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Question about licensing re: flightgear art.

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Question about licensing re: flightgear art.

Postby chriscalef » Sun Sep 14, 2014 6:57 pm

Hi,

I was just wondering about how the GPL works vis-a-vis art assets, i.e. if I included one of FG's airplane models in my private proprietary project, would that then force my whole project into the GPL? I've been assuming so, and avoiding doing so, but it would help to know if any of the aircraft models actually were adopted from other more permissive licenses - if so then I could go to the source and use them from there.

Any information would be welcome.

Thanks,
Chris
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Re: Question about licensing re: flightgear art.

Postby Johan G » Sun Sep 14, 2014 7:42 pm

chriscalef wrote in Sun Sep 14, 2014 6:57 pm:I was just wondering about how the GPL works vis-a-vis art assets, i.e. if I included one of FG's airplane models in my private proprietary project, would that then force my whole project into the GPL?

While I am not a lawyer, I think that art assets are treated just as software as far as the license goes, and yes I think that using GPL:ed assets would force the rest of the project into GPL, see GNU General Public License, version 2 (my emphases):
2. b) You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License.


chriscalef wrote in Sun Sep 14, 2014 6:57 pm:...it would help to know if any of the aircraft models actually were adopted from other more permissive licenses - if so then I could go to the source and use them from there.

I am quite sure that some aircraft models are adopted from more permissive licenses. The big question is: Will your project be used commercially? Because a lot of the 3rd party aircraft hangars uses models that originally was not Creative Commons, but more or less public domain, but not to be used commercially (for example many of the aircraft in Dave Culp's hangar). Unfortunately, while some aircraft authors generously attributes even public domain aircraft other do not (I would consider always doing it a good habit though).

Side note: This is one of those times when it actually would be nice to have all the at ones fingertips, as one then could grep them for for example "public domain".


As a last resort you could always ask the authors. ;)
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Re: Question about licensing re: flightgear art.

Postby ludomotico » Sun Sep 14, 2014 8:34 pm

In my opinion, using GPL models forces the whole project to be GPL. In any case, keep in mind the GPL license only forces to distribute the code to the same people you distribute the binaries. If you are concerned about your project to be GPL, tell us something about your project and maybe it is not as bad as you think if it is GPL :) Imagine a flight simulator in a fun park: you can use GPL models and the simulator will be GPL, but you only have to release the code to the fun park owners, not to the public. This is because the fun park owners have to have the right to modify the simulator if they want. Anyway, they are probably as uninterested as you are in releasing the code of the GPL simulator they have just bought.

If you are building a commercial project for the general public and do not want to release the code, I think the fair thing to do is contact the modelers and buy a commercial license from them for their models.
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Re: Question about licensing re: flightgear art.

Postby chriscalef » Sun Sep 14, 2014 9:31 pm

Thanks for the feedback!

As I think about it more I guess I actually have two different use cases in mind which may be treated differently.

To explain more about my situation, my proprietary project is an animation/modeling program I've been working on for years, called Ecstasy Motion (ecstasymotion.com). It is built on top of the MIT-licensed Torque engine, and my business model so far has been to stick with a traditional closed source application, with licenses costing a couple of hundred bucks, intended market being independent film makers, machinima artists and game developers. I have already open sourced certain major subcomponents of the application, and intend to do more, but I'm still not convinced of the free speech vs free beer argument (my real beers actually do cost me money, lol) and for now at least feel the need to play it safe, keep my source closed and sell the binaries.

However, where this connects to flightgear is I have recently had a brainstorm connected to some work I did last year, establishing a socket connection between flightgear and a standalone game engine. (viewtopic.php?f=19&t=19626&hilit=unity3d) The new brainstorm is that I just realized it probably would be very easy to also send a stream of data re: an airplane (position/orientation/flight surface controls/bombable shots fired/etc) to my client application, and hence be able to render the plane flying around in Unity or Torque, either from a static camera or by attaching the camera to the flightgear viewpoint.

Doing this into Ecstasy Motion would also give me the ability to save the plane's motion (and actual mesh/texture data) into fbx files for import into another destination app, such as Maya, 3DS Max or Unity.

Beyond general interest in including this ability as a feature or add-on for Ecstasy, I am also involved in production of my own war movie, which is going to require at least attack helicopters and possibly other aircraft. I had been assuming we would just fake the helicopter flight by moving it at a constant velocity, but now that I can actually start to fly the things in flightgear it is quickly becoming obvious how much better it will look if it is run by an actual FDM instead.

So, in reality I have two distinct license questions, but I suspect they have the same answer: one is to include a single airplane model with Ecstasy Motion or an add-on package, and the second is to use a rendering of an airplane or helicopter model in a movie. The answer is probably that they are both commercial projects and in both cases I need to buy the art, unless I'm lucky enough to find a totally free and unencumbered model. Which is cool, there are reasonably priced models out there. It would be great to be able to buy models from FG contributors for this purpose instead of finding models elsewhere though, since they would be guaranteed to have all required moving parts and match the flight characteristics precisely.

Anyway, thanks for helping me figure this out!
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Re: Question about licensing re: flightgear art.

Postby Johan G » Mon Sep 15, 2014 10:45 am

chriscalef wrote in Sun Sep 14, 2014 9:31 pm:...the second is to use a rendering of an airplane or helicopter model in a movie.

In that particular case, the GPL will not impose any limits (from section 0): :D
Activities other than copying, distribution and modification are not covered by this License; they are outside its scope.
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Re: Question about licensing re: flightgear art.

Postby ludomotico » Mon Sep 15, 2014 12:09 pm

"Outside its scope" must be understood as "under the general law" instead of "not impose any limits" :D

If this is the case of renders (I don't really know, but it seems fair to me), the modelers of the aircraft maintain all the "image rights" of their models.

In my opinion, the GPL cannot be used in these scenarios and the models are fully protected by the copyright law as any other work. You must license the models from their authors in the usual way.

Please, keep in mind this is only my opinion!
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Re: Question about licensing re: flightgear art.

Postby stuart » Mon Sep 15, 2014 1:59 pm

Hi Chris,

IANAL, but I think including a GPL model within Ecstacy Motion would definitely breach the GPL. You might be able to include one as part of a GPL add-on to it, provided it was completely separate.

Including a GPL model within a movie is an interesting point. I think you would be OK, because the copyright of the image resides with whoever has the artistic input, not the source material. So provided that the image/movie showed some artistic input, it would be OK as it would not be a copy of the aircraft model.

(Note that this is different from a Trademark)

Again, IANAL.

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Re: Question about licensing re: flightgear art.

Postby Hooray » Mon Sep 15, 2014 3:03 pm

Like Johan_G said: you're allowed to distribute any GPL'ed software, including FlightGear, along proprietary/closed-source software.
And it is up to your own software to use the data, or not.

Artwork, like a 3D model or texture, isn't "linked into an application's address space" usually.
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Re: Question about licensing re: flightgear art.

Postby chriscalef » Mon Sep 15, 2014 4:57 pm

Hm, that's kind of what I was getting at with the original question, ie GPL affects executable code that is linked in to an application, but how would that apply to art? Theoretically if I redistributed all of flightgear alongside my application, then my app could just go inside the flightgear folder and find whatever models it wanted to, without them being "part of" my application in any way... but overall, it sounds like the polite thing to do would be see if I can track down the artist in question and shove some cash at them in exchange for explicit commercial rights.

In the end I might have to end up hiring an artist to make a custom model anyway, though, for purposes of fitting the actual movie. As a totally random thread hijack, does anyone happen to know what kind of helicopters the Chinese army is using these days? :-)

EDIT: to un-hijack my own thread, I googled it myself, the WZ-10 looks nice! Not seeing one in my current copy of the aircraft folder though, so yeah, I may end up having to source this from elsewhere anyway.

http://chinesemilitaryreview.blogspot.c ... -take.html
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Re: Question about licensing re: flightgear art.

Postby Hooray » Mon Sep 15, 2014 5:19 pm

The GPL is pretty clear about what you can do and what rights you are granted, and thereby also granting to others once you are using/distributing any GPLed work.

While most contributors/aircraft developers will not appreciate such a discussion due to its ethical/controversial side - the GPL is simply not the right tool to protect artwork like a texture or 3D model from being used like this.

Unfortunately, FlightGear as a project has quite a history of mis-interpreting what the GPL entails, which includes long-term contributors and core developers who've violated the GPL at times, or who're overly paranoid about what is allowed and what isn't. As long as you can read the GPL license and understand its text, you can easily come up with numerous scenarios/setups -like your's- that would fully comply with the GPL, while not being exactly popular around here.

FlightGear being based on the principles of the GPL, all this is a bit unfortunate, but obviously a project like FlightGear tends to attract coders more so than "lawyers" - and most coders probably have never bothered reading, and fully understanding, the GPL, and its implication for non-code work (or even just Nasal scripts!).

Thus, people would state their opinions in a "IANAL" fashion (no offense to Stuart!) - even though y/our best bet is to simply get in touch with the FSF and discuss your question there if you want to be on the safe side, you'll find that fully-compliant/legal use-cases are not difficult to construct at all - but you'll also find that it is probably a good idea to get in touch with the people who've created the corresponding artwork upfront, not out of necessity - but out of "courtesy".

The GPL is not the right tool for artwork, and unfortunately it also isn't the right tool for an increasingly distributed application like FlightGear - HLA will make it dead-easy to circumvent the GPL without having to worry about licensing at all.

Regardless of that, aircraft like for example the P51d obviously represent thousands of hours of work and the people who did all the hard work, would understandably be pretty pi**ed if someone were to come up with a workaround to make money off open source without contributing back, without getting in touch upfront - I am sure that most people will usually be happy to work out some kind of "deal".

All that said, all these GPL discussions are very unfortunate - if people cannot be bothered to look at the GPL, read & understand it, please just get in touch with the FSF and have it spoon-fed to you :mrgreen:

(seriously, that's the only sane way to back up any decision making here - which is even superior to getting in touch with your own lawyer (or contributors/core developers!), simply because a project like FG will be mainly bothered by what the FSF has to say, and not YOUR lawyer or some other contributor)

There really is too little networking happening here unfortunately - contributors and users should consult back with the FSF much more often, that would get rid of a number of ridiculous threads and emotional discussions, on both, the forum and the devel list. The currently ongoing debate on the devel list about possibly adopting DDS/S3TC is another good example actually ...
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Re: Question about licensing re: flightgear art.

Postby adrian » Mon Sep 15, 2014 5:26 pm

GPL doesn't make much sense for works other than code, there are a number of other licenses which are better suited for this kind of art works, but the Flightgear project has chosen it and now we have to deal with it.
I would disagree with most of the people posting here and say that as long as the model is reasonably separated from other parts of your software, and as long as the model and rest of the stuff using GPL are distributed with the original license and with full source material, you would not have a problem. I'm not a lawyer though. The key issue to be concerned with is: would your application work without content licensed under GPL? If it does, then it's not going to be affected by GPL licensing terms. You would need to obey the license to the letter though when distributing the model and other artwork related to it, minus rendered images of it which don't fall under GPL either.
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Re: Question about licensing re: flightgear art.

Postby hvengel » Mon Sep 15, 2014 5:29 pm

Also it is possible for works to be duel (multi) licensed. If you are really concerned about possible issues you should contact the authors of the models you want to use and ask. Worst case is that they say no but I think that most would agree to commercial use for a modest license fee. Of course this is assuming the the model in question is the work of a single individual.
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Re: Question about licensing re: flightgear art.

Postby chriscalef » Mon Sep 15, 2014 9:37 pm

Cool. I'll probably just skirt the whole issue - in the end, the need to provide actual artwork shipped with Ecstasy Motion is much less than the need to make sure people know how to get their own artwork into the program. I'll probably provide at most one airplane model, maybe a complete freebie from somewhere or a programmer art hack, but in reality anyone using the program to make a movie will need to procure their own models anyway.

@Hooray, sorry for contributing to the noise, but I do appreciate the patient spoon feeding I've received. =-)
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