Terrain not visible

[LDRobertson]

I have converted my .dwg elevation file (supplied by survey) to .dxf .  I have made several successful drawings and the terrain displays properly.  I now have a new drawing I started.  I imported the same .dxf but the only terrain showing is the part under the building. It looks very funny, I can change the thickness of the display and my house rises on a tall green pedestal!  It does not display the entire terrain perimeter.  If I click off on the "do not display terrain intersecting building" then I loose it all together. I have tried to follow the same settings as my successful plans.  I have tried to reload the data but I end up with the same thing, no full display.  I know I am missing a button somewhere, I just can not figure it out.

Does anyone know what I am doing wrong?

Using Professional 2017

Thanks in advance, Dianne

[LDRobertson]

A good nights sleep solved everything.  I had a hidden terrain perimeter I could not see, hence the small rectangle under my foundation where the terrain intersected the building.  I opened my plan in 3D and then hit the edit arrow.  I was able to pull out the terrain perimeter enough so I could see the edges outside my foundation.   I went back to floor plan view and adjusted the rest of my edges.  All is solved.  You do need to have the box checked to " show terrain intersection" or it may stay hidden forever.  Thanks, from a real novice.