1. Quick Intro to Unity
Lecture 2

2. My (totally-biased) Thoughts
Very clean organization
More programmer-friendly (than Unreal)
A good model for (parts of) our engine.
Licensing is OK
…but not for universities

3. interface Start it up! Hierarchy: a Scene Graph
Parent-child relationships
Project: collection of assets
Inspector:
View / create components
Edit component properties
Scene / Game view: the current scene
Warning: don’t do big things in game mode!
Render mode
Lighting mode

4. View manipulation
Hand-tool selected (Q to enable, W to switch to move):
Left-drag to pan
Right-drag to rotate
Any:
‘F’: Frame selected object (or double-click name)
Right-click + WASD + QE
Scroll-wheel to zoom
Click on axes “cones” to switch to 2d view
Click on central box to toggle perspective / ortho

5. Object manipulation [Add a 3d cube]
W, E, R toggle translate, rotate, scale
Local / Global button
Numeric values

6. Game object / component model
A very clean organization (imo)
Add components to add functionality
All game objects contain a Transform
contains a parent-offset transform matrix
internally contains pointers to parent / child g.o.’s
Collider (Box, Capsule, Sphere, Mesh, etc.)
ParticleEmitter
Camera
3D Sound Sources …
By adding components, you can call / listen for script methods / callbacks.

7. prefabs A GameObject “template”
Any instances of that prefab can:
Modify a component value – that takes precedence
Leave a component value alone:
If the prefab changes, all of these values are updated.
E.g. Make a “coin” prefab (collider, mesh, scale)
Drag 100 instances onto scene.
Each can have its own position
If you modify the collider, all instances automatically change!
Create by dragging from Hierarchy to Assets
Make instances by dragging from assets to Scene
Note the blue name in Hierarchy.

8. tags and layers Tags Layers A value (integer) attached to each object
[Show editing of Tags]
e.g. Pickups, DeathTriggers, Player, etc.
Very useful in scripts.
Layers
Similar idea, but more applied to Rendering
e.g. Transparent layer, Water, Ignore-Raycast, etc.

9. Input System Axes and Actions [Show in Settings]
Configurable (remappable)
Note the names
e.g. “Horizontal” / “Vertical” axes
e.g. “Jump” button
Intentionally not a gamepad / key id or name.
[Discuss benefits for game designers]

10. Scripting overview What’s it for? Basic process
Without: static objects that do nothing – boo!
Determine what a game object does and when it does it.
Examples:
Handle collisions
Start background music when level starts
Update a gui when points are earned. …
A taste of “real” programming.
Basic process
Create a new script asset (text file)
Attach to one or more game objects
Add / edit functionality to / in script
Test in Unity
Go back to step 3 until finished.

11. Scripting overview, cont.
[Create a C# script and edit]
Documentation: Highlight item, then…
Visual Studio: Ctrl + Alt + M, then Ctrl + H
MonoDevelop: Ctrl + ‘
Example:
Make a player object controlled by input axes
Make a pickup prefab and trigger removal on hits.
Naming convention
e.g. Transform is the class, transform is this object’s instance.
The classes sometimes have static-like variables / methods:
e.g. Time.deltaTime; // an up-to-date float
e.g. Quaternion.Slerp(Quaternion a, Quaternion b, float pcent);

12. scripting overview, cont.
A sampling of methods you can override (events)
Start
Update
FixedUpdate [if we have a RigidBody component]
OnCollisionEnter [if we have a Collider component] …
public vs. private members
Getting components:
transform always exists (b/c all GameObjects have it)
others you have to do this:
e.g. Animator anim = GetComponent<Animator>();

13. Interacting with other G.OBJ’s
Option1: Make a public GameObject variable
plus: level-designer can set it
negative: fixed before run-time
Option2: Find it by name / tag
GameObject.Find or method
GameObject.FindGameObjectsByTag or FindGameObjectByTag
Can modify what you search for at run-time.

14. Mecanim overview A rigged / animated model has n clips
walk, run, idle, etc.
Mecanim does the following:
Blends between two animation clips
Models a state-diagram
You modify animation variables in code.
The state diagram will transition to a new animation.
Frees you from a lot of repetitive code.
First step:
Import a model with animation clips
(optional) Under import settings, set the clip to loop

15. mecanim overview, cont. Step2: Open Animator (not Animation) window
Step3: Drag clips onto stage
Step4: Create transitions between clips
Step5: Tweak transition criteria / variables
Step6: Set variables in script.
[There’s much more you can do with Mecanim]
Modify how the two clips are blended over time.
Mask off parts of the skeleton …

16. GUI Overview A 2d overlay (HUD’s, minimaps, etc.) Composed of:
A canvas: Unity automatically creates one
Buttons, Text-boxes, etc.
The layout is pretty self-explanatory
Unless you get into sprites…another topic!
The 2D button (near the top) is very handy.
These elements can (and often do) have scripts!
NOTE: import UnityEngine.UI or you won’t see UI objects in script!