DWG/DXF

[ANDY CANFIELD]

The problem is the open DWG libraries are not open source and have pretty
restrictive licensing agreements to using them, especially if you are
putting them into a commercial product.

So far they are also the only ones to have broken the 2004 dwg's encryption.
AutoDesk officially says it's not encryption but under an NDA with the open
Design Alliance I've seen the algorithm and it's very definitely an
encrypted format.

There are roughly four formats of dwg out there and they are not compatible
with each other. Dwg release 12, Dwg release 14, Dwg release 2000, Dwg
release 2004. They are all different, it was AutoDesk's attempt at making
sure competitors had a rough time using their format. They have also said
they will change the format again some time in the future.

The 2004 format is the only one of the bunch that is encrypted. The Open
Design Alliance skirts all the legal battles by doing all their reverse
engineering in Russia. So it's definitely not a little thing to try and put
Dwg into OGR. You can be almost certain that if we were to do it AutoDesk
would issue a legal challenge. Most likely under the DMCA whoever reverse
engineers the format would win but you'd still end up in court settling the
dispute and AutoDesk has deep pockets.

That in a nutshell is why more people don't have dwg compatibility in their
libraries and applications.


>From: Arnulf Christl <arnulf.christl at CCGIS.DE>
>Reply-To: Arnulf Christl <arnulf.christl at CCGIS.DE>
>To: MAPSERVER-USERS at LISTS.UMN.EDU
>Subject: Re: [UMN_MAPSERVER-USERS] DWG/DXF
>Date: Fri, 24 Sep 2004 15:56:06 +0200
>
>Frank Warmerdam wrote:
>
>>David Bitner wrote:
>>
>>>About a year ago Frank Warmerdam wrote that he may have the
>>>opportunity to
>>>work on implementing DWG/DXF support in OGR via the OpenDWG toolkit.
>>>I was
>>>wondering if he, or anyone else has done anything with direct DWG
>>>access for
>>>mapserver?
>>
>>
>>David,
>>
>>I have not done any work with the OpenDWG libraries since then.  The
>>project I was referring to did not materialize.
>>
>>Best regards,
>>--
>>---------------------------------------+--------------------------------------
>>
>>I set the clouds in motion - turn up   | Frank Warmerdam,
>>warmerdam at pobox.com
>>light and sound - activate the windows | http://pobox.com/~warmerdam
>>and watch the world go round - Rush    | Geospatial Programmer for Rent
>>
>Hi,
>I believe there is a lot of potential for extending OGR to support
>DWG/DXF. Anybody else out there who yould join forces?
>
>Best regards,
>Arnulf.

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