player can miss it because they are too focused on what needs to be done immediately.

Imagine each attachment is a bullet point on the back of the box. Sure, the back of the box looks impressive, but when put into effect, this is all secondary without any primary to hold it together.

The secondary action is often what players notice first, and often times is what they are instantly drawn to.  Because they are so emotionally and visually loaded, its easy to overdose on them.  But they themselves are only a way to help add attention to the weight of the core, and should be only heavy enough to not get lost in the rest of the game.  Just remember them as a flag.  It says a lot about the people, country, and ideology of where it is located, but without a flagpole to attach it to what is really important, it is just a piece of cloth floating in the breeze.（source:gamasutra）