Expert Training

All about DWF

The AutoCAD DWG format works well for storing drawing information on local and network disks, but the high precision and large number of object properties that AutoCAD uses make for comparatively large files.

To overcome this size problem and encourage people to publish drawings on the Web, Autodesk developed an alternative lightweight vector format for representing AutoCAD drawings: DWF (Drawing Web Format). A DWF file is a more compact representation of a DWG file. DWF uses less space — and less transfer time over the Web and e-mail — because it’s less precise and doesn’t have all the information that’s in the DWG file.

The other intended use of DWF files is that people who don’t have AutoCAD can view and plot them. All you need is the free Autodesk Express Viewer program, which is available on Autodesk’s Web site, www.autodesk.com. (In fact, Autodesk Express Viewer can view and plot ordinary AutoCAD DWG files as well, but DWF files are smaller and thus may work better for recipients who don’t need your full DWG files.)

ePlot, not replot

DWF files and Autodesk Express Viewer aren’t just for the Web. Beginning with AutoCAD 2000, Autodesk has pushed DWF as an electronic plotting or ePlotting format. A DWF file captures a single, plotted view of your drawing, so, unlike a DWG file, it can provide a relatively unambiguous snapshot of what you want to see on paper. With a DWG file, on the other hand, you have to provide lots of information to other people — drawing view, scale, plot style settings, and so on — in order for them to get the same plotting results that you did.

Potential ePlotting scenarios include

• Architects and other consultants on a building project periodically upload DWF files to the project Web site. CAD drafters from the various companies can save the DWF files as DWG in order to extract (approximate) geometrical information. Architects and engineers with some minimal CAD knowledge can review the drawings on-screen and create their own hard-copy plots, if necessary. Principals and clients who don’t want anything to do with CAD, or even with computers, can have their secretaries or other employees create hard-copy plots for them to examine.

• When Internet-savvy people need hard-copy prints of your drawings, you e-mail a zipped file containing DWF files, along with the URL for Autodesk Express Viewer and simple instructions for creating plots from the DWF files. (Be ready to walk them through the process by phone the first time or two to reduce anxiety on everyone’s part.)

• A CAD plotting service bureau encourages its customers to send DWF files instead of DWG files for plotting. The DWF files are much smaller and require less intervention on the part of the service bureau’s employees.

Warning The ePlot concept debuted in AutoCAD 2000 and hasn’t yet caught on in a big way. Autodesk hopes to establish ePlot and the DWF format as a standard for CAD documents similar to Adobe’s PDF (Portable Document Format) for word processing documents. It remains to be seen whether ePlotting will become a popular way to generate hard-copy output. In particular, many people outside of CAD-using companies don’t have access to large-format plotters. They’re limited to 81⁄2-x-11-inch — or, at best, 11-x-17-inch — reduced-size check plots. Consequently, many people won’t be able to plot your DWF files to scale, and may not even be able to plot them large enough to read everything.

Don’t be afraid to try ePlotting with colleagues inside or outside your company, but don’t become too dependent on it until you see whether the rest of the CAD world shares your enthusiasm. Otherwise, you risk becoming the only one who’s willing to use your DWF files for plotting — in which case the next version of the feature will be called mePlot.

New for 2004 With AutoCAD 2004, Autodesk has introduced version 6 of the DWF format. (The DWF format changes at least as often as the DWG format, as Autodesk adds new features to AutoCAD and new Drawing Web Format capabilities.) The most important new feature in DWF 6 is multiple sheets in a single DWF file, as shown in Figure 15-3. It’s like stapling together a set of drawings, except that you never have to worry about your stapler being empty of staples. This enhancement required an upgrade to the Autodesk Express Viewer. Make sure that you and your recipients are using an up-to-date version. See the “Autodesk Express Viewer” section later in this chapter for details.

Making DWFs with ePlot

As I describe in the previous section, AutoCAD 2004 treats DWF files like electronic plots, or ePlots. You create a DWF file from the current drawing just as if you were plotting it to a piece of paper, as I describe in Chapter 12. The only difference is that, on the Plot dialog box’s Plot Device tab, you choose the plotter configuration named DWF6 ePlot.pc3, as shown in Figure 15-4. When you do so, AutoCAD automatically turns on the Plot To File setting, and you can specify a filename and location for the DWF file that gets created. The location can be a folder on a hard disk or a Web server.

Tip Pay particular attention to the Scale setting on the Plot Settings tab. If you’re creating a DWF simply for viewing in a browser, you can plot Scaled To Fit. If you want to enable others to ePlot your DWF file to scale, as described earlier in this chapter, you need to choose the desired plot scale factor. Chapter 12 describes how to choose an appropriate plot scale factor.

Making DWFs (or Plots) with PUBLISH

The ePlot method of creating DWF files described in the previous section works fine for single drawings. But if you want to create DWF files for a lot of drawings or plot a bunch of drawings the good ol’ fashioned way (on paper, that is), you can use the Publish Drawing Sheets dialog box, shown in Figure 15-5, to speed the process.

New for 2004 The Publish Drawing Sheets dialog box is new in AutoCAD 2004. It replaces the Batch Plot utility in previous versions of AutoCAD, but now it’s wired specifically to support DWF as well as regular (paper) plotting. For now, more people are likely to use it for paper plotting or for creating plot files to send to a plotting service bureau. But if you do decide to go into large-scale DWF publishing, including multi-sheet DWF files, use the Publish Drawing Sheets dialog box, as in the following steps.

1. Using the PUBLISH command (FileðPublish), open the Publish Drawing Sheets dialog box (refer to Figure 15-5).

   The dialog box lists all tabs (Model and paper space layouts) of the current drawing for plotting, but you can remove tabs from the list and add other drawings to it.

2. After you’ve specified the drawings and tabs that you want to include, specify whether you want to plot to a multi-sheet DWF file or an actual plotter or plot file.

   You can select a specific plotter configuration for each sheet by choosing a Page Setup in the List of drawing sheets. See Chapter 12 for more information about page setups.

3. When you’ve specified the drawing and plot settings, click the Publish button to start the process.

4. Click the Save List button to save the current drawings and settings list, if you anticipate having to publish the same group of drawings again.

   Use the dialog box’s Help button to find out more about any of these steps.

Warning Don’t confuse the PUBLISH command (FileðPublish) with the PUBLISHTOWEB command (FileðPublish to Web). The PUBLISH command, a new AutoCAD 2004 utility, creates sets of DWF files, plot files, or actual plots. The PUBLISHTOWEB Wizard creates a Web page containing images of your drawings. The results of this Wizard won’t put any Web designers or programmers out of work, but you can use it to create primitive Web page paste-ups of your drawings. See “PUBLISHTOWEB command” in the AutoCAD online help system if you’d like to give it a whirl.

Hand-y objects

No Web file format would be complete without hyperlinks, and DWF has those, too. You can attach a hyperlink to any drawing object in AutoCAD, not just to a text string. As you pass the cursor over an object with a hyperlink, the cursor changes from the ordinary pointer to a globe and two links of a chain (as in “World Wide Web” and “link,” not “world-wide chain gang”). Right-click the object and select the Hyperlink option from the menu, which opens your browser and navigates to the URL that’s attached to the object. If you create a DWF file that includes objects with hyperlinks, Autodesk Express Viewer embeds the links in the DWF file so that you can Ctrl+click to navi-gate to them.

Hyperlinks on objects are a clever trick, but they’re of limited practical value in most DWG and DWF files:

• The drawing images are so small that it’s difficult to distinguish the hyperlink on one object from the hyperlink on another object.

• Most people aren’t used to associating hyperlinks with individual lines and other objects. The interface is likely to leave them perplexed.

If you’d like to experiment with hyperlinks in objects, look up “HYPERLINK command, about” in the online help system.

Autodesk Express Viewer

After you create DWF files, whether with ePlot or PUBLISH, you or the recipient of your DWF files can use Autodesk Express Viewer (formerly called Volo View Express) to view and print them. Autodesk Express Viewer, shown in Figure 15-3 earlier in this chapter, is a free viewer from Autodesk. You can download the current version from Autodesk’s Web page, www.autodesk.com (click on Product and Solutions and then Autodesk Express Viewer).

New for 2004 When you install AutoCAD 2004, the setup program by default installs Autodesk Express Viewer as well. Choose StartðProgramsðAutodeskðAutodesk Express Viewer, or simply double-click on a DWF file in Windows Explorer, to launch it.