Step1: 添加玩家角色动画
    在Animator中 创建JohnLemon动画控制器
    选中它，点击open
    添加参数 Iswalking
    然后添加 Idle 状态以及walking 状态
    添加过渡关系

Step2：更改动画bug
        1）人物会自动向上飘
        Update Mode 不再默认状态，选择 Animate Physics
        Freeze position 选中Y轴
        Freeze Rotation 选中X，Z轴

Step3：玩家移动以及转向代码
    using System.Collections;
    using System.Collections.Generic;
    using UnityEngine;

    public class PlayerMovement : MonoBehaviour
    {
        // Start is called before the first frame update
        //获取玩家输入，进行操控
        //玩家转动
        //考虑动画
        Vector3 m_Movement;
        float horizontal;
        float vertical;
        Rigidbody m_Rigidbody;
        Animator m_Animator;

        Quaternion m_Rotation = Quaternion.identity;
        //旋转速度
        public float turnSpeed = 20.0f;

        void Start()
        {
            m_Animator = GetComponent<Animator>();
            m_Rigidbody = GetComponent<Rigidbody>();
        }

        // Update is called once per frame
        void Update()
        {
            horizontal = Input.GetAxis("Horizontal");
            vertical = Input.GetAxis("Vertical");

        }
        void FixedUpdate()
        {
            //将用户输入组装成3D运动需要的3维矢量
            m_Movement.Set(horizontal, 0.0f, vertical);
            m_Movement.Normalize();

            bool hasHorizontal = !Mathf.Approximately(horizontal, 0.0f);
            bool hasVertical = !Mathf.Approximately(vertical, 0.0f);
            bool isWalking = hasHorizontal || hasVertical;
            //将变量传给动画管理器
            m_Animator.SetBool("Iswalking", isWalking);

            //用三维矢量来表示转向后的玩家角色
            Vector3 desiredForward = Vector3.RotateTowards(transform.forward,m_Movement,turnSpeed*Time.deltaTime,0f);
            m_Rotation = Quaternion.LookRotation(desiredForward);
        }

        void OnAnimatorMove()
        {
            m_Rigidbody.MovePosition(m_Rigidbody.position + m_Movement * m_Animator.deltaPosition.magnitude);
            m_Rigidbody.MoveRotation(m_Rotation);
        }
    }

Step4：添加场景以及光照
    点击 Directional Light
    改变 Type
    点击windows rendering，设置环境光照

Step5：设置导航
    windows -- AI -- Navigate
    选中Level 点击static
    选择ceilingfloor 然后取消static勾选

Step6：选择照相机跟随
    cinemacamera --- virtual camera
    调整  Rotation  45度
    选择主人公跟随
    Body Framing Transposer
    Aim Do nothing
    Camera distance 6