DXF and DWG are two common file formats used to exchange information between different CAD and drawing programs. DXF is a semi-public standard promoted and controlled by Autodesk, Inc. DWG is a proprietary, closed format used by Autodesk for its products. DXF and DWG files contain almost identical information, and both store all of the same objects. Recent versions of AutoCAD have issues when reading some DXF files, such as losing links to images, so DWG is usually a safer choice in that case. As of this writing, the most recent DXF/DWG version is version 2015. The Vectorworks program imports versions 2.5 through 2015, and exports versions 12 through 2015.
DWF is a format developed by Autodesk to allow efficient sharing of design drawings with colleagues who do not have access to AutoCAD or other design software. DWF files are highly compressed, device and software independent, and can include 3D models. The Vectorworks program imports and exports versions 4.2, 5.5, and 6.0 (DWF text and binary); 4.2 and 5.5 (DWF compressed binary); 6.01 (3D DWF); and 6.02 (DWFx).
The following changes to the DXF/DWG and DWF translation procedure have been added:
● Standard leader and multileader lines now import as polylines or polygons with arrow markers; custom leader arrows import as symbols. Previously, all leader and multileader lines imported as a set of independent objects.
● New options allow you to import dashed lines as solid lines, and to set a minimum gap size. Previously, even lines with gaps too small to be seen were imported as dashed line types, which could affect the performance of the Vectorworks program.
● The precision settings for length and angle are now set according to the setting in the Units dialog box during export. Previously, only the length precision was set, to a fixed value.
● A new Location tab in the import options allows you to decide how to handle imported objects relative to the drawing’s internal origin. The default option centers the drawing about the internal origin, and shifts the user origin, if necessary, to preserve file coordinates. This prevents problems caused by objects located too far away from the internal origin. Subsequent imports match the user origin, keeping all files properly aligned with each other. Other options on the Location tab allow you to preserve the import behavior of previous versions of Vectorworks software.
● A new option allows you to import tables as worksheets, for easier modification. Previously, tables were always imported as sets of individual line and text objects.
● A new option allows you to export SIA dimensions as non-superscript AutoCAD dimensions that update automatically during reshape. Previously, SIA dimensions were always converted into non-dimension objects that looked exactly the same as they did in Vectorworks.
Importing from and exporting to DXF/DWG or DWF is not the same as saving or opening a Vectorworks file. It is a translation from one way of doing things to another; consequently, information can get lost in the translation. Following are some items that DXF/DWG and DWF handle differently. These can introduce unwanted effects in the translated file.
Item |
Description |
|
Units |
Version 2000 DXF/DWG and later supports the concept of units, so the file’s unit settings can be imported (if it includes units). Previous versions of DXF/DWG do not support units, and some version 2000 and later files may be unitless. There is no way for the Vectorworks program to tell whether these unitless drawings were made in meters, feet and inches, or microns. Communicate with the person providing the file to determine this information. Unitless DXF/DWG files do have five “units” settings (such as “Architectural” and “Engineering”) which are used to guess the original units, but the guess may need to be adjusted. |
|
Line Weights |
The Vectorworks program allows line weights and colors to be specified independently. AutoCAD has recently gained the ability to do so, but most AutoCAD users still use colors to map to line weights. Version 14 and earlier DXF/DWG files do not support true line weights at all. If you choose to export with line weights mapped to colors, then original object colors will be lost. |
|
Colors and Fills |
The Vectorworks program is more graphically rich than DXF/DWG can currently support. In all cases, the Vectorworks program chooses the closest possible translation given the limitations inherent in DXF/DWG. The default version in the export dialog box will always give the best results possible, assuming the recipient’s software can read all of the information. DXF/DWG versions prior to 2004 have a fixed color palette (which changes slightly depending on whether the background is black or white) and all objects have just one solid color associated with them. Objects such as circles in DXF have no fill color (just a line color). A few objects can have a fill color, but they have no separate line color. DXF/DWG version 14 and above supports a “solid hatch,” which is a separate object that can be associated with objects such as circles to make them look like they have a color fill. These hatches cannot be the same color as the background color (such as a white rectangle on a white background to mask objects underneath). Since these solid hatches can be associative, the Vectorworks program can import them and set the associated object’s fill color instead of having two separate objects for frame and fill. DXF/DWG version 2000 supports “wipeout” entities, which are essentially polygonal images filled with the background color. Some AutoCAD users may not want to receive files with wipeouts. DXF/DWG export includes an option to exclude solid fills (which includes both wipeouts and solid hatches). Since wipeouts can only be polygons and are not associative, if a white circle on a white background is exported and then re-imported into a Vectorworks file, the result is an unfilled circle and a polygon with a white fill and no pen inside the circle. The smoothness of the polygon (number of facets) depends on the 2D conversion resolution preference when it was exported. Objects with pattern fills export as a plain solid color. Surface hatches associated with a Renderworks texture must be exported as standard AutoCAD hatches. |
|
Layers and Classes |
Each Vectorworks design layer is similar to a DXF/DWG model space. A Vectorworks drawing can have many design layers visible at the same time, with different scales and views for each design layer, but only one model space is allowed in a DXF/DWG file. Therefore, the Vectorworks program has to merge the multiple design layers, and some information can be lost. The drawing should generally look and print the same after the export, but independent layer scales, object coordinates, and invisible objects can be lost. |
|
Groups and Symbols |
The Vectorworks program uses symbols, which are objects that can be inserted multiple times without greatly increasing the file size, and which need only one edit to update all copies. It also has groups, which are objects that are grouped together and act as one object. The DXF/DWG equivalent of a Vectorworks symbol is called a “block.” The closest DXF/DWG equivalent to a Vectorworks group is an “anonymous block,” which is like a symbol without a name. Unlike anonymous blocks, named blocks can be edited easily in AutoCAD, and new instances of the blocks can be inserted into the drawing. However, named blocks re-import into Vectorworks files as symbols, which may not be desirable. Therefore, the Vectorworks program has an option to export groups as anonymous blocks, if named blocks cause a problem. |
|
Attributes and Linked Text |
DXF/DWG does not have database records that correspond to Vectorworks record formats. It does have objects called attribute definitions (“attdefs”) which, when placed in blocks/symbols, behave somewhat like linked text in a Vectorworks file. The correspondence is very loose and as a result translation of these objects is not always smooth. DXF/DWG block attributes are created for things exporting as blocks (symbols, groups, plug-in objects, or layer links) that have record formats attached. Because only DXF/DWG blocks can have attributes attached, the record format information is not exported for other object types, such as lines or circles. |
|
Names |
When exporting to DXF/DWG version 2000 and later, the characters in layer and block names will not change. Accurate translation of lower case text, spaces and other Unicode characters is supported (except for the following illegal characters, which are converted during export: < > " `, / \ : ? * | = ). Export to previous versions converts all name characters to uppercase; all spaces and special characters are converted to underscores. DXF/DWG attribute tag names cannot have spaces in any version; any spaces found in record field names are converted to an underscore. |
|
Styled Multiline text |
Multiline formatted text includes various sized fonts that are bold, underlined, or italicized, and that wrap to the next line. This type of text is supported for DXF/DWG versions 13 and up. For earlier versions, wrapped text is split into separate lines. |
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Layer Transfer Mode / Transparency |
DXF/DWG does not support layer transfer modes or transparency, so use only paint transfer mode (100 percent opaque on Mac systems and on Windows systems that have GDI+ imaging enabled) |
|
Dimensions |
The Vectorworks and AutoCAD programs handle dimensions, units, and dimension standards very differently. Dimensions exported to DXF/DWG look exactly the same when opened in AutoCAD, but they may change appearance slightly if edited. The Vectorworks program also creates appropriate dimension styles for all dimension standards that are used in the file, so even if the recipient modifies the dimensions or creates new ones, they should not look significantly different. During import, the dimension styles from the DXF/DWG file will be created as custom dimension standards in the Vectorworks file, to preserve the original look. |
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