Unity中摄像机绕物体旋转和拉近拉远视角的操作

Unity中摄像机的重要性毋庸置疑，关于摄像机的操作也有很多，比如第一人称跟随，第二人称跟随，摄像机的拉近拉远等等，下面就暂时实现摄像机的拉近拉远和旋转：

创建新的场景，场景中添加一个cube，然后给cube添加新的脚本，脚本内容如下：

using UnityEngine;
using System.Collections;

public class TestCube : MonoBehaviour {
    private GameObject rotateObj;
    private GameObject camera;
    public float speed = 3f;

    private bool rotate = false;

    public float maxView = 90;
    public float minView = 10;
    void Start()
    {
        rotateObj = GameObject.Find("Rotate");
        camera = GameObject.Find("Main Camera");
    }
	void Update () {
        //滑动鼠标滑轮控制视角的大小
        float offsetView = Input.GetAxis("Mouse ScrollWheel") * speed;
        float tmpView = offsetView + Camera.main.fieldOfView;
        tmpView = Mathf.Clamp(tmpView, minView, maxView);
        Camera.main.fieldOfView = tmpView;

        //绕主角旋转摄像机
        if(rotate)
        {
            camera.transform.RotateAround(transform.position, Vector3.up, speed * Input.GetAxis("Mouse X"));
        }
        if(Input.GetMouseButtonDown(0))
        {
            rotate = true;
        }
        if(Input.GetMouseButtonUp(0))
        {
            rotate = false;
        }
	}
}