Unity3D VR app: fade to another scene after a certain time - unity3d

Question

I'm trying to develop a VR app where you can move around and interact with music (moving the audio sources, and so on). So, you can't actually die in this app, which is why a fade to black on trigger wouldn't help me. I'm trying to get a fade to black and show the credits after a certain amount of time (specifically, when the music is over). Maybe even a fade out (black) and a fade in (to another scene containing the credits) would do the trick. I know very little about programming, so I could really use some help.
I'm using Unity3D 2018.2.9f1
The app is for the Samsung's Gear VR

Answer 1

Timer
For any stuff using timers or wait I find Coroutines most of the time the best options.
You could either get the audio clip length and than wait for it
public AudioClip clip;
private void Start()
{
StartCoroutine(Wait(clip.length));
}
private IEnumerator Wait(float seconds)
{
yield return new WaitForSeconds(seconds);
// start fadeout here
}
or you could wait until it finishes playing
public AudioSource source;
// or wherever you start the music adioclip
private void Start()
{
source.Play ();
yield return new WaitUntil(()=> !source.isPlaying);
// start fadeout here
}
Fading
Here it depends a lot ... do you really switch Scenes by using LoadScene etc or do you just want to enable/disable certain content within one Scene?
And do you have 3D objects with materials and renderers or only 2D content using Unity.UI components?
The simplest solution for sure would be to place one overlay Canvas with the desired color as Image and simply fade it in and out. This is actually already available in the AssetStore and basically does
Uses an Overlay Canvas on top of everything with a certain color and animates it's alpha value (again using a Coroutine)
Makes sure that canvas is DontDestroyOnLoad so it isn't removed when we switch scenes
FadeIn the Canvas/Image => Fades out the current Scene
Load the other scene
FadeOut the Canvas/Image => Fades in the new Scene
Here is the source code (just cleaned it up a little)
using System.Collections;
using UnityEngine;
using UnityEngine.SceneManagement;
using UnityEngine.UI;
public class Fader : MonoBehaviour
{
private string _fadeScene;
private float _alpha;
private CanvasGroup _myCanvas;
private Image _bg;
private float _lastTime;
private bool _startedLoading;
private float _fadeInDuration;
//Set callback
private void OnEnable()
{
SceneManager.sceneLoaded -= OnLevelFinishedLoading;
SceneManager.sceneLoaded += OnLevelFinishedLoading;
}
//Remove callback
private void OnDisable()
{
SceneManager.sceneLoaded -= OnLevelFinishedLoading;
}
public void InitiateFader(CanvasGroup canvasGroup, Image image, string scene, Color fadeColor, float fadeInDuration, float fadeOutDuration)
{
DontDestroyOnLoad(gameObject);
_fadeInDuration = fadeInDuration;
_fadeScene = scene;
//Getting the visual elements
_myCanvas = canvasGroup;
_bg = image;
_bg.color = fadeColor;
//Checking and starting the coroutine
_myCanvas.alpha = 0.0f;
StartCoroutine(FadeIt(FadeDirection.Out, fadeOutDuration));
}
private enum FadeDirection
{
In,
Out
}
private IEnumerator FadeIt(FadeDirection fadeDirection, float fadeDuration)
{
var timePassed = 0.0f;
switch (fadeDirection)
{
case FadeDirection.Out:
do
{
_alpha = Mathf.Lerp(0, 1, timePassed / fadeDuration);
_myCanvas.alpha = _alpha;
timePassed += Time.deltaTime;
yield return null;
} while (timePassed < fadeDuration);
_alpha = 1;
SceneManager.LoadSceneAsync(_fadeScene);
break;
case FadeDirection.In:
do
{
_alpha = Mathf.Lerp(1, 0, timePassed / fadeDuration);
_myCanvas.alpha = _alpha;
timePassed += Time.deltaTime;
yield return null;
} while (timePassed < fadeDuration);
_alpha = 0;
Initiate.DoneFading();
Debug.Log("Your scene has been loaded , and fading in has just ended");
Destroy(gameObject);
break;
}
}
private void OnLevelFinishedLoading(Scene scene, LoadSceneMode mode)
{
//We can now fade in
StartCoroutine(FadeIt(FadeDirection.In, _fadeInDuration));
}
}
and
public static class Initiate
{
private static bool areWeFading;
//Create Fader object and assing the fade scripts and assign all the variables
public static void Fade(string scene, Color col, float fadeOutDuration, float fadeInDuration)
{
if (areWeFading)
{
Debug.Log("Already Fading");
return;
}
var init = new GameObject("Fader", typeof(Canvas), typeof(CanvasGroup), typeof(Image), typeof(Fader));
init.GetComponent<Canvas>().renderMode = RenderMode.ScreenSpaceOverlay;
var fader = init.GetComponent<Fader>();
areWeFading = true;
fader.InitiateFader(init.GetComponent<CanvasGroup>(), init.GetComponent<Image>(), scene, col, fadeOutDuration, fadeInDuration);
}
public static void DoneFading()
{
areWeFading = false;
}
}
than You call this in a dedicated component like in order to be able to do it e.g. in a button's onClick
public class DemoScript : MonoBehaviour
{
//name of the scene you want to load
public string TargetSceneName;
public Color LoadToColor = Color.black;
public float FadeInDuration = 1.0f;
public float FadeOutDuration = 1.0f;
public void GoFade()
{
Initiate.Fade(TargetSceneName, LoadToColor, FadeOutDuration, FadeInDuration);
}
}
or since it is static simply use
Initiate.Fade(TargetSceneName, LoadToColor, FadeOutDuration, FadeInDuration);
from anywhere.
Instead of the LoadSceneAsync you could also do your enabling and disabling stuff if you prefer to do it in only one scene.
However in VR it is actually a bad idea to fade to completely black and let the user see nothing. It might lead to disorientation and cybersickness ...