设置 相机跟随 主角及视角 滑动

using UnityEngine;
using System.Collections;

public class CameraFllow : MonoBehaviour {

    private Transform player;
    public float speed = 3;

    void Start()
    {
        //向服务器实时更新数据的时候 将Player信息也更新
        player = GameDataUtil.playerModel.transform;
    }

    void Update()
    {
        //由 摄像机 和 玩家固定距离偏量 构建插值
        Vector3 targetPos = player.position + new Vector3(0.28f,20.56f,60f);
        //移动
        transform.position = Vector3.Lerp(transform.position , targetPos , speed * Time.deltaTime);
        //角度的移动 lookRotation 是按向量变换时的长度 来变的 ,相减 是由相机位置指向玩家
        Quaternion targetRotation = Quaternion.LookRotation(player.position - transform.position);
          // Slerp是根据 变换过程中角度的变化 插值的
        transform.rotation = Quaternion.Slerp(transform.rotation , targetRotation , speed * Time.deltaTime);
    }
}

using UnityEngine;
using System.Collections;

public class FollowPlayer : MonoBehaviour {

    private Transform player;
    private Vector3 offsetPosition;//位置偏移
    private bool isRotating = false;


    public float distance = 0;
    public float scrollSpeed = 10;
    public float rotateSpeed = 2;

    // Use this for initialization
    void Start () {
        player = GameObject.FindGameObjectWithTag(Tags.player).transform;
        transform.LookAt(player.position);
        offsetPosition = transform.position - player.position;
    }
    
    // Update is called once per frame
    void Update () {
        transform.position = offsetPosition + player.position;
        //处理视野的旋转
        RotateView();
        //处理视野的拉近和拉远效果
        ScrollView();
    }

    void ScrollView() {
        //print(Input.GetAxis("Mouse ScrollWheel"));//向后 返回负值 (拉近视野) 向前滑动 返回正值(拉远视野)
        distance = offsetPosition.magnitude;
        distance += Input.GetAxis("Mouse ScrollWheel")*scrollSpeed;
        distance = Mathf.Clamp(distance, 2, 18);
        offsetPosition = offsetPosition.normalized * distance;
    }

    void RotateView() {
        //Input.GetAxis("Mouse X");//得到鼠标在水平方向的滑动
        //Input.GetAxis("Mouse Y");//得到鼠标在垂直方向的滑动
        if (Input.GetMouseButtonDown(1)) {
            isRotating = true;
        }
        if (Input.GetMouseButtonUp(1)) {
            isRotating = false;
        }

        if (isRotating) {
            transform.RotateAround(player.position,player.up, rotateSpeed * Input.GetAxis("Mouse X"));

            Vector3 originalPos = transform.position;
            Quaternion originalRotation = transform.rotation;

            transform.RotateAround(player.position,transform.right, -rotateSpeed * Input.GetAxis("Mouse Y"));//影响的属性有两个 一个是position 一个是rotation
            float x = transform.eulerAngles.x;
            if (x < 10 || x > 80) {//当超出范围之后，我们将属性归位原来的，就是让旋转无效 
                transform.position = originalPos;
                transform.rotation = originalRotation;
            }

        }

        offsetPosition = transform.position - player.position;
    }
}