Workshop for School For Games 2015 at InnoGames, Hamburg, Germany. Introduction to game lifecycles and Unity3D.

1. Game Development
Grundlagen der Unity-Engine
Nick Prühs

2. About Me
“Best Bachelor“ Computer Science
Kiel University, 2009
Master Games
Hamburg University of Applied Sciences, 2011
Lead Programmer
Daedalic Entertainment, 2011-2012
Co-Founder
slash games, 2013
Microsoft MVP
2015
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3. First Things First
• At npruehs.de/teaching you‘ll find all slides
• Ask your questions – any time!
• Contact me any time at dev@npruehs.de!
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4. Objectives
• To understand the fundamentals of game lifecycles
• To learn how to build a small game with Unity3D
• To get an idea of how to learn from others
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5. New Unity Project
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6. New Unity Project
Unity projects contain
multiple different
files and folders
• Assets (3D Models,
Images, Code)
• Settings (Input,
Phyiscs)
• Temporary Files
(imported assets,
see later)
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7. Unity Editor Layout – 2 by 3
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8. Unity Editor Layout – 2 by 3
The scene view shows
all objects of the level
and allows free
movement.
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9. Unity Editor Layout – 2 by 3
The game view shows
the level as seen by
the camera.
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10. Unity Editor Layout – 2 by 3
The hierarchy
provides an overview
of all scene objects.
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11. Unity Editor Layout – 2 by 3
The project view
contains all assets (3D
models, code) of your
project.
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12. Unity Editor Layout – 2 by 3
The inspector shows
the details of the
selected game object.
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13. Unity Camera
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The camera draws
scene objects as seen
from its position.

14. Asset Import
Unity imports all of
your assets so it
understands how to
use them properly.
(Thanks, Unity!)
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15. Asset Import
Unity imports all of
your assets so it
understands how to
use them properly.
(Thanks, Unity!)
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16. Game Loop
Update
Draw
16
Init Shutdown
The game lifecycle is split up into four major steps.

17. Game Loop
Update
Draw
17
Init Shutdown
During initialization, the game sets up everything to run properly, such
as preparing the graphics device, loading all assets, or opening a log file.

18. Game Loop
Update
Draw
18
Init Shutdown
In each update, all game objects may change their properties, such as
position, health, or cooldown timer.

19. Game Loop
Update
Draw
19
Init Shutdown
Then, the game tells the graphics device what to draw, where, and how.

20. Game Loop
Update
Draw
20
Init Shutdown
Finally, the game needs to shut down properly, returning the graphics
device to the operating system, for example.

21. Our First Script!
Now that we’ve got our little space ship ready, it’s
time to add some action!
We want to do two things now:
1. Check if the player pressed a button.
2. Move the space ship if he or she did.
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22. Our First Script!
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In Unity, we can
attach scripts to
game objects.
Each script will
describe the behavior
of that particular
game object.

23. Our First Script!
C#
23
// Use the magic code Unity provides for us.
using UnityEngine;
using System.Collections;
// Name of the script.
public class KeyboardMovement : MonoBehaviour
{
// Use this for initialization.
void Start ()
{
// Nothing to do here, yay!
}
// Update is called once per frame.
void Update ()
{
// Check if player pressed any button.
if (Input.GetKey(KeyCode.W))
{
// Add "forward" vector to current position.
this.transform.localPosition += Vector3.forward;
}
}
}

24. Our First Script!
// Use the magic code Unity provides for us.
using UnityEngine;
using System.Collections;
Whew, that’s a lot of
stuff. Let’s take a detailed
look at that!
First, game engines like
Unity and frameworks
like .NET save us from
writing the same code
over and over again (e.g.
vector math, lists).
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25. Our First Script!
// Name of the script.
public class KeyboardMovement:MonoBehaviour
{
…
}
Clearly, Unity needs to
know the name of our
script.
The other stuff (public,
class, MonoBehaviour,
that strange colon, …)
won’t be covered here.
Go to a dedicated
computer science class
for that ;)
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26. Our First Script!
// Use this for initialization.
void Start ()
{
// Nothing to do here, yay!
}
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Remember the
initialization we
sometimes need to do
before entering the game
loop?
Unity allows us to that
right here, right now!

27. Our First Script!
// Use this for initialization.
void Start ()
{
// Nothing to do here, yay!
}
Remember the
initialization we
sometimes need to do
before entering the game
loop?
Unity allows us to that
right here, right now!
(Thanks, Unity!)
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28. Our First Script!
// Check if player pressed any button.
if (Input.GetKey(KeyCode.W))
{
…
}
Unity even intercepts
keyboard input for us.
All we need to do is
ask ;)
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29. Our First Script!
// Add "forward" vector to current position.
this.transform.localPosition += Vector3.forward;
Unity stores
information relevant
for drawing the scene
with our camera in a
transform.
This includes the
position of an object,
its rotation, and its
scale.
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30. Vector Math
Think of vectors as sets of coordinates in our
coordinate system:
𝑣 =
𝑥
𝑦
𝑧
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31. Vector Math
Just as numbers, you can add vectors, resulting in a
new set of numbers:
𝑣1 + 𝑣2 =
𝑥1
𝑦1
𝑧1
+
𝑥2
𝑦2
𝑧2
=
𝑥1 + 𝑥2
𝑦1 + 𝑦2
𝑧1 + 𝑧2
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32. Vector Math
Just as numbers, you can add vectors, resulting in a
new set of numbers:
𝑣1 + 𝑣2 =
1
2
3
+
4
5
6
=
5
7
9
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33. Our First Script!
// Add "forward" vector to current position.
this.transform.localPosition += Vector3.forward;
We can access the
transform of the game
object the script is
attached to using the
this keyword.
Then, we can modify
its position by using
the += operator.
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34. Our First Script!
Whew, that was fast!
Maybe we should improve our code here a bit.
1. Our spaceship should have its own speed value.
This will also allow us to have different ships with
different speed!
2. We should take the frame time of our game into
account. Otherwise, our spaceship would be
faster if our PC is faster – unfair!
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35. Our First Script!
C#
35
// Use the magic code Unity provides for us.
using UnityEngine;
using System.Collections;
// Name of the script.
public class KeyboardMovement : MonoBehaviour
{
// Speed of this game object.
public float Speed;
// Use this for initialization.
void Start ()
{
// Nothing to do here, yay!
}
// Update is called once per frame.
void Update ()
{
// Check if player pressed any button.
if (Input.GetKey(KeyCode.W))
{
// Add "forward" vector to current position.
this.transform.localPosition += Vector3.forward * this.Speed * Time.deltaTime;
}
}
}

36. Our First Script!
// Speed of this game object.
public float Speed;
Here, speed is a
variable (like x in your
math class).
public means,
everybody can change
the speed value.
float means, speed
may be a fraction (like
1.4)
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37. Our First Script!
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Unity exposes public
variables in the
inspector we were
talking about earlier.
Change the speed
value and see what
happens!

38. A Nice Space Background
Lets pick up a nice space
image from the official
NASA website:
http://apod.nasa.gov/ap
od/ap120828.html
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39. A Nice Space Background
Now, let’s change the
texture import settings of
our background:
Set Wrap Mode to Clamp.
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40. A Nice Space Background
Next, we need to create a
material for the skybox to
use with our camera.
• Set the shader to
Skybox/6 Sided.
• Assign the texture to all
six slots.
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41. A Nice Space Background
Finally, we can change
the scene lighting
settings to use our
brand-new skybox!
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42. Let’s make a side-scroller!
Just change the
position and rotation
of your camera –
easy!
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43. Let’s make a side-scroller!
You can also reduce
the field of view to
ensure the skybox
looks nice.
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44. Adjusted Movement
C#
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// Update is called once per frame.
void Update ()
{
// Check if player pressed any button.
if (Input.GetKey(KeyCode.W))
{
// Add “up" vector to current position.
this.transform.localPosition += Vector3.up * this.Speed * Time.deltaTime;
}
if (Input.GetKey(KeyCode.S))
{
// Add “down" vector to current position.
this.transform.localPosition += Vector3.down * this.Speed * Time.deltaTime;
}
if (Input.GetKey(KeyCode.A))
{
// Add “back" vector to current position.
this.transform.localPosition += Vector3.back * this.Speed * Time.deltaTime;
}
if (Input.GetKey(KeyCode.D))
{
// Add "forward" vector to current position.
this.transform.localPosition += Vector3.forward * this.Speed * Time.deltaTime;
}
}

45. Now for some real action!
We want our spaceship to fire its weapons!
For this, we need to:
1. Add a projectile to our project.
2. Create a projectile whenever the player presses a
button.
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46. Unity Prefabs
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Unity allows us to
create prefabs of our
game objects.
Think of prefabs as
“Schablonen” for new
game objects.

47. Our Second Script!
C#
47
// Use the magic code Unity provides for us.
using UnityEngine;
using System.Collections;
// Name of the script.
public class KeyboardFire : MonoBehaviour
{
// Prefab to use as projectile.
public GameObject ProjectilePrefab;
// Use this for initialization
void Start ()
{
// Still nothing to do, yay!
}
// Update is called once per frame
void Update ()
{
// Check if player pressed the SPACE button.
if (Input.GetKey(KeyCode.Space))
{
// Fire projectile!
Instantiate(this.ProjectilePrefab, this.transform.position, this.transform.rotation);
}
}
}

48. Boring projectiles are boring
C#
48
// Use the magic code Unity provides for us.
using UnityEngine;
using System.Collections;
// Name of the script.
public class AutomaticMovement : MonoBehaviour
{
// Speed of this game object.
public float Speed;
// Update is called once per frame
void Update ()
{
// Fly "forward" automatically.
this.transform.localPosition += Vector3.forward * this.Speed * Time.deltaTime;
}
}

49. Hint
Splitting up your code across
multiple components is always a
better idea than writing huge,
monolithic code files!
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50. Game Objects
• objects in your game world can (or cannot)…
• be visible
• move around
• attack
• explode
• be targeted
• become selected
• follow a path
• common across all genres
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51. Game Objects
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52. There are probably hundreds of ways…
Then one day your designer says that they want a
new type of “alien” asteroid that acts just like a heat
seeking missile, except it’s still an asteroid.”
- Scott Bilas
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53. 53 / 12

54. Camera Movement
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Right now, we can easily
leave the screen, if we want
to.
Let’s change that:
1. Reparent the camera
to our player ship.
2. Add the automatic
movement script to the
player ship.

55. Unity Hierarchy
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If a game object in
Unity is a child of
another, its transform
is relative to the one
of its parent:
• Position
• Rotation
• Scale

56. Adding Enemies
Time to add our first enemies!
We need to …
1. Create a prefab for our enemy space ship.
2. Rotate enemies correctly.
3. Modify their movement.
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57. Automated Movement
With Direction
C#
57
// Use the magic code Unity provides for us.
using UnityEngine;
using System.Collections;
// Name of the script.
public class AutomaticMovement : MonoBehaviour
{
// Velocity of this game object.
public Vector3 Velocity;
// Update is called once per frame
void Update ()
{
// Fly "forward" automatically.
this.transform.localPosition += this.Velocity * Time.deltaTime;
}
}

58. Adding Enemies
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59. Taking Damage
Next, we want to keep track of the health value of
each ship. After all, we want to destroy our enemies,
don’t we?
We need to:
1. Write a script keeping track of spaceship health.
2. Check for collisions of projectiles with ships.
3. Reduce health when projectiles hit ships.
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60. Spaceship Health
C#
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// Use the magic code Unity provides for us.
using UnityEngine;
using System.Collections;
// Name of the script.
public class Health : MonoBehaviour
{
// Health of this game object.
public float CurrentHealth;
// Update is called once per frame
void Update ()
{
// Destroy when dead.
if (this.CurrentHealth <= 0)
{
Destroy (this.gameObject);
}
}
}

61. Hint
The if operator in C# allows us to
add conditions to our code.
It’s always a good idea not to
compare numbers for exact values
(<= instead of ==)
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62. Handling Collisions
As you can imagine,
finding out whether
two objects collide can
include some terrible
math.
In Unity, colliders can
be used to approximate
the extents of a game
object for easier
collision detection.
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63. Handling Collisions
Let’s add a sphere
collider for our space
ship and projectiles!
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64. Handling Collisions
If your collider moves
(just like our ships and
projectiles), we need to
add a rigidbody as well.
Make sure to disable
“Use Gravity”, or Unity
will make our
spaceships fall down.
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65. Handling Collisions
Whenever two
objects collide, Unity
won’t allow them to
intersect each other.
Check “Is Trigger” to
allow these objects to
intersect!
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66. Handling Collisions
C#
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// Use the magic code Unity provides for us.
using UnityEngine;
using System.Collections;
// Name of the script.
public class DamageOnCollision : MonoBehaviour
{
// Damage this game object deals on collision.
public float Damage;
// OnCollisionEnter is called whenever we collide with somebody else.
void OnTriggerEnter(Collider other)
{
// Get the health component of the other object.
Health health = other.gameObject.GetComponent<Health> ();
if (health != null)
{
// Reduce health.
health.CurrentHealth -= this.Damage;
// Destroy this game object.
Destroy (this.gameObject);
}
}
}

67. Finishing Touches
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Now, your job as
programmer is done
– time for the
designer in you!
Add enemies to the
level any play, play,
play!

68. Building The Game
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Finally, we can build our
game, to show everyone
and share the fun 

69. Where To Go From Here
As with every software
project, there’s always more
to do…
• Enemy Fire
• Enemy AI
• Menus
• Explosions
• Score
• Cheats
• More Enemies
• More Levels
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70. Learning From Others
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StarCraft II Galaxy Editor

71. Learning From Others
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StarCraft II Galaxy Editor

72. Learning From Others
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StarCraft II Galaxy Editor

73. Learning From Others
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World of Warcraft LUA UI API

74. Learning From Others
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Hearthstone Log File

75. Learning From Others
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StarCraft II Screenshot

76. Learning From Others
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StarCraft II Screenshot

77. Learning From Others
77 / 60
StarCraft II Screenshot

78. Learning From Others
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StarCraft II Screenshot

79. Learning From Others
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StarCraft II Screenshot

80. Learning From Others
80 / 60
StarCraft II Screenshot

81. Learning From Others
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StarCraft II Screenshot

82. Learning From Others
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StarCraft II Screenshot

83. Learning From Others
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Unreal Tournament 3 Splash Screen

84. Learning From Others
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Unreal Tournament 3 Login Screen

85. Learning From Others
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Hostile Worlds Screen Transitions

86. Learning From Others
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Steam Server Browser

87. Learning From Others
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WarCraft III Lobby

88. Learning From Others
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WarCraft III Loading Screen

89. Learning From Others
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WarCraft III Score Screen

90. Learning From Others
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StarCraft II Options Screen

91. Learning From Others
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Doom 3 GPL Release on GitHub

92. Learning From Others
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Post-Mortem of WarCraft

93. Don’t Reinvent The Wheel
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HOTween

94. There might even be cookies.
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Source: UTWeap_LinkGun.uc (August UDK 2010)
/** Holds the list of link guns linked to this weapon */
var array<UTWeap_LinkGun> LinkedList; // I made a funny Hahahahah :)

95. Thank you for your attention!
Contact
Mail
dev@npruehs.de
Blog
http://www.npruehs.de
Twitter
@npruehs
Github
https://github.com/npruehs
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