LT Unlimited

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.)

In-Place Reference Editing

Today it's time for my follow-up post on reference editing. It's new to LT 2010, along with Clip and Open Reference.

In-Place Editing of external DWG references means that you don't have to open an xref in a separate instance in order to modify it. This is helpful when the changes you need to make depend on geometry in the host drawing.

You can find In-Place Editing in several places in LT 2010:

• At the command line (REFEDIT)
• On the expanded portion of the Reference panel of the Insert tab
• On the External Reference contextual ribbon tab (after the reference is selected)
• In the right-click menu (after the reference is selected)

When you start it, you get a dialog asking what, exactly, you want to edit.

The top level in the tree represents the whole drawing, while each item in the list below is an individual block definition. You'll likely want to choose the whole drawing, since the Block Editor is usually better for editing blocks. (Obviously there are exceptions, though!)

Those block definitions are considered "nested objects" -- you can either include them in your editing session automatically, or choose them individually. It's basically the same as choosing the whole drawing or selecting items in the list above.

Once you press OK, you're in the Reference Editing environment, helpfully identified with a contextual ribbon panel.

While you're here, you can do anything you would in an ordinary drawing: create, modify, or delete content as much as you like.

The two tools at the end of the tab, though, are unique to In-Place editing.

"Add to Working Set" is used to transfer content from the host drawing to the referenced file. "Remove from Working Set" goes the other way, transferring objects from the referenced file to the host drawing. Use these with caution, or you'll have objects end up in unexpected places.

When you're done editing, you can either save your changes or discard them. Either way, you're prompted to confirm your choice.

Choosing Cancel puts you back in to the Reference Editing environment.

When you save your changes, the original file is actually modified. All files referencing the changed file will show the updates next time they're opened. Chances are this is what you wanted anyway, but it is good to keep in mind.

New-to-LT External Reference Tools

A couple weeks ago I told you about the improved reference clipping in LT 2010, but that's not the only new external reference feature.

In-place editing (REFEDIT) is now supported, along with the ability to open a referenced file (XOPEN).

Watch out for Open Reference, though -- except for DWG references (as in the above image), the only place to find it is in the External References palette.

Stay tuned for more on In-place Editing in a future post...

Reload all References

In AutoCAD LT, the easiest way to reload a referenced file (to see the results of changes made to that file) is through the External References Palette.

You can either right-click on each reference to reload...

...or you can reload them all at once with the middle icon at the top of the palette.

Watch out for the "Refresh" option -- it's not the same as Reload. (As best I can tell, Refresh and Reload are similar to Redraw and Regen...close but not quite the same.) But once you've selected Reload all, the icon changes and becomes the default for the next time.

<edit> No sooner did I finish this than I found an old post that reminded me there's another way to reload drawing files: at the status bar. Right-click on the xref icon (marked below with a red arrow) and choose "Reload DWG xrefs." This one won't catch other types of references, but it's stll there.

Clip External References

This seems to be the week to revisit old posts. Back in November, I told you about how you could clip various types of referenced files, including DWF, and DGN, and images.

It's time to come back to that, because in LT 2010, that ability has been expanded to include DWG and PDF files.

The Clip function, on the Reference panel of the Insert tab, enables you to clip any referenced file -- DWG, DWF, PDF, DGN, or image -- to a boundary of any shape. You can even invert the clip, to hide the part of the reference that's inside the clipping boundary intstead of the part that's outside.
For the command line fans, type CLIP to launch this, not XCLIP -- XCLIP will work, but only on DWG files. CLIP works on any kind of reference.

Save Changes to Xref Layer Properties

If you use xrefs in your daily drafting work, you've probably seen the following situation at least once:

1. Start a new drawing.
2. Attach a DWG file as an external reference.
3. Make lots of changes to the xref's layers, setting color and linetype to emphasize the areas you need.
4. Do some work on top of the xref.
5. Save.
6. Close.
7. Re-open the drawing later.
8. Realize that all the layers you changed in the xref have reverted to their original state.
9. Sigh.
10. Put all the layers back.

Familiar, yes? I know it's happened to me more times than I can count. Fortunately, there's an easy way to keep all your changes without having to redo them every time or use some other workaround.

Like so many other settings, this one's in the Options dialog. On the Open and Save tab, there's an area for External References. Look for the checkbox labeled "Retain changes to xref layers." When this is checked, any layer property changes you make will be remembered for future sessions. If you want the layers to always keep their original properties, uncheck the box.

The DWG icon next to the checkbox indicates that this option is saved per drawing, not per computer. In recent versions at least, the box is checked by default, but you can always set it to your preferred option in your template file. Then you'll always know what to expect.

(And for all you command line fans, this variable is known as VISRETAIN. Set it to 1 to remember layer settings, and to 0 to forget them.)

Edit Xref Path

In LT 2009, it's not necessarily obvious to how to change the saved path of an external reference. As you see in the screenshot below, the "Saved Path" field is grayed out -- you can't type in that field.

What you can do, though, is change the "Found At" path. When you save that path, it becomes the new Saved Path.

But wait, you say -- there's no "save" button. Nope, but that's not a problem. All you have to do is press Enter after you finish editing the "found" path, and it saves it for you.