AutoCAD Civil 3D

[#1]

We want to show two surfaces, an existing ground and a proposed ground, on a cross section. When the proposed ground meets up with existing ground, it would be nice for the line to end. With just existing ground continuing on. The surface is data referenced, and I would like to not break either of them. I thought adding a surface mask would cause the proposed surface to stop at the mask, but that doesn't appear to be the case. Are there any other options for achieving this?

[#2 · Accepted solution]

Change or edit the FG surface style to display the border and extract it. (Select the surface, go to the ribbon and find the Extract objects button)

Since you have the Data Ref, create a new surface and paste the EG surface into it. (Select the surface and find the Surface Edits button on the ribbon)

Add the FG border extracted above as a hide boundary to the new surface you created. (Select the surface and find the Add Data button.

Sample the new surface in the sections and remove the EG you are using.

[#3]

That is exactly the work around I was looking for. Thanks!