screenfader8

    public static void FadeIn(float delayBefore = 0, float delayAfter = 0, System.Action callback = null)
    {
        if (callback == null) callback = DefaultCallback;
        group.gameObject.SetActive(true);
        StopActiveFades();
        fadeInCR = instance.StartCoroutine(instance.FadeInCoRoutine(delayBefore, delayAfter,callback));
    }

    IEnumerator FadeInCoRoutine(float delayBefore, float delayAfter, System.Action callback)
    {
        yield return new WaitForSeconds(delayBefore);
        while (group.alpha > 0)
        {
            group.alpha = Mathf.MoveTowards(group.alpha, 0f, instance.speed * Time.deltaTime);
            yield return null;
        }
        yield return new WaitForSeconds(delayAfter);
        if (callback != null) callback();

        group.gameObject.SetActive(false);
    }