Using the "Surface Inquiry" command and selecting an existing surface, the user may click on any point on it and a vector will be created, showing the direction of its slope. Additionally, the following dialog box will appear, which will be updated for every new surface point the user selects:
The user can either select points directly in the drawing, or manually assign their coordinates inside the dialog box. For each one, its elevation and slope (in three different formats) will be diplayed.