I searched the internet before asking, but could not find anything about the following.
When creating a geographic map, if you use the right mouse button on the map you can change the perspective, lowering the point of view.
This suggests the possibility of setting up a z direction, with points posessing a given z "height" with respect to the map, seen in the form of vertical bars emerging vertically from each point.
I tried with some keywords, such as z, elevation, etc. without success.
Is it an existing feature? could it be added?

Thanks a lot.

Alberto