On 3/23/19 12:52 PM, Greg Bernard wrote: > As an Autocad user for 25 years, I can say the issue of file formats not > being backward compatible is really not a significant problem. All Autocad > versions have the option of saving the file in an older .dwg or .dxf > format. There may be some minor problems with formatting of dimensions, > etc. but when they do occur it's usually not a big deal to correct them.
DXF export may be true of AutoCAD but it was not the case with the ill fated AutoSketch which would export a DWG so I could start leasing AutoCAD, or some version of DXF that I was never able to import into anything. AutoDesk had a reputation of creating the industry "standard" DXF format so they could control it. In theory, it was a standard file format that allowed CAD data to be interchanged between all CAD programs. That seems like a very user oriented concept. However, the DXF "standard" was anything but a standard. It was extremely problematic when I tried to use it. AutoCAD competitors inevitably had data import menus that listed six different versions of the DXF "standard" depending on which version of AutoCAD exported the DXF, and very often, none of them would work. The numerous versions of DXF files also made it very difficult for CAD developers to know which version to use for exporting. When I last looked a dozen years ago, I think the other companies had finally standardized on one version of the DXF "standard" to use, but there was still some lingering confusion. To this day, LibreCAD can export to DXF R12, DXF R14, DXF 2000, DXF 2004, and DXF 2007. I can only assume that AutoDesk loves standards because they created so many of them. :-/ It could be argued that a bad industry standard from the dominant manufacturer greatly delayed the development of a true industry standard for CAD data and hindered data exchange to protect market share. In order to ensure compatibility, most commercial CAD manufacturers were forced to give up and pay AutoDesk to license the proprietary DWG format. That wasn't an option for open source software because it's free as in "free beer" so there wasn't money to pay AutoDesk, and it's free as in "free speech" so it couldn't incorporate licensed proprietary software. https://en.wikipedia.org/wiki/AutoCAD_DXF /"As AutoCAD has become more powerful, supporting more complex object types, DXF has become less useful. Certain object types, including //ACIS//solids and regions, are not documented. Other object types, including AutoCAD 2006's dynamic blocks, and all of the objects specific to the //vertical market//versions of AutoCAD, are partially documented, but not well enough to allow other developers to support them. For these reasons many CAD applications use the //DWG//format which can be licensed from //Autodesk//or non-natively from the //Open Design Alliance//." / Microsoft has engaged in similar proprietary data strategies. Every year or two, there would be a new version of Word, and it would read files from the last version or two, but no others. Toward the end, there was only the pretense of new features in their mature word processing and spreadsheet products. The "upgrades" were nothing but designed inoperability to force the market to buy new software as soon as customers could no longer exchange files. Meanwhile, LibreOffice Writer and LibreOffice Calc can import every version of Open Document file ever used. 100% backward compatibility, without the need to try different import filters. I have no problem paying for commercial software that makes my life easier, but I don't like being forced to buy software that makes my life more difficult by deliberately rendering my data useless to me unless I pay their annual extortion fees. _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
