Is the output of a generator tool copyrighted? [GPL3 and CC BY-SA 3.0] I am developing a game right now and wanted to use character sprites created by a generator under a GPL and CC BY-SA 3.0 license. In my understanding the GPL license does not cover the output of the program, but the program itself. But I can't really tell if the Creative Commons licence prevents me from using the generated images. I'm not planning to publish my game anytime soon, but I don't want to regret using open source software later on. I don't want to be forced to publish my whole game under the same license, just because I use some generated images. Is that possible?
Your understanding of the GPL is a bit off. GPLed code doesn't generally force you to GPL the output of the program, but that's just because the output of the program is normally not a derivative work of the program. For instance, if you write a novel in Emacs, your novel is an entirely original work. The fact that you used Emacs as a tool doesn't mean that your novel is somehow based on Emacs. This generator is different. It generates sprites by putting together art assets made by the program's creator. That means that the output contains a substantial amount of content made by the program creator, which means that it would likely be covered by the program creator's copyright. If the content was licensed to you under the GPL, you normally have to abide by GPL restrictions when you redistribute the content or incorporate it into your own program. Copyright holders can, if they want, grant additional permissions to their content and allow you to incorporate that content into nonfree software. For instance, the GCC compilers have an additional permission for their runtime libraries to let you use them in any GCC-compiled code; without that permission, GCC could only be used to compile GPL-compatible code. But unless the copyright holder has granted those permissions, when program output contains large amounts of their copyrighted content you're bound by the GPL when using it. In this case, the program specifically says that the art is dual-licensed under GPLv3 and CC-BY-SA-3.0. Since the generator's output is a combination of premade art assets (the buttons just let you tell the program which art assets to combine), the output is a derivative work of those assets. You can't use it unless your use is compatible with the GPL v3 or CC-BY-SA-3.0 (either works, since dual licensing lets you pick either license).
The creator of the derivative work has copyright in the derivative work. The copyright would protect only the new elements of the derivative work. Wikipedia is a good place to start. In the case of a book with updated grammar, depending on the extent of the changes, it would probably be easier to copy the original directly than to eliminate the updates from a copy of the derivative work.
The image is almost surely protected by copyright. The model used in the game would probably be a derivative work of the original image. As such, permission from the copyright holder on the original image would be required. In the absence of such permission, the copyright holder could sue for infringement, and have a reasonable chance of winning. Whether such a holder would choose to sue cannot be predicted. It would depend on whether the holder ever learned of the infringement in the first place, whether it could be proven, and the degree of damages that might plausibly be claimed. It would also depend on the holder's attitude toward such circumstances. In addition, the gun makers might claim trademark infringement. This would depend on how recognizable the guns are, and what trademarks the makers have secured protection on. If a logo is visible and recognizable, that would strengthen a claim by the maker. On the conditions described in the question, trademark infringement seems a bit unlikely, but exact details will matter in such a case, so one cannot be confident in any generic answer on that point.
IF part of your code and data is non-open-source, you can't release this software under the MIT license. However, from what I know, CS:GO uses real-life weapons, and their names aren't protected by copyright. Weapon stats aren't copyrightable either. With skin names, you should be safe as well, since there isn't enough (or any) lore around them to establish them as literary works. However, if you are using any in-game descriptions or images, they are copyrighted content and can't be legally copied without permission from Valve. Which might be easy to obtain by writing them.
Yes. The copyright owner of a work has the exclusive right to "reproduce the copyrighted work" or to make "derivative works" of it. 17 USC 106. Copyright law is older than the photocopier, and it applies to copies made by means of any technology. If your intent is to duplicate the protected work, whether you do it by tracing, photocopying, or even freehand, you are infringing that right. It is possible that you could squeeze into one of the copyright exceptions, such as fair use, but these are much narrower than people tend to assume they are (especially outside of the U.S.), and they boil down to: "Well, yes, I copied your copyrighted work, but..." The bottom line is: is it copyrighted? Did you copy it, in whole or in part? Then, unless you have a very good reason, you've infringed the copyright. Whether you do it by means of tracing paper, jellygraph, or iPhone doesn't matter.
Using it without permission is copyright infringement and illegal. Legally, you can try offering money to the company for the copyright or for a suitable license. For example offer them $1000 for a copy of the code licensed under the GPL license. If they accept, you are fine.
No. That clause does not give other users a licence to reproduce the work (other than what is necessary to access or use it) or create derivative works. The copyright owner has the exclusive right to do those things. (See 17 USC 106.) The clause you quote only indicates that other users can "access" (download for viewing) your "information" and use it, too. It doesn't give away any of your exclusive copyright in the work. You do grant Facebook a licence to do certain things with your work in section 2.1 of the Terms of Service, though.
In general, the output of a program is not copyrighted by the author of the program. When you write a novel in Word, Microsoft doesn't own any copyright in your novel. When you prepare financial statements with Excel, Microsoft doesn't own any copyright in those either. There can be exceptions. Some programs (like GNU Bison, a parser generator) actually do output parts of their own source code, and their source code is copyright to the author. To clarify things, GNU made a statement in the license for Bison that officially says they don't have copyright to what it outputs. You should expect programs of this type to have such an exception, and if they don't, maybe ask the author or don't use them.