using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Shield : MonoBehaviour
{
    public GameObject effectPrefab;
    public AudioClip sound1;
    public AudioClip sound2;

    void Start()
    {
        Invoke("DestroyShield", 5.0f);
    }

    private void OnTriggerEnter(Collider other)
    {
        if(other.gameObject.tag == "EnemyMissile")
        {
            Destroy(other.gameObject);
            AudioSource.PlayClipAtPoint(sound1, Camera.main.transform.position);
            GameObject effect = Instantiate(effectPrefab, other.transform.position, Quaternion.identity);
            Destroy(effect, 0.5f);
        }
    }

    void DestroyShield()
    {
        Destroy(gameObject);
        AudioSource.PlayClipAtPoint(sound2, Camera.main.transform.position);
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class ShieldItem : Item
{
    public GameObject shieldPrefab;
    private GameObject player;
    private Vector3 playerPos;

    private void OnTriggerEnter(Collider other)
    {
        if(other.gameObject.tag == "Missile")
        {
            base.ItemBase(other.gameObject);

            // プレーヤーの位置情報を取得する。
            player = GameObject.Find("Player");

            if(player)
            {
                playerPos = player.transform.position;

                // プレーヤーの位置に防御シールドを発生させる。
                GameObject shield = Instantiate(shieldPrefab, playerPos, Quaternion.identity);

                // 発生させた防御シールドをプレーヤーの子供に設定する（親子関係）
                // 親子関係にすることで一緒に動くようになる（ポイント）
                shield.transform.SetParent(player.transform);
            }
        }
    }
}