using UnityEngine;

public class FaceCamera : MonoBehaviour
{
    public Camera mainCamera;

    // 是否启用UI与屏幕XY轴对齐功能
    public bool alignWithScreenXY = true;

    void Start()
    {
        // 如果没有手动设置摄像机，自动获取主摄像机
        if (mainCamera == null)
        {
            mainCamera = Camera.main;
        }
    }

    void LateUpdate()
    {
        // 使3D UI面向摄像机
        transform.LookAt(transform.position + mainCamera.transform.rotation * Vector3.forward,
                         mainCamera.transform.rotation * Vector3.up);

        // 如果启用了UI与屏幕XY轴对齐功能
        if (alignWithScreenXY)
        {
            transform.rotation = Quaternion.Euler(mainCamera.transform.rotation.eulerAngles.x,
                                                  mainCamera.transform.rotation.eulerAngles.y,
                                                  0f);
        }
    }
}