我在Unity游戏引擎上做了一个游戏，你可以控制一只鸟。当我把我的脚本附加到鸟上并点击播放时，鸟不会转动。鸟能够旋转，但实际上不能左右转动。我的上下运动也很像机器人，我想知道是否有办法改进它。我对Unity和编码很陌生，如果有帮助，我会非常感激。
我使用的代码：

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

public class BirdController : MonoBehaviour
{
    public float FlySpeed = 5;
    public float YawAmount = 1;
    public float PitchAmount = 1;

    private float Yaw;
    private float Pitch;

    // Update is called once per frame
    void Update()
    {
        //move forward
        transform.position += transform.forward * FlySpeed * Time.deltaTime;

        //inputs
        float horizontalInput = Input.GetAxis("Horizontal");
        float verticalInput = Input.GetAxis("Vertical");

        //yaw, pitch, roll
        Yaw += horizontalInput * YawAmount * Time.deltaTime;
        Pitch += verticalInput * PitchAmount * Time.deltaTime;
        float pitch = Mathf.Lerp(0, 50, Mathf.Abs(verticalInput)) * Mathf.Sign(verticalInput);
        float roll = Mathf.Lerp(0, 70, Mathf.Abs(horizontalInput)) * -Mathf.Sign(horizontalInput);

        //apply rotation.
        transform.localRotation = Quaternion.Euler(Vector3.up * Yaw + Vector3.right * pitch + Vector3.forward * roll);
        transform.localRotation = Quaternion.Euler(Vector3.right * Pitch + Vector3.left * pitch + Vector3.forward * roll);

    }
}