Recover Corrupted DWG with Data objects

Occassionally, a sheet file will get corrupted for many different reasons. AND, trying to resolve those reasons may never happen. So, in the end, it is just simpler to start from scratch.  Before Civil 3D, the slickest trick for doing this was doing a Map query of the bad DWG into a clean new DWG.  But with Civil 3d, we have more than just lines and text.  Stay tuned for a process that may just help you keep what’s left of your hair.

Before we lay out the recovery process, lets think a bit about what we’re trying to do; recreate our existing drawing within a new “clean” template. I say it like that only to shed light on the issue that the corruption may come from the template.  Try this process first with the OOTB template shipped with C3D.

Alright, when we examine our &^%&%* DWG, we have XRefs, Data Refs, maybe some C3D labels, some annotative text, linework and maybe a layout or 2. How did we build the contents of this file? Let’s see, it might look something like this:

• Load XREFs
• Create DREFs
• Draw/import linework
• Create C3D objects
• Label as needed (either annotative or civil 3d labels)
• [Optional] Layout for presentation

In order to rebuild this process, we essentially need to flip the order to export the information. That might look like this:

• Wblock layouts (to temp location, typically DESKTOP)
• LandXML out any C3D objects
• Wblock model space linework and labels
• Note Data References
• Note XREFs

And now, we start the painful process of recreation….

• Create a new DWG from template
• Attach XREFs (note, “Wblock”ing XREFs might work faster for you, it’s all what your comfortable with)
• Create DREFs
• LandXML import
• Insert model space linework / labels
• [Optional] Create blank layouts as needed in Insert Layout blocks

That’s it!  I should mention that the subscription support helped with this endeavor.  Oh yeah, the original issue – contour labels wouldn’t update when a DREF surface would change. Our changes were typically subtle and the overall slope of the site was minimal. The effect was that contour lines would shift greatly from version to version.  And sometimes, contour lines at one elevation would be in the vicinity of previous contours. Except the labels wouldn’t update the elevation…. Was a very weird thing indeed.  Moving on…