Unity3D screen fading script (using new UI)

FadeInOut.cs

using UnityEngine;
using UnityEngine.UI;
using System.Collections;
using UnityEngine.SceneManagement;

public class ScreenFader : MonoBehaviour
{
    public Image FadeImg;
    public float fadeSpeed = 1.5f;
    public bool sceneStarting = true;


    void Awake()
    {
        FadeImg.rectTransform.localScale = new Vector2(Screen.width, Screen.height);
    }

    void Update()
    {
        // If the scene is starting...
        if (sceneStarting)
            // ... call the StartScene function.
            StartScene();
    }


    void FadeToClear()
    {
        // Lerp the colour of the image between itself and transparent.
        FadeImg.color = Color.Lerp(FadeImg.color, Color.clear, fadeSpeed * Time.deltaTime);
    }


    void FadeToBlack()
    {
        // Lerp the colour of the image between itself and black.
        FadeImg.color = Color.Lerp(FadeImg.color, Color.black, fadeSpeed * Time.deltaTime);
    }


    void StartScene()
    {
        // Fade the texture to clear.
        FadeToClear();

        // If the texture is almost clear...
        if (FadeImg.color.a <= 0.05f)
        {
            // ... set the colour to clear and disable the RawImage.
            FadeImg.color = Color.clear;
            FadeImg.enabled = false;

            // The scene is no longer starting.
            sceneStarting = false;
        }
    }


    public IEnumerator EndSceneRoutine(int SceneNumber)
    {
        // Make sure the RawImage is enabled.
        FadeImg.enabled = true;
        do
        {
            // Start fading towards black.
            FadeToBlack();

            // If the screen is almost black...
            if (FadeImg.color.a >= 0.95f)
            {
                // ... reload the level
                SceneManager.LoadScene(SceneNumber);
                yield break;
            }
            else
            {
                yield return null;
            }
        } while (true);
    }

    public void EndScene(int SceneNumber)
    {
        sceneStarting = false;
        StartCoroutine("EndSceneRoutine", SceneNumber);
    }
}   

LevelChanger.cs

using UnityEngine;
using System.Collections;

public class LevelChanger : MonoBehaviour {

    ScreenFader fadeScr;
    public int SceneNumb;

    void Awake()
    {
        fadeScr = GameObject.FindObjectOfType<ScreenFader>();
    }

    void OnTriggerEnter(Collider col)
    {
        if (col.gameObject.tag == "Player")
        {
            fadeScr.EndScene(SceneNumb);
        }
    }
}

Edited, thank you.

I have also noted that this can break when using prefabs of the canvas, and also seems to be costly in performance, generating serious lag. Not exactly sure why, as the image used was as low a quality as one could possibly have, and the prefab of the canvas was identical to the original.

why is it Fade fadeScr;?

The type or namespace name `Fade' could not be found. Are you missing a using directive or an assembly reference?

Woops, its for previous version
use ScreenFader fadeScr;
I changed my second comment, thank you

I think you should make "EndScene" stub method that starts a CoRoutine (EndSceneCoRoutine), this way you will be able to call EndScene from another script and the fading out will start.
As it is now, it will only decrease the curtain's darkness a little but nothing else:

I did this:

public void EndScene(int SceneNumber)
    {
        sceneStarting = false;
        StartCoroutine("EndSceneRoutine", SceneNumber);
    }

    public IEnumerator EndSceneRoutine(int SceneNumber)
    {
        // Make sure the RawImage is enabled.

        FadeImg.enabled = true;
        do
        {
            // Start fading towards black.
            FadeToBlack();

            // If the screen is almost black...
            if (FadeImg.color.a >= 0.95f)
            {
                // ... reload the level
                SceneManager.LoadScene(SceneNumber);
                yield break;
            }
            else
            {
                yield return null;
            }
        }while (true);


    }

How do you create a Pull request in Gist? Is it possible?

@NovaSurfer I don't understand the following implementation code

using UnityEngine;
using System.Collections;

public class nextLevel : MonoBehaviour {
    ScreenFader fadeScr;
    public int SceneNumb;

    void Start(){
        fadeScr = GameObject.FindObjectOfType<Fade>();
    }

    void OnTriggerStay2D(Collider2D col){
        if(col.gameObject.tag == "Player"){
            fadeScr.EndScene(SceneNumb);
        }
    }
}

ScreenFader fadeScr; and <Fade> are giving me errors as well... Is there an easier way to trigger the function, say from a button?

@shaneparsons, hi check out new revision. I updated the script and added an example

hello, i'm trying to call the function EndScene(SceneNumb) from another script but it gives me an error ( NullReferenceException: Object reference not set to an instance of an object
StartMenu.StartLevel () (at Assets/Scripts/StartMenu.cs:130)
UnityEngine.Events.InvokableCall.Invoke (System.Object[] args) (at C:/buildslave/unity/build/Runtime/Export/UnityEvent.cs:153)
UnityEngine.Events.InvokableCallList.Invoke (System.Object[] parameters) (at C:/buildslave/unity/build/Runtime/Export/UnityEvent.cs:630)
UnityEngine.Events.UnityEventBase.Invoke (System.Object[] parameters) (at C:/buildslave/unity/build/Runtime/Export/UnityEvent.cs:765)
UnityEngine.Events.UnityEvent.Invoke () (at C:/buildslave/unity/build/Runtime/Export/UnityEvent_0.cs:53)
UnityEngine.UI.Button.Press () (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/UI/Core/Button.cs:35)
UnityEngine.UI.Button.OnPointerClick (UnityEngine.EventSystems.PointerEventData eventData) (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/UI/Core/Button.cs:44)
UnityEngine.EventSystems.ExecuteEvents.Execute (IPointerClickHandler handler, UnityEngine.EventSystems.BaseEventData eventData) (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/EventSystem/ExecuteEvents.cs:52)
UnityEngine.EventSystems.ExecuteEvents.Execute[IPointerClickHandler](UnityEngine.GameObject target, UnityEngine.EventSystems.BaseEventData eventData, UnityEngine.EventSystems.EventFunction`1 functor) (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/EventSystem/ExecuteEvents.cs:269)
UnityEngine.EventSystems.EventSystem:Update())

can you help me please ?

Awesome stuff! But I'm curious, why do you not disable the image after the fade is over, for efficiency's sake?