[Unity菜鸟] 摄像机

using UnityEngine;
using System.Collections;

public class CameraVirtual : MonoBehaviour
{
    //旋转的物体
    public GameObject building;

    //用来记录鼠标的位置，以便计算旋转幅度
    Vector2 p1, p2; 

    // Update is called once per frame
    void Update()
    {
        if (Input.GetMouseButtonDown(1))
        {
            p1 = new Vector2(Input.mousePosition.x, Input.mousePosition.y);//鼠标右键按下时记录鼠标位置p1
        }
        if (Input.GetMouseButton(1))
        {
            p2 = new Vector2(Input.mousePosition.x, Input.mousePosition.y);//鼠标右键拖动时记录鼠标位置p2
            //下面开始旋转，仅在水平方向上进行旋转
            float dx = p2.x - p1.x;
            transform.RotateAround(building.transform.position, Vector3.up, dx * Time.deltaTime);
        }
    }

}