Demon_接金币（三个掉落物品预设体，一接物体的工具）

using UnityEngine;
using System.Collections;

public class Tool : MonoBehaviour {

    float hor;

    Vector3 moveDir;

    public float moveSpeed = 3f;

    int score = 0;

    void Update()
    {
        hor = Input.GetAxis ("Horizontal");
        //获取移动方向向量
        moveDir = hor * Vector3.right;
        //移动
        transform.position += moveDir * Time.deltaTime * moveSpeed;
    }

    void OnTriggerEnter(Collider other)
    {
        if (other.tag == "Gold") {
            Destroy (other.gameObject);
            Debug.Log (++score);
        }
    }

}

using UnityEngine;
using System.Collections;

public class GoldCreater : MonoBehaviour {

    //金币预设体
    public GameObject goldPrefab;
    //生成金币的时间间隔
    public float interval = 1f;
    //计时器
    private float timer;
    //索引号
    private int index;

    void Update()
    {
        //计时器计时
        timer += Time.deltaTime;
        //计时完成
        if (timer >= interval) {
            ///TODO:生成金币
            GoldInit();
            //计时器归零
            timer = 0;
        }
    }

    /// <summary>
    /// 生成金币
    /// </summary>
    void GoldInit()
    {
        //子对象索引号（随机）
        index = Random.Range (0, 3);
        //生成位置
        Vector3 initPos = transform.GetChild (index).position;
        //生成金币
        Instantiate (goldPrefab, initPos, Quaternion.identity);
    }


}