Unity相机与物体之间距离控制标签显示隐藏

public class DeviceNameItem : MonoBehaviour
{
    public Text Devicenametext;
    public RectTransform rect;
    private Camera mainCam;
    private TipItemModel ItemDate;
    private Vector3 mWorldTarget;
    private Canvas mCanvas;
    private string modelType = "";
    private float distance = 0f;
    private float currentAngle = 0;
    private bool isHover = false;
    private bool isShowLine = false;
    private float MaxSizeDistance = 9;
    public CanvasGroup mCanvasGroup;
    private void Start()
    {
        mainCam = Camera.main;
        rect = transform as RectTransform;
    }

    private void Update()
    {
        //transform.forward = mainCam.transform.forward;
        if (mWorldTarget==null||mCanvas==null)
        {
            return;
        }
        transform.localPosition = UnityTool.WorldToUGUILocalPosition(Camera.main, mWorldTarget, mCanvas);
        distance = Vector3.Distance(mWorldTarget, mainCam.transform.position);
        currentAngle = Vector3.Angle(mWorldTarget - mainCam.transform.position, mainCam.transform.forward);
      
            currentAngle = Vector3.Angle(mWorldTarget - mainCam.transform.position, mainCam.transform.forward);

        }
      
    }
    public void SetShowState(bool isShow)
    {
        //Debug.Log(isShow);
        mCanvasGroup.alpha = isShow ? 1 : 0;
        mCanvasGroup.blocksRaycasts = isShow;
    }
    public void SetDeviceName(TipItemModel item, string modelType)
    {
        ItemDate = item;
        this.modelType = modelType;
        Devicenametext.text = item.DeviceName;
        //Debug.Log(modelType);
      
    }
    public void SetTarget(Vector3 worldPos, Canvas canvas)
    {
        mWorldTarget = worldPos;
        mCanvas = canvas;
        transform.localPosition = UnityTool.WorldToUGUILocalPosition(Camera.main, worldPos, canvas);
        //  TipRect.sizeDelta = new Vector2(0,50);
        // SetShowState(true);
    }
}```