Unity滚轮调整摄像机的远近 点击小地图切换摄像机的位置

using UnityEngine;
using System.Collections;

public class MapHyp : MonoBehaviour {
主摄像机
public GameObject bigCamera;
//小地图的摄像机
public Camera smallCamera;
// Use this for initialization
void Start () {

}

// Update is called once per frame
void Update () {
//滚轮控制
if (Input.GetAxis("Mouse ScrollWheel") < 0)
{
//控制的范围自行调整
if (Camera.main.fieldOfView <= 80)
Camera.main.fieldOfView += 2;
if (Camera.main.orthographicSize <= 20)
Camera.main.orthographicSize += 0.5F;
}
if (Input.GetAxis("Mouse ScrollWheel") > 0)
{
if (Camera.main.fieldOfView > 2)
Camera.main.fieldOfView -= 2;
if (Camera.main.orthographicSize >= 1)
Camera.main.orthographicSize -= 0.5F;
}

//点击小地图  主摄像会找到和小地图一致的位置
//将小地图的屏幕坐标转为视口坐标：
Vector3 v1 = smallCamera.ScreenToViewportPoint(Input.mousePosition);
//主地图和 小地图重合的位置（根据情况自己设定范围）：
if ((v1.x >= 0.1f && v1.x <= 0.95f) && (v1.y >= 0.1f && v1.y <= 0.9f))
{
if (Input.GetMouseButtonDown(0))
{
//视口坐标转为世界坐标
Vector3 v2 = smallCamera.ViewportToWorldPoint(v1);
//增加一个 偏移量
bigCamera.transform.position = new Vector3(v2.x+13, bigCamera.transform.position.y, v2.z+11);

}
}
//按F1 键  回到某个物体的视角
GameObject huan = GameObject.Find("HuanHuan");
if (Input.GetKey(KeyCode.F1))
{
bigCamera.transform.position = new Vector3(huan.transform.position.x+10, huan.transform.position.y+15 , huan.transform.position.z+10);
}
}
}