What is Procedural Content Generation?

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Ira Daniels
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1 Sectin 5 ( ) Endless Runner In this tutrial we are ging t create an Endless Runner game. In this game character can nly mve right and left and it is always ging frward. The grund (tile r platfrm) are generated in runtime (prcedural cntent generatin r PCG). What is Prcedural Cntent Generatin? Prcedural cntent generatin (PCG) is the prgrammatic generatin f game cntent using a randm r pseudrandm prcess that results in an unpredictable range f pssible game play spaces. 1 It is used t autmatically create large amunts f cntent in a game. Advantages f prcedural generatin include smaller file sizes, larger amunts f cntent, and randmness fr less predictable gameplay. Creating Our Prject Let s start by creating a new Unity 3D prject call it Endless Game Runner. Creating the fllwing Directry hierarchy in the Prject Windw: Animatins It will cntain bth Animatin Clips and Animatin Cntrllers each n its Directry. Animatins Cntrllers Materials Textures Mdels It will cntain ur character 3D mdels. Prefabs It will include that prefabs we will make during making ur game. It will als include ur characters after adding sme cmpnents and change sme f its prperties. Scenes Scripts Packages Include imprted packages frm Asset Stre r surces. Save the Scene in the Scenes directry as Scene01. Preparing ur character prefab Imprt the ybt 3D character mdel that we had used befre. If yu dn t have it dwnlad it frm Mixam. Yu shuld place it in the Mdels flder Add the character t ur Scene. Then reset its Transfrm Cmpnent. T d that: Select the Character frm the Scene view r frm the Hierarchy. After selecting the Character, the Inspectr will change t shw the cmpnent f the selected GameObject (ur character). G t the Transfrm Cmpnent, and the Gear icn and select Reset. 1 Definitin frm

Sectin 5 (25-03-2018) Figure 1 Change the Tag frm untagged t Player.

Fr example, Yu might define Player Tags fr player-cntrlled characters and an Enemy Tag fr nn-player-cntrlled characters.

Tags help yu identify GameObjects fr scripting purpses.

yu are using the same script cde in multiple GameObjects.

2 Sectin 5 ( ) Figure 1 Change the Tag frm untagged t Player. Tags A Tag is a reference wrd which yu can assign t ne r mre GameObjects. Fr example, Yu might define Player Tags fr player-cntrlled characters and an Enemy Tag fr nn-player-cntrlled characters. Yu might define items the player can cllect in a Scene with a Cllectable Tag. Tags help yu identify GameObjects fr scripting purpses. They ensure yu dn t need t manually add GameObjects t a script s expsed prperties using drag and drp, thereby saving time when yu are using the same script cde in multiple GameObjects. Tags are useful fr triggers in Cllider cntrl scripts; they need t wrk ut whether the player is interacting with an enemy, a prp, r a cllectable, fr example. Yu can use the GameObject.FindWithTag() functin t find a GameObject by setting it t lk fr any bject that cntains the Tag yu want. Surce: Tags frm Unity Dcumentatin. If the Character GameObject has any Clliders remve it and add a Character Cntrller Cmpnent. Figure 2 Character Cntrller Cmpnent

Sectin 5 (25-03-2018) Character Cntrller The Character Cntrller is mainly used fr third-persn r first-persn player cntrl that des nt make use f Rigidbdy physics.

It will slide alng walls, walk upstairs (if they are lwer than the Step Offset) and walk n slpes within the Slpe Limit.

3 Sectin 5 ( ) Character Cntrller The Character Cntrller is mainly used fr third-persn r first-persn player cntrl that des nt make use f Rigidbdy physics. It is simply a capsule shaped Cllider which can be tld t mve in sme directin frm a script. The Cntrller will then carry ut the mvement but be cnstrained by cllisins. It will slide alng walls, walk upstairs (if they are lwer than the Step Offset) and walk n slpes within the Slpe Limit. The Cntrller des nt react t frces n its wn and it des nt autmatically push Rigidbdies away. Prperties Prperty: Functin: Slpe Limit Limits the cllider t nly climb slpes that are less steep (in degrees) than the indicated value. Step Offset The character will step up a stair nly if it is clser t the grund than the indicated value. This shuld nt be greater than the Character Cntrller s height r it will generate an errr. Skin width Tw clliders can penetrate each ther as deep as their Skin Width. Larger Skin Widths reduce jitter. Lw Skin Width can cause the character t get stuck. A gd setting is t make this value 10% f the Radius. Min Mve Distance If the character tries t mve belw the indicated value, it will nt mve at all. This can be used t reduce jitter. In mst situatins this value shuld be left at 0. Center This will ffset the Capsule Cllider in wrld space and wn t affect hw the Character pivts. Radius Length f the Capsule Cllider s radius. This is essentially the width f the cllider. Height The Character s Capsule Cllider height. Changing this will scale the cllider alng the Y axis in bth psitive and negative directins. Surce: Character Cntrller frm Unity Dcumentatin.

Sectin 5 (25-03-2018) After adding the Character Cntrller cmpnent, green lines in capsule shape will appear, this is the cllider.

a Figure 3 Befre (a) and after (b) changing the Center f the Character Cntrller b The Character Cntrller gives yu the same type f cllisin as Capsule

Let s add a new Script call it PlayerMvement.

First things first, yu shuld add the newly created script t the Player. Add a new field f type CharacterCntrller in the script call it cntrller.

Since we are ging t create an Endless Runner game we want ur character t cntinuusly mve, s we will call Mve methd in the Update functin.

4 Sectin 5 ( ) After adding the Character Cntrller cmpnent, green lines in capsule shape will appear, this is the cllider. Mdify the Center and Height f the Character Cntrller t make the Cllider fit ur character. a Figure 3 Befre (a) and after (b) changing the Center f the Character Cntrller b The Character Cntrller gives yu the same type f cllisin as Capsule Cllider but it allws yu t mve the GameObject using functin called Mve(). We want t add sme actins t ur player. Let s add a new Script call it PlayerMvement. In rder t mve the player we need a reference t the Character Cntrller cmpnent and then call the Mve() functin. First things first, yu shuld add the newly created script t the Player. Add a new field f type CharacterCntrller in the script call it cntrller. Use GetCmpnent methd t get a reference t ur Character Cntrller Cmpnent and assign it t cntrller field. That shuld be dne in the Start methd. Since we are ging t create an Endless Runner game we want ur character t cntinuusly mve, s we will call Mve methd in the Update functin. The Mve functin need t take a mtin, which is a Vectr3 bject. Let s try t use Vectr3.Frward, which is a shrthand fr writing Vectr3(0,0,1). Try t play the game nw. CharacterCntrller.Mve public CllisinFlags Mve(Vectr3 mtin); Attempts t mve the cntrller by mtin, the mtin will nly be cnstrained by cllisins. Surce: CharacterCntrller.Mve frm Unity Script Reference. The character is mving frward but it is very fast. Let s handle this, we multiply the Vectr3.Frward with Time.deltaTime.

5 Sectin 5 ( ) If we try t play the game, we will ntice it is nw mving t slw. T handle that we are ging t add speed. S, declare a new variable speed and set it t 5.0. Then multiply it with ther values in the Mve functin. Our cde shuld lk like the cde snippet belw. using System.Cllectins; using System.Cllectins.Generic; using UnityEngine; public class PlayerMvmentCntrller : MnBehaviur { private CharacterCntrller cntrller; private flat speed = 5.0f; // Use this fr initializatin vid Start () { cntrller = GetCmpnent<CharacterCntrller>(); // Update is called nce per frame vid Update () { cntrller.mve(vectr3.frward * Time.deltaTime * speed); Cde Snippet 1 Rename ur character t Player and drag it t the Prefabs directry. Character Animatin, Mvement and Gravity Our character can mve frward but withut any animatin and it is nt falling despite that there is n grund. It als can t d any thing but mving frward. We nw will d the fllwing: Add a running animatin Handle right and left mvement. Add gravity. Let s start: Create a new Animatr Cntrller call it YBtAnimCntrller. Mve it t Animatins/Cntrllers directry. Imprt Running Animatin that we used befre r dwnlad ne frm Mixam. Of curse yu shuld Imprt it in Animatin/Animatins directry. Select the Animatin frm the Prject Windw, then g t the inspectr the Animatin tab and make sure t check Lp Time and Lp Pse and click Apply. Why we did that? Because ur character will always be running. Open the Animatr View and drag the animatin t it. A new state will be created as the default state and a default transitin will g frm Entry State t the newly created state. Rename the state t Running.

Sectin 5 (25-03-2018) Figure 4 Animatr Windw after adding a new state and renaming it.

Cmpnent. Nw try t play the game, yu shuld see yur character running frward. Nw let s wrk n the left and right mvement: Since we will tackle gravity later let s add a flr beneath ur character.

6 Sectin 5 ( ) Figure 4 Animatr Windw after adding a new state and renaming it. Finally, we shuld add the Animatr Cntrller t ur Character by chsing it frm the Inspectr r Scene View, then g t the Animatr Cmpnent and add the Animatr Cntrller t the Cntrller prperty f the Animatr Cmpnent. Nw try t play the game, yu shuld see yur character running frward. Nw let s wrk n the left and right mvement: Since we will tackle gravity later let s add a flr beneath ur character. Create a new Plane. Reset its psitin. Scale it up by 5 by 5 by 5. Figure 5 Our Scene after adding and scaling ur grund. T make ur Character mve right and left, let s pen ur PlayerMvement script. Declare a new Vectr3 field name it mvevectr. Our gal with this is t replace what is inside cntrller.mve functin by mvevectr. In every

7 Sectin 5 ( ) single frame we are ging t recalculate the mvevectr, in this way we can have a mvement that is new in every frame. We are ging t d that in the Update methd: In the first line f the Update methd we shuld reset ur mvevectr, we can d that by assigning it t a zer vectr as fllw mvevectr = Vectr3.zer; In this way we reset the mvevectr. Cde Snippet 2 Nw we are ging t calculate the X value, the Y value and the Z value. In Unity the X is mving right and left, the Y is mving up and dwn and the Z is mving frward and backward. The X value r mvevectr.x shuld equal either right r left depending n which directin yu are pressing n the keybard. S, we need t get user input. We will d that as fllw: mvevectr.x = Input.GetAxisRaw("Hrizntal"); Cde Snippet 3 We used GetAxisRaw because we dn t want t be affected by sensitivity and gravity f the input. We must remember t multiply the previus value by speed. If we change ur Mve functin parameter t the fllwing: cntrller.mve(mvevectr * Time.deltaTime); Cde Snippet 4 And then play the game, we can ntice that we can mve right and left. We will fix the mve frward sn. The Z value r mvevectr.z is fr Frward and Backward mvement, but since we are making an Endless Runner we nly need t mve Frward and hence mvevectr.z shuld equal t speed which is a psitive value which indicate mving frward. If yu play the game nw, yu shuld be able t mve right and left while mving (running) frward. We are ging nw t handle Gravity, we can d that as fllw: Declaring a verticalvelcity as flat and set it t zer. Every single frame we are ging t calculate this verticalvelcity it will be incremented if I am n falling r resting it if I am n the flr. S, befre actually ding X r Y r Z, I am ging t ask my Character Cntrller Are yu grunded right nw? If I am n the flr set verticalvelcity t zer r t a add a really slight value t make sure that yu are really n the flr. Else verticalvelcity will be decrement by gravity, which we will declare as flat t and set it t 12.0 fr example. Finally, we need t mdify the mvevectr.y and set it t verticalvelcity. The fllwing cde snippet shws this step:

8 Sectin 5 ( ) mvevectr = Vectr3.zer; if(cntrller.isgrunded){ verticalvelcity = 0.5f; else{ verticalvelcity -= gravity * Time.deltaTime; //X is left and right mvevectr.x = Input.GetAxisRaw("Hrizntal") * speed; //Y is up and dwn mvevectr.y = verticalvelcity; //Z is frward and backward mvevectr.z = speed; // cntrller.mve(mvevectr * Time.deltaTime); Cde Snippet 5 Camera Mvement We nw want t make ur Camera fllw ur character. We will d that using a Script in ur Camera. We will use a different methd than the ne we used befre. We will make a Script that will put the Camera n ur Character and give it a certain ffset. But instead f writing the ffset value manually in the cde we want t be able t change it (the ffset) by changing the psitin f the Camera in the editr. Chse the Camera frm the Inspectr and add a new Script n it, call it CameraMvement. Then mve the file t the Script directry. The first thing we need t d is t get a reference t the Transfrm cmpnent f ur Character (the player). We will d that as fllw: Declare a private Transfrm, call it lkat. Remember that I asked yu befre t make sure that yu change the Tag f ur character t Player, its time t use that nw. We are ging t use GameObject.FindGameObjectWithTag, which return a GameObject with tag name. We will call it in the Start methd and get the Transfrm Cmpnent frm the returned GameObject and assign it t lkat. lkat = GameObject.FindGameObjectWithTag("Player").transfrm; Cde Snippet 6 Nw we need t get the ffset, t d that: Declare a private Vectr3 and call it startoffset. We want the startoffset t equal the difference the initial psitin f the Camera and ur Character befre the game begin r at the very begging f the game. T d that we will calculate the difference between Camera psitin and Player psitin in the Start methd and assign the result t startoffset. startoffset = transfrm.psitin - lkat.psitin; Cde Snippet 7 Till nw we didn t mve the Camera r make it fllw the Player. T d that we are ging t update the psitin f the camera every frame and assign the Player psitin plus the startoffset t it.

9 Sectin 5 ( ) The cde in CameraMvment shuld lk like the fllwing cde snippet. public class CameraMvement : MnBehaviur { private Transfrm lkat; private Vectr3 startoffset; // Use this fr initializatin vid Start () { lkat = GameObject.FindGameObjectWithTag("Player").transfrm; startoffset = transfrm.psitin - lkat.psitin; // Update is called nce per frame vid Update () { transfrm.psitin = lkat.psitin + startoffset; Cde Snippet 8 Restrict Camera mvement In the previus part we make the Camera fllw the Player, but it fllws it even when it mves left and right. In my pinin in an Endless Runner it shuld be the center f and nt mving right and left. S, we want t restrict the mvement f the camera in the X axis and keep it centered at X = 0. T d, let s first change the dimensins (Scale) f ur Plane t 1 by 5 by 15. Nw its time t mdify ur CameraMvement Script. Declare a private Vectr3 and call it mvevectr. We want t d the fllwing: Making mvevectr cntain the new psitin f the Camera. Change the X value f mvevectr t zer. Assign this value (the value f mvevectr after changing its X value) t Camera psitin. The fllwing cde snippet cntains the cde after making the abve changes: vid Update () { mvevectr = lkat.psitin + startoffset; // X value mvevectr.x = 0; transfrm.psitin = mvevectr; Cde Snippet 9 Gameplay Prefabs (Tiles) Nw we are ging t make prefabs that we are ging t create at run time. We make mre than ne because we want t generate different tiles t make different bstacles. Remve the Plane we made at the begging. Create a new Plane, mve it s that ur Characters stand at the edge f it. Fr me I mved it -5 in Z.

Sectin 5 (25-03-2018) Figure 6 Nw Imprt the fllwing Packages frm the Asset Stre: GrassRadRace it

Barrel It cntains Prefabs that we will use as Obstacles.

10 Sectin 5 ( ) Figure 6 Nw Imprt the fllwing Packages frm the Asset Stre: GrassRadRace it cntains prefabs that we will use as ur Tiles (Platfrm r Grund). Barrel It cntains Prefabs that we will use as Obstacles. Crate It als cntains Prefabs that we will use as Obstacles. Figure 7 Drag Grund01 t the Scene and Reset its psitin then snap it using Vertex Snap(V ) t align it next t the player.

Sectin 5 (25-03-2018) Figure 8 If we play the game yu will ntice that the player may fall frm right r left s add Bx Cllider t the fences.

Make ther Prefabs the same way but add sme Obstacles t them. Make sure that the bstacles has Clliders n them.

11 Sectin 5 ( ) Figure 8 If we play the game yu will ntice that the player may fall frm right r left s add Bx Cllider t the fences. Use Edit Cllider t reshape the cllider. Figure 9 Rename the Object t Tile_GrassBridge and make a Prefab frm it. Make ther Prefabs the same way but add sme Obstacles t them. Make sure that the bstacles has Clliders n them. I have created the fllwing Prefabs: Tile_GrassBridge Tile_GrassBridge_WithBarrelBthSides Tile_GrassBridge_WithBarrelLeft Tile_GrassBridge_WithBarrelRight Tile_GrassBridge_WithCrateBthSides

Sectin 5 (25-03-2018) Figure 10 Fe Tiles ne after anther, each with different bstacles Spawning Algrithm In this sectin we are ging t write a script that create GameObjects, in ur case tiles, in

Reset its psitin and make sure that it is in psitin X = 0, Y = 0, Z = 0. Create a new Script in that GameObject and call it TileManager.

12 Sectin 5 ( ) Figure 10 Fe Tiles ne after anther, each with different bstacles Spawning Algrithm In this sectin we are ging t write a script that create GameObjects, in ur case tiles, in runtime. Remve the tiles yu created befre r the ne yu used them t create the prefabs. Yur Inspectr shuld lk like the fllwing image Figure 11 Create a new Empty GameObject call it TileManager. Reset its psitin and make sure that it is in psitin X = 0, Y = 0, Z = 0. Create a new Script in that GameObject and call it TileManager. The first thing ur script needs t knw is what are the prefabs it can spawn. T give it this infrmatin we will declare a public GameObject array, let s call it tilesprefabs. If yu save the cde and select the TileManager GameObject and lk n the inspectr yu will ntice that it has a new prperty, tilesprefabs. It has a small arrw n the left if yu click it, it will expand and yu will be able t input the size f the Array.

Sectin 5 (25-03-2018) Figure 12 I will make the size equals t 3 and add the 3 f the Prefabs that I made befre. Figure 13 The Spawning (Creatin f new Objects in Runtime) can be achieved in many ways.

13 Sectin 5 ( ) Figure 12 I will make the size equals t 3 and add the 3 f the Prefabs that I made befre. Figure 13 The Spawning (Creatin f new Objects in Runtime) can be achieved in many ways. But I want the triggering f the Spawning happen based n the Psitin f the Player. S, we will need reference t the Player. Declare a private Transfrm call it PlayerTransfrm and assign it the player transfrm in the same way we did in the CameraMvement script. The tiles that we will create will have the same X and Y psitin, the difference between them is nly Z psitin that s because the psitive Z axis is the Frward Directin. We will need a reference t the psitin in Z where the new GameObject (Tile) will be created. This reference will be updated every time we create a new GameObject. Declare a private flat call it spawnz and initialize it t 0.0. This variable indicates where in Z shuld we spawn the GameObject (Tile). We will als need t knw the Length f tiles t be able t update the spawnz. Declare a private flat call it tilelength initialize it t the length f the tile. T make things easier we will use tiles f the same length. Fr me the tile length is One mre infrmatin we want t add, which is Hw many tiles we want n the Screen?. Declare a new private int and call it amuntoftilesonscreen and initialize it t 7. Create a new functin call it SpawningTile. This will be the functin that d the actual spawning. It will d the fllwing: Create (Instantiate a new GameObject). We will Clne (make a cpy f) ne f the Prefabs we reference in tilesprefabs. We can d that using Instantiate methd.

Sectin 5 (25-03-2018) Object.Instantiate public static Object Instantiate(Object riginal); Parameters riginal An existing bject that yu want t make a cpy f. Returns Object The instantiated clne.

14 Sectin 5 ( ) Object.Instantiate public static Object Instantiate(Object riginal); Parameters riginal An existing bject that yu want t make a cpy f. Returns Object The instantiated clne. This functin makes a cpy f an bject in a similar way t the Duplicate cmmand in the editr. If yu are clning a GameObject then yu can als ptinally specify its psitin and rtatin (these default t the riginal GameObject's psitin and rtatin therwise). If yu are clning a Cmpnent then the GameObject it is attached t will als be clned, again with an ptinal psitin and rtatin. When yu clne a GameObject r Cmpnent, all child bjects and cmpnents will als be clned with their prperties set like thse f the riginal bject. Surce: Object.Instantiate frm Unity Script Reference. Make that GameObject a child f TileManager Mve the GameObject t the right psitin. Update spawnz. private vid SpawnTile(int tileindex = -1){ GameObject tile; tile = Instantiate(tilesPrefabs[0]) as GameObject; tile.transfrm.setparent(transfrm); tile.transfrm.psitin = Vectr3.frward * spawnz; spawnz += tilelength; Cde Snippet 10 Finally, we need t call SpawnTile functin n the Update methd, but we need t limit the Spawning t the amuntoftilesonscreen. Fr nw, we will just make sure that amuntoftilesonscreen tiles will be ahead f ur character. vid Update () { if(playertransfrm.psitin.z > spawnz - amuntoftilesonscreen * tilelength ){ SpawnTile(); Cde Snippet 11

Sectin 5 (25-03-2018) A small nte, fr sme reasn the (0,0,0) f the Grund01 is at the end f it. That means when it is in the rigin its length is in the negative directin.

15 Sectin 5 ( ) A small nte, fr sme reasn the (0,0,0) f the Grund01 is at the end f it. That means when it is in the rigin its length is in the negative directin. That means that if we run the previus cde the first tile will be behind ur Character as shwn in the image belw. T slve this prblem, we will add the tilelength t the spawnz when we repsitin the newly instantiated GameObject. Figure 14 private vid SpawnTile(int tileindex = -1){ GameObject tile; tile = Instantiate(tilesPrefabs[0]) as GameObject; tile.transfrm.setparent(transfrm); // tile.transfrm.psitin = Vectr3.frward * (spawnz); tile.transfrm.psitin = Vectr3.frward * (spawnz + tilelength); spawnz += tilelength; Cde Snippet 12

Using the Swiftpage Connect List Manager

Using the Swiftpage Connect List Manager Quick Start Guide T: Using the Swiftpage Cnnect List Manager The Swiftpage Cnnect List Manager can be used t imprt yur cntacts, mdify cntact infrmatin, create grups ut f thse cntacts, filter yur cntacts