Thanks for summarizing what I’ve been mulling over in my head.

I’m going to comment+close the Issue with something to this effect.

Andrew.

On 05/02/2015 05:29 AM, MichaelAtOz wrote:

Right, I agree the functionality would be much more useful than just
another import/export format. But then I think the effort spent on a
simple exporter would be not too big, I guess the biggest thing is to
find a nice cross platform solution to read/write the ZIP file (which
would come in useful for AMF handling too).

Still, I guess the best strategy for now is to sit back, fetch some
popcorn and watch what happens :-).

ciao,
Torsten.

The DRM relevant features of the spec are all optional, the only required
part is the 3D model. So I think a conformant implementation need not
process any DRM.

I understand there is great suspicion of Microsoft, but in my reading 3MF
is a genuinely open spec, there are no strings attached. It actually makes
clear it is royalty free, unlike AMF. It also can be freely downloaded,
unlike AMF which costs $49 and you have to agree to inspection of your
premises and computer systems by a third party to ensure you are complying
with the copyright (i.e. not made ANY copies), otherwise the agreement is
cancelled and you must destroy all copies.

Personally I find it a lot easier to implement 3MF than AMF.

On 27 May 2015 at 08:02, frankv drifter.frank@gmail.com wrote:

The only version of the AMF spec that I've studied is the 0.47 draft from
this URL:

http://creativemachines.cornell.edu/sites/default/files/AMF_V0.47.pdf

If there are substantive differences in the $49 version, I have no way of
finding about them. The legal risks involved in obtaining the actual
standard sound too high. If I create a context diff comparing 0.47 with
1.0, I'm breaking the law. On the other hand, most of the other people
implementing AMF are probably also basing their implementation on V0.47, so
whatever text happens to be in the pay version of the AMF standard probably
doesn't matter all that much.

I agree that Microsoft has done a better job, in making their standard
freely available and explicitly royalty free.

On 27 May 2015 at 05:28, Bob Cousins bobcousins42@googlemail.com wrote:

Von: "doug moen" doug@moens.org

Actually there are some details that are fairly important for interoperability
across different programs. In general the file structure is pretty well
explained in Wikipedia and most information (especially the XML schema is
freely available).
Also Hod Lipson, technical contact and ASTM F42 Task group chair is pretty
helpful and also answers specific questions in the google group. Unfortunately
he failed to convince others to make the specification freely available.
This is likey an ASTM/ISO issue and not related to the actual specification,
but still it's hugely annoying.

released spec version. Last time I looked, the netfabb implementation did
not follow the specification regarding the actual file storage when using
ZIPed format.

I can't see much difference there and AMF is pretty trivial when ignoring
the curved triangles (where I'm still not convinced that's extremely useful,
especially due to the fixed 5 level recursion, but I might be wrong here
as I did not dig into the details).

And basic AMF support is already implemented, the export is included in
the release version. The restrictions are mainly coming from limitations
present in current OpenSCAD and are not related to AMF.

ciao,
Torsten.

Well, an XML reader/writer is cake to drop in if you wanted to; I suspect
the non-gcc part made liberal use of Windows-only stuff.

--Joseph Lenox

On Thu, Jul 23, 2015 at 12:26 PM, Torsten Paul Torsten.Paul@gmx.de wrote:

On 07/23/2015 07:38 PM, Joseph Lenox wrote:

Sort-of, yes. It uses the OPC stuff which 3MF is based on, so it gets
most of the XML / ZIP / Packaging infrastructure for free.
(https://msdn.microsoft.com/en-us/library/windows/desktop/dd371025%28v=vs.85%29.aspx)

They did model the C++ interface after COM but according to the docs
it's only "A COM-like DLL Interface" which would work without the COM
magic.

ciao,
Torsten.