Unity:我如何才能仅在y轴上平移场景？

using UnityEngine;

public class SceneMovement : MonoBehaviour
{
    public float speed = 5f; // 平移速度

    void Update()
    {
        // 获取当前位置
        Vector3 currentPosition = transform.position;

        // 计算新的位置
        float newY = currentPosition.y + speed * Time.deltaTime;
        Vector3 newPosition = new Vector3(currentPosition.x, newY, currentPosition.z);

        // 更新位置
        transform.position = newPosition;
    }
}