[antiuniverse]

Very impressive, and I'm also seriously tempted to look into a pipeline to take these into Unreal Engine as an alternative to SpeedTree.

There's something I've been curious about, though, which is that since Blender is licensed under the GPL, aren't all these add-ons also forced to release under a GPL license? Which means the first person to pay the ~$500 is legally within their rights to reupload this product for the rest of the world to download freely?

Not trying to troll, though I worry it may come across that way. It's just that I've actually had a friend try to convince me to work on Blender add-ons for supplemental income, and it seemed like a bad idea for that reason... so I'd like to make sure I'm not missing something.

(I guess you can make the case that all the comparable non-GPL software gets pirated too, but this seemed somehow more demoralizing to me.)

[TylerE]

Blender plugins are python. No linkage.

[antiuniverse]

Hmm, I swear this must be new since last time I checked the Blender site, but it seems to address my concerns very succinctly, and apparently that's not relevant:

> Sharing or selling Blender add-ons (Python scripts)

> Blender’s Python API is an integral part of Blender, used to define the UI or develop tools for example. The GNU GPL license therefore requires that such scripts (if published) are being shared under a GPL GPL compatible license. You are free to sell such scripts, but the sales then is restricted to the download service itself. Your customers will receive the script under the same license, with the same free conditions as everyone has for Blender. Sharing Blender or its scripts is always OK and not piracy.

[vetinari]

This one looks like standalone application, that has integration plugin into Blender. Otherwise, you can export into other 3D packages and not use Blender at all.

[TylerE]

I would be very curious to see what a lawyer would make of that statement. It isn't consistent with what I've heard in the past regarding "scripting".

[nineteen999]

By the same token, anybody who distributed a fork of the said script is free to charge for it as well, as long as the source code (or patches thereto) is/are distributed under the GNU GPL or compatible license.

[elihu]

> Which means the first person to pay the ~$500 is legally within their rights to reupload this product for the rest of the world to download freely?

I'm not a lawyer, but I'm pretty sure that's not how the GPL works. If some company were violating the GPL with their product, the owners of the GPL work could sue them to stop them from shipping their product. Nothing in the GPL causes infringing works to automatically become GPL (though it would be one way for the infringing company to resolve the issue, if they so choose).

I don't know how or if the GPL applies in this particular situation, I'm just referring to how the GPL works in cases where actual infringement is happening.

[belorn]

Add-ons licensing are often debated and the answer to it is sadly the subjective answer to a very specific question: Would a judge see it as part of a single work or two works that operate independently and simply interacts with each other.

The common understanding is that in a single static linked software the different source files are just components that makes for a single work. They are not independent. Dynamic linked software could be argued as two works but FSF has a clear opinion that a judge will see the combination as a single work and has publicly stated they will bring it to the court if challenged, and so far no one has challenged them on that view.

Blender core is written in C and Blender engine is in c++. As such I would say the consensus is that all contributions to either of those must be under GPL.

But you are asking about blender add-ons and those are connected via the blender API that is written in python. Python is an interpreted language so what happens here? The answer goes back to the original question, what will a judge think, and the answer is that people don't know. Some say that it changes nothing and the code parts are just as dependent as if it had been dynamically linked, in which case the add-ons need to be GPL. Other disagree, through I do not know any case law here either so it mostly just people with different view about what the judge will say.

The API aspect is also an important part of the question. If the Blender API is closely connected to the internals of Blender then the distinction between an component and an independent work is blurred.

Last there is two more bits I would like to add. First, just like the other comment say, GPL can not force anything to be released as GPL. Copyright law create by default a law against distribution. A copyright license like GPL is a document that describe when you have permission. The only thing that happens when someone breaks the condition of gpl is that you loose that permission. As a side effect, if you loose permission and distributed the work at the same time you can get sued under the crime of copyright infringement.

The second additional bit is that interaction with non-code assets and code is itself a grey area of copyright law, but I think there is a small consensus that it would be seen by a judge as separate independent work.

[rgoulter]

AFAIU, only the code is licensed under GPL, but this wouldn't necessarily grant license to the assets the code relies on.