Data clip boundary and data shortcut surface

[Kundertk]

Don't data clip boundaries work on surfaces that have been referenced into the drawing via data shortcuts?  I'm trying to reduce the size of a relatively large master surface during the preliminary design stages of a project where my alignment may change, so I'd rather not clip the source drawing. 

What I did was create a closed polyline boundary around the current area of interest, create a new surface and set a data clip boundary.  I brought in the master surface via data shortcut.  Then I pasted the master surface into this new surface.  However, viewing the triangles shows that the entire surface area is being added to my new surface.  I can add a normal outer boundary and it reduces the area accordingly, but the file size and resultant slow speed in working with the surface remains.

Civil 3D 2011, although I think I tried this in 2009 before and also had the same trouble.  Perhaps it's just operator error or maybe my expectations are too high, but I really expected the file size for the new surface to be in the general order of 1/10 of what it is because the area is about 1/10 of the original area. 

[ericcollins6932 · Accepted solution]

You could always create a new cropped surface into a new dwg, and keep the original for reference.

Then data shortcut the new dwg with the cropppedd surface, and you will be faster and smaller...

[mathewkol]

Eric's cropped surface suggestion should be the best method.  They are actually linked!  If you edit the original, the cropped surface will update (but only if you remove the snapshot).

[Kundertk]

Haha, I could not figure out what you were talking about with this cropped surface so I put that term into the help file search and discovered a function I have not used yet.  AeccCreateCropSurface.  Well, who'd have thought this would be so easy.  I had no idea that this command existed. 

Not that I want to see an annoying Mr. Clippy like MS Office releases of the past, but it might have been actually useful in this one instance, to have something point out, "hey nimrod, you're doing it the old, slow way".  

Just tried it out and my new surface is 15% of the size of the full version.  The speed is now a lot more manageable. Thanks.

[ericcollins6932]

On the home tab, create ground data panel, if you click on the surfaces dropdown, create cropped surface is the final item (at least in C3D 2011). Glad it worked out.

[rsanchez]

I know this is an old discussion but, it is easier by adding a mask to the data referenced surface, I am using ver 2012