LT Unlimited

Xref Change Notification

When you’re working with a team on a project using xrefs, it can be really handy to know when somebody makes a change to a file that your current drawing references.

Fortunately, a relatively new feature in AutoCAD LT makes it quite obvious that a referenced file may need to be reloaded. (Sorry to say, I don’t remember exactly when this came in. Anybody? Although I’m pretty sure it was in AutoCAD before it was in LT, so they may be two different answers.)

The notification bubble even provides a link that you can use to reload the affected file without going through the Reference Manager. You can turn these notifications off with the system variable XREFNOTIFY, but personally, even when I’m the one who made the change, I like to use the bubble to reload the drawing. It feels like the fastest way to get to the file, and it helps me remember to actually reload it.

Two Xref Macros

Today’s tip comes to you courtesy of Cadalyst Magazine’s “Tips & Tools Weekly” newsletter. Sign up for your own copy or browse the archives here. Admittedly a lot of the tips are LISP-based, but there are plenty that aren’t, or are like this one and can be adapted.

CAD Designer Sam Lucido writes:

"I often find myself working in a drawing with one or two very large external references attached. Sometimes I just want to unload (not detach) those files to focus on the area I am working in. These macros will do just that— un them and AutoCAD will load or unload all references within the file. This clears up the area and saves on regen time as well!

• This macro will unload all references: ^C^C-XREF;U;*
• This macro will load all references: ^C^C-XREF;R;*

You can put these on a toolbar, ribbon panel, tool palette, or in a menu—wherever they might make your day easier. Enjoy!

Copy Named Objects from Xrefs

AutoCAD LT 2012 introduced the NCOPY command, which lets you bring objects from referenced files into the host drawing.

But what if you just want to grab a dimension style (not a dimension object) from an xref? Try a much older command: XBIND!

XBIND (which is not the same as BIND) is most easily available at the command line. It lets you import named objects—layers, dimensions styles, text styles, blocks, linetypes—from a referenced DWG into the current file.

Bound items bring in their drawing prefix; the layer imported above would become “MapBuildings$0$_EDIFICIOS”. If you want to get rid of that, you can always use the RENAME command.

Easier Underlay Selection

I’ve posted before about the frame options for underlays, but in case you’ve forgotten, here they are again:

• FRAME=0: Frames are not displayed
• FRAME=1: Frames display and plot
• FRAME=2: Frames display but do not plot

Before now, having the frame visible in the drawing (whether or not it plots) was the only way to select an underlay. But now, the new FRAMESELECTION variable gives you even more options.

When FRAMESELECTION is on (set to 1), as it is by default, and FRAME is set to 0, simply passing your cursor over where the border would be (if it were visible) is enough to highlight the underlay and let you select it. If your underlay is a PDF or DWF, with internal geometry, passing your cursor over that also highlights the reference.

For example, this circular structure (it’s actually a parking garage—trust me) is a PDF underlay in the drawing.

When I move the cursor over it—either where the frame would be or over the geometry itself—the underlay is highlighted.

  

I can then select it and use its contextual ribbon tab, the Properties palette, grips, or regular commands to modify it as necessary.

I’ve used the word “underlay” in this post because it’s PDF, DWF, DGN, and image files that always have frames, but clipped DWG files have frames too, and everything in this post applies to them as well.

System Variable for Xref Highlighting

You’re probably aware by now of the new external reference highlighting in AutoCAD LT 2011. (At least, if you’ve been reading the blog for a while, you are.)

But apparently some of you might want to turn it off. Why? Well, if you have a large or complex drawing, the highlighting might slow you down a bit. It’s related to why you might want to turn off preview highlighting for xrefs.

Fortunately, as Without a Net pointed out today, there’s a variable for that.

Set ERHIGHLIGHT to 0 turns off the highlighting of selected xrefs; to turn it back on, set it back to 1.

External Reference Highlighting

If you work with drawings that have lots of external references in them, chances are you’ve spent a good deal of time trying to figure out which name in the Reference Manager matches a particular reference in the drawing.

A new feature in AutoCAD LT 2011 aims to help with that. When you select a reference file in your drawing, the corresponding name in the Reference Manager is highlighted. And when you select a item in the Reference Manager, the corresponding reference is highlighted (but not selected – you have to do that yourself).

I admit the highlighting is a little subtle, which is why I’m not even going to try to show it full-size in the blog. Instead, I’ll let you click on the image to see the detail.

Control Layer Visibility in Underlays

When you create a PDF or DWF from a DWG file, you have the option of including layer information. If you do, then you can turn individual layers on and off in your PDF or DWF viewer.

But did you know that you can also turn on and off layers when you use that PDF or DWF file as an underlay in another drawing? The underlay contextual ribbon tabs put that option right in front of you when you select a PDF or DWF underlay:

Even if you don't have a reference selected, you can find the Underlay Layers option on the Reference panel of the Insert tab.

However you get there, once you open the Edit Layers dialog, there are a few things you can do. You can turn layers on or off (although you can't change any other properties), you can search for particular layer names, and you can switch to a different underlay to control its layers instead. Like many other dialogs, SHIFT and CTRL work to select multiple layers or ranges of layers.

Control Reference Frame (aka Border) Visibility

When you bring an underlay into an AutoCAD -- an image, DWF, DGN, or PDF -- it comes with a frame or border around it. (Clipped references, DWG or otherwise, have frames too.) You have three choices for this frame's visibility and plotting:

• 0 -- Off. You can't see the frame, so it won't plot, but you can't select the underlay or modify it either.
• 1 -- On. The frame plots, and you can use it to select the underlay, resize it, move it, etc.
• 2 -- On, but non-plotting. The best of both worlds. You can see the frame, and use it to select and modify the underlay, but it won't plot.

Each reference/underlay type has its own frame variable.

• IMAGEFRAME (Default: 1)
• DWFFRAME (Default: 2)
• DGNFRAME (Default: 0)
• PDFFRAME (Default: 1)
• XCLIPFRAME (Default: 2)

But you can also globally control the frame visibility/plotting with the FRAME system variable. FRAME can be set to 0, 1, 2 or 3. 0, 1, and 2 correspond to the regular off/on/non-plotting states, and 3 means that the individual frame variables control instead of the global setting. (FRAME is set to 3 by default.)

Fade Objects: Xrefs

The last object type that can be faded in AutoCAD LT (after locked layers and underlays) is a DWG external reference. Unlike the other two kinds, this one is new to the 2010 release.

You can find the fade setting for xrefs on the expanded portion of the Reference panel on the Insert tab, in the Options dialog on the Display tab, or at the command line as XDWGFADECTL.

 

The default value is 70, the minimum is 0, and the maximum is 90. (Again, this keeps you from inadvertantly making an xref invisible.)

The icon at the left side of the slider bar enables you to quickly fading on and off without changing the fade value.

This setting is applied to every xref in the drawing -- you can't have different xrefs faded differently.

For more on external references, don't forget to sign up for the External References webcast next Tuesday!

Fade Objects: Underlays

Next up in the Fade series is fading an underlay. All sorts of underlays can be faded -- DWF, DGN, PDF, and images. You can fade whatever underlay types your version supports (DWF in LT 2007, DWF and DGN in LT 2008, etc.).

In AutoCAD LT 2010, you can set fading with the Adjust command on the Reference Panel of the Insert tab. In other releases, you can use the ###ADJUST commands (like DWFADJUST) or the Properties palette.

Valid values for fading underlays are from 0 to 100.

(Note: Fading is not the same thing as transparency. A faded underlay will still obscure objects behind it.)