投掷后生成

我正在从事一个足球比赛项目。我想要一个球体，在抛出第一个球体后，我必须生成另一个球体。这是我尝试过的：

public class spawn : MonoBehaviour {
    public Transform[] SpawnPoints;
    public float SpawnTime;
    public GameObject ball;

    // Use this for initialization
    void Start () {
        InvokeRepeating ("SpawnBalls", SpawnTime, SpawnTime);
    }

    void SpawnBalls(){
        if (transform.position.z > -0.904 ) {
            int SpawnIndex = Random.Range (0, SpawnPoints.Length);
            Instantiate (ball, SpawnPoints [SpawnIndex].position, SpawnPoints [SpawnIndex].rotation);
        }
    }
} 

如果最后一个球扔得足够远，只需实例化一个新球即可。尝试这个：

public class spawn : MonoBehaviour {
    public Transform[] SpawnPoints;
    public GameObject ball;
    public GameObject lastBall;

    // Use this for initialization
    void Start () {
        int SpawnIndex = Random.Range (0, SpawnPoints.Length);
        lastBall = Instantiate (ball, SpawnPoints [SpawnIndex].position, SpawnPoints [SpawnIndex].rotation) as GameObject;
    }

    void Update(){
        if (lastBall.position.z > -0.904 ) {
            int SpawnIndex = Random.Range (0, SpawnPoints.Length);
            lastBall = Instantiate (ball, SpawnPoints [SpawnIndex].position, SpawnPoints [SpawnIndex].rotation) as GameObject;
        }
    }
}