.dwg
| Filename extension |
.dwg |
|---|---|
| Internet media type |
application/acad application/x-acad application/autocad_dwg image/x-dwg application/dwg application/x-dwg application/x-autocad image/vnd.dwg drawing/dwg[1] |
| Type of format | CAD |
DWG ("drawing") is a format used for storing two and three dimensional design data and metadata. It is the native format for the AutoCAD Computer Aided Design package, as well as Intellicad[2] (and its variants), and PowerCAD.[3] DWG is supported non-natively[4] by several hundred other software applications.
History of the DWG format
DWG (denoted by the .dwg filename extension) was the native file format for the Interact CAD package, developed by Mike Riddle in the late 1970's[5], and subsequently licensed by Autodesk in 1982 as the basis for AutoCAD[6][7][8][9]. From 1982 to 2007, Autodesk created versions of AutoCAD which wrote no less than 18 major variants of the DWG file format, none of which it publicly documented[10].
The DWG format, has become a de facto standard for CAD drawing interoperability. It has been estimated that there are in excess of two to four billion DWG files in existence.[11]
Several commercial software libraries exist for accesing DWG format files. Autodesk provides a read/write library, called RealDWG[12], under selective licensing terms, for use in non-competitive applications. The Open Design Alliance[13], a non-profit consortium created in 1998 by a number of software developers (some of which were competitors to Autodesk), provides a read/write/view library, called DWGdirect, under a level playing-field license. There are no open-source DWG libraries currently available, and neither RealDWG nor DWGdirect are licensed on terms that are compatible with the gnu gpl, or similar free software license.
In 1998, Autodesk added file verification to AutoCAD R14.01, through a function called DWGCHECK. This function was supported by an encrypted checksum and product code (called a "watermark" by Autodesk), written into DWG files created by the program.[14][15]. In 2006, Autodesk modified AutoCAD 2007, to include "TrustedDWG technology", a function which would embed a text string within DWG files written by the program : "Autodesk DWG. This file is a Trusted DWG last saved by an Autodesk application or Autodesk licensed application."[16][17] AutoCAD would pop up a message, warning of potential stability problems, if a user opened a 2007 version DWG file which did not include this text string.
On 22nd November 2006, Autodesk sued the Open Design Alliance alleging that its DWGdirect libraries infringed Autodesk's trademark for the word "Autodesk", by writing the TrustedDWG code (including the word "AutoCAD") into DWG files it created. In April 2007, the suit was dropped, with Autodesk modifying the warning message in AutoCAD 2008 (to make it more benign), and the Open Design Alliance removing support for the TrustedDWG code from its DWGdirect libraries.[18]
In 2006, Autodesk applied for a US trademark on "DWG", as applied to software (as distinct to its application as a file format name.) [19]. In a non-final action in May, 2007, the examining attorney refused to register the mark, as it is "merely descriptive" of the use of DWG as a file format name (for which Autodesk does not claim any trademark rights.) In September, 2007, Autodesk responded, claiming that DWG has gained a "secondary meaning," separate from its use as a file format name. [20]. As early as 1996, Autodesk has disclaimed exclusive use of the DWG mark in US trademark filings. [21]
Software which supports DWG
- ArchiCAD (using DWGdirect)
- AutoCAD (using RealDWG)
- Autodesk Inventor (using RealDWG)
- Autodesk Revit (using RealDWG)
- Autodesk 3ds max (using RealDWG)
- Bricscad (using DWGdirect)
- DataCAD (using DWGdirect)
- IntelliCAD (using DWGdirect)
- MicroStation (using DWGdirect)
- SolidWorks (using DWGdirect)
- VectorWorks (using DWGdirect)
- PowerCAD (using DWGdirect)
Free Viewers
There are no OpenSource/GNU viewers for DWG files since the licensing of the libraries needed by lx-viewer[22] now restricts their use to members of the Open Design Alliance.
- Free DWG Viewer by Infograph, 14 Mb. Does not allow printing. For Windows 2000/XP.
- Autodesk Design Review 2008 (41 MB) (cannot view DWG files natively, requires DWG TrueView)
- Autodesk DWG TrueView 2008 (120 MB) For Windows 2000/XP/Vista, also 64-bit.
- Volo View Express 1.14 (discontinued and superseded by Design Review) - 26 Mb
- DWG Gateway v3 by SolidWorks, 9 Mb. (Requires any version of AutoCAD).
- Bentley View by Bentley, 58.2 Mb. For Windows 98/ME/NT/2000/XP.
Note: Autodesk DWG TrueView and Autodesk Design Review 2008 by Autodesk requires a questionnaire to be filled before downloading.
References
- ^ "File Extension .DWG Details". FILExt - The File Extension Source. Computer Knowledge. Retrieved 2007-07-12.
- ^ http://www.intellicad.org
- ^ http://www.givemepower.de
- ^ Non-natively: i.e., the file format is supported by translation from or to another file formats.
- ^ http://www.retrothing.com/2007/05/mike_riddles_pr.html
- ^ http://www.fourmilab.ch/autofile/www/subsection2_3_12_1.html#SECTION00312100000000000000
- ^ http://www.fourmilab.ch/autofile/www/f/246.html
- ^ http://www.digibarn.com/stories/mike-riddle/index.html
- ^ http://www.opendesign.com/about/whtpaper/alwhtpap.htm
- ^ http://betaprograms.autodesk.com/history/autocad_release_history.htm
- ^ Autodesk, Inc. "DWG Unplugged". Archived from the original on 1998-01-19.
With over two billion AutoCAD® DWG files worldwide...
Brown, Adrian (2003-07-09). "Digital Preservation Guidance Note 4: Graphics file formats" (PDF). UK National Archives. p. 11. Retrieved [2007-08-31].according to current estimates there are in excess of 4 billion DWG files in existence worldwide.
{{cite web}}: Check date values in:|accessdate=(help) - ^ http://www.autodesk.com/realdwg
- ^ Originally, OpenDWG Alliance. "Open Design Alliance".
- ^ http://autodesk.blogs.com/between_the_lines/2005/06/how_to_tell_if_.html
- ^ http://www.opendesign.com/dwg2007update.asp
- ^ This "TrustedDWG code" is encoded into DWG files in a fashion that is not humanly readable. This may be validated by using a binary editor to search a DWG file.
- ^ Autodesk originally used the term "Trusted DWG", with an embedded space. They modified it removing the space, prior to filing a US trademark application in September, 2006. See http://tarr.uspto.gov/servlet/tarr?regser=serial&entry=77009317
- ^ http://www.adskvoda.com
- ^ http://tarr.uspto.gov/servlet/tarr?regser=serial&entry=78852808
- ^ http://portal.uspto.gov/external/portal/tow?SRCH=Y&isSubmitted=true&details=&SELECT=US+Serial+No&TEXT=78852798#
- ^ http://tarr.uspto.gov/servlet/tarr?regser=serial&entry=75156366
- ^ http://lx-viewer.sourceforge.net/
See also