Topic: Learn XRefs??

[Dinosaur]

Xrefs are a great tool - even better when you have access to the Express Tools functions that allow easy ID and manipulation of the xref layers by pick.  Perhaps this would be a good time to ask for the upgrade.  I also think I remember you having an office policy of using only layer "0" - that may have to change, at least to the point of making a new layer to place the xref on in the drawing in order to control visibility and properties of the xref layers.
You will have to learn how to use visretain to get the results you want.  When you load the xref into your drawing the first time, all of the layer settings will transfer exactly into your drawing (including on-off & freeze-thaw).  If you want for some reason for these layers to appear differently from the original xref you can make the changes you want and preserve those settings by setting the visretain variable to "1".  Thereafter, no matter what has been changed to the layers in the original, the changes made in your drawing will remain intact UNLESS you change the variable to "0".  If you do that, the next time the xref is reloaded or the drawing is opened, all of the layers will import like the first time the xref was loaded.  With either setting, if there is a new layer in the xref, that layer will come in exactly the same as in the xref when it is loaded the first time.

[PHX cadie]

Yes Krushert + Dino have very good points. (I humbly bow before the Jedi Masters)
Xref+ layer 0=bad juju, no changes allowed to xref'd layers!
The past 2 employers insist on overlayed xrefs to avoid circular reference problems. I remember my book exercise on Xrefs. Dwg 1 had a triangle, dwg 2 had a circle in the same area as dwg1's triangle. Now xref #1 into #2 as an attachment and close. With a new dwg 3 if you attach xref #2, both dwg 1 and 2 will show, if you overlay #2 into #3 only #2 will show. I may not be able to explain circular references well, but if you have 2 xrefs that have the same xrefs attached in them and those 2 files are attached to another it creates a circular reference and 9 times out of 10 in my case a plastic mouse pieces smashed against the wall and 3 or 4 cigarettes gone.
As Dino mentioned "visretain". If your changes to a Xref layer don't save the next time you open the file that uses the xref check visretain. If I may suggest, in the beginning check that setting frequently, it seems in CA we had a lisp or something that  would change the visretain setting and I would lose some changes, very frustrating when I didn't know why!
Sorry I didn't think of mentioning only model space entities come in, so xred'd title blocks need to be in model, then xref'd into your sheet in paper
Do you use paper space? A couple of years ago with Rebar CAD we did everything in model, so not everyone uses PS.

Hope to C-Ya tomorrow.

[craigr]

Well, I've made a couple of X-Refs & I think they are going to work fine for us. - Though the 'Nested XRef' sounds like something I don't want to start. I believe I am going to mandate that we NEVER use them. They sound too scary for a bunch of people that do not have much experience with XRefs.

Thanks for all of the suggestions,

craigr

[hudster]

If you want to avoid any problems with nested xrefs, always attach your xrefs as overlays rather than attachments.

[Bryco]

The temptation to refedit the xref in place is high. However you can start getting some pretty funky layer and block names pretty quick, craigr. So doyourselfafavor and teach everyone to use xopen, which will allow the user to select the xref and it will open.

[Dinosaur]

One addition to my comments above regarding visretain . . . if there are any drawing elements in the xref file that have color or linetype properties set by entity rather than bylayer, those elements can NOT have their properties affected by layer or visretain settings in your new drawing.  They will have to be modified within the xref drawing.

[Krushert]

INHO; Autodesk (or someone smarter than me in programming <hint hint>) ought to expand the visretain variable setting.  The On or Off switch is cumbersome and the real world doesn’t always fit into it yes or no configuration.  There is times that I had to detached an Xref Base from the host drawing and reattached it, reset all the layer view settings just because the freakin Architect wanted a different line type (deviating from the standard) that resided in the base dwg.

For example, I could have a variable setting in the host drawing that controls the layers freeze-thaw and/or on-off status but any line type changes in the base would update in the host drawing. 

Just me whining over here.   

[CADaver]

There is times that I had to detached an Xref Base from the host drawing and reattached it, reset all the layer view settings just because the freakin Architect wanted a different line type (deviating from the standard) that resided in the base dwg.

ummm... detaching and reattaching was unnecessary.  Just pick that xref'd layer in the layer manager and change it's linetype.  If you REALLY need the file to reflect the source file's layer display, turn off visretain, reload the xref in the xref manager, then reset visretain. 

There's a lisp routine around here that does that without fiddling with th e Freeze/Thaw status of the layers in viewports.

[craigr]

Uh Oh.....

All of these various XRef settings & such are starting to get me afraid of them

Hopefully we will only need the simple stuff.

craigr

[Bob Wahr]

There's no more reason to fear xrefs than there is to fear any other block.  Do you use dimensions?  There are a lot more settings for dimensions than there are for xrefs and unlike dimensions, xrefs pretty much always do what you expect them to.

[PHX cadie]

Randy's post has me thinking of an question I've had before:

Often I'll xref a file for reference and force a color/LT as a reminder to unload before closing or printing. I can't think of the reason now, but there have been times I would like to get the default color or LT back to original settings of the xref. Will Randy's procedure of on/off the visretain do that w/o detaching then re attaching the xref?

[Bob Wahr]

yes.

[Krushert]

Just pick that xref'd layer in the layer manager and change its linetype. 

  Easy way out.  Again defeats the purpose of Xrefs if you change something in more than one spot.

If you REALLY need the file to reflect the source file's layer display, turn off visretain, reload the xref in the xref manager, and then reset visretain. 

  Ah thanks for this tid bit.  Just goes to show that you learn something everyday.  However when we are controlling a lot of xref layers on-off/freeze-thaw status with the host drawing.  Still doesn’t get around that.

There's a lisp routine around here that does that without fiddling with the Freeze/Thaw status of the layers in viewports.

  It looks like I will have to go fishing trip.

[Krushert]

yes.

yes it will, just tested it.  But you will have to reset all your layer viewport settings that are associated with the xref.

[Dinosaur]

There's no more reason to fear xrefs than there is to fear any other block.  Do you use dimensions?  There are a lot more settings for dimensions than there are for xrefs and unlike dimensions, xrefs pretty much always do what you expect them to.

Exactly, Bob . . . xrefs are quite easy to deal with once you become familiar with them.  I have a few rules I follow that keeps me out of trouble with them.
I make a new layer for each xref I attach.  This allows for complete visibility control in any viewport without affecting any others - freeze that layer in that viewport and the xref won't show or plot there but still may be visible in others.
Unless I am doing something quite complex with an xref, I use the overlay option when I attach it.  This eliminates any unnecessary nested xref confusion.
I always keep my visretain set to "1" to maintain the changes I make to the layering.  If I run into a problem like Krushert described, I will just "borrow" the new linetype by copying an object using it from the xref into my drawing.  The the linetype can be easily established for that layer.  There is no rule that the linetypes for an xreffed element have to use one from the xref.
There is also no rule that the xref name has to match the drawing name being referenced.  If you suddenly receive an new plan to replace the old xref, you can just use attach the new file under the old xref name.  Any scaling, rotation and layer changes you made to the old reference will then be maintained with the new file.