David Cohn: Understanding What Gets Written to a DWF File

David Cohn of Cyan Research Corporation presented a class entitled "Designing a Website to Host AutoCAD® Content." His handout had some great information on publishing DWF files. It is reproduced below. I added a few notes indicated by text in [brackets].

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A DWF file is truly an electronic version of a plot file. When you plot the DWF file, you specify settings such as paper size, rotation, scale, and pen assignments, just as you do when plotting to any other device. Only those layers that are visible, actually contain data, and set to plot are written to the DWF file. In addition, the DWF file contains all the linetype, lineweight, and color settings in effect when you plot the drawing to create the DWF file. Once the DWF file is created, you can use the tools contained in any of Autodesk’s DWF viewers to display a particular sheet, turn selected layers on and off, and pan and zoom to limit what is displayed, just as with an AutoCAD drawing. You can also snap to geometry in the DWF file just as you can in AutoCAD and take accurate measurements. Any hyperlinks contained in the original drawing are retained and active in the resulting DWF file. External references are also preserved.

Including Raster Images in DWF Files
Raster images are stored in the DWF file [as JPEG images].

Including Named Views in DWF Files
Any named views that are saved in the DWG file when the DWF file is created are saved to the resulting DWF file and can be restored using any of Autodesk’s DWF viewers. For convenience, a view named INITIAL, if not already defined in the drawing file, is also saved as part of the DWF file. The INITIAL view corresponds to the current view of the drawing at the time the DWF file was created.

Including Layers and Blocks in DWF Files
Any layers that are visible in the DWG file when the DWF file is created, except those marked as not to be plotted, can be saved to the resulting DWF file. The DWF file also contains the colors, linetypes, and lineweights as determined by the plot settings when you create the DWF file. You can then use any of Autodesk’s DWF viewers to turn these layers on and off individually. Any layers that are not visible in the DWG file when the DWF file is created, however, are not included. Beginning with AutoCAD 2006, individual blocks can also be saved to the resulting DWF file. But even if blocks are not included, all the visible geometry associated with a particular block is saved in the DWF file with the layer on which the block was inserted in the original drawing file. You can, therefore, turn blocks on and off in the DWF file by turning their layer on and off.

Including Fonts in DWF Files
When a drawing file contains text created by using AutoCAD SHX fonts, the font geometry is converted into simple vectors that mimic the appearance of the text in the resulting DWF file. In this way, the user who is viewing the DWF file does not need to have the SHX fonts loaded on their system. When a drawing contains text that is created by using a Windows TrueType font, however, the text and the actual font are recorded to the resulting DWF file. You can then configure the DWF6 ePlot driver to control whether these fonts are included in the resulting DWF file. [If included the DWF file is larger since a subset of the font is included. The subset is limited to the characters that are used in the DWF file.] If not included in the DWF file, then the TrueType font must be available on the system of the user who is viewing the DWF file or else the text may not appear properly. [If the font data was not included, and the font is not available on the system, a substitute font is used.]

Controlling DWF Properties
You can control many of the properties of DWF files - such as the resolution, format, background color, and inclusion of layer information - by changing the DWF plotter configuration.

Note: If you make changes while the PLOT command is active, you can apply those changes to the current plot only or save the changes to the DWF plotter configuration file. The PUBLISH command uses a specific plotter configuration - DWG6 ePlot.pc3. Although you can save DWF6 plotter configuration files under other names for use with the PLOT command, no other name will work with the PUBLISH command. Any changes you make to DWF6 ePlot.pc3 will be used whenever you use the PUBLISH command until you change the configuration again.

All changes to DWF properties are made from the DWF6 ePlot Properties dialog box, which in turn is accessed from the Plotter Configuration Editor. You can display the Plotter Configuration editor for the DWF6 ePlot.pc3 file by either selecting the DWF plotter configuration in the Page Setup or Plot dialog box and then clicking the Properties button, or by opening the plotter configuration using the Plotter Manager.

Controlling the Resolution
You can specify the resolution for vector and raster graphics in the DWF file. Higher resolutions produce more precise DWF files, but at the expense of larger file sizes. The default value for vectors is 1200dpi. You can set separate settings for color and black and white raster images. If you’re creating DWF files intended for plotting, select a resolution to match the output of your plotter or printer. High resolutions (over 2400dpi) are for viewing. If you’re creating a DWF file of a drawing with a lot of detail, such as a large topographic map, using a higher resolution will enable you to zoom in to view finer detail. Resolutions over 40,000 dpi may produce very large files. As you increase the resolution setting, the speed of printing decreases and memory requirements increase.

Controlling Font Handling
You can control the inclusion and handling of TrueType fonts in DWF files:

• Capture None - No fonts are included in the DWF file. In order for fonts to be visible in the resulting DWF file, the fonts must be present on the system on which the DWF file is being viewed. If a particular font used in the DWF file isn’t present, another font will be substituted (which can sometimes produce undesired results).
• Capture Some - The fonts used in the source drawing for the DWF file that are specified in the Available True Type Fonts dialog box (displayed by clicking the Edit List button) will be included in the DWF and therefore don’t need to be available on the DWF viewer’s system in order for them to appear in the DWF file.
• Capture All - Specifies that all fonts used in the drawing will be included in the DWF file. (Note that if you select this option and also select All as Geometry, the fonts used in the drawing will be included as vector geometry rather than as text.)

Controlling Additional Output Settings
The controls in the lower portion of the DWF Properties dialog box enable you to control the following other DWF properties:

• DWF Format
  DWF files can be saved in one of two possible formats: Compressed Binary Produces a compressed binary DWF file, resulting in the smallest DWF file size. This is the default format. Zipped ASCII encoded 2D stream (advanced) Produces DWF files in zipped ASCII Encoded 2D Stream (plain text) format. You can use WinZip to unzip the files.
• Background Color Shown in Viewer
  Determines the background color that is applied to the DWF files when they are viewed in the DWF viewer. (Note that DWF files intended for plotting should be configured with a white background color.)
• Include Layer Information
  Determines whether layer information is included in the DWF file. DWF files include all objects on layers that are visible and plotted. If layer information is included, when viewing the resulting DWF file users will be able to turn layers on and off. By default, the DWF6 ePlot.pc3 configuration does not include layer information, so that anyone viewing the DWF file will not be able to turn layers on and off.
• Show Paper Boundaries
  Determines whether the paper boundary is visible in DWF files plotted from a layout tab. (Note that for DWF6, this option is always selected.)
• Save Preview in DWF
  Specifies that a preview of the DWF file is saved in the DWF file. (Note that a small thumbnail is always saved and you should only select this option if the recipient of the DWF file will use Buzzsaw.com to access the preview.)

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Thanks David!

Comments

[clg]

Thanks - TrueView is fairly tricky. It is not always easy to get the views you want to publish as output. This is helpful.