i am trying to create a parking garage that is below grade (topography) so that the topo in section will show the earth pattern above the lid of the parking garage and not have the topo show inside the parking garage.
There is a way I came across on the internet. You should model your topography as a mass element and change its material to earth. Empty the part where your structure is
Another alternative: Put the Toposurface in a separate file (and link it in). Create a "white-filled" element (such as a Floor with a material w/ solid-white cut fill) in the area you want to take out. You can filter out the white elements and/or make the link an underlay. I used this technique to model subgrade layers (though for that, it wasn't worth it).
