Unity相机的跟随移动

一、固定相机跟随

       这种相机有一个参考对象，它会保持与该参考对象固定的位置，跟随改参考对象发生移动

using UnityEngine;
using System.Collections;

public class CameraFlow : MonoBehaviour
{
    public Transform target;
    private Vector3 offset;
    // Use this for initialization
    void Start()
    {
        offset = target.position - this.transform.position;

    }

    // Update is called once per frame
    void Update()
    {
        this.transform.position = target.position - offset;
    }
}

二、固定相机跟随，带有角度旋转

       这一种相机跟随是对第一种相机跟随的改进，在原有基础上面，添加了跟随角度的控制。

using UnityEngine;
using System.Collections;

public class CameriaTrack : MonoBehaviour {
    private Vector3 offset = new Vector3(0,5,4);//相机相对于玩家的位置
    private Transform target;
    private Vector3 pos;

    public float speed = 2;

    // Use this for initialization
    void Start () {
        target = GameObject.FindGameObjectWithTag("Player").transform;

    }

    // Update is called once per frame
    void Update () {
        pos = target.position + offset;
        this.transform.position = Vector3.Lerp(this.transform.position, pos, speed*Time.deltaTime);//调整相机与玩家之间的距离
        Quaternion angel = Quaternion.LookRotation(target.position - this.transform.position);//获取旋转角度
        this.transform.rotation = Quaternion.Slerp(this.transform.rotation, angel, speed * Time.deltaTime);

    }
}

三、第三人称相机

      这种相机跟随，是第三人称角度看向对象的，也就是一直看向对象的后面，如一直显示玩家的后背。

using UnityEngine;
using System.Collections;
//相机一直拍摄主角的后背
public class CameraFlow : MonoBehaviour {

    public Transform target;


    public float distanceUp=15f;
    public float distanceAway = 10f;
    public float smooth = 2f;//位置平滑移动值
    public float camDepthSmooth = 5f;
    // Use this for initialization
    void Start () {

    }

    // Update is called once per frame
    void Update () {
       // 鼠标轴控制相机的远近
        if ((Input.mouseScrollDelta.y < 0 && Camera.main.fieldOfView >= 3) || Input.mouseScrollDelta.y > 0 && Camera.main.fieldOfView <= 80)
        {
            Camera.main.fieldOfView += Input.mouseScrollDelta.y * camDepthSmooth * Time.deltaTime;
        }

    }

    void LateUpdate()
    {
       //相机的位置
        Vector3 disPos = target.position + Vector3.up * distanceUp - target.forward * distanceAway;
        transform.position=Vector3.Lerp(transform.position,disPos,Time.deltaTime*smooth);
        //相机的角度
        transform.LookAt(target.position);
    }


}

四、相机跟随，鼠标控制移动和缩放

      相机与观察对象保持一定距离，可以通过鼠标进行上下左右旋转，通过鼠标滚轮进行放大和缩小操作

using UnityEngine;
using System.Collections;

public class CameraFlow : MonoBehaviour
{
    public Transform target;
    Vector3 offset;
    // Use this for initialization
    void Start()
    {
        offset = transform.position - target.position;
    }

    // Update is called once per frame
    void Update()
    {
        transform.position = target.position + offset;
        Rotate();
        Scale();
    }
    //缩放
    private void Scale()
    {
        float dis = offset.magnitude;
        dis += Input.GetAxis("Mouse ScrollWheel") * 5;
        Debug.Log("dis=" + dis);
        if (dis < 10 || dis > 40)
        {
            return;
        }
        offset = offset.normalized * dis;
    }
    //左右上下移动
    private void Rotate()
    {
        if (Input.GetMouseButton(1))
        {
            Vector3 pos = transform.position;
            Vector3 rot = transform.eulerAngles;

            //围绕原点旋转，也可以将Vector3.zero改为 target.position,就是围绕观察对象旋转
            transform.RotateAround(Vector3.zero, Vector3.up, Input.GetAxis("Mouse X") * 10);
            transform.RotateAround(Vector3.zero, Vector3.left, Input.GetAxis("Mouse Y") * 10);
            float x = transform.eulerAngles.x;
            float y = transform.eulerAngles.y;
            Debug.Log("x=" + x);
            Debug.Log("y=" + y);
            //控制移动范围
            if (x < 20 || x > 45 || y < 0 || y > 40)
            {
                transform.position = pos;
                transform.eulerAngles = rot;
            }
            //  更新相对差值
            offset = transform.position - target.position;
        }

    }
}