It could be you’re looking for

Tweeng

The crack cocaine of game programming!

The basic syntax is

 time.Tweeng( do something )

so (in pseudocode)

StartCoroutine( 2f.Tweeng( .. move the ball .. ) );
StartCoroutine( .5f.Tweeng( .. spin the spaceship .. ) );
StartCoroutine( 1f.Tweeng( .. fade the text .. ) );

Those examples are,

• move the ball over two seconds
• spin the spaceship in 1/2 second
• fade the text over one second.

More…

// tweeng z to 20 degrees in .12 seconds
StartCoroutine(.12f.Tweeng( (t)=>transform.Eulers(0f,0f,t), 0f,20f) );

// fade in alpha in .75 seconds
StartCoroutine(.75f.Tweeng( (u)=>{c.a=u;s.color=c;}, 0f,1f) );

// duck volume..
StartCoroutine(  .3f.Tweeng( x=>{current.volume=x;}, current.volume, 0f) );

// move something..
StartCoroutine(secs.Tweeng( (p)=>parked.transform.position=p,
  parked.transform.position,
  landing.transform.position) );

// twist image
yield return StartCoroutine( .3f.Tweeng(
  (u)=>polaroid.localEulerAngles = new Vector3(0f,0f,u),
  0f,9f) );

You can Tweeng anything, certainly including fades.

Basic code base for Tweeng :

Just put this in a file Extns.cs:

public static class Extns
    {
    public static IEnumerator Tweeng( this float duration,
               System.Action<float> var, float aa, float zz )
        {
        float sT = Time.time;
        float eT = sT + duration;
        
        while (Time.time < eT)
            {
            float t = (Time.time-sT)/duration;
            var( Mathf.SmoothStep(aa, zz, t) );
            yield return null;
            }
        
        var(zz);
        }

    public static IEnumerator Tweeng( this float duration,
               System.Action<Vector3> var, Vector3 aa, Vector3 zz )
        {
        float sT = Time.time;
        float eT = sT + duration;
        
        while (Time.time < eT)
            {
            float t = (Time.time-sT)/duration;
            var( Vector3.Lerp(aa, zz, Mathf.SmoothStep(0f, 1f, t) ) );
            yield return null;
            }
        
        var(zz);
        }
}

(Note that those examples include smoothing. You may need no-smoothing in some cases. In fact, in projects now we always have both “Tweeng” and “SmoothedTweeng”.)

(If you’re interested, you can use a generics approach – fascinating QA on that.)

Tweeng – it could save your life!