Using 08.11.09.878 I can't get the Z difference. I analyze point on the lower vertical alignment with Civil Accudraw set as level difference and offset locked to 0. So the blue cross is following the ground and I get the elevation of the design but not the Z difference.
The best way I found to get the level difference is to analyze point on the ground and move cursor along the design with snap point set to nearest. But it does not answer because it should be independent from the cursor position. The question is: what do you want to achieve that requires this?
