The document summarizes an introduction meeting to Unity3D game engine. It discusses what a game engine is and how Unity manages entities and subsystems. It then walks through exercises having attendees create and modify a spinning cube prefab to demonstrate core Unity concepts like hierarchies, components and scripting basics. The document stresses that the goal is to understand how to learn and explore Unity rather than fully learning game development.

1. Unity3D Introduction Meeting
GarageGeeks HQ
25 / 1 / 2012

2. Hi !
● I am Noam Gat
● (Ex) Game Developer at Omek (with Unity)
● Team member in Ogre3D graphics engine
● GameIS Member (Join us!)

3. And you are...
● Mostly programmers
● Little to no experience in game-dev
● Disagree? Raise your hand!

4. Lama Anglit?
כי זה יותר נוח! ●
נלמד כמה מושגים, עדיף שיהיו מקושרים ●
לסביבה שנעבוד בה.
אני מפחד מעברית. ●

5. Mission Statement
What are we NOT going to do ?
● Learn how to program / design games
● Learn enough to develop a game on our own
● Be 100% punctual and exact

6. Mission Statement
So what are we going to do ?
● Understand what a GAME ENGINE is
● Get a broad sense of how to work with unity
● Be able to work / talk with other UNITY devs

7. What is a game ?
Lets look at it from a
programmer's point of view...

8. What is a game ?
My “Hello world” program :
● Has a start point and an end point
int main()
{
print(“Hello world”);
}
Often called a “procedural” program

9. What is a game ?
My “GUI / Forms / Widgets” program :
● Doesn't have a known end point / time.
void OnButtonDown()
{
MessageBox.Show(“Hello world”);
}
Often called an “event based” program

10. What is a game ?
But why does “OnButtonDown” get called?
● Because the RUNTIME ENGINE invokes it.
We already don't control everything, but have
just enough power to do what we need.

11. What is an event ?
Depends on who you ask.
● GUI Apps? Mouse and keyboard movement
and presses, socket connections etc.
● Games? Input, network, physics, and
(IMO the difference) - Time

12. What is a game ?
“A game is just an event-based application
in which things happen even if nobody does
anything”
Noam Gat, “Unity 3D Introduction Meeting”, 25.1.2012

13. What is a game engine?
A GAME ENGINE is an environment that
manages the different ENTITIES and
SUBSYSTEMS of a game and sends the
correct events to the code that the
developer writes.

14. What subsystems?
Central managers of different aspects
● Scene graphs (Hierarchy)
● Presentation (Graphics and Audio)
● Input (On-site and remote)
● Resources (Art and tech - Project)
● Logic (Physics, AI, Behaviors)

15. Entities ?
● ENTITIES are a design pattern in which
systems are broken down into small
pieces that work together to create
complex behavior. In UNITY these are called
GAME OBJECTS.

16. Hello box

17. Hello box
What's in the box?
● A TRANSFORM (position in the world)
● A MESH (visual geometry)
● A MATERIAL (rendering properties like color)
● A COLLIDER (physics geometry)
● A RIGID BODY (physical properties like mass)

18. Hello box
TRANSFORM
MESH
COLLIDER
MATERIAL
RIGID BODY
Do we always need everything?

19. Modularity
If we don't need physics, we can remove components.
Can we remove any more components?

20. Unity Editor
The INSPECTOR shows the components of an object
The SCENE view shows us the world as it is
The GAME view shows us the world from the camera
The HIERARCHY shows us the objects in the current scene
The PROJECT shows us all of the assets in the project

21. I want to code !
Coding in Unity is done via custom BEHAVIORS written
in the Mono (like .NET) environment.
Unity supports C# and variants of javascript, python.
We will use javascript / C# today.

22. I want to code
But first : How to navigate in the world in the editor.
MOVIE

23. Exercise #1 : Spinning Cube
1. Split into groups of 2 – 4 people
2. Create a new (empty) unity project
3. Create a scene and put a box in it, without physics
4. Create a javascript script in the project, and put the
following line in the Update function :
transform.RotateAroundLocal(Vector3.up, 1);
5. Attach the script to the cube in the scene
6. Press play and watch the magic happen!

24. Exercise #1 : Post Mortem
What happened?
1. The cube has a BEHAVIOR on it
2. UNITY calls its Update() function (why? docs)
3. The cube spins around a bit :
transform.RotateAroundLocal(Vector3.up, 1);
4. After spinning a bit for a lot of frames, it spins a lot

25. Exercise #1 : Post Mortem
Do we really know what is happening?
How fast is the cube spinning?

26. Exercise #2 : In Control
In the same group, modify the script so that
A: It contains a modifyable rotating speed, called
“turns per second”. Do this with this line :
public var turnsPerSecond = 1.0f;
B: The cube rotates along that speed. Hint :
Time.deltaTime, Mathf.PI
C: Try changing the parameter at
Runtime!

27. Exercise #2 : In Control
Solution :
transform.RotateAroundLocal(Vector3.up,
Time.deltaTime * turnsPerSecond * Mathf.PI * 2);
(Not important if you missed the 2)

28. Exercise #2 : In Control
We just learned how to configure our entities!
- It makes it easy to separate logic (code) from design
decisions (parameters for components).
- Even <Insert none-coder stereotype here> can
control the spinning cube!

29. Exercise #2.1 : In Control-er
Its not a game if we don't have any gameplay...
OMG LETS CONTROL THE SPINNING SPEED!!!
1. Declare two new parameters :
public var turnMoreKey = KeyCode.D;
public var turnLessKey = KeyCode.A;
2. Use Input.GetKey(...) to control the spinning speed.

30. Prefabs
After a few components your objects could get complicated.
You might want to classify a “cube with a transform spinner”
A “spinning cube”.

31. Exercise #2.2 : In Control-est
1. Create a prefab by dragging the cube to the project view.
2. Create one instance of the prefab for each team member
by dragging it to the scene.
Give each instance different control keys.
3. Battle it out for the spinningest cube!

32. Summary
Yadda yadda yadda.
I'll crowdsource this one.

33. Congratulations !
You now know Unity!
You can do anything you want with it!
Lets play spinning cube!

34. No, really.
You understand how different systems connect to each
other (we used the INPUT subsystem to control a
TRANSFORM COMPONENT of a specific
GAMEOBJECT)
Lets try to learn how to learn.

35. Exercise #3 : Gone Fishing
We want to know how each player is doing.
For each cube, display an on-screen string in the form of :
“Dudu's cube : Y rotation is 121.221 degrees”
How will we do this?
Help → Manual / Reference Manual / Scripting Reference
We are looking for a Graphical User Interface (GUI)
No cheating (Forums / internet) for this one please!

36. Hierarchies
Pretty good video here as well, I'll just play it

37. Exercise #4 : Tabletop
1. Create a simple scene of a table, a tray on the table
and some fruits on the tray.
2. Use parenting to create a correct hierarchy.
3. Place transform spinners on many elements in your
scene. Check that the scene makes sense when you
move them.

38. Summary
What have we learned?
● What should a GAME ENGINE give us
● How does UNITY separate itself into different
SUBSYSTEMS and COMPONENTS
● How can we extend UNITY and make our code run in it
● How to answer our own questions about UNITY

39. Exercise #5 : Explore!
1. Open the “Angry Bots” sample project.
2. Spend about 5-10 minutes looking around, another
three minutes deciding on something to do in it,
then take 15-20 minutes to do it (if time permits).
3. GL HF!

40. What now ?
You don't know how to make games... YET

41. Be like the squirrel
You should (hopefully) be able to take a big problem
(“how to create a game?”) and rip it apart to smaller
questions and research into them on your own.

42. Give it a whirl
1. Global game jam
This weekend!
2. Advanced unity meetings
Israeli Unity3D developers UNITE!
3. Facebook groups.
Israeli Unity3d developers
4. The only limit is yourself.
Welcome to zombo.com

43. Questions?

44. Cheers!