Fading UI Using Lerp?

Unity Engine
1

I am looking for the best way to fade into and out of a UI elements alpha level.
I am trying to effect just the alpha level on the color field of the Image component and am having quite lot of trouble with it.

Before anyone mentions it, I know I am doing it wrong, I am looking for the correct way to do this.

public void FadeIn (Image fadeObject)
    {
        fadeObject = Color.Lerp(0, 255, Time.deltaTime);
    }
2

Color.Lerp lerps colors. you’re passing in integer values of 0 to 255.

Image has a property for its base color, Image.color.

Pull that value, lerp the alpha on it, and set it back to the Image.

Oh, and you’ll probably want something like SmoothDamp, I think I’ve seen you in a thread where it was explained to you what lerp is, and that it may not actually be the best for this type of stuff:

3

This is being done for a UI object, and I am calling it as a public void, so I cannot use the Update function.

4

Not sure why update can’t be used. But ok.

Start a coroutine, use that instead.

Get a tween engine, like iTween or HOTween, use that instead.

5

With the lerp the end number is the percentage of progress made using 0 - 1. You need to change that Time.deltaTime to something like this:

Float prog;
prog += Time.deltaTime;

Then you use the prog as the third value.

6

I have never even touched coroutines before and I am having trouble understanding the Unity documentation on it(Here).
All I need to be able to do is make this run properly.

public void fadeIn(CanvasGroup fadeObject)
    {
        fadeObject.alpha = Mathf.Lerp(fadeObject.alpha, 1, Time.deltaTime);
    }
7

something like this:

    float progress = 0.0f;
    bool fadeIn = true;

    void Update(){
        if(fadeIn){
            progress += Time.deltaTime;

            if(progress >= 1.0f){
                progress = 1.0f;
                fadeIn = false;
            }
            fadeObject.alpha = Mathf.Lerp(0.0f, 1.0f, progress);
        }
    }

If you want to use InvokeRepeating then you can do something this:

float progress = 0.0f;

    void Start(){
        InvokeRepeating("FadeIn", 0.05f, 20);
    }

    void FadeIn(){
        progress += 0.05f;
        fadeObject.alpha = Mathf.Lerp(0.0f, 1.0f, progress);
    }

if you are lerping between 0 and 1 you don’t really need the lerp function though as you can just set the alpha to the progress variable.