crop surface and a boundary

[eleonard]

What is the difference between a crop surface and a boundary?

I have a support tech telling me there really isn't a difference.

[gandocadguy]

What version?

[eleonard]

Civil 3D 2011, sorry I forgot to mention that.

[gandocadguy]

If you crop a larger surface in 2011 it will make a new smaller surface still linked to the old one.

If you add a boundry it disregards all the info outside of the boundry. They are close but not quite the same thing.

[sinc]

To clarify, if you put a boundary around a surface, all of the surface data outside the boundary is still there. A cropped surface contains only the data within the crop area.

So the cropped surfaces are designed to allow you to work with very large surfaces, without as much of an impact in performance. You can crop out only the area you need for a given task, and work with that smaller surface, rather than bogging your drawing down with the entire large surface. Yet you can still update or change your large surface, and propagate those changes to the cropped surfaces.

[eleonard]

So how do the snap shots know where the source surface is located? What happens if you have a source surface that was for one project and located in a completely different project you have your copped surface? What will happen to that cropped surface at the time of archiving to a disk, if that source surface is not a part of that archive?

[gandocadguy]

The crop is basically a data shortcut. It behaves the same way it would if you made a data shortcut of the larger surface. If you archive the file with the shortcut then it will be missing in the nonarchived files. Same as a xref or any other data reference.