Физическое движение персонажа, в сторону, в которую он смотрит в Unity 3D

Итак, я сделал нормальное(вроде) физическое движение объекта(персонажа), но как сделать так, чтобы он шёл в сторону, в которую смотрит(Я поворачиваю игрока вместе с камерой)? Реализация движения: PlayerMovement:

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

    public class PlayerMovement : MonoBehaviour
    {
        [SerializeField] private Rigidbody _rigidbody;
        [SerializeField] private SurfaceSlider _surfaceSlider;
        [SerializeField] private float _speed;

    public void Move(Vector3 direction)
    {
        Vector3 directionAlongSurface = _surfaceSlider.Project(direction.normalized);
        print(transform.forward);
        Vector3 offset = directionAlongSurface * (_speed * Time.deltaTime);

        _rigidbody.MovePosition(_rigidbody.position + offset);
    }
}

KeyboardInput:

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

public class KeyboardInput : MonoBehaviour
{
    [SerializeField] private PlayerMovement _movement;
    [SerializeField] private FollowCamera _camera;
    private void Update()
    {
        float vertical = Input.GetAxis("Vertical");
        float horizontal = Input.GetAxis("Horizontal");
        float vertical_cam = Input.GetAxis("Mouse Y");
        float horizontal_cam = Input.GetAxis("Mouse X");
        _movement.Move(new Vector3(horizontal, 0, vertical));
        _camera.Rotate(new Vector3(-vertical_cam, horizontal_cam, 0));
    }
}

SurfaceSlider:

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

public class SurfaceSlider : MonoBehaviour
{
    private Vector3 _normal;

    public Vector3 Project(Vector3 forward)
    {
        return forward - Vector3.Dot(forward, _normal) * _normal;
    }
    private void OnCollisionEnter(Collision collision)
    {
        if(collision.gameObject.tag != "Finish")
        {
            _normal = collision.contacts[0].normal;
        } 
    }

    private void OnDrawGizmos()
    {
        Gizmos.color = Color.black;
        Gizmos.DrawLine(transform.position, transform.position + _normal * 3);
        Gizmos.color = Color.red;
        Gizmos.DrawLine(transform.position, transform.position + Project(transform.forward));
    }
}