Xref Confusion: Attachment or Overlay?

[Mamma Jamma]

yeah, good organization...

Unfortunately, the organization/standards we DO have get ignored by some (who I don't have the power to fire or beat). Can't really say by "rogue" operators since that implies actual thought and intent, which might be an improvement...

[r.grandmaison]

[COLOR=Navy]
There IS a valid use for the Overlay option. If you need to reference a drawing, but not have it show on other drawings down the line, that is the time to use Overlay. This could simplify the whole Unload/Reload business that seems to be happening on some of our drawings.

Once an Xref source file has been attached, the attachment option (attachment/overlay) can be changed by double clicking it (attach/overlay) in the Xref Manager.

A really good example of when to use Overlay is if you're getting files from a client and you want to OVERLAY their file atop yours for making adjustments to your drawing, or comparing changes, etc.- but don't actually use their drawing (they never know how to draw very well or ever practice good layering!) Well, by OVERLAYing their file into your file, you're free to ATTACH your file into any of your plotting sheets withoug bringing their messy work into your pretty work!

Cheers,

Robert

[Hammer.John.J]

being in civil/la we never attach because our drawings all reference each other so we could never do them as attachments

i should say there are times we get supplement survey or some utilities and we do ATTACH that file to our survey.

[sschramm]

This very topic has arisen in my company where we have a monthly CAD Standards meeting. Unfortunately, I missed an unofficial impromptu meeting where it was decided that from now on, we ONLY use the OVERLAY selection when attaching xrefs. I have thoroughly researched the differences between ATTACH and OVERLAY and know when to use what. However, there is a mountain of anecdotal evidence by my coworkers that things "just go bad" when you attach. I hear horror stories of frozen base files, destroyed completely, base files with multiple entities (I think the culprit here was REF EDIT), and a great fear of circular references, though it does warn you now if you have a circular reference. Personally, I've always ATTACH-ed (except when I choose to overlay) and have had no problems.

We are a firm that works with other firms that vary in a full spectrum of experience. In many cases, we get drawings that are scaled, rotated, and moved in all sorts of ways. I prefer to ATTACH and make the adjustments once, in one drawing. In addition, these drawings are changing as we design and we get updates frequently, naming the new drawings the same to avoid having to repath. The alternate solution is to put what you did on defpoints in the base drawing ("move a,b,c to x,y,z, rotate xxdegrees, scale xxx"). Ugh.

I think that education is the best answer, which is difficult in a rapidly-growing company, but my coworkers feel that an all-or-nothing approach is better. I've tried but the horror stories ensue. Any advice?

[Hammer.John.J]

suggestions...

you have 3 drawings A,B, & C, then D is added at the end of all the setup.

A is overlayed into B
A & B are overlayed into C
A & C are overlayed into B
B & C are overlayed into A (but do not print, no plot layers)

say D comes along and needs to be supplemental to A, and therefore B & C. this is a good time to "attach" D into A if you don't intend on inserting the raw data as drawing objects into A, and you only want to reference the supplemental info. All other instances should be "overlay".

[philpiper]

Our policy is to OVERLAY all raw data files and only to use ATTACH when compiling final drawing sheets that will be plotted. The logic is as a number of people have already suggested - it minimizes the problems of forming chains that reference themselves and data showing up on final drawing sheets that shouldn't be there because someone has ATTACHED a file somewhere back down the line.

[framedNlv]

A really good example of when to use Overlay is if you're getting files from a client and you want to OVERLAY their file atop yours for making adjustments to your drawing, or comparing changes, etc.- but don't actually use their drawing (they never know how to draw very well or ever practice good layering!) Well, by OVERLAYing their file into your file, you're free to ATTACH your file into any of your plotting sheets withoug bringing their messy work into your pretty work!

Cheers,

Robert

Wow!!! I hope these are not my files you are referring to. I do work for a consulting firm and am proud of our work (including our layering).

I (we) overlay all files that do not belong to us (period). I would suggest as mentioned above that you should overlay any file that is not yours.

Example that I run across often is receiving updated files that have our work attached with our nested xrefs unloaded. Now when I open MY file with MY xref it will be unloaded and will not stay loaded (after reopening) because of what someone did with a file they didn't create in the first place. I don't know if this still applies in 2008 version.

Chris

[framedNlv]

Our policy is to OVERLAY all raw data files and only to use ATTACH when compiling final drawing sheets that will be plotted. The logic is as a number of people have already suggested - it minimizes the problems of forming chains that reference themselves and data showing up on final drawing sheets that shouldn't be there because someone has ATTACHED a file somewhere back down the line.

That would work for us when we receive these type of files. We typically will overlay the Architectural sheet so our files will match and pick up any new xrefs.

Chris

[richardarchitect]

ok as the architect, i have been providing my consultants with dwg files via our ftp site. Our xrefs are all no path attached, which i feel gives our consultants the same ability we have to unload xrefs as they see fit to create their drawings and sheets. Each of our sheets is developed individually by xrefing in what is required on that sheet. Granted this method brings in many unecessary xrefs, but by creating each sheet as a seperate dwg, it gives us the ability to reload xrefs temporarily to look at other aspects of a particular design challenge. I guess I am wondering how this method impacts on the process from your end? Dang I can't edit this to add a quote, I was replying to Sue.

[richardarchitect]

Wow!!! I hope these are not my files you are referring to. I do work for a consulting firm and am proud of our work (including our laying).

I (we) overlay all files that do not belong to us (period). I would suggest as mentioned above that you should overlay any file that is not yours.

Example that I run across often is receiving updated files that have our work attached with our nested xrefs unloaded. Now when I open MY file with MY xref it will be unloaded and will not stay loaded (after reopening) because of what someone did with a file they didn't create in the first place. I don't know if this still applies in 2008 version.

Chris

Hey thx for the heads up Chris, that makes perfect sense. All consultants drawings will be overlays in the future at my firm