Bullet prefab gets stuck to target after hitting

Question

As the title says, I am having an issue with prefabs: I am trying to make a bullet follow a curve and then hit a target using this method:

private IEnumerator BezierShooting()
{
    GameObject shotInstance = new GameObject();
    shotInstance = Instantiate(shotPrefab, transform.position, Quaternion.identity);
    Vector3 currentPosition = new Vector3();
    if (shotInstance != null)
    {
        while (t < 1 && shotInstance != null)
        {
            currentPosition = Mathf.Pow(1 - t, 3) * controlPoint0.position +
                            3 * Mathf.Pow(1 - t, 2) * t * controlPoint1.position +
                            3 * (1 - t) * Mathf.Pow(t, 2) * controlPoint2.position +
                            Mathf.Pow(t, 3) * controlPoint3.position;
            Debug.Log(currentPosition);
            shotInstance.transform.position = currentPosition;
            t += 0.02f;
            yield return new WaitForEndOfFrame();
        }
    }
    else
    {
        currentPosition = transform.position;
        t = 0;
        yield break;
    }

}

Where t is a float variable that I initialised before as well as the transforms controlPoint0, controlPoint1, controlPoint2 and controlPoint3.

The bullet is succesfully following the path that I created, however the problem is that once the bullet hits an object in position (x, y, z) and gets destroyed, if I call the method again the prefab will spawn in the last position it was on. I thought that final else statement would do the trick, but appearantly I am missing something. Can somebody help me please?

Answer 1

It looks like you want this:

private IEnumerator BezierShooting()
{
    var shotInstance = Instantiate(shotPrefab, transform.position, Quaternion.identity);
    while (t < 1 && shotInstance != null)
    {
        float invT = 1f - t;
        var currentPosition = invT * invT * invT * controlPoint0.position
                            + 3 * invT*invT * t  * controlPoint1.position
                            + 3 * invT * t * t   * controlPoint2.position
                            +     t * t * t      * controlPoint3.position;
        Debug.Log(currentPosition);
        shotInstance.transform.position = currentPosition;
        t += Time.deltaTime/bezierDuration;
        yield return null;
    }

    t = 0;
}

Some mistakes I corrected above:

• Don't create a new GameObject() you never use, only to replace the reference with the result of Instantiate.

• Your while already doubles as an if, so you don't need to wrap it in an if.

• You want t = 0 to execute once you're done no matter what, so don't restrict it to an else branch. (Or, if you don't use t outside this coroutine, you could just make it a temporary variable in this method, initialized at the start, so you don't need to do anything to reset it later)

• currentPosition = transform.position doesn't accomplish anything - it's a temporary variable that's about to be thrown out when we end this coroutine anyway.

• Mathf.Pow() is generally more expensive than a multiplication, if all you need is a low power.

• You'll want to use Time.deltaTime to get a consistent speed along this curve regardless of frame rate.