注意本脚本是用刚体移动一定要给物体叫加上刚体组件，并且人物动作动画使用mecanima的混合树“forward”播放

[Header("===== 控制移动和方向的各项数值 ======")]
    private float h = 0.0f;
    private float v = 0.0f;
    //向量
    private Vector3 moveDir;
    //移动变量
    public float moveSpeed = 2.0f;
    //旋转速度
    public float rotSpeed = 100.0f;
    //奔跑速度
    public float runSpeed = 4.0f;
    private float mag;
    private float velocityh;
    private float velocityv;
    private float targeth;
    private float targetv;
    private Transform tr;
    private Animator ani;
    private Rigidbody rb;
    public bool run;


    //输入特殊按键
    public string keyA = "left shift";
    // public string keyB;
    // Start is called before the first frame update
    void Awake()
    {
        tr = GetComponent<Transform>();
        ani = GetComponent<Animator>();
        rb = GetComponent<Rigidbody>();


    }

    // Update is called once per frame
    void Update()
    {

        targeth = Input.GetAxis("Horizontal");
        targetv = Input.GetAxis("Vertical");
        run = Input.GetKey(keyA);


        h = Mathf.SmoothDamp(h, targeth, ref velocityh, 0.1f);
        v = Mathf.SmoothDamp(v, targetv, ref velocityv, 0.1f);

        Debug.Log("H=" + h.ToString());
        Debug.Log("V=" + v.ToString());

        


        //计算前后左右移动的方向向量


        moveDir = (Vector3.forward * v) + (Vector3.right * h);
        mag = Mathf.Sqrt(targeth * targeth + targetv * targetv);
        if (mag > 1.0f)
        {
            mag = 1.0f;
        }


        //移动动画

         float runani = ((run) ? 2.0f : 1.0f);

         ani.SetFloat("forward", mag *Mathf .Lerp (ani .GetFloat("forward") , runani,0.5f));
         //走动
         if (mag > 0.1f)
         {
             Vector3 targetforward = Vector3.Slerp(tr.forward, moveDir, 0.3f);
             tr.forward = targetforward;
         }
       //下面是用bool来实现人物动画播放
        /* if (moveDir != Vector3.zero) 
         {
             tr.rotation = Quaternion.LookRotation( moveDir  );

             if (run) {
                 ani.SetBool("run", true);

             }

             ani.SetBool("walk", true);

         }  else
         {
             ani.SetBool("walk", false);
         } */


    }





    void FixedUpdate()
    {
        //用刚体来使物体移动（移动速度*方向向量*tiem.fixeddeltatime）

       rb.position += moveSpeed * moveDir * Time.fixedDeltaTime * ((run) ? 2.0f : 1.0f);
    
        
    }