Why is the alpha on my UI Image not decreasing properly?

Questions & Answers
1

I’ve been at this for an hour now and I’m starting to lose my mind.

trying to make a simple blood overlay that is set active by an outside object, that reduces in alpha until its at 0 alpha, at which point it disables itself. Instead, it seems to only do two states for the alpha: fully on, or fully off. It disables and enables like it should, and even seems to detect when the Alpha should be 0 to turn itself off, but it doesn’t do a proper fade-out.

Here’s my code

public float alphaReduce=1f;
    public Image myImage;
    void OnEnable()
    {
        Color c = myImage.color;
        c.a = 255;
        myImage.color = c;
    }
    void Update () {
        Color c = myImage.color;
        c.a =c.a - alphaReduce;
        myImage.color = c;
        if (myImage.color.a <= 0) gameObject.SetActive(false);
    }

Any help is appreciated.

2

Remember that Unity’s build in Color takes r,g,b,a 0 to 1. I wrote sth like this:

public class Fade : MonoBehaviour {

    public Image myImage;
    public Color fadeColor; //you could arrange fade color from inspector too i assigned it manually here

    void Start () {
        //this line here is unnecessary if you assign fadeColor from inspector
        fadeColor = new Color(myImage.color.r, myImage.color.g, myImage.color.b, 0f);
    }
	
    void Update () {
        myImage.color = Color.Lerp(myImage.color, fadeColor, Time.deltaTime);
        if (myImage.color.a < 0.02) { //having a threshold is a better option
            gameObject.SetActive(false);
        }
    }
}
3

You are decreasing value without considering the performance of the computer.

float alphaReduce = 1f;
void Update () {
     Color c = myImage.color;
     c.a =c.a - alphaReduce * Time.deltaTime;
     myImage.color = c;
     if (myImage.color.a <= 0) gameObject.SetActive(false);
 }

this will take 1s to complete if c.a is 1.