XREF? Whose ref?

March 11, 2007 8:29 PM

CAD Filter: Can someone explain to me why all the layers in my file seem to be in a layer called xref?

I use progeCAD 2006 and autocad LT 98. However I am absolutely unschooled in how to use a CAD program. What I usually do is select the layers that I don't want and freeze them, and then I delete those layers. So then I save the layers that I want as a dxf and import into my mapping program.


So the problem is that this cad file that was given to me to work with seems that all the layers are attached (I don't know if that's what it's called) to a layer called xref. I know that xref has to do with some external reference to a drawing, but the layers that I want are in the file that I am working with (There is only one file - a dwg, from the other person in the folder) .

So for example:

This is an example of the layers:


0
1
Outerline 1
Outerline 2
Outerline 3
Outerline 4
Outerline 5
Outerline 6
Outerline 7
Outerline 8
Outerline 9
Outerline 10
Outerline 11
Outerline 12
Outerline 13
Outerline 14
Innerline 1
Innerline 2
Innerline 3
Innerline 4
Innerline 5
Innerline 6
Innerline 7
Innerline 8
Innerline 9
Innerline 10
Innerline 11
Innerline 12
Innerline 13
Innerline 14
xref


So I try to select layer Innerline 10 with a mouse and it selects everthing and it shows that layer xref is selected.

I can turn Innerline 10 on and off, freeze it, delete it, etc, etc. in the layer explorer, I just can't select it in the "model" view.

Normally this wouldn't be a problem, but I dealing with over 200 layers and I don't know which layer I am trying to select is called.

Please make my pain go away.

On a related note, is there a book that one would recommend to learn progeCAD, because I am not paying a few grand for AutoCAD.

posted by bigmusic to Computers & Internet (4 answers total)

Best answer: Well it looks as if what I am working with is blocks. So that is the external reference that I didn't understand. (Something that is external is embedded. - that makes all sorts of sense.) Before tonight I didn't even know what blocks were. So what I needed to do was explode the blocks. Which under progeCAD LT 2006 is under Modify | Explode. Select what you want in it's orginal components and then press explode.
posted by bigmusic at 9:00 PM on March 11, 2007

In autocad, "blocks" are things which are grouped together, and the definition of that group is held within the file that contains the block. Xrefs are external references - the definition of what's in an xref is held externally. The advantage of this is (besides smaller file size) the architect can change the backgrounds - walls, etc - of a building in the backgrounds, send it out to everyone else on the project, and then their drawings (for me, plumbing) can now refer to the updated wall layout.

What you need is to "bind" your xrefs (look it up in help, I use LT and the commands are probalby in different places) to the drawing, which makes them into blocks. Then explode, yes that's the phrase, the newly made blocks. Then you can turn off whatever you damn well please.
posted by notsnot at 3:28 AM on March 12, 2007

It sounds like you are working with an XREF that is already BINDed but which needs to be EXPLODEd. Alternatively use LIST to determine the layer a particular element is on, even if it is in a BLOCK or an XREF. I believe that when an XREF is BINDed then it appends the "xref" tag to the layer name.

An XREF is actually an external DWG file whereas a BLOCK is an external file that has been brought into the drawing. I don't know anything about progeCAD, only about Microstation and Autocad.
posted by JJ86 at 5:51 AM on March 12, 2007

An XREF is a REFerence to an eXternal file, which can contain layers in itself. When you try to select 1 object (or 1 layer) it selects the whole XREF. You need to explode it to be able to work with individual layers / objects.
posted by signal at 7:19 AM on March 12, 2007