AutoCAD

DWF Secrets Revealed! (Learning Curve AutoCAD Tutorial)

1 May, 2007 By: Bill Fane

The DWF file format and Design Review team up.


It was a dark and stormy evening. Rain was pouring down. It was only March 22, Captain LearnCurve's 64th birthday, and already Vancouver had broken the record for March rainfall.

"I'm sick of this terrible weather," moaned the Captain, "We need a tropical vacation."

"I agree," replied his gorgeous wife, "but it's less than four days since we got back from nine days in Puerto Vallarta!"

Well, it was worth a try. The really bad news is that this opening doesn't even give me a clean segue into this month's topic.

My last two columns covered attribute definitions and use. I was all set to roll with a followup column on attribute extraction only to realize at the last moment that Lynn Allen had done an excellent article on the topic about a year and a half ago. This was compounded by the fact that AutoCAD 2008 changes attribute extraction significantly, and for the better, so I decided to shelve that topic until more of you are using 2008.

Design Web Format
Perusing the index to the 181 Learning Curve columns that I've written so far, I realized that I've never discussed DWF files.

Let's start by clarifying a basic item, which is that DWF is pronounced exactly as it is spelled. You know, I have often wondered why "phonetic" is spelled that way . . .

DWF stands for Design Web Format, although when it was introduced many people referred to it as the Drawing Web Format. And, even though this article is titled "DWF Secrets Revealed!" you will soon come to realize that DWF secrets are about as complex as the recipe for ice cubes.

DWF was originally introduced to be a small, compact version of AutoCAD drawing (DWG) files to be posted on Web pages. Being smaller, they download faster and are easier to send via e-mail.

In effect, a DWF file is simply the electronic version of a paper plot. As such, it has all the advantages and disadvantages of a piece of paper.

Recipients can open them, pan and zoom, freeze and thaw layers, plot and mark up, but they can't edit any content and they can't save their changes other than their mark-ups. Like paper plots, they are a read-only format so you can supply full design information to the recipient, but they can't modify or copy any of the design content.

DWF functionality is built directly into AutoCAD. In fact, it's simply a Plot option, reinforcing our piece of paper analogy.

The best part of all this is that the recipient doesn't need to own a copy of AutoCAD to open and view DWF files. Autodesk has always supplied a free copy of its DWF Viewer software, but recently things have gotten even better.

Design Review
One of the uses for DWF files is that they support mark-ups. You can send a DWF file to people such as clients, customers or a checking department for approval. They can indicate any necessary or desired changes and then send the file back so you can make the revisions to the original DWG file. Previously Autodesk sold this mark-up software for a nominal price under the name DWF Composer, but recently it changed the name to Autodesk Design Review and is giving it away for free.

Before we go any further, download your copy. While you're waiting for it to download, I get to share pictures of my grandchildren.

figure
The grandchildren: Rebecca is 7, and Bryan and Brodie were 5 on Halloween night. Cleo does not march to a different drummer; she doesn't even have a drummer.

Welcome back. Now that you've downloaded and installed Design Review, let's start using it.

There are several ways to create a DWF file from within AutoCAD. Let's start with the quickest and easiest two. Actually they are exactly the same with two different ways of getting there.

Open the sample drawing C:\Program Files\AutoCAD ....\Sample\db_connect.dwg and activate the Model space tab. Start the Plot command, go to the Name window and select DWF6ePlot.pc3 from the drop list.

The other method is to start the DWFOut command, but all this does is to launch the Plot command with the DWF plotter preselected. You can select any other plot options such as the paper size, plotting the current display or the extents or named views, plotting to scale, plot stamping and so on. When you click OK, a standard Windows file dialog box appears where you can select a file location and enter a name. Call it db_samp-Model-Plot, and then click OK.

When the operation finishes, use Windows Explorer and double-click on the DWF file you just created. This launches the Design Review program you just installed, displaying your new DWF file.

figure
Design Review is used to display, manipulate, mark up and print DWF files.

A bit of experimenting will reveal that you can pan and zoom, plot and perform a number of other functions that we will come back to later.

Wait a minute! There are no layers available! You promised us that we could freeze and thaw layers!

You can, albeit under the right conditions. And those conditions depend on how you created the DWF. I used the Plot/DWFOut command to create this DWF, so it created a simplified version that doesn't include layer data.

Let's go back and repeat the process, but this time select File/Publish from the menu bar to start the Publish command, which brings up the Publish dialog box.

figure
The Publish command gives many options to apply when creating DWF files.

The first thing to notice is that it shows two sheets to publish: model space plus the one paper space layout. To be consistent with our earlier plot from model space, right-click on the second entry as shown and then select Remove from the context menu that appears. Make sure the DWF File radio button is active in the Publish To window.

Next, click on Publish Options to bring up the Publish options dialog box.

figure
Use the Publish Options dialog box to enable layer information in a DWF file.

Click in the Layer Information window and then select Include from the drop list. Click OK to return to the Publish dialog box and then click Publish.

This time, name the file db_samp-Model-Publish and then click OK. Click No when invited to save the current sheet list. An alert box pops up to remind you that Publishing takes a little longer. Click OK.

When Publish has finished, open your new file in Design Review. Now the Layers navigator palette is populated with all the layer names from the original DWG file. Each has a light bulb beside it. Click on the light bulbs to turn layers on and off.

Layers that are off will not show in a plot of the file.

It Is Smaller
I stated earlier that a DWF file is quite a bit smaller that its parent DWG. Let's check out the numbers to see just how much smaller it is. A quick check of our statistically insignificant sample size of 1 reveals that the original DWG file was 219kb, while the layerless DWF is just 47kb, and the layered one is only 48kb. That is indeed quite a reduction.

Ah, but there is a price to pay for all that nothingness. As indicated earlier, a DWF file is simply an electronic representation of a piece of paper. Yes, you can zoom in, and yes, you can plot the zoomed view, but stop for a moment to think about what would happen if you took a magnifying glass and looked at a paper plot.

Within AutoCAD, you can zoom out so the screen shows an object considerably larger than the known universe, and then you can zoom in until it shows an object considerably smaller than the smallest subatomic particle.

On the other hand, the paper plot and its DWF analogy can only show the detail that can be printed. If you have a complex E-size architectural drawing and plot it to an A-size sheet of paper, you'll obviously lose a lot of small detail. A DWF file does the same thing. Under a magnifying glass, your printed lines on paper would appear thicker, but nothing new would come into view. This also happens in a DWF file when you zoom to or plot a small region.

The trick to creating effective DWF files is to remember the plotting-to-paper analogy. If you have a complex E-size drawing, then you should set the paper size to E when publishing the DWF file. If the recipient then prints it to an E-size sheet, he or she will see everything you would see if you plotted to E-size paper.

Similarly, if you want to emphasize a small detail to a recipient then you should zoom in to the desired region and print the display or a window when creating the DWF file. It's no accident that AutoCAD calls it the Publish command; we are effectively publishing a piece of paper and all that implies.

Okay, that's a pretty good start for this month. Be sure to come back next month when we investigate tricks and tips on creating DWF, on how recipients can study, analyze and mark them up and on how to get the mark-up information back into the original drawing.

And Now For Something Completely Different . . .
After you arrive at the Puerto Vallarta airport and clear Customs, you pass through a room full of people offering free rides to the hotels and resorts. Ignore them and press on. They are high-pressure, time-share salespeople.

If you must take a taxi, cross over the pedestrian overpass over the main road. The taxis on the other side don't have to pay an airport pick-up fee and are considerably cheaper.


AutoCAD Tips!

Lynn Allen

Autodesk Technical Evangelist Lynn Allen guides you through a different AutoCAD feature in every edition of her popular "Circles and Lines" tutorial series. For even more AutoCAD how-to, check out Lynn's quick tips in the Cadalyst Video Gallery. Subscribe to Cadalyst's free Tips & Tools Weekly e-newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!
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