Lecture 5: Unity, part 3

# Creación de Videojuegos

### Unity

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# FDG - Foundations of Digital Games

# Conference

## San Luis Obispo, California, 2019

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# FDG 2019

* As I mentioned, I went to a conference last week

* It was very interesting!

* There was a panel of the IGDA's games education curriculum

* I also talked to many people about potential future projects

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# Keynote: Tarn Adams

<blockquote class="twitter-tweet"><p lang="en" dir="ltr">Keynote Speaker Tarn Adams <a href="https://twitter.com/Bay12Games?ref_src=twsrc%5Etfw">@Bay12Games</a> at <a href="https://twitter.com/hashtag/fdg19?src=hash&ref_src=twsrc%5Etfw">#fdg19</a> speaking on providing systems to help players form their own narratives <a href="https://t.co/za9BjBS8gS">pic.twitter.com/za9BjBS8gS</a></p>— FDG 2019 Conference (@FDGconf) <a href="https://twitter.com/FDGconf/status/1166764570544705542?ref_src=twsrc%5Etfw">August 28, 2019</a></blockquote>

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# FDG 2019

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# FDG 2019

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# FDG 2019

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# FDG 2019

Why am I telling you all this?

* Conferences are an important part of academia

* It's nice to get out of your bubble, collaborations spark innovation

* UCR/ECCI benefits from increased recognition in the research community

* Maybe some of you want to work on a master's and/or PhD thesis?

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# Unity

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# Controller support

* Controller support is very easy!
  
  * Just use Input.GetAxis, Input.GetButton etc.
  
  * Controllers should work out of the box!

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# Particle Systems

* Consist of a generator and particle properties
  
  * The generator emits particles 
  
  * Particles are usually simple sprites with colors
  
  * Can be used to make nice fire, smoke, etc.
  
  * Built-in system in Unity!
  
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# Particle Systems

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# Animations

* Animations in Unity use two parts: 
     
      - Animator Component
      - Animation Controller
      
  * Of course you also need Animation Clips
  
  * You can make your own to animate basically anything
  
  * Window - Animation - Animation (or Ctrl+6)
  
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# Animations

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# Animator

* The Animator defines which animation clips are played at what time

* This is done with a state machine (the Animation Controller), with transitions between states when conditions are satisfied

* For example, when the movespeed is sufficiently high, an idle animation turns into a walk animation, and when the speed further increases that turns into a run animation

```C#
GetComponent<Animator>().SetFloat("movespeed", movespeed);
```

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# Animations

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# Coroutines

* Remember threads?
  
  * Sometimes all you want is for a function to run independently, pause for a bit and then continue
  
  * Or you need to wait for a download of some resource 
  
  * Use Coroutines! They run in the main thread, and can use all Unity API functions 
  
  * Alternative: IJob interface
  
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# Coroutines

```C#
IEnumerator HighlightGO(GameObject go)
{
  MeshRenderer renderer = go.GetComponent<MeshRenderer>();
  if (renderer == null) 
      yield break;

Color original = renderer.material.color;
  renderer.material.color = Color.white;

yield return new WaitForSeconds(3);
  renderer.material.color = original;
}

...
StartCoroutine(HighlightGO(someGameObject));
```

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# Raycasts

* Sometimes you want to know what the user clicks
   
   * `Camera.main.ScreenPointToRay(Input.mousePosition);`
   
   * `Physics.Raycast(ray, out res)`
   
   * Returns true if you hit anything
   
   * You will get information about what you hit in `res`
   
   * Also works with other rays (targeting, line-of-sight calculations, etc.)

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# Raycasts

```C#
if (Input.GetMouseButtonDown(0))
{
    Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
    
    RaycastHit res;
    if (Physics.Raycast(ray, out res))
    {
        StartCoroutine(HighlightGO(res.collider.gameObject));
    }
}
```

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# Prefabs

* Prefabs are collections of game objects and components that you want to reuse

* Assemble in Scene, drag into Assets

* You can edit the Prefab separately (since Unity 2018.3)
  
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# Prefabs

Create a fireball:

```C#
if (Input.GetButtonDown("Fire1")) {
    Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
    Instantiate(fireball, transform.position + 
                          ray.direction * 0.5f, 
                 Quaternion.LookRotation(-ray.direction));
}
```

Fireball:
```C#
void Update() {
   transform.position += transform.rotation * 
               (new Vector3(0, 0, -5) * Time.deltaTime);
}

private void OnTriggerEnter(Collider other) {   
    Destroy(gameObject);
}
```

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# Tags and Layers

* You can assign Tags and Layers to game objects 
  
  * Tags can be used to tell you which type of game object you have (player, enemy, etc.)

* Layers are used by the Camera to determine what to show 
  
  * Can also be used by Raycast to ignore certain objects

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# Render-to-Texture

* Usually, Cameras render what they see to the screen
  
  * You can also set up a Camera to render to a texture 
  
  * And then put that texture onto a game object 
  
  * Model surveillance cameras, add a minimap, mirrors, portals, etc.
  
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# Render-to-Texture

.right-column[
* Create a second camera 
  
* Select which layers that camera should render (avoid showing particle systems, use different symbol for the player on minimap, etc.)
  
* For a minimap you probably want to set the camera projection mode to "Ortographic"
]

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# Some Further Notes

* Use [this .gitignore](https://github.com/yawgmoth/UnityDemo2D/blob/master/.gitignore) file when working with Unity projects in git 
  
  * **Be careful** with scenes: Only one person can edit a scene at the same time (git merge will most likely **not** work)
  
  * It's easiest if everyone has their own scene to develop their parts

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# From elsewhere

Andres Cartín from [Tree Interactive](https://treeinteractivecr.com/) made a presentation with Unity tips and tricks for the Global Game Jam 2019. He has graciously allowed me to share it with you. 
.centered[
## Watch it [here](/CI-2807/assets/unity/cartin/index.html).
]

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# More Opportunities

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# ASODEV Costa Rica

- Asociación de Desarrolladores de Videojuegos de Costa Rica 
  
  - One of the goals of the organization is to grow the games industry in Costa Rica

- For this year's GDC they had 16 (free) passes that they gave out to applicants 
  
  - Every first Wednesday of the month they have a breakfast, 10-12am, at Match Cafe!

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# ASODEV Breakfast

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# GameDevDays Graz

* [Johanna Pirker](https://twitter.com/JoeyPrink) from TU Graz (Austria) is organizing a 3-day conference on game development, called [GameDevDays](https://gamedevdays.com)

* All talks will be on youtube and in English

* You can also watch talks from [previous years](https://www.youtube.com/channel/UCLuPXw4Yr6UxoCLqulli4xg/videos)

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# Resources

* [Unity Animation Clips](https://docs.unity3d.com/Manual/animeditor-CreatingANewAnimationClip.html)

* [Unity Animator Controllers](https://docs.unity3d.com/Manual/AnimatorControllers.html)

* [Unity Coroutines](https://docs.unity3d.com/Manual/Coroutines.html)

* [Unity Coroutines Tutorial](http://www.unitygeek.com/coroutines-in-unity3d/)

* [Unity Prefabs](https://docs.unity3d.com/Manual/Prefabs.html)

* [Unity Minimap Tutorial](https://blog.theknightsofunity.com/implementing-minimap-unity/)