how do i Mathf.lerp the SpriteRenderer.alpha?

Question

         var colorAlpha = new Color32(255, 255, 255, 255);

         colorAlpha.a = (byte)Mathf.Lerp(255, 0, 1.5f * Time.deltaTime);
         ChestRender.color  = colorAlpha;

I'm trying to fade a image when it's clicked... Is there a way to mathf.lerp the spriterenderer alpha?

Answer 1

this'll do the trick.

 public IEnumerator SpriteFade(
 SpriteRenderer sr, 
 float endValue, 
 float duration)
 {
     float elapsedTime = 0;
     float startValue = sr.color.a;
     while (elapsedTime < duration)
     {
         elapsedTime += Time.deltaTime;
         float newAlpha = Mathf.Lerp(startValue, endValue, elapsedTime / duration);
         sr.color = new Color(sr.color.r, sr.color.g, sr.color.b, newAlpha);
         yield return null;
     }
 }

Remember to think of Lerp as having the first argument at 0 and the second argument at 100%. The third argument is where between 0 and 100% the value should fall. (You can also put an argument that's higher than 100% proportionally, but that's not going to be needed here.) elapsedTime / duration will get you the percentage of time completion of the blend. Since elapsedTime won't be higher than duration (since the while loop will stop if that happens) we can be confident that it will be between 0 and 1, making it ideal for blending between the two values.

Note that Unity's native Color struct uses color values between 0 and 1 rather than 0 and 255. I recommend going with Unity's native Color struct unless there's something specific you're trying to achieve with Color32 instead.

how do i Mathf.lerp the SpriteRenderer.alpha?

1 Reply

Your answer

Follow this Question

Related Questions