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

public class Background : MonoBehaviour
{
    private Vector3 startPosition;
    public float border;

    void Start()
    {
        startPosition = transform.position;
    }

    void Update()
    {
        Vector3 pos = transform.position;
        pos.z -= Time.deltaTime * 5;
        transform.position = new Vector3(pos.x, pos.y, pos.z);

        // （ポイント）zの値が境界線以下になったら初期位置に戻す。
        if (pos.z <= border)
        {
            transform.position = startPosition;
        }
    }
}