Unity Raycast2D忽略了实例化的预制对象

Question

I'm currently making a small game for a university assignment. It's a simple 2D game where you shoot birds using the mouse.

I did collission detection by hand at first (check for x/y boundaries) but now I wanna use a collider.

So I added a CircleCollider2D to my objects and I perform the Raycast like so

Vector3 mousePosition = Camera.main.ScreenToWorldPoint (Input.mousePosition);

RaycastHit2D[] hits = Physics2D.RaycastAll (mousePosition, Vector3.forward, Mathf.Infinity);
        Debug.Log (hits.Length);

Now when I add my prefabs manually into my scene it works as expected. The log outputs 1, or even 2 if I have multiple birds on top of each other.

But my game instantiated a lot of birds randomly and they are not detected when performing the raycast. I already checked, they definitely have colliders.

The instantiation code looks like the following:

Bird bird = Instantiate (birdPrefab, birdPosition, Quaternion.identity) as Bird;

I googled around for 2 hours now, but nothing could actually solve my problem.

I don't know if this is important, but the collision detection does not happen within the bird object's attached script.

I'm really cofused because it works with manually put objects, but not with instantiated ones. Has anybody experienced this before?

Edit:

The mouse position is on (x, y, -10) and the birds are on (x, y, 0) and both the manually placed ones and the instantiated ones are direct children of the scene.

Edit2:

Bird start

// Use this for initialization
void Start () {
    this.animator = this.GetComponent<Animator> ();

    this.camera = Camera.main;

    this.rigidBody = this.GetComponent<Rigidbody2D> ();
    // get the ammunition script
    this.ammunition = GameObject.Find ("Ammunition").GetComponent<Ammunition> ();
    // get the score script
    this.score      = GameObject.Find("Score").GetComponent<Score>();
}

Manually Placed Bird

Instantiated Bird

Both have the collider and both are on the same Z level for the RayCast.

Answer 1

There do not seem to be any issues with your raycast or instantiation of the Bird, given the information you have provided. This leads me to believe there is a problem elsewhere in the code or in the way the scene is set up, especially if the non-instantiated bird works as expected.

If you can post a screenshot of both the manually placed Bird and instantiated Bird Gameobject information during gameplay , as well as any code performed on "bird" after instantiation, we can take a closer look.