Option "SAME" in 2D histograms


When I use the option “SAME” in the drawing of a 2nd histogram in 1D, I see the 2 histograms superimposed on the same pad, which is ok.
When I do the same for 2 histograms in 2D, using option “LEGO” for the first and “LEGOSAME” for the second, I see only one histogram, the bin content of which is the sum of 2 histograms, which is not what I wanted. Is it a feature or a bug? Is there a way to obtain in 2D the same behaviour as in 1D? Thanks a lot in advance.

The LEGO and SURF representations use hidden line/surface algorithms. So, doing a additional plot on top of a LEGO cannot work because with such drawing techniques all the data to be drawn should be known to produce a correct plot in one go. For a such representation (Lego on top of each other) I would recommend to use the TStack class (see examples in the tutorials directory)