Unity小行星场景角色朝向移动方向旋转异常问题求助

我们正在进行一项学生项目，开发一款类似《马里奥银河》的带有小行星与重力系统的平台游戏（这对我的第一个编程项目来说算是个不小的挑战，但如今已无法退出）。目前我遇到的难题是，无法让角色朝向移动方向而不出现抽搐现象。我仅拥有约2个月的编程经验，还请包涵。

角色运动实现代码 #

using System.Collections.Generic;
using UnityEngine;

public class SC_RigidbodyWalker : MonoBehaviour
{
    public float speed = 5.0f;
    public bool canJump = true;
    public float jumpHeight = 2.0f;
    public Camera playerCamera;
    public float lookSpeed = 2.0f;
    public float lookXLimit = 60.0f;


    bool grounded = false;
    Rigidbody r;
    Vector2 rotation = Vector2.zero;
    float maxVelocityChange = 10.0f;

    void Awake()
    {
        r = GetComponent<Rigidbody>();
        r.freezeRotation = true;
        r.useGravity = false;
        r.collisionDetectionMode = CollisionDetectionMode.ContinuousDynamic;
        rotation.y = transform.eulerAngles.y;

        Cursor.lockState = CursorLockMode.Locked;
        Cursor.visible = false;
    }

    void Update()
    {
        
    }

    void FixedUpdate()
    {
        if (grounded)
        {
            // Calculate how fast we should be moving
            Vector3 forwardDir = Vector3.Cross(transform.up, -playerCamera.transform.right).normalized;
            Vector3 rightDir = Vector3.Cross(transform.up, playerCamera.transform.forward).normalized;
            Vector3 targetVelocity = (forwardDir * Input.GetAxis("Vertical") + rightDir * Input.GetAxis("Horizontal")) * speed;

            Vector3 velocity = transform.InverseTransformDirection(r.velocity);
            velocity.y = 0;
            velocity = transform.TransformDirection(velocity);
            Vector3 velocityChange = transform.InverseTransformDirection(targetVelocity - velocity);
            velocityChange.x = Mathf.Clamp(velocityChange.x, -maxVelocityChange, maxVelocityChange);
            velocityChange.z = Mathf.Clamp(velocityChange.z, -maxVelocityChange, maxVelocityChange);
            velocityChange.y = 0;
            velocityChange = transform.TransformDirection(velocityChange);

            r.AddForce(velocityChange, ForceMode.VelocityChange);

            if (Input.GetButton("Jump") && canJump)
            {
                r.AddForce(transform.up * jumpHeight, ForceMode.VelocityChange);
            }

            
        }

        grounded = false;
    }

    void OnCollisionStay()
    {
        grounded = true;
    }
}

重力功能实现代码 #

using System.Collections.Generic;
using UnityEngine;

public class SC_PlanetGravity : MonoBehaviour
{
    public Transform planet;
    public bool alignToPlanet = true;

    float gravityConstant = 9.8f;
    Rigidbody r;

    void Start()
    {
        r = GetComponent<Rigidbody>();
    }

    void FixedUpdate()
    {
        Vector3 toCenter = planet.position - transform.position;
        toCenter.Normalize();

        r.AddForce(toCenter * gravityConstant, ForceMode.Acceleration);

        if (alignToPlanet)
        {
            Quaternion q = Quaternion.FromToRotation(transform.up, -toCenter);
            q = q * transform.rotation;
            transform.rotation = Quaternion.Slerp(transform.rotation, q, 1);
        }
    }
}

内容的提问来源于stack exchange，提问作者Happy Bell