本章代码基于前两章。
1. 我们新建CameraController脚本，将其挂载到Camera上
2. 在角色Player下新建一个空物体，命名为cameraTargetPoint，并将该物体挂载至CameraController脚本中【注意代码中的这行：public Transform cameraTargetPoint;】，将该空物体放在人物头部附近位置
3.将PlayerController脚本绑定至CameraController中【public PlayerController playerController;】
4.本章代码的实现原理是让摄像机对准空物件，并保持一定距离
5. 具体代码如下

using System.Collections;
using System.Collections.Generic;
using UnityEngine;public class CameraController : MonoBehaviour
{private static float lower_upper_bound = 60f;public Transform cameraTargetPoint;public float cameraDistance = 5.0f;public Vector2 verticalRange = new Vector2(-lower_upper_bound, lower_upper_bound);public float cameraSensitivity = 120f;private Transform verticalObj;private Transform horizontalObj;private float horizontalValue;private float verticalValue;public PlayerController playerController;// Start is called before the first frame updatevoid Start(){horizontalObj = new GameObject("Camera Horizontal").transform;horizontalObj.SetParent(cameraTargetPoint);horizontalObj.localPosition = Vector3.zero;horizontalObj.localRotation = Quaternion.identity;verticalObj = new GameObject("Camera Vertical").transform;verticalObj.SetParent(horizontalObj);verticalObj.localPosition = Vector3.zero;verticalObj.localRotation = Quaternion.identity;transform.SetParent(verticalObj);transform.localPosition = new Vector3(0,0,-cameraDistance);transform.localRotation = Quaternion.identity; }// Update is called once per framevoid Update(){cameraMoving();DoNotTouchTheGround();}private void cameraMoving(){horizontalValue += Input.GetAxis("Mouse X") * Time.deltaTime * cameraSensitivity;horizontalObj.localRotation = Quaternion.Euler(new Vector3(0, horizontalValue, 0));verticalValue += Input.GetAxis("Mouse Y") * Time.deltaTime * cameraSensitivity;verticalValue = Mathf.Clamp(verticalValue, verticalRange.x, verticalRange.y);verticalObj.localRotation = Quaternion.Euler(new Vector3(-verticalValue, 0, 0));}private void DoNotTouchTheGround()    // 摄像机与角色点中间有物体时，让摄像机处于物体前，避免遮挡{Vector3 distanceVec = transform.position - cameraTargetPoint.position;float distance = distanceVec.magnitude;RaycastHit hit;if(Physics.Raycast(cameraTargetPoint.position,distanceVec, out hit,distance)){if(hit.transform.tag != "Player"){transform.position = hit.point;}else{transform.localPosition = Vector3.Lerp(transform.localPosition, new Vector3(0, 0, -distance), 0.3f);}}else{transform.localPosition = Vector3.Lerp(transform.localPosition, new Vector3(0, 0, -distance), 0.3f);}}
}

Tips:以上代码中，DoNotTouchTheGround()方法不是必须的，该方法是用于限制当摄像机与角色之间有障碍物时，把摄像机放在障碍物前方以避免视觉阻碍，可以看情况添加。

至此，我们可以实现摄像机跟随角色移动，并且鼠标能操控摄像机绕着角色转动，但仍有一个问题：当摄像机位于人物前方时，人物前进方向仍是我们的后方，这是由于参考坐标系的缘故，具体修复如下：

1. 在PlayerController脚本中，添加

public Transform cameraTargetPoint;

在Move方法中添加【moveingVec = cameraTargetPoint.TransformDirection(moveingVec);】：

private void Move(){float horizontalInput = Input.GetAxis("Horizontal");float verticalInput = Input.GetAxis("Vertical");Vector3 moveingVec = new Vector3(horizontalInput, 0f, verticalInput) * Time.deltaTime * speed;moveingVec = cameraTargetPoint.TransformDirection(moveingVec);transform.Translate(moveingVec);}

2. 在CameraController脚本中的cameraMoving()方法中添加下句：

playerController.cameraTargetPoint = horizontalObj;

于是即可实现摄像头跟随鼠标，并围绕角色运动，并且角色运动方向【仅仅是方向，如果要人物转向，则还需其他修改，本系列其他章节会有涉及】可以自适应为当前摄像头的前方