第三人称射击游戏的相机控制

（关于其他几种角色移动的控制在我之前的博客有写到）

首先我们需要先理解一下第三人称相机控制的原理：
我们要实现的效果就是：获取鼠标的移动输入，转化成角色以及相机的旋转，通过鼠标输入Input.GetAxis(“Mouse X”)让相机围绕目标角色旋转（transform.RotateAround）角色通过相机改变的角度改变自身方向（Quaternion.Euler）。

那么先介绍一下transform.RotateAround（目标物体位置，轴，旋转角度）方法，这个方法是让自身围绕目标物体旋转，所以我们用

float inputX = Input.GetAxis("Mouse X");
float inputY = Input.GetAxis("Mouse Y");
transform.RotateAround(CameraPivot.transform.position, Vector3.up, rotateSpeed * inputX);
transform.RotateAround(CameraPivot.transform.position, TargetBody.transform.right, -rotateSpeed * inputY);

CameraPivot是相机的焦点物体（最好是设置角色的头部）；
然后 我们将相机的这个旋转角度记录下来（transform.localEulerAngles），并且用Quaternion.Euler改变角色的面向；

Quaternion TargetBodyCurrentRotation = TargetBody.transform.rotation;
TargetBody.transform.rotation = Quaternion.Lerp(TargetBodyCurrentRotation, Quaternion.Euler(new Vector3(TargetBody.transform.localEulerAngles.x, transform.localEulerAngles.y, TargetBody.transform.localEulerAngles.z)), TargetBodyRotateLerp);
    

为了方便理解，给大家画一个示意图：

下面给大家简单操作一下！
还是先创建一个新的场景，里面添加一个plane和一个cube并且调整一下相机位置：

然后上代码！把代码加载摄像机上：

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
 
public class cameraFollow : MonoBehaviour {
    [Header("相机距离")]
    public float freeDistance = 2;
    [Header("相机最近距离")]
    public float minDistance = 0.5f;
    [Header("相机最远距离")]
    public float maxDistance = 3;
    [Header("是否可控制相机距离(鼠标中键)")]
    public bool canControlDistance=true;
    [Header("更改相机距离的速度")]
    public float distanceSpeed = 1;
 
    [Header("视角灵敏度")]
    public float rotateSpeed = 1;
    [Header("物体转向插值(灵敏度,取值为0到1)")]
    public float TargetBodyRotateLerp = 0.3f;
    [Header("需要转向的物体")]
    public GameObject TargetBody;//此脚本能操作转向的物体
    [Header("相机焦点物体")]
    public GameObject CameraPivot;//相机焦点物体  
 
    [Header("是否可控制物体转向")]
    public bool CanControlDirection = true;
    
    private Vector3 offset;//偏移

    // Use this for initialization
    void Start () {
        //获取目标与相机之间的差值
        offset = transform.position - CameraPivot.transform.position;

    }
 
    
 
    void FreeCamera()
    {
        offset = offset.normalized * freeDistance;

         transform.position =  Vector3.Lerp(transform.position,CameraPivot.transform.position + offset,1f) ;//更新位置
 
        if (CanControlDirection)//控制角色方向开关
        {
            Quaternion TargetBodyCurrentRotation = TargetBody.transform.rotation;
            TargetBody.transform.rotation = Quaternion.Lerp(TargetBodyCurrentRotation, Quaternion.Euler(new Vector3(TargetBody.transform.localEulerAngles.x, transform.localEulerAngles.y, TargetBody.transform.localEulerAngles.z)), TargetBodyRotateLerp);
    
        }
 
        //限制相机距离
        if(canControlDistance)//控制距离开关
        {
            freeDistance -= Input.GetAxis("Mouse ScrollWheel") * distanceSpeed;
        }
        freeDistance = Mathf.Clamp(freeDistance, minDistance, maxDistance);
 
      
        //保证相机的注视
        transform.LookAt(CameraPivot.transform.position);
        
        
        //控制相机随鼠标的旋转
        float inputY = Input.GetAxis("Mouse Y");
        float inputX = Input.GetAxis("Mouse X");
        transform.RotateAround(CameraPivot.transform.position, Vector3.up, rotateSpeed * inputX);
        transform.RotateAround(CameraPivot.transform.position, TargetBody.transform.right, -rotateSpeed * inputY);
       
        
        //旋转之后以上方向发生了变化,需要更新方向向量
        offset = transform.position - CameraPivot.transform.position;
        offset = offset.normalized * freeDistance;
        transform.position = CameraPivot.transform.position + offset;
           
        
    
    }
 
    // Update is called once per frame
    void FixedUpdate () {
        FreeCamera();
	}
 
    private void Update()
    {
        
    }
}

稍微配置一下参数：

之后 就有相机的初步效果了：

给cube添加上移动的代码 就完成啦！

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Control : MonoBehaviour {
	float ver = 0;
	float hor = 0;
	public float turnspeed = 10f;
	public float speed = 6f;
	// Use this for initialization
	void Start () {

	}
	// Update is called once per frame
	void Update () {
		hor = Input.GetAxis ("Horizontal");
		ver = Input.GetAxis ("Vertical");
	}
	void move (float hor, float ver) {
		transform.Translate (hor * speed * Time.deltaTime, 0, ver * speed * Time.deltaTime);
	}
	void FixedUpdate () {
		if (hor != 0 || ver != 0) {
			//转身
			move (hor, ver);
		}
	}

}

完成！