FixedUpdate logic step by step

Questions & Answers
1

Hi! I`m try make object animation.
Animation can work only on SetActive(true)
How i can change code for stop my animation without Thread.Sleep()?

C# code :

void FixedUpdate()
    {
        while (idleAnimation & anim_obj.activeInHierarchy)
        {
            anim_obj.transform.localPosition = startPos;
            anim_image.color = targetColor;
            // Fade 0->1
            for (float t = 0; t < 1; t += Time.deltaTime / anim_Speed)
            {
                anim_obj.transform.localPosition = startPos;
                anim_image.color = Vector4.Lerp(targetColor, startColor, t);
            }
    
            anim_image.color = startColor;
            Thread.Sleep(1000);
    
            // Move up
            // Fade 1->0
            for (float t = 0; t < 1; t += Time.deltaTime / anim_Speed)
            {
                anim_obj.transform.localPosition = Vector3.Lerp(startPos, targetPos, t);
                anim_image.color = Vector4.Lerp(startColor, targetColor, t);
            }
            //Animation end
            anim_obj.transform.localPosition = startPos;
            anim_image.color = targetColor;
    
            Thread.Sleep(500);
        }
    }
2

Hi there,

first a few basic ideas: FixedUpdate() is called once every time the physics model is updated, which is at a fixed time rate, 0.02 seconds by default. FixedUpdate() is used almost exclusively for modifying physics, e.g. adding forces, changing velocity, or moving kinematic objects.

Update() is called on every frame rendering, depending on your FPS, at about every 0.016 seconds when running at 60 FPS, but this varies.

So your animation logic should use the fact that these functions are called repeatedly over time, which means you don’t need Thread.Sleep(), you need variables that measure time for you, and possibly use a Coroutine as well.

Also, never call Thread.Sleep() in the Unity main thread, because the logic runs on a single thread so you would halt the whole application (this is an oversimplification, but in practice it is a useful model).

Now, to animate your object the way I think you want you would use a Coroutine the following way:

private void Start () {
    StartCoroutine(Animate());
}

private IEnumerator Animate() {
    anim_obj.transform.localPosition = startPos; // you only need to set the position once
    float t = 0;
    while (t < anim_speed) { // better way of transitioning over anim_speed seconds
        anim_image.color = Color.Lerp(targetColor, startColor, t / anim_speed); // go from target color to startColor over anim_speed seconds
        yield return null;
        t += Time.deltaTime;
    }
    anim_image.color = startColor; // making sure you precisely arrive at the final color

    t = 0;
    while (t < anim_speed) {
        anim_image.color = Color.Lerp(startColor, targetColor, t / anim_speed);
        anim_obj.transform.localPosition = Vector3.Lerp(startPos, targetPos, t / anim_speed);
        yield return null;
        t += Time.deltaTime;
    }
    // making sure you precisely arrive at the target color and position
    anim_image.color = targetColor;
    anim_obj.transform.localPosition = targetPos;

    yield return new WaitForSeconds(0.5f); // no need for this, because there are no more instructions after it, but this is the equivalent fo Thread.Sleep(500);
}