I am trying to create a FG surface for a dredging project. I've made a corridor representing the maximum elevation that the channel can be; in some areas it is cutting and in some areas it is filling but I really only want the cut to show up on my FG.
Is there a way to build an assembly that will result in a corridor that only cuts or, alternatively, is there a way to define a new surface that looks at two source surfaces and takes the lower elevation?
Note that at a given station, there may be both cut and fill at different offsets so I don't think using, say, a ditch subassembly would work since it checks for cut/fill at only one offset (at least as I understand it.)
Thanks for the help,