Screen fade not working in Daydream VR since I migrated to Unity 5.6

Question

I'm building a DayDream VR game. I've previously had a script to fade out the screen when the user is clicking somewhere to change levels/scenes.

Since I've migrated to Unity 5.6 / Google VR SDK 1.2, any fading effect stopped working. But it still works in Preview mode on my desktop. This is because they changed the way the Camera works. I've tried different scripts online but none of them work, would anyone have an idea on how to do a screen fade on scene change please?

Here is the current main part of the code:

// Derived from OVRScreenFade
float elapsedTime = 0.0f;
Color color = fadeColor;
color.a = 0.0f;
fadeMaterial.color = color;
while (elapsedTime < fadeTime)
{
    yield return new WaitForEndOfFrame();
    elapsedTime += Time.deltaTime;
    color.a = Mathf.Clamp01(elapsedTime / fadeTime);
    fadeMaterial.color = color;
}

I've also attempted to use Autofade script. As I mentioned they all work when tried the game on my desktop, they just don't work on the Android phone :(.

Any idea why please?

EDIT: Here is some extra code

public Material fadeMaterial = null; //starts NULL

        //applied to cameras inside a function
        foreach (Camera c in Camera.allCameras)
        {
            var fadeControl = c.gameObject.AddComponent<ScreenFadeControl>();
            fadeControl.fadeMaterial = fadeMaterial;
            fadeControls.Add(fadeControl);
        }

FINAL SOLUTION

Using the answer given here, I've created a script file with instructions, feel free to download it and use it if you need the same thing:

https://gist.github.com/xtrimsky/0d58ee4db1964577893353365903b91a

Answer 1

If you want to fade the entire screen I suggest:

1. In Unity add a Panel (make sure that it covers the whole screen).
2. Make a new Material and attach it to the Panel.
3. The Material should have Rendering Mode set to Transparent.
4. Attach the following Script to the Panel.

public Material m;
public float _colorSpeed = 0.01f;
private Color c;
private bool start = false;

void Update()
{
    if (start)
    {
        if (c.a < 1.0f)
            c.a = c.a + _colorSpeed;
        m.color = c;
    }
}
public void Fade()
{
    c = m.color;
    c.a = 0.0f;
    start = true;
}

5. Call the Fade() method when necessary.
   Hope that solves your problem!