float h = Input.GetAxis("Horizontal");//對(duì)應(yīng)鍵盤(pán)的上下
float v = Input.GetAxis("Vertical");//對(duì)應(yīng)鍵盤(pán)的左右

void Update()
{
 role.SetBool(StealthConst.SNEAK, Input.GetKey(KeyCode.LeftShift));
 float h = Input.GetAxis("Horizontal");
 float v = Input.GetAxis("Vertical");
 if (Mathf.Abs(h) > 0.1f || Mathf.Abs(v) > 0.1f)
 {
 //5.6由動(dòng)畫(huà)控制器中的參數(shù)決定
 float currentSpeed = Mathf.Lerp(role.GetFloat(StealthConst.SPEED), 5.6f, moveSpeed * Time.deltaTime);
 role.SetFloat(StealthConst.SPEED, currentSpeed);//Animator通過(guò)速度控制移動(dòng)的快慢
 Vector3 targetDir = new Vector3(h, 0, v);
 //Vector3.up相當(dāng)于（0，1，0）繞著Y軸，看向目標(biāo)位置
 Quaternion newRotation = Quaternion.LookRotation(targetDir, Vector3.up);
 transform.rotation = Quaternion.Lerp(transform.rotation, newRotation, rotateSpeed * Time.deltaTime);
 }
 else
 {
 role.SetFloat(StealthConst.SPEED, 0);
 }
}

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

public class FollowPlayer : MonoBehaviour
{
 private Vector3 offset;
 public Transform role;
 public float moveSpeed = 3;
 public float rotateSpeed = 3;
 
 // Start is called before the first frame update
 void Start()
 {
 offset = transform.position - role.position;
 offset = new Vector3(0, offset.y, offset.z);
 }

 // Update is called once per frame
 void Update()
 {
 Vector3 beginPos = role.position + offset;//攝像機(jī)正常偏移位置，起點(diǎn)
 Vector3 endPos = role.position + offset.magnitude * Vector3.up;//offset.magnitude向量的長(zhǎng)度
 ///從起點(diǎn)到終點(diǎn)分別取3個(gè)點(diǎn)，通過(guò)射線判斷攝像機(jī)是否有遮擋
 Vector3[] posArr = new Vector3[] {
  beginPos,
  Vector3.Lerp(beginPos,endPos,0.25f),
  Vector3.Lerp(beginPos,endPos,0.5f),
  Vector3.Lerp(beginPos,endPos,0.75f),
  endPos
 };
 Vector3 targetPos = posArr[0];
 foreach (var pos in posArr)
 {
  RaycastHit hitInfo;
  ///第一個(gè)參數(shù)射線的起點(diǎn)，第二個(gè)參數(shù)射線的方向
  if (Physics.Raycast(pos, role.position - pos, out hitInfo))
  {
  if (hitInfo.collider.tag == StealthConst.PLAYER)
  {
   targetPos = pos;
   break;
  }
  else
  {
   continue;
  }
  }
  else
  {
  targetPos = pos;
  break;
  }
 }
 this.transform.position = Vector3.Lerp(transform.position,targetPos,Time.deltaTime*moveSpeed);//通過(guò)插值平滑移動(dòng)
 Quaternion nowRotation = transform.rotation;
 this.transform.LookAt(role.position);//攝像機(jī)轉(zhuǎn)向目標(biāo)
 this.transform.rotation = Quaternion.Lerp(nowRotation, transform.rotation, Time.deltaTime * rotateSpeed);//通過(guò)插曲平滑旋轉(zhuǎn)
 }
}