Professional Quality CAD on Linux with DraftSight (Linux.com) [LWN.net]

Nathan Willis reviews the zero-cost-but-proprietary beta release of DraftSight, computer-aided design (CAD) software for Linux. "Although this new app is not open source, it is the first professional-level package available for free on Linux that can read and write the industry-standard .DWG file format. Free software CAD still has a long way to go, but for now DraftSight offers Linux users a rare glimmer of hope."

He goes on to look at some of the alternatives. "As frustrating as it is, those are the options right now for CAD on Linux: non-free software that supports DWG, or free software that doesn't. All this stems back to the need to reverse-engineer the DWG file format itself. An independent group called the Open Design Alliance (ODA) did just that, and created a Linux-compatible library called OpenDWG. Yet as is too often the case, the organization and product do not live up to their names. You must be a paid-up member of the ODA in order to access its software, and you are not allowed to share it with others."

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Professional Quality CAD on Linux with DraftSight (Linux.com)

Posted Apr 5, 2011 21:43 UTC (Tue) by einstein (subscriber, #2052) [Link] (1 responses)

While it would be great to have FOSS software packages with these capabilities, it would be foolish to spurn this offering, which fills a real need, on rigid ideological grounds.

IMHO It's a foot in the door, and a welcome first step.

Professional Quality CAD on Linux with DraftSight (Linux.com)

Posted Apr 6, 2011 2:11 UTC (Wed) by iabervon (subscriber, #722) [Link]

On the other hand, if this release is due to legal wrangling between CAD vendors, it might not be a good idea to get too reliant on it. I'd guess that, in 5 years, it will be no longer available from the authors and require installing old versions of libraries to get it to run if you can track it down.

Professional Quality CAD on Linux with DraftSight (Linux.com)

Posted Apr 5, 2011 21:53 UTC (Tue) by rahvin (guest, #16953) [Link] (7 responses)

Not everyone thinks .DWG is the industry standard. It's a proprietary standard that's used as a weapon against the other CADD companies just as MS uses MSOffice file formats as a weapon against other Office packages.

FOSS software should be using the open standard DGN format not reading and writing the horribly proprietary DWG format. I'm not opposed to converters that allow the import and export because interoperability is important, but any FOSS program should not be natively using DWG.

Professional Quality CAD on Linux with DraftSight (Linux.com)

Posted Apr 5, 2011 22:23 UTC (Tue) by jimparis (guest, #38647) [Link]

Some related reading which convinces me that you've got a good point: http://en.wikipedia.org/wiki/.dwg#Legal_issues

Professional Quality CAD on Linux with DraftSight (Linux.com)

Posted Apr 5, 2011 22:51 UTC (Tue) by wdbeal (guest, #74085) [Link] (1 responses)

rahvin,

I could not find any reference that DGN is a truely open standard. Is it now ISO or something?

Professional Quality CAD on Linux with DraftSight (Linux.com)

Posted Apr 6, 2011 17:05 UTC (Wed) by rahvin (guest, #16953) [Link]

I'd understood that they were attempting for standard certification although I'm not sure it was ISO. This information is several years old so maybe they abandoned the effort when AutoCADD dropped their lawsuits on everyone in the industry.

I do know that they will give you the specs for the DGN file format by simply requesting them.

http://www.bentley.com/en-US/Products/MicroStation/OpenDGN/

I haven't filled out the form so I don't know what terms they demand for the download.

Professional Quality CAD on Linux with DraftSight (Linux.com)

Posted Apr 5, 2011 23:16 UTC (Tue) by PaulWay (guest, #45600) [Link] (3 responses)

And what about .DXF? QCAD reads and writes it natively, Autocad supports import and export from it, Autocad has published the specs publicly, it was designed as an interchange format for CAD files so other programs could use it as well. I'll bet there's a whole bunch of legacy junk in the .DWG format, too, so writing a library that reads and writes .DWG natively is probably more mind-bending than one would like. That's probably not the sole reason, or even an important reason, why Autocad is blocking anyone reverse engineering their format; but it is a reason to not bother.

One thing that has helped 'office' applications on Linux is the existence of a common, open standard. Whether it's .DXF or something else blessed by the OSI or whoever, if a bunch of programs work with it then it becomes more popular and more useful as a result. If the Open Design Alliance isn't truly Open, then get together and do something else.

Have fun,

Paul

Professional Quality CAD on Linux with DraftSight (Linux.com)

Posted Apr 6, 2011 3:56 UTC (Wed) by grindstone (guest, #71208) [Link]

Dunno about DGN, but there are ISO standards, or at least one. "Open" is always relative to barriers to entry and how much of the standard is commonly implemented. I'm no expert, but I gotta believe anything you can hold in a dwg can be represented in a step file (ISO 10303). Seems, though, that the narrow target of the review subject is "talks DWG" with the implicit constraints of flat/2-D drawings. As on old mcad guy, I can say that the office file format analogy has been painfully accurate.

Professional Quality CAD on Linux with DraftSight (Linux.com)

Posted Apr 6, 2011 10:56 UTC (Wed) by metan (subscriber, #74107) [Link] (1 responses)

Qcad is dead, long life to librecad.

The ribbonsoft started to be "evil" and stopped community releases some time ago, the last one available is old qt3 version.

And because of that we now have a fork http://librecad.org which is ported to qt4.

I wish it good luck.

Professional Quality CAD on Linux with DraftSight (Linux.com)

Posted Apr 6, 2011 23:30 UTC (Wed) by antifuchs (subscriber, #34569) [Link]

Nice! I didn't know about librecad. I actually bought QCAD a while ago, but was a bit frustrated with bugs in block handling that never got fixed. Now that people actually take care of it in the open, maybe there'll be more momentum behind it. (-:

Professional Quality CAD on Linux with DraftSight (Linux.com)

Posted Apr 6, 2011 8:55 UTC (Wed) by ejmarkow (guest, #56170) [Link]

I personally like the Java based "Cademia" CAD application. Take a look at it. It's free, cross platform, and actively being developed. Link: http://www.cademia.org

Professional Quality CAD on Linux with DraftSight (Linux.com)

Posted Apr 6, 2011 10:57 UTC (Wed) by Klavs (guest, #10563) [Link] (1 responses)

The article mentions DXF has reduced functionality and is less widespread appearently.

I've qcad to be a fine tool for my needs (drew building plans for my new house, for authority approval), and I've found the DXF format in latest qcad only works in autocad 2004 version though.

But I've heard from several autocad users, that they often have problems with older projects - not working in newer autocad versions etc. - so it's autocad who keeps changing the game appearently.

I don't know how "standard" DWG is in this aspect.

Professional Quality CAD on Linux with DraftSight (Linux.com)

Posted Apr 6, 2011 17:07 UTC (Wed) by rahvin (guest, #16953) [Link]

DXF stands for AutoCADD document exchange format. I have no doubt they will sue over it some day just like they did and have with DWG. That doesn't even consider that the format is substandard and nearly worthless.

Professional Quality CAD on Linux with DraftSight (Linux.com)

Posted Apr 6, 2011 17:39 UTC (Wed) by wookey (guest, #5501) [Link] (7 responses)

I've been doing a lot of CAD recently, and it's fair to say that one makes life hard for oneself by doing it on Linux, and with free software. I am now a QCAD expert, and whilst it's a very solid program, it is old-fashioned 2D vector CAD with some annoying features. It's a pity that Ribbbonsoft didn't find opening up their code to provide enough benefit to keep doing it.

The article says that LibreDWG is a long way from a release, but my experience is that's it actually works quite well for reading DWG files. The problem is that nothing uses the library, so it is of limited use on its own. QCAD/libreCAD using libreDWG would be extremely useful, because it's true that a lot of manufacturer-provided drawings are now DWG-only. I have no idea hard it would be to get libreCAD to read DWGs, but I hope someone gets enthused to do that work soon. I've package libreDWG for Debian. Needs a little more love then it can be uploaded.

Of course what we really want is 3D CAD so you can't accidentally make a building where the plan doesn't match up with the elevations. I did try doing CAD in blender, but it was pretty painful as blender was never really designed as a CAD tool. brlCAD was just too scary and complicated - it may be _really_ good, but again probably only in 1980's kind of way.

Something with the user interface from sketchup would be great for most people. It has issues too, but for many tasks it's brilliant, and the cloud-sourcing of subcomponents is a really useful concept. But again sketchup is proprietary software that can only be run on linux using wine (and I can't get the new version going at all) and the format is proprietary too (SFAIK), so that's no good.

The building-design area is desperately in need of a good dose of free-software. There are lots of sums that needs doing, many of them very easy which could be integrated into some Building Information Management software, with an online database of products, and using CAD tools to draw up shapes and layouts. The whole area is wide-open for some commoditisation, and I'd be very keen to get together with other like-minded souls to make something happen. I have a selection of evil spreadsheets that need turning into real software for structural calcs, heating design, energy efficiency and thermal analysis. There is some free software in this area, such as ESP-r which does 2D thermal calcs (but I've found it hard to even build, never mind use). It needs packaging...

Here's hoping for some more fundamental progress than freeware DWG-reading apps (nice as that is).

FreeCAD

Posted Apr 7, 2011 8:10 UTC (Thu) by amonnet (guest, #54852) [Link] (6 responses)

FreeCAD looks promising for 3D CAD et architecture. Have you tried it ?

FreeCAD

Posted Apr 7, 2011 11:28 UTC (Thu) by wookey (guest, #5501) [Link]

No, I had not seen that. Thanks for pointing it out. It does indeed look very promising, and even better it's already in Debian. I will give it a go.

FreeCAD

Posted Apr 7, 2011 11:44 UTC (Thu) by rahulsundaram (subscriber, #21946) [Link] (4 responses)

FreeCAD is not really free software. It depends on Open CASCADE which is not under a free license.

https://bugzilla.redhat.com/show_bug.cgi?id=459125#c6

FreeCAD

Posted Apr 7, 2011 20:45 UTC (Thu) by jrn (subscriber, #64214) [Link] (3 responses)

I fear the situation is more complicated (but would gladly accept corrections). You might be interested in http://packages.debian.org/changelogs/pool/main/o/opencas... and the mailing list conversation it references.

FreeCAD

Posted Apr 7, 2011 21:18 UTC (Thu) by rahulsundaram (subscriber, #21946) [Link] (2 responses)

See Tom Callaway's posts in

http://www.opencascade.org/org/forum/thread_15859/

Also refer to discussions in

http://lists.fedoraproject.org/pipermail/legal/2011-March...

If you need any further clarifications, you can post to the legal mailing list in Fedora.

FreeCAD

Posted Apr 12, 2011 10:35 UTC (Tue) by jrn (subscriber, #64214) [Link] (1 responses)

Thank you. I had missed the phrase "on a non-exclusive basis" in section 7 which is indeed bizarre. It says that the disclaimer of warranty in section 8 cannot be waived on an exclusive basis.

Tom's comment was: "Why can't someone choose to offer support exclusively to customer A but not any other customer?" But as long as you are not guaranteeing that customer A is the only one that gets a warranty, you're okay. I don't see how this would come up in practice.

So while I see how a reasonable person or distribution might want to steer clear of this license and I wish the outcome were different so this obnoxious license could quickly fade into obscurity, I am not convinced it violates the guidelines Debian uses to determine what software is free, nor their spirit. (For what little that's worth. I am neither a lawyer nor a Debian Developer.)

FreeCAD

Posted Apr 12, 2011 10:39 UTC (Tue) by rahulsundaram (subscriber, #21946) [Link]

I am convinced that it does and they need to relook carefully at the license. It doesn't qualify as free software.