Create Entire Cities Automatically With PCG Splines! Procedural Content Generation in Unreal Engine

Summary

このビデオでは、Unreal Engineのプロシージャルコンテンツ生成フレームワークを使って中世の町を数分で作り上げる方法を紹介します。スプラインを使用して町の形を定義し、スプラインロードで町を通過させ、スプラインに沿って道路ジオメトリーを生成して効果を豊かにします。PCG初心者向けガイドもリンクしています。プロシージャルな森の周りに町を生成し、スプラインを用いた建物の配置と道路のカットアウトを学ぶことができます。

Takeaways

• 🏰 スクリプトはUnreal Engine内でプロシージャルコンテンツ生成フレームワークを使用して中世の町を短時間で作成する方法を紹介しています。
• 🛠 スプラインを使用して町の形状を定義し、スプラインロードを通して町を切り抜き、スプラインに沿って道路ジオメトリを生成する方法を学びます。
• 🔍 PCGの初心者向けガイドは、ビデオの下にリンクされているため、必要な場合は参照できます。
• 📐 まず、既存のPCGボリュームを切り抜くためのスプライン形状を作成する必要があります。
• 🔌 「modeling tools editor mode」というプラグインを有効にする必要があり、編集とプラグインのセクションで「modeling」を入力して確認します。
• 🎨 「Modeling」ツールを使用してスプラインを作成し、地面上に円を描画し、ループをチェックして閉じる方法が紹介されています。
• 📂 スプラインにタグを追加し、PCGボリュームで使用するスプラインと他のスプラインを区別します。
• 🌳 フォレストのPCGボリュームを設定し、スプラインを使用して木々が生える地域を定義します。
• 🏠 新しいPCGグラフを作成し、町に建物を自動生成するための設定を行います。
• 🛤️ 町を通過するロードを作成し、スプラインを使用して建物との重なりをカットアウトします。
• 🌲 ロードに沿って繰り返し生成される地面メッシュを追加して、自然な道のりを実現します。

Q & A

ビデオで紹介されている Unreal Engine のプロシージャルコンテンツ生成フレームワークとは何ですか？

ビデオでは、Unreal Engineのプロシージャルコンテンツ生成フレームワーク（PCG）を使用して中世の街を短時間で作成する方法が紹介されています。これは、ランダム性やルールに基づいた方法でコンテンツを自動生成する機能です。

ビデオで使用されているスプラインとは何で、どのような役割を果たしますか？

スプラインは、Unreal Engineのモデリングツールの一つで、曲線や形状を定義するために使用されます。ビデオではスプラインを使用して街の形状を定義し、道を通過させるためのスプラインも作成されています。

ビデオのチュートリアルでは、どのようにして森に囲まれた中世の街を作成する予定ですか？

ビデオでは、まずPCGボリュームを作成し、森を生成した後、スプラインを使用して街の形状を定義し、その中に街を生成するプロセスが説明されています。

スプラインを使用する前に、Unreal Engineに必要なプラグインを有効にする必要がありますか？

はい、ビデオでは「modeling tools editor mode」プラグインを有効にする必要があると説明されています。これにより、スプラインなどのモデリングツールを使用できるようになります。

スプラインを描画する際に「World」オプションをオフにすることによって何が得られますか？

「World」オプションをオフにすることで、スプラインを地面平面上に限定して描画することができます。これにより、スプラインが周囲の木々などに描画されることを防ぎます。

ビデオで紹介されている街の形状を定義するスプラインにタグを追加する目的は何ですか？

タグを追加することで、PCGボリュームが特定のスプラインを認識し、その形状に基づいてコンテンツを生成するように指定することができます。

PCGグラフ内で「Difference」ノードを使用する目的は何ですか？

「Difference」ノードは、スプラインから得られるポイントと、他のポイント（例えば森の木々のポイント）を比較し、重複するポイントを削除する役割を果たします。これにより、街のクリアリングが作成されます。

ビデオで使用されている「Spline Sampler」ノードの「Interior」オプションとは何を意味しますか？

「Interior」オプションは、スプラインの内部にあるポイントのみをサンプリングするように指示します。これにより、街の形状の内部にポイントが生成されるため、建物が適切に配置されるようになります。

建物をランダムに配置する際に「Attribute Noise」ノードを追加する理由は何ですか？

「Attribute Noise」ノードは、メッシュスポーンのランダム性を調整し、建物の配置をより自然に見せるために使用されます。ノイズの値を調整することで、建物の配置のランダム性をコントロールできます。

ビデオで作成される道のスプラインにはどのようなタグが付けられますか？

道のスプラインには「Road shape」というタグが付けられます。これにより、PCGグラフが道を特定し、それに沿ってポイントを生成するように指示されます。

ビデオの最後に、道に沿って繰り返される地面メッシュを追加する目的は何ですか？

地面メッシュを道に沿って繰り返すことで、道に自然な土の道のような見た目を与えることができます。これにより、街の道にリアルな雰囲気が生まれます。

Outlines

00:00

🏰 制作中世纪城镇的开始

このビデオでは、Unreal Engineのプロシージャルコンテンツ生成フレームワークを使用してわずか数分で中世の町を作り上げる方法を紹介します。スプラインを使用して町の形状を定義し、スプライン・ロードで町を通過させ、ロードジオメトリをスプラインに沿って生成する方法を説明します。PCG初心者向けガイドもリンクしてあります。

05:00

🛠 スプラインを使用した町の形状の定義

Unreal Engineのモデリングツールを使用してスプラインを描き、町の輪郭を作ります。スプラインを閉じるためにループオプションをチェックし、タグを追加してPCGボリュームから他のスプラインと区別します。次に、PCGグラフ内で差分ノードを使用して、スプラインが定義する領域のポイントをカットアウトします。

10:02

🏘️ 中世の町の建物の配置

新しいPCGグラフを作成し、スプラインデータを取得して町の内側のポイントをサンプリングします。ポイントサイズを調整して建物が適切に配置されるようにし、静的メッシュスポナーを使用して様々な中世の建物を追加します。建物の配置が不自然な場合は、シードを調整するかノイズノードを追加してランダム性を増します。

15:02

🛤️ 道のスプラインと路面の生成

町を通過する道のスプラインを作成し、そのスプラインデータをPCGグラフに取り込み、ポイントを距離ベースで均等に配置します。路面として森の床面メッシュをスポーンし、サイズと回転を調整して自然な道の見た目を作り出します。最後に、道が建物を通過するように差分ノードを設定し、路面を道に沿って繰り返しスポーンさせることで完成します。

🎨 プロジェクトへの応用とさらなる学習へのリンク

このビデオを通じて学んだ技術を使ってどんなプロジェクトに応用するかコメント欄で共有を呼びかけています。ビデオが役立った場合は好評を示し、さらなる複雑な効果やアニメーション、フィルム作成に関するUnreal Engineの学習を希望者はリンクされた無料トレーニングや関連ビデオをチェックするよう促します。

Keywords

💡プロシージャルコンテンツ生成（PCG）

プロシージャルコンテンツ生成とは、コンピュータプログラムがランダム性やアルゴリズムを用いてコンテンツを生成する技術です。ビデオでは、Unreal Engine内のPCGフレームワークを使って中世の街を作り上げる方法が紹介されています。これは、手動での作成より効率的で柔軟性があります。

💡スプライン

スプラインは、数学やコンピュータグラフィックスにおいて、曲線を定義する一種の多項式です。ビデオでは、スプラインを使用して中世の街の形状を定義し、スプライン・サークルで街の輪郭を作り、スプライン・ロードで街を通過させる方法が説明されています。

💡Unreal Engine

Unreal Engineは、エピックゲームズが開発した3Dゲームエンジンで、ビデオ制作やVRアプリケーションにも使われています。ビデオでは、このエンジン内でPCGフレームワークを活用して街を生成する方法が紹介されています。

💡スプラインサークル

スプラインサークルは、スプラインを使用して作られる閉じた輪郭形状です。ビデオでは、スプラインサークルを使って中世の街の外形を作り、その内部に建物や道路を配置する方法が説明されています。

💡スプラインロード

スプラインロードは、スプラインを使って作られる道路を意味します。ビデオでは、スプラインロードを通して街を通り、その沿いに建物を生成するプロセスが紹介されています。

💡タグ

タグは、オブジェクトやデータに関連性を付けるラベルのようなもので、検索や識別に使われます。ビデオでは、スプラインにタグを付けてPCGボリュームに伝え、特定のスプラインだけを使用するように指示する方法が説明されています。

💡PCGボリューム

PCGボリュームは、プロシージャルコンテンツ生成フレームワーク内で使用される空間的なパラメーターです。ビデオでは、森を周囲に持ち込むPCGボリュームを設定し、その中で街を生成するプロセスが紹介されています。

💡ステンシルデータ

ステンシルデータは、スプラインなどの形状情報をコンピュータが理解する形式に変換したものです。ビデオでは、ステンシルデータをPCGグラフに取り込み、街の形状を定義するのに役立てる方法が説明されています。

💡静的メッシュスポナー

静的メッシュスポナーは、3D空間に静的な3Dモデルをランダムまたは一定のパターンで配置する機能です。ビデオでは、中世の建物を街にランダムに配置する際にこの機能を使って建物をスポーンする方法が紹介されています。

💡属性ノイズ

属性ノイズとは、ランダム性を加えることで生成物のバラつきを増やす技術です。ビデオでは、建物の配置が均一でないように見えるために属性ノイズを使ってランダム性を加える方法が説明されています。

Highlights

展示如何在几分钟内使用Unreal Engine中的程序化内容生成框架制作中世纪城镇。

使用样条曲线圆定义城镇的形状。

使用样条道路切割城镇并生成沿样条的道路几何体。

为初学者提供程序化内容生成(PCG)的入门指南链接。

介绍如何设置PCG体积以生成围绕中世纪城镇的森林。

启用建模工具编辑模式插件以创建样条。

使用建模工具直接创建样条比使用蓝图更简单快捷。

通过绘制样条工具在地面上绘制城镇的圆形样条。

使用标签区分不同的样条，以便PCG体积正确识别。

通过差分节点和样条数据创建一个清除点，以生成空地。

创建新的PCG图来生成城镇本身的结构。

调整样条采样器的参数以控制建筑物的分布。

使用静态网格生成器添加不同的中世纪建筑。

通过调整种子和属性噪声增加建筑物分布的随机性。

添加变换点节点以调整建筑物的方向。

创建道路样条并使用它来切割城镇的点。

使用变换点和静态网格生成器沿道路生成地面网格。

鼓励观众分享他们如何将此效果应用于不同项目。

提供链接到更多关于Unreal Engine动画和电影制作的免费培训。

Transcripts

hello in this video I'm going to be

showing you how I made this medieval

town in just a few minutes using splines

with the procedural content generation

framework inside of Unreal Engine I'm

going to be showing you how to use a

spline Circle to define the shape of

your town how to use a spline road to

cut through that town and then how to

spawn a road geometry along that spline

in order to fill out the effect and if

you're new to PCG and you want more of a

beginner's guide I will link that video

below this so let's get into it so

here's the town we're going to be

building I'm just going to come over

here to the spline actors and the PCG

actors and go ahead and delete them and

you'll notice I have already set up a

PCG volume inside of this level to spawn

the forest that's going to be around

this medieval town but if you'd like

tutorials on how to do that I will link

that as well below this video so what we

need to do to make a Town spawned inside

of this Forest is first to create a

spline shape that will cut out the

existing PCG volume that I've already

set up here so we need to make sure sure

there's one plugin enabled here and that

is under edit and plugins we're going to

type in modeling and you want to make

sure you have modeling tools editor mode

checked on and if it prompts you to

restart the engine go ahead and do that

now I'm going to come up here to the

drop down in the top left corner and I'm

going to choose modeling here this is

going to open some modeling tools for me

on the left side here and this is a much

easier way to make a spline then to make

a blueprint with a spline inside of it

which some of you may be familiar with

if you've made splines before this is a

much easier way and gets us the result

we want much quicker so I'm going to go

ahead and come to the draw spline tool

here and you can find that if you're not

in it in the create button on the top

left corner here so click on that click

on draw spline and one thing I want to

check here is that I uncheck world I

really just want to Draw It On The

Ground plane I don't want the spline to

like draw onto trees up and down so I'm

going to uncheck world but if you need a

draw spline on other objects make sure

that's checked on so then I'm just going

to go ahead and click around in a circle

however big I want my town to be here

and in the top left corner here where it

says Loop I'm going to go and check that

so it closes the loop for me and I'm

going go ahead and hit accept right here

so now I have a spline for the shape of

my town this can always be changed later

as well if you want to edit it I just

come out of the modeling mode and I can

choose one of these points and move them

around so the way that we're going to

tell the PCT volume to use this spline

and not other splines we're making in

our level like the one we're going to

make for the road is to add a tag to it

with that spline actor selected I'm

going to come over here and on the right

side here I'm just going to go ahead and

search tag to save us some time in the

search bar here and under the actor tag

section here I'm going to hit the plus

button to add a new tag to this object

and we're just going to call it town and

then outside and pay attention to what

you name it here cuz you'll need to

remember it and type it into the PCG

volume later so I'm going to go ahead

and hit enter I come over here to my PCG

volume here for the forest uh I click

clear the tag section here that I added

and I scroll down to the PGG component

open the PCG and graph instances and

then instance this is a PCD graph that's

connected to the volume here so I'll

double click on that to open it okay so

this is what I have set up for the

forest I have just a landscape surface

sampler coming into a transform points

to give the trees some random rotation

and then I have some density filters to

adjust how many points are on the

surface and then I have a static mesh

spawner for trees rocks and things like

that okay super simple so what I need to

do is cut out these points in this area

here right before they're used to spawn

so once I've done all the adjustments to

those points that I want we're going to

be creating a difference node so I'm

going to draw off here and type in

difference and I'll hold alt and click

on this input here to disconnect it and

reconnect it to the output and you want

to make sure that the source here which

is the point spawning those trees is

plugged into source and then the

differences section here that's where

we'll plug in the data from our spline

so in the difference node I need to

change the density function here to

Binary what this is doing is it's

basically telling this node that when we

give it the points that the spline has

created inside of it which we're going

to set up in a second to either choose

one or the other so basically to

completely remove all the points that

overlap with the points from the spline

so now we're going to right click in the

empty space down here and I'm going to

type in spline I'm going to choose get

spline data first because we need to get

this spline into the PCG graph and with

that node selected I'm going to come

over to the actor filter drop it down

and choose all World actors so it's

going to sample all the splines I have

in my scene but I'm going to choose by

tag here so it's going to choose the

spline with the correct tag which if

you'll remember we made as town outside

and if that tag exists in the world

you'll see the error on that spline data

go away so it's got that's a good thing

that means it's gotten the data from our

spline now I'm going going to drag off

of the get spline data here and we need

to make a sampler just the same way we

would sample a landscape so I'm going to

type in spline again to get spline

related stuff and we're going to choose

a spline sampler here in the spline

sampler there's a few different ways we

could sample this spline and later on

we'll use a different one but for this

we want the inside of the spline so if I

come up to the dimensions and instead of

on spline I switch it to Interior it's

going to get all the points inside that

shape that closed shape that we made so

let's actually take a look and make sure

this is working so I'm going to come

over and disconnect my mesh spawning so

that we can actually see what the graph

is doing then I'll contract this down so

this is the shape of our town here and

in the spline sampler I'm going to go

ahead and press D to debug and we have

one problem which is that this is only

being sampled inside the bounds of our

PCG volume which I actually turned off

for the trees so it would fold the

entire landscape so we actually have to

to turn that off for the spine sampler

as well and it's not actually super

important to have only things spawn

inside that volume because we're

actually using the spline itself to tell

us where the points are so we don't

actually need that bounding shape of the

volume so I'm going to come over to the

spline sampler and choose Unbound here

once we do that it's going to show you

that it's spawned all these points all

over the place so now we can come over

to the differences node and let's take a

look at what the points that we're using

to spawn the trees look like so UND

debug the spine sniper and debug the

transform point and these are all the

points I'm using for the trees and rocks

so if we plug the spine sampler into the

differences node here and we debug that

you can see that the spline sampler is

using the points from the spline data

node to cut out those tree points so now

if we plug it back into our mesh spawner

section we can see we have successfully

created an empty

clearing all right so let's make a new

pcga volume for or the town itself I'm

going to close this for now right click

in my content browser and come to PCG

and choose PCG graph as I mentioned in

other tutorials if you don't have the

PCG option in your content browser it

means you need to enable the plugin

procedural content generation framework

plug-in so I'm going to call this new

PCG graph

PCG town and I will drag it in to the

environments I'll hit generate on the

right side here and then I'll double

click on it to open okay so we're going

to come into the empty space here right

click and type in and get the get spline

data node here like we used before and

we'll come over here to the action

filter on the right side and choose all

World actors and again under the buy Tag

section we will type in town outside

there we go so we're going to drag off

of the out again here type in spline and

get the spline sampler same as before

this time let's go ahead and hit D to

debug this particular node so we can see

what we're working with and same as

before we need to come over to this

blind sampler and choose under Dimension

where it says on spline you want to

switch it over to on interior and scroll

down again and choose Unbound or you

could scale the PCG volume up far enough

so that it would cover the whole spline

shape it's up to you okay so it's pure

white here and that's because all of the

individual points are too big so I need

to actually mess with those Point sizes

so that it doesn't spawn too many

buildings when I actually connect up the

geometry spawner to it so we can start

modifying these options here right now

the interior sample spacing is 100 that

means there's 100 units in between each

sample if I increase that number to say

something like 500 we can see it makes

the dots smaller because it's giving a

500 space in between them I'm going to

go ahead and actually increase this to

2,000 and you'll notice by default these

points are getting spawned in a grid

which is what we want for a town if you

were to sample the landscape not using

this method you would get points in a

more random layout or random format and

in this case we're getting a grid by

default which is good one thing I do

want to modify here is the bounds of

each point since they're kind of small

if I were to run a road through it which

we're going to do in a in a second they

would not actually probably overlap any

of the points and therefore not cut them

out they need to be roughly the size and

shape of the buildings that we're about

to add later so I'm going to go ahead

and drag off of the out here and type in

bounds and choose bounds modifier and

we'll just up the bounds m Max to 10 on

all of these once we've done that we can

go ahead and debug that node and we can

see these are much larger cubes which

will work a lot better when we're

cutting it out with the road okay now

it's time to add our static mesh spawner

to put our buildings in I'll drag off of

the bounce modifier here type in static

mesh spawner okay so we have the static

mesh spawner I'll come over here to the

mesh entries and expand that now I have

downloaded a medieval buildings pack

which I will link below this video if

you're interested in using those as well

but it contains all of these buildings

here so I have a bunch of different

buildings that I'm going to be adding to

my mesh spawner so I'll just add one to

show you how to do it which is to expand

the mesh entries under the static mesh

instance here and drag in a building of

your choice then contract it hit the

plus button again add another one open

the descriptor drag in another building

and we can see that we're already

starting to populate our little village

here now this is actually going to

really look the best if you have a lot

of different building options and I

actually do I have around 22 of these

buildings so I'm going to go ahead and

plug all of those into this mesh spawner

all right now they're all plugged in and

we can see we already have a village

that's looking pretty good here if

you're not really happy with sort of the

placement of the buildings or it doesn't

quite look random enough you can come

over here to the static mesh spawner and

you can adjust the seed which is going

to choose a just a random different

selection of buildings here or if you're

still not getting enough random

something I have noticed helps a little

bit is to add an additional node which

I'll grab by typing in noise and I'll

choose attribute noise and I'll plug

that in in between and in the attribute

noise under the input source I'm going

to click on the little plus button here

and choose seed and by default it's

going to have only one building and then

as I increase this noise Max here it's

going to just creep increasing the

randomness till I get something that I

like that looks pretty good and if we

have our buildings pointing in the wrong

direction we you can always modify that

as well by adding a transform points

note here in between coming over here to

the rotation Min and Max and adding a

rotation in Z maybe 9° and that will

rotate all of the buildings 90° now this

really works best if you've modeled or

at least rotated your building assets

that you're starting with to be all

facing the correct direction if they're

all have the front of the building faced

in different positions they're not going

to quite look that well here and instead

of adding like a lot of logic in to make

sure they're all pointing the same

direction it's just simpler to make sure

each of your assets is you know

efficiently pointing in the direction

that you want them to point you could

also use this rotation to add like a

slight bit of Randomness maybe not too

much but maybe between -5 and 5 that

just rotates the building ever so

slightly depends how gridlike you want

them to look so now we're ready to add

our road and the road is going to be

another spline that we add on top here

and it's going to cut through the points

that we've already laid out for the town

so come back over here to the mod

modeling drop down and choose my draw

spline option here I'm just going to

have it go straight through the middle

of my town I'll go ahead and hit enter

switch back to selection mode and our

second spline actor here we need to add

a tag as well too so I'm going to come

over here and insert type in tag for the

asset and choose a little plus button

here and type in Road shape or whatever

you want to add next we'll come back

into our graph here we'll right click

and get spline data again and and this

time we'll choose all World actors and

the tag will be Road shape then we'll

drag off of that sample it and I'm going

to actually disconnect the houses here

so that I can actually see the points

that this new road is making so hold

down alt and disconnect the static

meshes and we'll go ahead and hit D to

look at the spline sampler and I'm going

to come over here to the mode here where

it says subdivision and switch it to

distance this is going to lay the points

out along the curve more evenly we will

keep it as on spline here in contrast to

what we did for the town earlier and

we'll drag off of here and make a bounds

modifier we'll debug that and let's

expand those points because right now

there are actually points being

simulated but they're too tiny to see so

we'll just come over to the bounds Min

and Max and let's in the Y AIS increase

it to 500 here we can see the points

have expanded the width of about the

shape of the road that we want however

they're only getting simulated again

within the volume the PCD shape so

probably we should have just made it

bigger but at this point I'm committed

to using the Unbound option here so I'll

come over to the spinee sampler and

check on Unbound and now you can see the

points are being simulated all along

this line okay so now we have our road

and we have the points of the town so we

need to make a difference node in

between here so drag off of the

transform points that we're using to

simulate the buildings make a difference

node and the difference is going to plug

into those points from the road let's go

ahead and look at what that looks like

and you can see the road is cutting

right through the building here however

nothing is happening as because in the

difference Zone we need to come back

over here if you remember earlier we

need to switch the density function to

Binary and then it will cut out the

buildings that overlap with those points

now we can plug it back into our static

mesh spawner and we have a road that

will dynamically cut through our town

and to make this road look a little bit

better I'm going to add a mesh to be

simulated and spawned along it and

repeated to make kind of a muddy path so

I'll drag off of the actual Road points

here and make a transform points node so

I know I will need it to modify the mesh

then I'll drag off of that and type in

static mesh spawner and I will be adding

the forest ground mesh which you can

find in the quickel bridge so add a mesh

entry here drag that in and we can see

it is a bit too small so we'll come over

to the transform points and increase the

scale Min and Max by five We'll add a

random rotation as well in the rotation

Max section here under the Z axis We'll

add a 360 so it'll rotate from 0 to 360

and to push it down into the ground ever

so slightly to help it blend a little

bit better I'll come over to the offset

mid and Max and add in a negative one to

the Z axis and if I feel like there are

maybe too many meshes getting spawned in

a line here I can just come over to the

spline sampler here and this distance

increment is very similar to the one we

used for the placement of the buildings

so I can come over here and increase

this to 500 so create fewer points um

along the spine there you have have it

that's how you make a medieval town in

just a few minutes this can go very

complicated very quickly if you'd like

to add additional Logic for how the

buildings are placed or how the road

maybe spawns other meshes I could

imagine you having Street lamps that are

spawned along the outside of the spline

on either side but the starting point is

really to get that spline shape in the

overall shape of the town and then the

road spline that goes through it let me

know in the comments what you end up

actually using this effect for I'm very

curious to see how you all will apply it

in different types of projects if you

found this video helpful shoot me a

thumbs up so I know to make more on this

type of thing and if there you're out

there and you're a beginner and you're

just confused and you want more of an

onramp up to these more complicated

effects and specifically making

animations or films with Unreal Engine I

have a free training which you can take

a look at which is linked below this

video as well as a bunch more videos on

ptg specifically right here so I will

see you in the next one