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开发者分享《天际》的模块式关卡设计法

发布时间:2013-05-08 16:24:57 Tags:,,,,

作者:Joel Burgess

虽然许多开发者都知道模块系统的基本概念,有些甚至已经在一两个项目中有所接触,但他们极少在工作中充分利用它。然而,我和Nate已经深入挖掘该系统的价值,并且有所收获。我们现在的项目是我们认识和共事近十年以来的第15次合作了。我们的每一个项目包括加入Bethesda工作室以前的作品,都使用了这个方法。

我们最近发现我们和同事之间在开发过程中达成了许多默契的理解、期望和假设。新美工和新设计师一加入我们团队,我们就会为其作一番详尽的解释。在本文中,我们将对探索多年而积累下来的知识进行详细地介绍。为了理解我们的方法,有必要先了解一下我们成为开发者以及Bethesda工作室发展的历程。

首先,我们的游戏都很大。如果你玩过或看过《天际》、《辐射3》或任何我们的其他开放世界游戏,那么你就知道我们的游戏范围是很大。这是我们的游戏必不可少的特点和我们工作室的传统。你无法在6个小时内设计出另一款《天际》,还指望提供相同的游戏体验。范围不是我们的游戏的随机属性,而是主要特点。

当你玩Bethesda游戏(或你参与制作)时,你就会知道我所说的“我们的游戏都很大”是怎么回事了。游戏的大小,影响到我们在工作室所做的方方面面。生产方法、技术和工具、工作流程、流水线——一切都讲究效率。像《天际》这样的游戏需要数年的开发时间,每一个环节都必须尽可能地高效进行。对于这么大的游戏,不可能在几个小时或几天内发现失误,而需要数周乃至数月。

核心价值、团队规模和我们的合作经验组成了普遍称之为“工作室文化”的东西。即使激励你的团队的文化与我们的不同,你也有可能从我们这里汲取经验,就好像我们也可能借鉴你的经验一样。

请把本文当作一个案例研究。在此,我们分析的模块化关卡设计法只是Bethesda工作室文化的一个体现。

在深入分析我们的做法以前,让我先定义一下“套件”是什么。首先,套件是系统。比如,《辐射3》中的一个基本管道套件,可能是由四个简单的图形部件组装在一起的。这个套件基本上是用网格系统贴合在一起的。套件的最重要的属性是,它不是部件的简单相加之和。美工不是只给我们四个部件,还要给我们一个可以在编辑器中制作无数个管道组合的系统。

gdc2013pipes(from gamasutra)

gdc2013pipes(from gamasutra)

管道套件只是美术套件的一个简单的例子。本文的主题是建筑化套件的制作。我们使用的案例包括《天际》中的Nord Crypts,以及《辐射3》中的地窑。套件对我们的游戏玩法是非常重要的,因为在Bethesda中,我们把它作为关卡设计的基础模块。套件并不是一个新概念,也不是Bethesda和我们做的游戏类型的专属。想一下桌面游戏《Carcassone》。它与《Monopoly》或《Scrabble》不同,每一次玩这款游戏,它的面板都会发生变化。贴图的拼接方式使道路与道路相通,河流与河流相连,从而生成一种高度随机但视觉上连贯的画面。当观察《Carcassone》的面板时,很容易看到它的网格,和贴图如何产生这种独特的游戏区域。面板贴图本身就是环境美术套件的绝好例子。

许多基于子画面的2D游戏很依赖类似于我们现在要谈的这种思路和技术。子画面或纹理贴图集技术是许多2D游戏系统的核心,所以很容易看出这些游戏如何利用统一大小的可重复拼图。多亏了这种技术,美工不必手动绘制整个游戏世界。游戏可以在节省内存的情况下,利用重复贴图来快速刷出地图。

2002年11月,Lee Perry在《游戏开发者》杂志上发表了一篇文章,探讨了模块化关卡设计和世界构建法,在当时,这种方法特别有助于增强游戏的真实感。Bethesda使用这种技术已经有好一段时间了——到撰写本文为止,应该是18年了。我们工作室在《终结者:未来冲击》和《上古卷轴2:匕首雨》中都使用了模块化世界构建法,这为我们现在的思路和技术打下坚实的基础。

所以请记住,本文探讨的概念不只是我们自己过去十多年的工作成果。我们现在的工作流程也借鉴了许多其他人的想法,我们还有很多东西要学习。

webVaultAntFarm(from gamasutra)

webVaultAntFarm(from gamasutra)

模块化的优势与劣势

正如前面所提到的,许多开发者都理解模块化关卡设计的原理,但我们希望根据我们对这个论题的广泛研究,为读者提供更深刻的见解。为此,我们将回顾我们过去几年发现的这个方法的优势与劣势,以便最充分地挖掘利用其价值。

首先,模块化最明显的优点就是,可循环利用。重复利用美术材料有助于制作游戏的庞大范围。在《天际》中,构建世界的工作量非常大,所以甚至尽量减少围栏和过道的制作量,对我们来说都是非常重要的。我们尽量合理地分配时间和精力,可以重复利用美术材料的地方就不另外制作,而把时间放在制作需要突出其特点的地方。

以下是《天际》的世界规模:

整个世界大小是16平方英里

5个主要城市

2个隐藏世界

300+地下城

140+景点

37全城镇、农场和村庄

现在再看看《天际》开发团队的成员合照。照片中共有90人。除了少量外包人员,其他都是各个部门的成员。我们抵住诱惑没有把小工作室扩张成包含上百个团队的大工作室,所以你所看到我们的相同大小的游戏都是由这么些人完成的。

Skyrim Team(from gamasutra)

Skyrim Team(from gamasutra)

现在,我们重点看看你们认为在Bethesda做的最接近传统的关卡设计法——世界构建中的地下城部件。照片中只有10人直接负责那些地下城制作。其他成员则专注于大量其他功能、内容、系统和支持工作。想到我们团队的规模之小,你应该为我们每个人所肩负的责任之大感到惊叹。

无论是早是晚读到本文,你大概为认为游戏的规模一定程度上限制了我们的能力发挥,成为我们的负担。而事实是,虽然我们的境况不同了,我们有无尽的时间、资源或才能,但我认为我们已经找到最适合我们的游戏制作方式了。

荷兰籍画家Piet Mondrian,以20年代时在巴黎的创作的作品而闻名。你可能不知道Mondrian这个名字,但你可能认得出他的作品,如下图。Mondrian可以使用不少四种颜色的颜料,当然可以画出更加复杂的作品。然而,他却选择自我约束,从而开创了属于他自己的特有风格。直到现在,他的风格仍然影响着艺术和时尚领域。

Mondria(from gamasutra)

Mondria(from gamasutra)

纵观科学史,技术史、音乐史以及任何人类创造物的历史,你会发现约束不但不会压制创造力,而是使人们更专注,更有利于发明和创新。我认为我们的工作流程也是这样的。如果我们因为处境改变而改变,那么我们也许就无法得出今天这个结论了。

再回到我们的主题,我们也不得不承认模块化也存在明显的缺陷:循环利用可能变成一种重复。这就导致了我们通常所说的“艺术疲劳”。在Steam平台,《天际》的玩家游戏时间中位数峰值超过100小时,这是对我们最大的褒扬。但是,这么长的游戏时间足够玩家发现游戏中一而再再而三地出现相同的岩石或农家或挂毯了。当这种重复过于明显时,玩家就会产生审美疲劳,游戏世界的真实感也大打折扣了。

我们已经想了一些办法来延迟艺术疲劳的出现。主要办法之一就是尽可能多地复制和粘贴。当我刚加入Bethesda时,《湮灭》正处于开发周期的冲刺阶段。它与《天际》的规模相当,但是开发人员只占后者的约一半。地下城美术团队弥补这个落差的办法之一是,在编辑器中制作大量“仓库”牢房。在这些仓库里复制粘贴不同的光源和零碎的物品,从而制作出“新的”地下城。虽然高效,但这个方法的效果不太理想,许多玩家甚至把《湮灭》的地下城称为“曲奇成型刀”。

我们还注意到的一个现象是,相比于大建筑的重复,玩家更容易发现细节元素的重复,且发应更消极。以下三张截图取自《湮灭》中的不同地下城。

Obliv02(from gamasutra)

Obliv(from gamasutra)

Obliv(from gamasutra)

Obliv(from gamasutra)

Obliv(from gamasutra)

Obliv(from gamasutra)

在各张图中,你可能会首先注意到重复的杂乱物,然后才是重复的建筑结构,特别是以第一人称视角观察场景时。为了尽量减少不必要的重复,我们放弃像在《湮灭》中的那种仓库牢房的做法。在《辐射3》的开发初期,我们组织了一队关卡设计师,确保我们能够更快地构成空间,尽可能减少重复的地方。

你还可以在更基础的层面上抵抗艺术疲劳。在项目早期,将特殊生物或特殊玩法与特定的场景联系起来,是很普遍的做法。例如,你可能觉得士兵只能站在军事基地,僵尸只能躲在隐蔽洞穴。请不要这么想。把你的套件当作空间的建筑学特性,以便使用其他元素来塑造这个空间的特殊性。你能够分解的东西越多,你能混合的元素就越多,场景的花样就越多。

这也适用于套件本身——积极鼓励混合+匹配套件的概念。这就叫作“套件混搭”。

再看出自《天际》的Dwarven地下城的例子。在《上古卷轴》系列中,所有Dwemer地下城的都有大量黄铜色光照和发条元素,形成地下城的特色。《天际》中有十个这类地下城,并且都非常大。如果这些地下城都是一样的,那玩家就会觉得太无聊,再次发现地下城也不会感到惊喜了。

Dwem01(from gamasutra)

Dwem01(from gamasutra)

为了将东西混合起来,我们开始考虑组合外部元素。在第二个例子中,我们引入一些Dwarven地下城专属的独特材料和敌人。这种视觉和玩法上的调整使场景和战斗部分更加新鲜,从而避免玩家产生审美疲劳。

Dwem02(from gamasutra)

Dwem02(from gamasutra)

在第三个例子中,关卡设计师只是用冰穴填充Dwarven的走道,效果却很显著,马上就改变了场景的基调和氛围。一些美工可能不太喜欢这么做。因为,你的美术概念被用在意料之外的地方可能会导致糟糕的混搭效果或光照问题。然而,在制作这类游戏时,你必须退让几步,宽容地接受这个做法。在你刚开始制作美术材料时,你应该允许这种实验。并非所有混搭都是合理的,但你可以尝试一下什么管用什么不管用——最重要的是,找到那些基本管用做法,而只需要你做一点点调整就可以达到非常棒的效果。

Dwem03(from gamasutra)

Dwem03(from gamasutra)

再次看看模块化的优点,最大的好处之一(特别是从生产的角度看)是模块化做法对那些美工不多的团队非常有利。还记得我说过《天际》地下城内容只有十个人在制作吗?其中八个是关卡设计师,只有两人负责全部的美术工作。他们制作了七个套件,关卡设计师用它们又设计了400多个内部不同的地下城牢房。从头到尾,我们大概花了两年半的时间构建完成这些地下城。

如果把我们的工作分配做成比例图,那就如下图所示。其中,黄色部分是套件美术,桔色部分是关卡设计,蓝色部分保守估计就是地下城内容。

GDC2013Infographic(from gamasutra)

GDC2013Infographic(from gamasutra)

这里我强调两点。第一点最明显:这个方法适用于美工较少而设计师较多的团队,利用模块化办法,两名的美工就可以完成远远超过两名美工原本可以完成的工作量。《天际》的例子证明了这种办法的高效性,特别是在只有两名美工能制作这么多内容的核心美术工作时。

第二点比较不明显但更加重要。想一想照片上的其他80个人。因为少数人就能够应付这么大的地下城,剩下的人就得以专注于游戏其他方面的工作,比如场景美化、任务编写和脚本、角色设计和动画、游戏代码等。

当然,《天际》只有两名全职套件美工还有另一个原因——套件实在是一种复杂的东西,不仅要求美工具有制作高品质贴图的能力,还要求纯熟地运用美术工具、深刻地理解编辑器和设计流程等等。这种需要左右脑协调的工作一定程度上没有体现美术专业人员的价值。我曾与优秀的美工共事,虽然他们很擅长套件制作,但又非常讨厌制作套件——所以他们就不做了。

所以,如果你要寻找具有制作套件才能又对此感兴趣的美工,你无异于寻找独角兽——太稀有了。

套件的过分复杂还产生另一个问题,也就是,很难确认和修复漏洞。套件与其他美术材料不同,因为你可能要修复糟糕的旋转点或纹理接缝,而这些东西很容易被忘记。套件美工在整个项目过程中都要牢记整套系统的规则,这是非常重要的,也是必须的。套件部件是贯穿于游戏的成千上百个实体化的时间。对可能产生特定漏洞的旋转点进行明显的修复,有可能导致那成千上百个其他实例产生新问题,而你却没有意料到。

我们的模块化办法的另一个优势就体现在这里。因为套件部件是高度实例化的,所以当套件发生改变时,这些改变会立即体现在整个游戏中。作为美工,执行输出就像低空飞行部署新艺术,无论关卡设计师是屏息等待还是毫不在意。

对于美工,模块化方法有助于立即查看真实的案例。开发者不必设置测试区,只要把任意用你的美术制作的关卡载入并查看在游戏中的表现。

这个部署过程对设计工作流程的影响最小。游戏画面应该如何,这是项目早期经常面临的问题,套件也不例外。这个美学构建的过程可能毫无组织,且耗费时间。问题是,设计师在这个阶段通常帮不上忙,而是等着看自己能做什么事。这就导致美工不得不加快进度,仓促地做出之后不又不得不变更的决定。后果就是,关卡设计被严重耽误了,许多工作要么白做要么必须大改。

为了避免这种情况,我们要求我们的套件“丑陋但是实用”。也就是,先保证套件达到要求的功能,这就让美工不至于匆忙制做视觉效果。

这种套件制作要求给我们带来额外的好处是:Bethesda的关卡设计相当高效。因为我们是在预制好的套件的基础上编辑,所以就能极快地实验各种关卡布局。有了套件,我们可以在编辑器中直接制作粗糙的样本,然后放进游戏中,立即看到结果。

事实上,我们甚至可以说,有了好的套件,关卡设计师在只看到套件、不依靠编辑器或工作流程的情况下就能迅速设想出最终的玩法效果。这是因为关卡设计师正在使用和实验真实的、最终的美术材料。我们不必推翻美术设计,不必烤材质,也不必编辑地理,所以我们的成本相当低。

但金无足赤,我们的办法也存在一个重大缺陷。当我们说Bethesda的关卡设计相当高效时,其实就已经是一个警告了。我们要求设计师在良好的套件的基础上作业。否则,他就不只是行业中速度最慢的关卡设计师了,而且完全没有成功的希望。我们对美术套件的依赖性非常大,所以美工和关卡设计师之间的关系非常重要。

游戏业中有一个近乎常识的关卡设计过程,虽然变体颇多,但基本上就是,在项目早期,设计师构思关卡的玩法。他可能使用到编辑器BSP、外部工具、纸质地图和文件等。无论具体怎么做,设计师会一直实验到自己满意才上交方案。

但愿大家都理解这个过程,但事实往往并非如此。美术团队不得不努力修整他们并不怎么了解的东西。他们要美化关卡的视觉效果。一旦他们自己觉得满意了,他们就会返回关卡给程序员。理论上,一旦制作到达这阶段,关卡应该算是完工了,对吧?

webHandoff(from gamasutra)

webHandoff(from gamasutra)

但通常不是。关卡设计师接收关卡的美术设计时,往往会发现一连串意料之外的问题。比如,沿街的掩蔽物太小,起不了掩蔽作用;本来要用作阻碍物的墙却变成链条连成的围栏;桥的支撑梁挡住了玩家枪战时的视线。

出现这样的误差,通常是因为交流沟通不足。这种事在游戏制作和团队合作中一次又一次地发生。最好的结果是,产品达不到最理想的效果,最坏的结果是,严重影响美工和设计师之间的协作关系。

我们对此并不陌生。我们都遇到过交流问题,也想办法避免问题。很大程度上,我们的解决办法就是寻找更加开放的交流方式和合作方式。

有些下载了我们创意工具包的用户评论道,套件看起来没什么个人特色。在这些人看来,我们的基于套件方法可能不像合作的结果。当你是终端用户时,你可能会觉得套件的限制性很大,在很多方面也确实如此。但这正是Bethesda开发者的体验远远不同于Bethesda建模师的地方。

套件并不是一天就能出现在编辑器中的,也无法靠美工的臆想就能完善而不需要进一步添加部件。我们制作任何套件都有一个过程,这需要关卡设计师和美工之间紧密配合。

须知

现在我们来谈谈技术问题,我们需要一些抽象的单位。如果你熟悉Unreal单位,那就你知道我指的是什么了。一个角色通常有123个单位,或都说6足高。另外提醒一下,我们习惯于将Z轴作为垂直轴。

在你开始制作套件以前,你还有许多关卡元素要确定。如前面所前到的,你应该尽早决定。比如说,我们觉得最好能先确定门框的统一大小。这么做的好处是,从套件到套件之间的转换不需要特殊部件,并且容易再次利用门;更重要的是,AI和动画有了一个固定的标准,便于在游戏开发过程中进一步强化。

webDovahScale(from gamasutra)

webDovahScale(from gamasutra)

另外,最好能确定游戏中最狭窄的通过空间。我们的最狭窄标准通常是两个角色宽。这样,无论在什么场景,都保证有足够的空间供两个AI角色同时通过,这就避免了寻径问题。你还应该知道确定AI能前进的倾斜度是多少。

在我们的游戏中,通常是60度,但也要考虑美观问题。在动画中,完全倾斜的效果通常不好,你的套件倾斜度应该介于30-45度。

最后,如果你的游戏玩法与场景元素有关,比如掩蔽射击或平台,那么你就要尽早考虑重要的玩法评估标准。如果你做的是平台游戏,那你就要想想玩家角色可以跳多远。玩家死亡或受伤前会跌落多深?如果是掩护射击游戏,那你就要知道允许玩家探出枪的掩蔽物高度是多少。

提前考虑这些问题,有助于制作出适合游戏外观和玩法的套件。

接下来我们就可以制作真正的套件了。

套件怎么来?

在我们的工作室,当我们准备开始制作套件时,首先要指派套件美工和关卡设计师。从开始到完成套件,他们经历的几个阶段如下:

1)概念阶段

制作套件的第一阶段就是概念阶段。这不同于字面上的“概念艺术”,尽管通常与之相关。在这个阶段,我们要决定套件的主导创意。

这的阶段的主要目标是,想出这个套件的大图景,以及它如何与游戏的其他部分相融合。这个阶段通常花不了多少时间,因为不需要制作任何实体内容。相反地,主要是回答以下问题:套件的视觉主题是什么?如何与游戏的其他区域相异?用它构造什么类型的空间?如何使用?使用频率是多少?这些回答中有些是由设计师决定的,有些是美工决定的——从一开始就要保证设计师和美工的观点都体现在答案中。

在这个阶段,大多视觉工作涉及收集参考资料、设计概念艺术以及确保套件的美术方向不发生偏离。然而,我们在这个阶段也有工作流程和一些逻辑问题要解决。

最重要的问题大概是:套件的使用频率是多少?这几乎决定了套件制作的方方面面。例如,《天际》的洞穴套件使用了200多次,但鼠道套件只使用了2次。也就是说,这两种套件的使用范围是非常不同的

webKitUsageBreakdown(from gamasutra)

webKitUsageBreakdown(from gamasutra)

这个问题也影响了各个套件具有多少个“副套件”。副套件是指套件互相作用的各个部分。比如,“小房间”副套件,或“大走道”副套件。上文提到的洞穴套件有7个套件,而鼠道套个把只有3个。不同套件的这些副套件的部件数量也各不相同。“小走廊”洞穴副套件大约有50个部件;鼠道副套件只有7个部件。知道这些副套件的部件数量有助于决定套件的大小以及需要多少制作时间。

2、验证阶段

完成主导套件的大创意后,我们就可以实验想法了。这就进入了“验证阶段”。

这个阶段的重点是,测试套件的主要概念,它是我们开始制作在编辑器中使用的实际资源的第一步。

不过,我们仍然要保持大局,避免过分深入美术部分。验证的部件几乎没有网格细节,也没有材质。相反地,我们只要处理比例、套件逻辑、命名惯例和其他基本要求。因此,这个阶段也进行得相当迅速,取决于套件的大小以及部件重制的次数,通常只需要1-3周。

在我们开始制作套件的第一版网格以前,你必须知道以下几个重要细节。

第一,在套件的最重要的细节——“足迹”上,我们必须达成一致意见。所谓的足迹是指整个套件的基底。套件最常见的足迹是等边形的,但其他部分可能导致套件形成特有的足迹。这些决定是非常重要的,因为它将影响最终套件的视觉特性。下图出自《天际》的完整洞穴套件,绿色网格代表组成简单空间的若干部件的足迹。

GridChop(from gamasutra)

GridChop(from gamasutra)

注意,尽管一个套件的不同副套件不一定具有相同的足迹,但这些足迹应该是彼此的倍数。否则,即使套件部件一开始是贴合的,随着套件自循环,它将不再呈线性。例如,一个512x512x512的房间总是用256x256x256的走道整齐地拼贴成的,但384x384x384的房间最终会产生缝隙或重叠部分。

使网格贴合尺寸尽量大也很重要。关卡设计师通常构建一个二分之一足迹大小的网格贴合设置。如果默认贴合尺寸很大,就很容易在套件上作业,部件可以迅速且轻易排列成线,并且容易找到部件不整齐形成的大缝隙。

避免制作拼接在所有轴上的套件。走道套件往往拼贴在一条轴上,而房间通常是两条轴。全轴向的拼贴套件不仅能够形成延展性空间,而且在水平和垂直轴上都产生堆叠和拼贴。这种套件给构建工作带来极大自由度,但制作和使用起来非常复杂。当垂直拼贴达到理想效果,通常最好能构建一个固定水平面大小的独立副套件(以《天际》的洞穴为例)。

注意,足迹是部件的完整边界,而不是部件的可穿越空间。它是将东西排列起来的虚构网格。部件总是存在于足迹内。部件在足迹边缘的情况只发生在它与另一个套件部件贴合的时候。不要沿着足迹的连线构建,更不要构建在足迹之外。

GDC2013footprintoverlap(from gamasutra)

GDC2013footprintoverlap(from gamasutra)

超出足迹边缘的情况在走道套件中表现得最显著。如果走道的墙体沿着足迹的边缘,墙体本身就没有存在的空间了;这样墙体就变成二维平面了。在上图显示的例子中,走道是用足迹的完整范围构建的。凹室嵌入各面墙,一直延伸到足迹区域之外,形成重叠,导致走道无法彼此相接。

webFootprintAlcovesCorrected(from gamasutra)

webFootprintAlcovesCorrected(from gamasutra)

上图显示的是相同部件的改进版。在图中,走道的凹室位于足迹之内,使走道完美地相接。注意,关卡设计师本来也可以在重叠版本上作业,但那么做会对布局产生随意的,有时怪异的限制。

验证阶段可以帮助你提前发现和解决这些问题——节约无数美术和设计工作时间、减少漏洞和急于制作完整视觉部件后产生的挫败感。

关卡设计师的作用

我们暂时脱离套件制作的下个阶段。我们一直强调美工的作用,你大概会好奇,关卡设计师在这些阶段中扮演什么角色。

记住,套件的制作并非先由美工单独操作,之后再放手给设计师,而应该是套件美工与关卡设计师时时互动的过程。美工与关卡设计师都是不同需要和利益的代表——其共同目标是尽早确定这些差异,然后展开对话讨论。否则这些差异可能成为之后困惑和争论的原因。

webFriendlyDebate(from gamasutra)

webFriendlyDebate(from gamasutra)

在这些阶中,关卡设计师应该不断地压力测试。美工应该早快交付达到基本功能的部件,关卡设计师应该在非理想条件下使用这些部件。只测试套件并不能告诉我们任何有用的东西。关卡设计师应该设想可能的(不可能的)使用案例,与套件美工讨论套件的作用,因为这些会暴露套件功能上的缺口。

最后,套件不可能支持每一个使用案例和发现所有可能性。关卡设计师与套件美工协商,决定套件能做什么和不能做什么。毕竟其他设计师最终会发现套件的局限性,而原来的设计师和美工必须尽可能解答。

在压力测试套件时,关卡设计师可以做以下几件事。

第一件事是自循环套件,通常穿过不同的副套件。在这个案例中,我们测试的是房间和走道副套件。小走道从房间西边开始循环拼接到南边的墙上。注意,南门没有对齐,似乎偏离它原本所在位置约二分之一个足迹。对此的通常解决办法可能是,减少走道一半的长度。这么做可以解决特定的问题,但这种我们称之为“补丁”的部件对于更大的问题只能是一小块“创口贴”。

webLoopbackStressTest(from gamasutra)

webLoopbackStressTest(from gamasutra)

我们关注的不是解决特定的问题;而是希望在正常的工作流程中避免这个问题。如果我们观察得更仔细,可以发现这显然是一个拐角的足迹问题。注意,一边是不是比另一边长?正是多出来的一截导致了问题。解决这个问题的正确办法是重制部件,使它位于足迹内部。最好避免制作补丁部件,因为它们可能使套件变大,增加随意和不明显的使用规则,通常只是你的核心套件的问题症状。

另一个值得一试的做法是将套件堆叠起来。在案例中,我们将走道一个一个地靠右叠起来。我们已先将旧的足迹界限覆盖在新足迹内,水平和垂直方向上都执行相同的操作。这个套件使用整个垂直足迹,形成一个二维平面天花板/地面。这个问题产生的原因有很多:这是一个视觉问题,比如从楼梯间可以看到它缺少厚度。此外,还可以产生Z轴上的闪烁,使优化和触发器放置变得困难,通常产生混乱的编辑器视图。

webVerticalFootprint(from gamasutra)

webVerticalFootprint(from gamasutra)

你应该提前决定墙面厚度,特别是在建筑套件上作业时。在构建《辐射3》中的高度建筑化、毁坏的场景时,这一点尤其有用。

一个更常用的测试是用门厅部件制作一个带柱子的房间。如果你是具有使用套件经验的关卡设计师,你应该知道怎么做。在这个例子中,我们把几个走道拐角沿着接头并排。这样,我们就做成了三个“柱子”,在图片中用绿框标出。这是一个使用套件的经典关卡设计案例,实现的办法出乎意料。这些柱子通常效果并不好,但那并不意味着不会有人尝试那么做。有些人总是那么做。这突出了关卡设计师在套件开发阶段的作用——关卡设计师应该尽早发起这些对话,与美工一道决定套件的用途。

webHallRoomPillars(from gamasutra)

webHallRoomPillars(from gamasutra)

压力测试的过程有时候也会充满争论,双方都必须记住大家的最终目标是制作出优秀的套件,最终产生好看又好玩的关卡。

3)灰盒阶段

下一个阶段就是“灰盒”。现在,我们已经想出套件的大概念,并且验证了套件的功能。灰盒阶段的目标是充实套件,并决定最通用的部件。

与验证阶段相同,美工并不做最终的材质工作,仍然是快速制作部件。这个阶段一般持续1-4周,取决于套件的复杂度。

第一个灰盒应该是主要的副套件,或最常用的副套件。这有助于我们提早发现问题,使关卡设计师能够尽快压力测试“真正的”布局。

记住,专注于套件的功能,而不是外观。然而,某些视觉元素的影响较大,应该在这个阶段做出草样——通常是所有沿着多个足迹拼贴的视觉部件。各个套件都有不同的要求,你必须从全局的角度(在概念阶段形成的)出发,想出各个元素是什么。如果你制作的房间套件有一个穿过中心的管道,那就要放进去。如果你想制作一个不对称的洞穴套件,你就要在灰盒部件中加入明显不对称的设计。如果你制作的灰盒太一般,你就解决不了任何问题。

webGrayboxSet(from gamasutra)

webGrayboxSet(from gamasutra)

此时,关卡设计师和美工要一起工作,想出命名惯例。这可能是一段乏味的过程,但必须尽早完成。

命名的关键是,既要简短又要易读。尽量选择没见过的人也能理解的命名惯例。如果命名省略过头,可能会造成编码和解码上的混乱,从而损害之后的创意过程,因为关卡设计师可能很难找到他们需要的部件。

当你决定好命名惯例时,请确保在所有套件中一致地使用。这应该作为工作室的通用语言,使关卡设计师容易学习和转换到新套件上,甚至在多个项目中使用。

我们以《辐射3》中的部件为例子。这个部件被命名为“UtlBayCorInMidPRTT01L01”。我们分解命名惯例,可以发现它的组成如下:

Utl - 表明它是实用套件的一个部件。

Bay - 表明它是海湾副套件的一个组份。

Cor - Cor是“Corner”的缩写,后面通常跟着“In”或“Out”。

In - 这告诉我们它是在拐角内部。

Mid - 这是贴图部件的常用速记法,通常表示地面。在这个案例中,海湾副套件是垂直平铺的。

PRTT01 - 不可解读。

L - 表示“Left”,我们通常把L/R(左/右)放在名称后面,以表示部件的镜像版本。

01 -表示这个部件可能有视觉变体。

大部分名称都能很容易有分解,并且与其他套件保持一致。但是,“PRTT01”的意义不明。它应该是表示该部件在上下左右与其他哪个部件相拼接——但因为很难记忆,所以没有充分利用。这真是耻辱,毕竟对于核心游戏,这个套件大有潜能未被挖掘,使制作它的某些努力白废了。

webNameBreakdown(from gamasutra)

webNameBreakdown(from gamasutra)

UtlBayCorInMidPRTT01L01的这个极端案例对我们很有警醒意义,但有些命名惯例并不能让局外人理解。比如,我们称笔直走道部件为“1way”,称走道拐角为“2way”,特别是称接头为“3way”和“4way”就更难想到了。我们选择这种惯例是因为在列表时,它能将这些功能类似的部件归为一类,比较容易发现。一旦你理解了这个名称,你会就知道它穿过所有走道副套件,因为我们一直使用它。这只是一个比较迟钝的命名惯例的例子,能提高效率,且经常使用并不难记。

正如前面简要地提到,最好能在有视觉变体的部件名称上添加01作为后缀,否则将无法识别这些看起来完全一样且占据相同足迹的部件。即使你才使用了一个部件,01/02/03的后缀在之后也是很有用的,因为列表会将那些部件放在一起,使你容易寻找和置换。

现在,轴点放置位置也应该决定了。通常来说,套件部件的轴点位于套件接地层的中心。但也存在例外。例如,管道套件的轴点可能在管道的边缘,这样它就可以像手臂一样旋转,使之更容易排列。平台套件的轴点可能在平台底部,而不是“接地层”,这样它就能与其他区域更容易贴合。改变轴点可能成为一个大难题,要求上百个实体同时更新,特别是如果轴点已经先改变了。

4)构造阶段

下一阶段是“构造”阶段。这时候,套件开始具有真正的视觉外观,大部分团队成员都能看到了。

在核心部件已得到验证,能够实现基本关卡的功能时,美工就可能开始制作这些部件的视觉效果了,同时根据使用案例添加不太重要的部件和变体。

DwarvenKitShot(from gamasutra)

DwarvenKitShot(from gamasutra)

这时候,负责这个套件的关卡设计师可以把该套件的思路、当前状态和未来计划介绍给其他关卡设计团队。在这个阶段,其他关卡设计师首次使用这个套件制作他们自己的布局,且会提供大量实用的反馈。

这个阶段持续的时间较长,因为要制作实际材质和模型。可能会耗费数个月,特别是如果副套件很多的话。如果灰盒阶段很成功,那么关卡设计师就不会被耽误太久,因为美工可以直接把最终的美术贴图置换到模型上。但也不一定总是这样,所以你应该意识到在构创造阶段可能会出现意料之外的问题,导致布局与当初设想有出路。

虽然本文没有深入探讨这个问题,但有必要在此强调一下:务必在制作变体以前完成一个外观完整的部件。如果根据反馈需要调整美术方向,调整一个部件(或少量部件)总是比修改整个套件更容易的。这可以节省大量时间。套件需要一直修饰美化,所以你首先要避免会影响其功能如足迹、贴合原则和轴点等的更改。

这时候,不要急于制作“主部件”。这类部件具有很多独特的幻想美术元素,如带雕塑或触发特定事件的开关的走道部件。即使这些部件看似重要,并且漂亮又吸引人,也不是早期的工作重点。主部件只使用几次,而你的常规部件却要使用上百次甚至上千次。专注于真正重要的东西:标准部件。主部件可以总是放在后面做,否则可能成为一些特定实例中的障碍物。

只有在我们当前工作中,我们才会发现一种我们称之为“辅助标记”的东西。这是编辑器中的标签,可以告诉我们关于套件的实用信息,比如套件如何贴合、正门在哪里等,这样就不必反复点击摄像机来选择那些部件。在关卡设计团队开始使用套件时,最好能使用这些标记,因为更加直观。

web_Helpermarkers(from gamasutra)

web_Helpermarkers(from gamasutra)

5)润色阶段

最后就到了润色阶段了。事实上接下来的项目周期一直都伴随着润色工作。在之后的几个月,套件美工可以专注于实际的使用案例、修复漏洞和额外的功能。其他美术润色工作也要按需进行,因为套件的部署方式,这个过程必须紧密配合。

关卡设计师和美工必须批判地讨论这个过程中产生的问题。美工可能会轻松地对所有要求都回答“是”,结果却导致套件过度膨胀,变得无法管理。记住,在制作套件时,必须考察决策的合理性,确保各个额外部件的存在价值。当给一个特定使用案例添加部件时,看看是否有其他合理的做法、使用案例是否确实值得拓展套件。答案不一定总是“否”,也不可能一直是“是”。

在这个阶段初期,美工通常与一名关卡设计师合作,完成有限的区域。在这个过程中,不同的关卡设计师会做出不一样的关卡。无论初期阶段的计划如何周全,总是会产生意料之外的问题。假设确实如此,那么就要为之后的修整过程计划额外的套件润色时间。

脱离网格

此时,你已知道如何在作为系统的网格上制作基于规则的套件、如何把诸如拐角部件、走道部件、门厅、房间等贴合在一起。

这种套件的问题是,它看起来就是一个套件。东西一直是90度角,玩家会感觉到系统,并产生审美疲劳。模块化关卡给人的感觉就是模块化关卡。

在制作《辐射3》时,我们开始考虑如何让套件看起来不像套件。我们花了很多时间研究这个问题,现在我们必须解决它了。

当你开始制定规则时,你应该总是记住规则之所以成为规则的原因。这些想法存在是有原因的,也许很难知道为什么,直到你犯下某些错误。

如果你找到融合套件逻辑的方法,你不一定要把它运用于后来制作的所有套件。最好能给各个套件制定一种特定的逻辑,否则你可能很快就发现一切都脱离自己的控制了。还必须记住,融合规则的代价。美工要花更多时间制作更多部件,并且美术设计也更加复杂。关卡设计过程也通常更复杂,更容易犯错误。确保二者平衡。

webBR2kit(from gamasutra)

webBR2kit(from gamasutra)

我们构造更复杂的套件时使用了一种叫作“对齐到对象”的关键技术。利用这一技术,编辑器可以把任何对象当作东西对齐的源头。这样,东西就不会总是呈僵硬的 90度角排列。你可以旋转部件,然后用它作为新的网格,这样新部件就会与这个旋转后的部件对齐。如果部件的旋转角度不同,显然会产生缝隙,但我们可以用很 多办法接合缝隙。

webSnapRefDiagram(from gamasutra)

webSnapRefDiagram(from gamasutra)

《天际》中引入的新套件之一是用于鼠道的“轴和边缘”系统。这是一个走道套件,作用几乎与管道套件一样。所有走道部件都可以旋转成某个角度,以形成更系统的通路。因为这些走道部件都以任意角度旋转,所以走道部件之间会产生缝隙。

webPivotFlange(from gamasutra)

webPivotFlange(from gamasutra)

我们使用拱门来弥补缝隙。你应该注意几个问题。首先,关卡设计过程更加线性。你不可能知道确切地知道房间之间有多少部件,因为部件被旋转了,数量和角度无从知晓,因此更难做调整。

这么做,也容易产生不明显的错误。因为这些拱门不能与大厅贴合,关卡设计师可能会不小心没有把弥补缝隙的拱门对齐到右边,这样就产生了从右边可以看到的小洞(所以你必须经常实验你的作品,而不是老是停留在编辑器中)。对很特殊的建筑,这也是糟糕的系统。因为它本质上是有组织的,且依赖堵塞物,如果你想要清楚的接头,图像就会崩坏。然而,如果你想要自然弯曲的走道,这个系统又相当好,不需要太多套件部件。因为鼠道应该让玩家觉得像是废弃的古代下水道系统,太完美了。

在构建《天际》的洞穴时,我们也对自己的规则做了实验。对于模块化构建法,洞穴总是很成问题,因为模块化套件严重依赖规则,并且是垂直的,但洞穴是高度自由的和组织化的。我们在《天际》中还使用了另一种系统,即基于壳体的构建系统。

在这个系统中,我们按照传统的方法构建好所有标准套件部件,但之后加入自由放置的墙体、柱子和露台,有组织地打破游戏区域。下图显示了用壳状部件建造空间的例子,相比于受严格网格贴合的壳体约束的拐角,使用自由墙体和柱子能够快速形成更加系统的形状。

webCaveShellStages(from gamasutra)

webCaveShellStages(from gamasutra)

这使得关卡设计师能够用确切的形状、按他们希望的流程制作无缝连接的关卡。视觉上说,要让东西看起来不一样是很简单的。美术工作量出乎意料地小,因为可以把贴图随机、混乱地组合起来。有些美工可能担心某些接头不好看,那就尝试一下监督贴图的使用情况,提供建设性反馈。好的光照和渲染如环境光散射也很有用,可以隐藏任何丑陋的接头。总之,按这种方式制作关卡,你充分发挥你的创造力(没有会发现这些小接头)。

从时间上看,我们在《辐射3》中第一次使用了方向性限制套件。传统套件可以在任意方向上旋转,且仍然贴合在一起。方向性套件却不是这样的,因为它们要求某些部件之间互相作用。借助方向性限制套件,美工可以制作出不对称的大厅、特定宽度的房间(如有大拱门的房间)或在四个方向上具有特殊部件的房间套件。

这会增加美术和设计的工作量,但对于组织性套件非常实用,因为它不要求表面和材质在所有方向上拼贴。这可能要耗费大量额外的工作,并且改变了套件的某些核心逻辑。虽然方向性限制对于制作自然套件极其有用,最好不要在高度建筑化的东西中使用。如果你能想到对象的外观差异,如下图所示的过道的A/B面,那么这个套件就更容易理解了。

webAsymmHall(from gamasutra)

webAsymmHall(from gamasutra)

这么做时,要注意的一件事是,需要走道套件中我们所谓的“去扭转”部件。当不对称走道只通向一个方向时,拼接效果不错。然而,有时候当与另一个方向不同的走道相接时,就会产生缝隙。去扭曲部件可以弥补这个缝隙。因此叫作“去扭转”。下图显示的就是不对称走道的循环,它就需要去扭转部件。

webDetwist(from gamasutra)

webDetwist(from gamasutra)

另一个可以灵活利用的套件概念是“平台”套件。平台套件位于其他表面的上层,用于在关卡设计时切断游戏的水平面。它们可能很大,也可能很小,大小两种平台套件均可在《天际》中找到。利用这种套件,关卡设计师不需要在套件中添加大量复杂的垂直逻辑就能制作出有趣的游戏空间。制作平台套件所需的部件数量很少,往往与几乎所有其他具有相同视觉主题的副套件一起使用。这些平台套件甚至在外部景点中独立使用。

平台套件属于一种特殊的、我们称之为“胶”套件的套件。在我们现在的项目初期,我们制作了许多小部件,主要用于多种套件和副套件之间的过渡。胶套件可以用于平台到隧道到壁架之间的过渡。它给我们省了不少工作量,也证明了发现和创新可以影响常规的工作流程。这是一件好事,因为工作流程的演进说明你仍然在学习。

结论

如果要深入套件制作的细节,我们要探讨的东西就更多了。但现在我们该结尾了。

webSkyrimFanShot(from gamasutra)

webSkyrimFanShot(from gamasutra)

如果没有采用上述工作流程,我想我们根本做不出《天际》。我们受到通过创新来探索世界的渴望的驱使,总是认识到我们花在润色想法的方方面面的时间是占用了我们可以构思其他想法的时间。我们之前说过,我们的游戏世界本身就是游戏的主要特点。在开发过程中,这些世界在我们每个人眼前生动起来。

不要误以为这些工作流程是我们被迫妥协的结果。相反地,这些是我们为了保持游戏世界的规模和一种让我们感到愉快又和谐的工作室文化而做的选择。

因为虽然我不认为我们的团队按其他方法可以做出《天际》,但我也认为除了我们,没有其他团队能做出这款《天际》。其他团队可以做出像《天际》这样的游戏,但可能还要花更多时间、金钱、人力以及采用不同的方法。

但无论他们做出的是什么游戏,总是和我们的作品不一样。我们为自己的成果感到骄傲。

你制作的游戏、你放在游戏世界中的元素都是你个人的自我表达。如果你是团队中的一分子,那么这个表达就不只是你个人的自我了,而是许多个自我。它是你们团队关系的外在表现。团队关系可能是你这一生收获的最有价值的东西。你应该想办法促进这种关系的成长,从而改进你们一起制作的游戏。(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

Skyrim’s Modular Approach to Level Design

by Joel Burgess

While many developers understand the basic concepts behind a modular system, and some have dabbled in it for a project or two, very few have made a career out of it.  That’s exactly what Nate and I have done, however.  Our current project will be our fifth together in the near-decade we have known and worked with each other.  Every one of these projects has taken this kit-based approach, including those we worked on before joining Bethesda.

We recently realized that there are many unspoken understandings we and our colleagues share; expectations and assumptions taken for granted as part of our process. We’ve struggled to explain ourselves in detail for new artists and designers who had joined our team.  This talk was a way for us to explore and articulate this accumulated knowledge. To understand our approach, it’s useful to know where we’re coming from as developers, and where Bethesda Game Studios is coming from as a whole.

Let’s begin with a pretty simple observation: our games are big.  If you’ve played or read about Skyrim, Fallout 3 or any of our other open-world games, scope is a big part of them.  It’s an integral part of our games and our DNA as a studio.  You couldn’t boil Skyrim down to a six-hour game and expect to provide the same experience.  Scope isn’t a random attribute of our games; it’s a major feature.

When you play a Bethesda game (or when you work on one) you know this going in.  The games are big!  This influences everything we do at the studio.  Production methodologies, tech and tools, workflow, pipeline – it’s all informed by a need for efficiency.  We need high bang-for-buck on everything we do.  Games like Skyrim take a few years to make, even moving as efficiently as possible.  With a game that big, missteps aren’t measured in hours or days, but scale to weeks and months.

These core values, along with the circumstances of team size, and our collective experience making games together all adds up to what you’d commonly refer to as studio culture.  Even if your team or your game isn’t driven by the same forces as ours, chances are you could take a lesson from us, just as we could probably take a lesson from you.

With that in mind, consider this a case study.  The modular approach to level design we’re analyzing here is just one manifestation of the BGS studio culture.

Before getting too far into things, let’s me define what a “kit” is.  Kits, first and foremost, are systems.  A basic pipe kit, like the one from Fallout 3, may only be four simple pieces of art which can be used together.  This kit, as most, snaps together using a grid system.  The most important attribute of a kit is that it adds up to far more than the sum of its parts.  This artist hasn’t just given us four pieces, but a system with which we can create infinite configurations of pipes, all on the editor side.

While the pipe kit is a good example of a simple art kit, our primary topic here is architectural kit creation.  Examples of architectural kits would include the Nord Crypts in Skyrim, or the

Vaults from Fallout 3.  This is important to topic for gameplay, because kits are the primary building blocks of level design at Bethesda Game Studios. Kits aren’t a new idea.  They aren’t unique to Bethesda or to the types of games we make.  Consider the board game Carcassone.  Unlike Monopoly or Scrabble, the board changes every time you play Carcassone.  The tiles are arranged so that roads meet roads, rivers meet rivers, and so on, creating an effectively randomized yet visually cohesive whole.  It’s easy to see the grid when looking at a Carcassone table, and how this system of art works together to make a unique play field.  The board tiles are themselves an excellent example of an environmental art kit.

Many sprite-based, 2D games make heavy use of similar ideas and techniques to those we’ll be discussing today.  Sprite sheet or texture atlas technology lies at the heart of many 2D game systems, so it’s easy to see how those games lend themselves to repeatable tiles of a uniform size.  Thanks to this, it’s not necessary to paint the entire world by hand. Designers and artists can use art systems of repeated tiles to draw out the map quickly and with less of memory footprint.

Back in November of 2002, Lee Perry (then of Epic, now BitMonster) authored an article in Game Developer magazine which explored a modular approach to level design and world building, specifically as a way to help cope with the increased fidelity of games at that time. Bethesda has been at this for quite some time – 18 year as of this writing. Terminator: Future Shock and the Elder Scrolls 2: Daggerfall, both games which far pre-date our (Nate and Joel’s) tenure at the studio, embraced a modular approach to world-building, which would become the foundation upon which much of our current thinking and technology are built.

So remember – the concepts discussed today are far more than the product of our work together over the past decade.  Many influences and ideas have contributed to our current workflow, and there are many lessons yet to be learned.

Going Modular: Pros and Con

As mentioned earlier, many developers understand the principles behind modular level design, but we hope to offer insights gained from our extensive exploration of this topic. To do this, we’ll go over the various benefits and drawbacks we’ve found over the years, with an emphasis on how to get the most out of the workflow.

The first, most self-evident benefit of working with modular art is that it’s reusable.  Reusing art helps us mitigate the huge scope of our games.  There’s a massive amount of world-building to be done in Skyrim, and not having to specifically create and export every fence post and doorway becomes very important to us.  We try to be smart about where we spend our time and attention, reusing art where it makes sense, and investing time where we want something more unique.

Consider this list of features, which together make up the rough measure of Skyrim’s world-building needs:

16 sq. mile Overworld

5 Major Cities

2 Hidden Worldspaces

300+ Dungeons

140+ Points of Interest

37 Towns, Farms & Villages

Now consider that alongside this photograph of the Skyrim development team.  There are 90 people in the photograph below.  With the exception of a small number of outsourced assets, you’re looking at the entirety of the dev team across all disciplines.  We’ve resisted the temptation to grow into a multi-studio team of hundreds, such as you often find behind games of similar scope to those we make.

Today we’re focused on what you’d most typically associate with traditional level design at Bethesda; the dungeons component of that world-building work.  Only ten people out of the 90 in that photograph are directly responsible for those dungeons.  The rest of the team is focused on the myriad other features, content, systems and support needed to build a game like Skyrim.  You can begin to appreciate how small our dev team really is when you consider how much responsibility each person needs to shoulder.

Sooner or later while reading this, you may think that the scope of the game is a restriction that limits our ability in some way, that it’s a burden we wish we could shrug off.  The thing is – even if our circumstances were different, and we had infinite time, resources, or talent – I don’t think the way we make games would look all that different  We’ve found a way that works for us.

Consider the Dutch artist Piet Mondrian, famous in particular for his work in Paris during the 1920’s.  You may not know Mondrian by name, but you’re likely to recognize his work, such as the
piece seen below.  Mondrian had access to more than four colors of paint, and was certainly capable of more technically complex work.  Yet he chose to self-impose restrictions which led him to pioneer a style he may not have otherwise discovered.  The influence of that style is still felt today in art and fashion.

Look throughout the history of science, technology, music, anywhere people are creating, and you’ll find examples of restrictions not limiting creativity, but focusing it and leading people toward new discoveries and innovations.  I think our workflow is like that.  To change it because of a shift in circumstance would be ignoring the belief systems and experience that led us to that conclusion.

Getting back to the topic at hand, we should also acknowledge the most self-evident drawback of using modular art: the fact that resused art can become repetitive.  This leads to what we commonly refer to as “art fatigue”.  The median play time of Skyrim on Steam has peaked at well over 100 hours, which is a huge compliment .  With that kind of time spent, however, players are bound to notice the same rock or farmhouse or tapestry used again and again.  And another two dozen times after.  Art fatigue sets in where this repetition becomes obvious and erodes the authenticity of the world.

We’ve found some ways to delay the onset of Art Fatigue.  One of the big ones is simply doing away with copy and paste design as much as possible.  When I first joined Bethesda, Oblivion was poised for the home stretch of its development cycle.  Oblivion was of similar scope to Skyrim, yet built by a team of about half the size.  One of the ways the dungeon art team coped with this disparity was to create a number of “warehouse” cells in the editor.  These warehouses contained fully lit and cluttered rooms to copy, paste, and then arrange to create “new” dungeons.  While efficient, this method left much to be desired, and many players rightfully called Oblivion dungeons out as being “cookie-cutter”.

One thing we noticed was that players were quicker to react negatively to repeated detail elements, as opposed to broad architectural repetition.  Consider the following three screenshots, each taken from a separate Oblivion Dungeon.

In each, you’re more likely to pick up on repeated clutter first, then the repeated architecture.  This is especially true in actual gameplay from a first-person perspective.  To minimize needless repetition, we abolished the use of warehouse cells as they existed in Oblivion. Beginning with Fallout 3, we staffed up a group of level designers and got tool support to make sure we were able to build spaces more quickly, and with the most granular art available, reducing the amount of repetition as much as we possibly could.

You can also fight art fatigue at a more fundamental level.  It’s common at the start of a project to strongly associate a particular setting with specific types of inhabitants or gameplay.  You
may want to only see soldiers in military bases, and zombies in crypts, for example.  Resist this. Think of your kits as the architectural identity of the space, and allow other elements to establish the specific identity of any given space in which it’s used.  The more you’re able to divorce these things, the more you’ll be able to mix elements up and keep the settings fresh.

This also applies to the kits themselves – try to actively encourage the notion of mix-and-matching your kits. This is sometimes called kit-bashing, kit-jamming, or a kit mashup.

Look the following examples of Dwarven dungeons from Skyrim.  The first delivers on the expectation of any Dwemer dungeon in an Elder Scrolls game.   There’s a chunkiness of proportion, an
emphasis on brass highlights and clockwork elements which are all hallmarks of that style. Skyrim features around ten of these dungeons, however, and they’re all pretty big.  If they were all the same, it’d be a dull, one-note experience, and take the thrill out of discovering one.

To try and mix things up, we started playing around with ideas like combining exterior elements.  In the second example we’ve introduced some lightweight unique assets and enemies you’ll only encounter in this particular Dwarven dungeon.  This twist on visual and gameplay expectation helps keep the setting fresh and combats art fatigue.

In the third example, the level designer simply tried bashing Dwarven hallways with ice caves.  What he achieved was an instant shift in tone and atmosphere.  Some artists will be uncomfortable with this idea.  The notion of your art being used in unforeseen ways could lead to bad intersections or lighting issues, for example.  To work on this kind of game, however, you need to take a couple of steps back and be open to this.  Allow for this kind of experimentation and have it in mind when you’re creating the art to begin with.  Not every combination will look good or make sense, but you can be part of a conversation about what works, what doesn’t – and most importantly, what almost works, but could work great – with a little tweak from you.

Looking again towards the benefits of working modular, one of the big bonuses (especially from a production viewpoint) is that a modular approach helps if your team has a low ratio of artists to designers.  Remember the ten people responsible for the dungeon content in Skyrim?  Eight of them are the level designers, and only two represent the entirety of our full-time kit art team.  They generated seven kits, which the level design team used to create well over 400 cells, or unique loaded interiors, of dungeon content.  And those dungeons were built in about two and a half years, from start to finish.

To put this into proportion, the infographic shown here represents the kit art team as yellow, level design as orange, and the blue-gray area as a conservative estimate of the dungeon content
created by that collective group.

There are two points to make here.  The first and most obvious: this approach allows a small number of artists to support a much larger team of designers, who can in turn generate a lot more content than those two artists otherwise could.  The example provided by Skyrim shows just how effective this approach can be, when only two artists were required to provide the core art behind so much content.

The second, less-obvious point is the more important one, however.  Think of the other 80 people in that team photograph.  Because such a relatively small group was able to handle the dungeon component of the game, it allowed the rest to focus on the myriad other needs of the game, whether it was landscaping the massive world, writing and scripting the many quests, contributing to character art and animation, working in the guts of our game code.

Of course, there’s another reason that Skyrim had only two full-time kit artists; kits are really complicated things to work on.  Kits require not only the artistic ability to produce high quality
visuals, but also a technical competency in their art tool, a deep understanding of the editor and design workflow, and so on.  This unique blend of left and right brain is somewhat at odds with what many art professionals value.  I’ve worked with great artists who make excellent kits but hate working on them – so they don’t.

So when you’re trying to identify somebody with the the aptitude and interest to be a great kit artist, you’re basically looking for a unicorn.  They’re rare.

Another example of the problematic complexity of kits is the process of identifying and fixing bugs with them.  Kits aren’t like other art assets, for which you might be asked to fix a bad pivot
point or texture seam, but are otherwise fire-and-forget.  It’s important and necessary that a kit artist can keep the entire system of rules in her head throughout the entire project.  Kit pieces
are instantiated dozens or even hundreds of times throughout the game.  Making an obvious fix to something like a bad pivot point may address a specific bug but create new problems in those
hundreds of instances elsewhere that you may not have thought to check.

This does bring us to one of the other benefits or our approach, however, which is the very fact that kit pieces are heavily instantiated.  When a change goes into a kit, those changes are instantly viewable across the whole game.  As an artist, performing an export is like a fly-by deployment of new art, whether the level designers were waiting with bated breath or don’t really care.

For artists this allows you to see your art in real-world use cases right away.  There’s no need to construct a test area.  Just load up any level making use of your art and check it out.  See how it really appears in game instantly.

This deployment process also has minimal impact on the design workflow, which is not free, but something we work very hard towards.  We’ll go into more detail later, but consider this.  It’s

often been the case that early in a project, art is trying to answer a lot of questions about how the game should look, and kits are no exception.  This aesthetic process can be unstructured and
time-consuming.  The trouble is – design is often twiddling their thumbs at this stage, waiting for something to work with.  This can result in art rushing through their process too quickly,
sometimes making decisions they’ll change later, in ways that can drastically effect level design and force work to be thrown out or heavily revised.

To avoid this, we get our kits to a “functional-but-ugly” state as soon as possible.  This is discussed in more detail later, but the high-level idea is that we figure out as much as we can about how kits work first, which allows design to get working while art then can focus on their visual direction without being rushed.

This is one of the contributing factors to another perk we enjoy; Bethesda level designers are quite fast.  Because we’re working editor-side with pre-established kits, our level designers are
able to iterate on layout extremely quickly.  We can sketch with kits right in the editor and push those to the game,  playing the results immediately.

In fact, we’d go so far as to suggest that a level designer working with a good kit that she understands is able to iterate faster and truer to final gameplay than any other designer with any other editor or workflow in the industry.  This is because she’s using the actual, final art and playing it almost as fast as she can work.  We don’t have turnaround with art, we don’t have to bake textures or compile geometry, and our markup is fairly minimal.

Ah, but there’s a catch, and it’s one of the major downsides of our approach.  When we say that a Bethesda level designer is the fastest, it’s with a big caveat.  We specify that she’s working
with a good kit.  Without that, she’s not just the slowest LD in the industry – she’s a non-starter.  We’re totally dependent on the art we work with, which is why the relationship between art
and design is so important.

Consider an all-too-common tale from throughout the game industry.  There are many variations of this story, but it’s typical that early in a project, designers are figuring out how their levels should play out.  They may do this with editor BSP, external art and previs tools, or through paper maps and documentation.  Whatever the method, design works on this until they’re happy enough with it to hand it off to art.

Hopefully this process has been well communicated – but in practice it often isn’t  and the art team ends up in the difficult position of trying to polish something they weren’t very involved with.

They’ll do an art pass, though, and make the level visually appealing   Once they’re at a place they’re happy with, they send it back to design for final markup and scripting. Once design has
done that, the level should theoretically be done – right?

Not usually.  Level designers often inherit a litany of unforeseen problems when receiving final art for their levels.  Cover along a street has been converted into poles too thin to take cover
behind.  A wall intended as a visual blocker is now a see-though chain-link fence.  A bridge now has support beams which occlude sight lines in a major gunfight you had planned.

When work is handed off like this, it’s often one of the main fault-lines of communication   This story plays out again and again across all manner of games and teams.  At best it’s non-optimal.

At worst it can be downright toxic and create an atmosphere of hostility between art and design.

We’re no strangers to this.  We’ve had our share of communication problems and finger-pointing, and have sought out ways to avoid the whole mess.  This has come largely from seeking more open communication and collaboration.

Some users who download our Creation Kit comment that kits seem impersonal.  To these people, our kit-based approach probably seems like anything except collaborative.  Kits can seem restrictive when you’re an end-user – and in many ways they are.  But this is one area in which the experience of a Bethesda developer differs greatly from that of a Bethesda modder.

Kits don’t simply appear in the editor one day, fully formed from the mind of the artist and complete, with no further pieces coming along.  There’s a process we’ve worked out to establish any
kit, and it takes place over a period of time during which a level designer and artist are in full collaboration.

Things To Know Before Beginning

This begins the technical portion, and it’s worth establishing a few items.  We’ll be referring to abstract units on occasion.  If you’re familiar with Unreal units, for example, these are much
the same.  All you really need to know is that a character is usually about 128 units, or six feet, tall.  We are also accustomed to a Z-up environment.  If you’re used to Y as the vertical axis, keep this in mind.

There are a number of things you want to establish at a game-wide level before you begin on kits.  As mentioned – you want to do this as early as possible.  One thing we’ve found very useful is to determine a uniform dimension for door frames.  This has a few benefits.  It allows us to transition from kit to kit without unique pieces, as well as allowing easy re-use of doors between kits.

More importantly, it gives AI and animation a fixed standard to work from, which can be reinforced throughout the game.

It’s also worth figuring out the most narrow traversable space in the game.  We usually stick to a minimum of two character widths.  This allows us to avoid pathing problems by ensuring there’s at least enough space for two AI characters to path around each other in any given space.  You should also know how steep of an incline your AI can navigate.  In our case this has usually been 60 degrees, but you should also know what looks good.  The full incline often looks bad for animation, and you may want to embrace 30-45 degree slopes in your kits.

Finally, if you’re making a game with environmentally contextual gameplay, like a cover shooter or platformer, figure out some important gameplay measurements early on.  If you’re making a platformer, figure out how far the player can jump.  How far can the player fall before dying or taking damage?  If a cover shooter, know what height of cover I can shoot out from.

Keeping this kind of information in mind early will allow you to build kits that make the game look and play its best throughout.

With that, we’re ready to get into what happens once we’re ready to actually start building a kit.

Where Kits Come From – Our Process

When we’re ready to begin any kit at Bethesda, a kit artist and a level designer are both assigned to that kit.  There are several stages they’ll go through in the initial establishment of that kit.

1) The Concept Phase

The first stage of building a kit is what we call the concept phase. This doesn’t literally mean “concept art”, although that is often involved.  Rather, this is the stage at which we’re first deciding upon the main ideas that will drive the kit.

The main goal of this phase is to figure out the big picture ideas of the kit and how it fits in with the rest of the game.  This usually takes a relatively short period of time because it doesn’t
involve any actual content creation. Instead, you’re mainly answering questions.  What is the visual theme of the kit? How is it different from other areas in the game? What kinds of spaces do you want to build with it?  How will be it be used?  How often will it be used? Some of these answers will be driven by design, others by art – it’s important that both voices are being represented
from the very beginning.

Much of the visual process at this stage consists of gathering reference, working with concept art when applicable, and making sure we’re all on the same page with the art direction for this kit.

There are workflow and logistical questions we start asking at this stage as well, however.

Probably the most important question to answer is this: How widely-used will the kit be? This drives almost every decision when it comes to kit creation. For instance, the Cave Kit in Skyrim is used  over 200 times, but the Ratway kit is only used twice. Consequently, the scopes of these two kits are very different.

This also influences the number of “Sub-Kits” that each kit has. A sub-kit is what we call each part of the kit that works with the rest of it. Common examples include a “small room” sub-kit, or a

“large hallway” sub-kit. The cave kit has seven sub-kits, while the Ratway has only three. The number of pieces in each of these sub-kits also varies between kits. The “small hallway” cave sub-kit has around 50 pieces. The Ratway hall sub-kit has only seven pieces. Knowing the scope of a kit will help you make good decisions about how robust the kit will need to be, and how much time should be spent building it.

2) The Proof Phase

Once we’re satisfied that we understand the big ideas driving the kit, we need to prove those ideas out.  This is called the “Proof Phase”.

The point of this phase is to start to test out the major concepts of the kit, and it’s the first point at which we’ll begin building actual assets to bring into the editor.

We’re still keeping everything fairly high-level and not getting too deeply involved with building the art, however. Proof pieces have almost no mesh detail and usually no textures at all. Instead, we’ll be playing with proportions, kit logic, naming conventions, and other basic needs. Because of that, this stage of the process is also relatively quick, often only 1-3 weeks, depending on the scope of the kit, and how many failed iterations of the proof pieces end up being created and disposed of.

Before we can create the first mesh, however, there are several important details you have to know about kit-building.

First, we have to agree upon one of the most important details for any kit – its footprint. The footprint is the foundation of the entire kit. The most common footprints for kits are equilateral,
but other proportions can lead to kits with their own distinct feel.  These fundamental decisions are very important, as it will influence the visual identity of the final kit.  In this image, the
green grid represents the footprint of several pieces used to build a simple room from Skyrim’s completed cave kit.

It’s important to note that although the various sub-kits of one kit do not have to share the same footprint, those footprints should be multiples of each other.  Otherwise, even if the kit pieces
initially snap together, as a kit loops back around on itself, it will no longer line up.  For example, a 512x512x512 room will always tile nicely with a 256x256x256 hallway, but a 384x384x384 room will eventually create gaps and/or overlaps.

It is also very important to have your grid snap sizes as large as possible. Level designers tend to build on a grid snap setting of one-half the size of the footprint.  If the default snap size is
large, it is very easy to work with a kit. Pieces line up quickly and easily, and large gaps make it obvious to spot where pieces aren’t lined up.

Avoid attempting to create a kit which tiles on all axes.  Hallways kits tend to tile on only one axis, while rooms typically tile on two.  An all-axis tiling kit is able to create spaces which stretch out not only horizontally, but also vertically stack and tile on themselves.  This kind of kit allows a great deal of building freedom, but is very complex to build and use.  When vertical tiling is desired, it’s generally wiser to build a separate sub-kit with a fixed horizontal plane size.  (See Skyrim’s cave and Nordic “shaft” sub-kits for examples)

It’s extremely important to note that the footprint is the full bounds of the piece, and not the traversable space of the piece. It is the imaginary grid that things line up on. Pieces always exist

within the footprint. The only time a piece is at the edge of the footprint is when it is actually snapping together with another kit piece. Avoid the temptation to build to the edge of the footprint, or even worse, outside of it.

This is most evident in something like a hallway kit. If the walls of the hallway are along the edge of the footprint, there is no room for the walls themselves to exist; they will be co-planar.

In the example pieces shown here, a hallway is built using the full extents of the footprint.  The alcoves set into each wall extend outside the footprint area, creating an overlap which prohibits
hallways running adjacent to each other.

The second diagram shows a revised version of the same piece in which the hallway alcoves are planned and accounted for – they now exist within the footprint, allowing the hallways to run adjacent without incident.  Note that level designers could have worked around the overlapping version, but doing so would be placing arbitrary and sometimes-awkward restrictions on layout.

The proof process will help you identify and solve these problems early – save art and design untold hours of work, bugs and frustration that may have come later if we dived too quickly into
building visually-complete pieces.

Sidebar: The role of the Level Designer

Let’s step away for a moment before continuing to the next phase of kit development. With all this emphasis on art, you may wonder what the role of the level designer is through these phases.

Remember that this isn’t something the artist does in isolation and hands off to design later.  The process is best when the kit artist and level designer are interfacing on a daily basis.  Each is
an ambassador of a sort, representing different sets of needs and interests – the shared goal is to preemptively identify these differences and make them topics of conversation.  They can otherwise become points of confusion and contention later.

The level designer should be constantly stress testing throughout these stages.  The artist should deliver pieces as soon as they are even rudimentarily functional, and the level designer should
use them in non-ideal conditions. Only testing a kit as it was intended won’t teach us anything useful.  The  level designer should anticipate likely (and unlikely) use cases and attempt them,
being sure to discuss the ramifications with the kit artist as these expose gaps in kit functionality.

Ultimately, the kit will not be able to support every use case and eventuality.  The level designer must choose what the kit does and doesn’t support in concert with the kit artist.  The idea here
is that other designers will eventually discover these limitations first-hand, and the original designer and artist should have answers whenever possible.

Here are a few specific things that the level designer can look for while stress-testing a kit.

One of the big things to do is loop the kit back on itself, usually through various sub-kits.  In this example, we’re testing a room and hallway sub-kit.  Small hallways tile from the west end of
the room and looped around to the south wall.  Notice that the southern door fails to line up.  It looks like it’s about a half-footprint away from where it should be.  A common reaction to this may be to request a half-length hallway.  This would fix the specific instance, but it’s what we call a “patch-up” piece, which is really just a band-aid over a deeper problem.

We don’t really care about fixing this specific case; we want to prevent this problem from recurring during normal workflow.  So if we look harder, it becomes apparent that we’ve got a footprint issue with the “2-way”, or hallway corner piece.  Notice how it’s longer on one side than the other?  That stub is what’s creating the problem.  The correct way to fix this problem is to rework that piece so it fits within the intended footprint.  It’s good to resist adding patch-up pieces, as they can bloat your kit, add arbitrary and non-obvious usage rules, are usually just symptoms of problems with your core kit.

Something else to try is stacking kits on top of each other.  In this example we’ve placed to hallways right on top of each other.  We earlier covered footprint bounds existing within the footprint, and it applies vertically as well as horizontally.  This kit uses the entire vertical footprint, creating a co-planar ceiling/floor.  This is problematic for a number of reasons: The
lack of thickness will be a visual issue if you can ever see it, say from a stairwell or if there’s a hole.  It can also cause z-fighting flicker, make optimization and trigger placement very
difficult, and generally create a confusing editor view for you.

Instead, predetermine how thick floors should be.  This is especially useful with highly architectural kits – something we especially appreciated building the highly architectural, destroyed
environments in Fallout 3.

One more common test is to create a pillared room from hall pieces.  If you’re a level designer with experience using kits, you probably know were this is going.  In this example we’ve placed a
few hallway corners along with several 3-way intersections.  In doing so, we’ve created three “pillars”, highlighted in green.  This is a classic example of level design using a kit in a way that
wasn’t intended.  These unintended pillars often look bad, but that doesn’t mean somebody won’t try it.  Somebody always does.  This underscores the role of a level designer in the kit development process – the LD should raise these conversations early on and work with the artist to determine what the kit can and cannot support.

The stress-testing process can at times seem combative, it’s important that parties both remember that the end goal is creating a great kit that will produce levels which look great and play great.

3) The Graybox Phase

The next stage is “Graybox”. By now, we’ve figured out the big ideas of the kit and proven that the kit will function. The goal of the graybox phase is to flesh out a kit and to figure out what the most common pieces will be.

Just like the proof phase, the artist is not doing final texture work, keeping piece iteration a relatively quick process. This typically takes 1-4 weeks, depending on the complexity of the kit.

The first graybox should be of the primary sub-kit, or whichever sub-kit we expect to be used most frequently. This helps to figure out the problems early on and enables the kit’s level designer to start stress-testing with “real” layout.

Remember to focus on how the kit functions, not how it looks. However; certain visual elements will have an impact and should be roughed in at this stage – usually any visual component that needs to tile across multiple footprints. Each kit has different needs, and you’ll have to rely upon your collective vision (established during the concept phase) to figure out which elements these are.

If you are making a room kit that has a pipe running down the center, put that in. If you want to build an asymmetrical cave kit, start building obvious asymmetry into the graybox pieces. If you make your graybox too generic, you do not actually solve any problems.

At this point, the level designer and the artist work together to figure out the naming convention. This can be a tedious exercise, but it’s important to sort out early.

The key to good naming is balancing brevity with readability.Try to choose naming conventions that will make sense to someone who has never seen it before. If you over-abbreviate, things can quickly become an encoded mess that require a decoder ring to decipher.  This can put stumbling blocks in creative process later, as level designers can stumble over looking for the piece they need.

When you have naming conventions that you’re happy with, be sure to consistently use them across all kits.  This builds a common studio language and makes it easier for level designers to learn and transition to new kits, even across multiple projects.

As an example, let’s analyze a piece from Fallout 3, named “UtlBayCorInMidPRTT01L01″.  If we break the naming convention down, it consists of the following components:

Utl – This indicates that it’s a piece of the Utility Kit.

Bay – Indicates it’s a member of the Bay sub-kit.

Cor – Cor is our shorthand for “Corner”, usually followed by “In” or “Out”

In – This tells us it’s an “Inside” corner.  “Outside” corners bend the opposite way.

Mid – This is common shorthand for a tiling piece, usually a floor.  In this case the bay sub-kit tiles vertically.

PRTT01 – No clue.

L – “Left” We often use L/R at the end of a name to indicate mirrored versions of a piece.

01 – Indicates that this may have visual variants.  Discussed in detail later.

Most of the name is easily decoded and consistent with other kits.  The “PRTT01″ component is indecipherable, however.  It was intended to help indicate what the piece will tile with above, below, and on each side – but because it was so difficult to internalize, the kit was underutilized.  Which is a real shame, because this kit had a great deal of potential that wasn’t tapped for the core game, making some of the effort put into it a waste.

The extreme case of UtlBayCorInMidPRTT01L01 is a useful cautionary tale, but some naming conventions won’t fulfill the obvious-to-an-outsider rule.  For example, we call a straight hallway piece a “1Way”, and a hallway turn/corner is usually called a “2way”.  More obvious are “3way” and “4way” junctions.  We chose this convention because it groups these functionally-similar pieces together in the list, making them easy to get to.  Once you understand this name, you’ll understand it across all hallway sub-kits because we use it consistently.  This is just one case where a slightly obtuse naming convention is justified by the iteration speed benefits and offset by consistent usage.

As briefly mentioned above, It’s wise to add 01 as a suffix to any piece which will feature visual variants but otherwise fill an identical role and occupy the same footprint. Even if you are only
starting with one of each piece in the beginning, the 01/02/03 suffix format will become useful later, because those pieces will sort together in the list and be easy to find and swap for.

At this point, pivot placement should also be decided upon. Generally, the pivots of our kit pieces are at the ground plane of the kit and in the center. Exceptions do exist however. For instance a pipe kit might have a pivot at the edge of the pipe so that it can hinge like an arm, which makes it easier to line up. A platform kit might have its pivot at the base of the platform instead of the “ground plane” so that it can snap to other areas easier. Changing pivots later can be a huge problem, requiring manual updates to hundreds of instances, especially if the pivot has changed before.

4) The Build-Out Phase

Next up is the “Build-Out” phase. This is when the kit starts to become real art, and can be introduced to the team at large.

With the core pieces proven out and functionally capable of laying out basic levels, the artist can begin developing those pieces visually and adding less-critical pieces and variants in response
to usage cases as they present themselves.

This is also a good time for the level designer who has been working on the kit so far to introduce the kit to the rest of the level design team, and give an overview of the thinking behind the
kit, its current status and future plans.  This is the first stage at which it’s a good idea to have other level designers start using the kit for their own layouts, which will generate a lot of useful feedback.

This stage can take much longer because actual textures and geometry are being made.  This can take a few months, especially if there are a lot of sub-kits. If the graybox phase was successful,
however, level design shouldn’t be held up very much: the art can be swapped out seamlessly once the final art exists. This isn’t always the case though, so be aware that unforeseen problems can undermine layout being done during build-out.

Even though this article won’t go into this in much depth, one very important thing to note is to build out one visually-complete piece before beginning the variants. If adjustments must be made based on art direction feedback, it is much easier to adjust one piece (or a small number of pieces) instead of an entire kit. This can be a massive time savings. Kits will get a lot of polish over time – you’re primarily trying to anticipate and avoid changes which will impact functional factors such as footprint, snap rules and pivot point.

Something to watch out for is the temptation to start working on “Hero Pieces”. This is a piece that has a lot of fancy unique art, such as a hallway piece with an embedded statue, or a one-off
setpiece for a specific event. Even though these pieces seem important, can look really nice and impress everyone on the team, they are ultimately not what is important early on. The hero piece is only used a few times, your normal piece is used hundreds if not thousands of times. Focus on what is actually important;  the standard pieces. The hero piece can always come later, and will only be a bottleneck for the handful of specific instances in which they are needed.

Something we’ve only discovered on our current, unannounced work are what we call “Helper Markers”. This is editor-only markup that can help convey meaningful information about the kit. Some examples of this are markers to show how a kit should snap together, where the doorways are or markers for the ceiling so that you don’t have to flip the camera upside down to select those pieces.

It’s good to think about these markers as the level design team starts using the kit, as they can help make usage more intuitive and straightforward.

5) The Polish Phase

Finally we are ready for the polish phase, which is really an ongoing process and that exists (to some extent) throughout the rest of the project. Over the coming months, the kit artist can respond to real usage cases, fix bugs, and additional functionality. Additional art polish will go in as needed, and due to the way that kit art is deployed, this should be a seamless process.

It is important for the level designer and the artist to talk critically about all the requests that come up throughout the process. It is very easy for an artist to say “yes” to every request that comes up. This can quickly lead to a kit that is bloated and unmanageable. Remember the reasons decisions were made while establishing the kit, and make sure that each additional piece is worth it.

When adding pieces for a specific use case, see if there is a reasonable alternative, if something else exists already, if the use case is actually worth expanding the kit.  The answer won’t always
be “no”, but it can’t always be “yes”, either.  Choose your battles.

During the initial process the artist usually worked with one level designer on a limited set of areas. Throughout the course of the game lots of different level designers will make lots of different levels. No matter how thorough the initial phases were, this always brings up unexpected issues. Assume that this will be the case and plan for additional kit polish time for course-
corrections down the road.

Going off the Grid: Advanced Techniques

At this point you know how to make a rules-based kit on the grid which works as a system. Things snap together, there are corner pieces, straight pieces, doorways, rooms, etc.

The problem with this kind of kit is that it will always feel like a kit. Things are always at 90 degree angles, the player will sense the system and art fatigue can set in.  Modular levels often feel like modular levels.

Starting with Fallout 3 we started to push kits beyond this to see how we could make a kit not feel like a kit.  We had spent our careers thus far learning the rules; now we needed to break them.
When you start to bend the rules, always keep in mind the reason they were rules in the first place. These ideas exist for a reason, and it can be hard to appreciate why until you’ve made certain mistakes firsthand.

If you find a way to bend kit logic, you shouldn’t necessarily apply that to all kits you make in the future. It is best if you embrace one particular logic quirk for each kit, otherwise things will quickly spiral out of control. It is also extremely important to remember the cost of bending the rules. Art has to spend more time making more pieces and the art is a lot more complicated.

The level design process is also usually more complicated and its easier to make mistakes.  Make sure these trade-offs are worth it on a case-by-case basis.

One of the key technologies that let us start building more complicated kits was something called “Snap to Reference”. With snap to reference the editor can treat any object as the origin for
things to snap for. This way, things don’t have to be aligned to rigid 90 degree angles. You can rotate a piece and then use that as the new grid, so new pieces will snap together with this rotated
piece. This obviously creates gaps between pieces rotated at different angles, but we bridge those gaps in a lot of ways.

One of the new kit types introduced in Skyrim was the  “Pivot and Flange” system used for the Ratway. This is a hallway kit that acts almost like a pipe kit. All of the hallway pieces can be rotated at unique angles, allowing for a much more organic flow. Because these hallway pieces are all rotated at arbitrary angles, there is a gap created between each hallway piece.

We covered up this gap using an archway that follows the full curvature of the walls, ceiling and floor. There are a few issues with that you should be aware of. For starters, the level design
process is more linear. Instead of knowing exactly how many pieces would be between a set of rooms, since things are rotated at strange angles, all of the numbers/angles are thrown off, which can make it harder to make adjustments.

It’s also easy to create non-obvious errors. Because these archways can’t snap to both halls, level designers may accidentally fail to align the gap-covering archway exactly right, which can lead to tiny holes that you might only see at just the right angle. (This underscores the importance of playing your work frequently, rather than staying editor-side for too long)  It is also a bad
system for highly specific architecture. Since it is inherently organic and relies on jamming things together, the visuals break down if you want clean, specific intersections. If you want organic
naturally curving hallways however, this system is fantastic and does not require many kit pieces.  Because the Ratway is supposed to feel like an ancient, decaying subterranean tunnel system,  it’s perfect.

We also found ourselves experimenting with our own rules when it came time to build the caves of Skyrim.  Caves have always been problematic for modular building, as modular kits are highly rules-based and orthogonal but caves are highly freeform and organic. Another system that we started using in Skyrim is the Shell-Based Building system.

This is a system in which we build all of the standard kit pieces in the traditional way, but then layer in freely placed walls, pillars and balconies to break up the play space in an organic way.

The diagram below shows a simple example where shell pieces are used to establish a room, and free walls and pillars are used to quickly create a more organic shape than the corner allowed by the strictly grid-snapped shell.

This allows level designers to build seamless levels with the exact shapes and flow that they want. Visually, it is very easy for things to never look the same. The amount of art that need is
surprisingly minimal, due to the random, chaotic way the art can be combined. Some artists might worry about things like specific intersections not looking great.  Try using an art-review process to monitor specific usage and provide constructive feedback when things aren’t working. Good lighting and rendering features like ambient occlusion also work out very well and go a long way to hide any awkward intersections.  The flexibility you can get from doing a level this way is astronomical. (Plus, no one really notices those little intersections.)

Delving further into our history, Directionally restricted kits are a technique we began in Fallout 3. Traditional kits can be rotated in any direction and still snap together. Directional kits do
not allow this, as they require certain pieces be used in relationship to each other. This allows art to do things like asymmetrical halls, specific width rooms (such as a room spanned by a large
arch) or room kits that have unique pieces for all of the cardinal directions.

This is a lot more work for both art and design, but it is extremely useful for organic kits, as it removes the need for surfaces and textures to tile in every direction. This can be a lot of extra
work, and it changes some of the core logic of a kit.   While extremely useful for creating natural kits, directional restrictions usually aren’t worth the extra effort for something highly architectural.  It can make the kit easier to understand if you start thinking of each unique surface differently, such as the A/B sides of the hallway pictured here.

One thing to watch out for when doing this is the need for what we call a “De-Twist” piece in the hallway kits. When an asymmetrical hallway flows in just one direction, it tiles just fine.

Sometimes, however, another hallway will meet up that happens to be flipped the other way. A de-twist piece bridges this gap over the course of a single piece by flipping which side meets up with the other. Hence the “de-twist”.  The following diagram shows an example of an asymmetrical hallway looping back on itself, where it then requires a de-twist.

Another simple kit concept that can add a lot of flexibility is a “platform” kit.  Platform kits are any that sit on top of other surfaces, and allow level design to cut up the horizontal planes of
play.  They can be very large or small, and both examples can be seen in Skyrim.  These empower level designers to create interesting playspaces without needing to add a great deal of complex vertical logic to the kits. The number of pieces needed to create a platform kit is minimal, and they tend to work with almost any other sub-kit with the same visuall theme. These platform kits were even used independently in the exterior as points of interest.

Platform kits are a specific example of what we’ve started to call “Glue” kits.  Beginning with our current project, we are now creating a number of small-scope kits which exist primarily to create transitions between multiple kinds of kits and sub-kits.  Glue kits are essentially made with kit-bashing in mind, and could be just about anything from platforms to tunnels to ledges.  They are so far giving us a good deal of mileage, and show how discoveries and innovations made along the way can begin to influence your formal workflow.  Which is good, because an evolving workflow is proof that you’re still learning.

Conclusion

There’s an awful lot more that we could cover if we were to get into the deeper details of kit-building, and you’re encouraged to reach out to us with any questions you may have.  For now,
however, let’s wrap up.

When you get down to it, I do not believe our team could have built Skyrim except through our decision to explore and embrace workflows like the ones discussed here.  We’re driven by a desire to  explore our worlds via their creation, always aware that the time we spend polishing every edge off one idea takes away from what we could be doing with another, and the thing after that.  We’ve said before that the worlds of our games are their own main characters.  Those worlds come to life before our very eyes during development.

Don’t mistake these workflows for a compromise into which we have been forced.  Rather, these are choices we have made in order to make the scope of our games possible while maintaining a working culture which keeps us happy and harmonious.

Because while I don’t believe our team could have built Skyrim any other way, I also believe that no other team could have made Skyrim.  Other teams could have made a game like Skyrim, and perhaps have spent more time or money, or worked with more people, or embraced different ideologies.  But any of those games would have been a different one that what we created, and we’re proud of the games we’ve made.

At the end of the day, the games you create – the art you put out into the world – is an expression of yourself.  If you’re working as part of a team, however, that art isn’t just an expression of
your own self, or even many individual selves.  It’s an outward expression of your relationships, and who you are as a group of people.  And these relationships are perhaps the most rewarding thing you’ll develop in your lifetimes.  It’s worth finding techniques that help grow those relationships and in turn improve the games you can make together.

Joel Burgess is a senior designer at Bethesda Game Studios, and Nathan Purkeypile is a senior environment artist.  Their shared gameography includes Skyrim, Fallout 3, Aeon Flux, Bloodrayne 2, and an unannounced project currently in development.  Nate and Joel were also co-leads on the Point Lookout DLC for Fallout 3.  They can be reached on twitter via @JoelBurgess and @NPurkeypile, respectively.(source:gamasutra)


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