You can steal his 3d model, make 32x32 image from it wihout mentioning the source. No one will know that, because it'll be very very hard to prove that you used exactly this model to do so. Then, you won't be able to sleep at nights, you'll think "Oh no, oh no. I stole the 3d model of Submachine Gun made by Kutejnikov from opengameart.org! How can I live after that?!". Then you'll lose your job, because of all that alcohol you consumed to forget about stealing 3d model of Submachine Gun made by Kutejnikov from opengameart.org. Then you will start taking drugs, your wife will leave you, she will take the house and children. You'll be lying on the street thinking about that 3d model made by Kutejnikov, how you stole it without mentioning his name. Then you won't be able to live any longer. You'll write a death note, where you will mention Kutejnikov, his 3d model of SMG and opengameart.org.

Or you can mention his work.

It depends on how Theseus's ship was replaced.

Did you use the original 3D model as a starting-point, as a base, or as a guide in any way when rendering the 32x32 pixel file? Did you use the original 3D model when rendering the single 1x1 pixel file? If so, Theseus must be credited as the original sailor.

In other words, if it was ever Theseus's ship, it is always Theseus's ship by copyright law. Even that 1x1 pixel black square is considered a derivative of Kutejnikov's model. Ridiculous? Of course, but you didn't ask if copyright laws make sense, only what it says about derivation. :)

this is good topic of discussion in general. i commented recently on buch's orthographic outdoor tiles  about how  incredibly similar the houses are to the ones from a link to the past on the snes. i really want to use those tiles in a game i'm working on, but when i zoom in on the door of buch's tile and i zoom in on the door of the same tile from the lttp tileset rip it is so very very close. it looks to my eye like derivative work. as i said in my comment, this is not intended to be an attack on buch's work or an indictment of the artist's ethical integrity, it is just my eye seeing something that looks like derivative work.

so what is derivative then? if i use the house from a link to the past as a "drawing reference" and my door that i created pixel by pixel looks identical or almost identical then it is still derivative legally is it not? even if i did not use any pixels from the door, am i  not still opening myself up to cease and desist? will shigeru miyamoto come to my house and punch me in the nose?

i used to be into making fan games using ripped sprites from nintendo games, back when i was a kid. it was a great way to learn gamedev, but it was illegal too. and now (so many years later) alot of kids are doing the same thing and getting their projects dmca'ed  into oblivion by nintendo. this is exactly what i am trying to avoid as i get back into hobbyist gamedev after a 15 year hiatus. i found this great resource that you guys and gals have put together, i love so much of the art work on here, but i wonder what kind of human oversight is going on (or even possible) to ensure that someone does not upload a stray nintendo pixel :p i jest somewhat, but seriously, this resource allows people to use this art commercially. if i make a game and sell it is it not my toosh that's on the line if that cc0 tileset i found actually had grass ripped and resized from some obscure korean rpg or something?

sorry to jump in on your post like vladimir, but i just joined and this is exactly the topic that i am struggling with as i navigate the art assets on this site.

cheers

"so what is derivative then? if i use the house from a link to the past as a "drawing reference" and my door that i created pixel by pixel looks identical or almost identical then it is still derivative legally is it not? even if i did not use any pixels from the door, am i  not still opening myself up to cease and desist? will shigeru miyamoto come to my house and punch me in the nose?"

If you used LttP art as a drawing reference, then yes, it would be derivative. If you created a door without using LttP art as a reference or guide, but you were simply inspired by the game LttP (as Buch did), then no it would not be a derivative. If your scenario is that you created a door that is pixel-per-pixel exactly the same as the doors in Legend of Zelda, but you didn't use any LoZ art as a reference or guide, then that would not be a derivative despite being identical. The problem with that is no one would believe you. I certainly wouldn't. The probability of recreating even a small 32x32 pixel tile of a door so exactly by chance is still 1 : 33,554,432 against. So, yes, in that scenario, Shigeru would still punch you in the face. Not because you're breaking copyright, but because no reasonable person would conclude that you did anything else. 

You did bring up a good point about Buch's artwork. It is very similar, intentionally so. I am not necessarily an expert on pixel art derivation, but I've gotten pretty good at telling the difference. Namely, if there are differences in shape, texture, proportion, and palette, that tends to indicate inspiration, not derivation. The whole point of deriving art from other preexisting art is to save time and effort in getting the colors, shapes, alignment, etc. from work that's already been done. There would be no advantage for Buch to mimic everything about Legend of Zelda art except for the very features that save him time and effort.

i get what you are saying, and having done quite a bit of work (back in the stone age) editing nintendo sprites i definately see your point about the shape and alignment, and the indication that these feature lend to the interpretation that it is inspirational and not derivative. i especially liked your transition from buch to lttp that you posted in the comments on that asset, it showed my eyes exactly what you are saying about the shape and significant deviations.

and i have decided to go ahead and use buch's awesome house sprites. but i changeed the door :p

i don't know why but it was the door that was really sticking out to my eye.

the tileset kind of reminds me of the old graal online game from back in the day, it had a spritesheet base that was heavily inspired by lttp but i believe they successfully defended themselves from a lawsuit or some such. that was a long time ago and i am so old i am going senile so who knows. but anyways, thanks a billion for the clarification and the kindness. i can tell that this is a great community.

and i am sure i won't be the only one using buch's lovely tileset, so we will all get punched by miyamoto together :)

about the door: i would argue that there are multiple ways to draw a door. in fact, because i am uncomfortable with the door in this sprite (not because it doesnt look good, but because it looks so much like lttp's door) i editing a door from a different cc0 sprite sheet and fitting it into the pallette of buch's house.

about russia and all that: i think this gets into another very tricky area. copyright law is different everywhere. i live in america, i don't where medicinestorm is from. but her interpretation aligns with my understanding of american copyright law. if a work is in any way derived from another work then it is derivative. how this would play out in court, and what "fair use" is under copyright law is all complicated and hard for us laypeople to understand. there is a reason why cc licenses have a "human" readable version so non-lawyers can try to understand the terms. but there is also a reason why those "human readable" versions are not the actual licenses and they explicitly tell you that what you are agreeing to is the terms of the lawyer'speak license, not the explanation of the terms in the "human readable" form.

i am trying to keep in mind both what is ethical and what is legal, and using rational, logical analysis to determine what is ok both ethically and legally. but i am a video game nerd who dropped out of college because i didn't like math. i am not a trained ethicist or a lawyer.

ultimately you will, as an individual, have to decide what is ethical and legal for you to do, and you will also have to accept the consequences (positive or negative) for those choices. noone at opengameart can make you use the art found on here, they can't make you follow the license the work is provided under, and likely will not sue you if you don't follow it. they can't stop you from using it correctly, and they can't really stop you from using it incorrectly. there may be consequences to using it incorrectly, but you will ultimately make your own choice. and maybe Kutejnikov will come and punch you in the nose for stealing his gun and turning it into a 1x1 black pixel. probably not.

for the sake of the conversation, i went ahead and drew (very poorly) a gun in mspaint. i did not copy the image from above and "trace" over it with layers, i just used it at as "drawing reference" and redrew it in mspaint. this file is therefore derivative work, atleast based on my understanding of american copyright law. so Kutejnikov can actually come and punch me in the nose if i don't release this under the terms of the license that he licensed it to me as. so in the spirit of that, this stolengun.png file is a derivative work of 

Submachine Gun (Scorpion-inspired) and licensed under CC-by-4.0

changes were made by rrodg84 and all license requirements of the original license apply to the derivative work.

furthermore, i could not (atleast in my understanding of the cc-by license) use this stolengun.png artwork in the game i am working on because i use a proprietary game engine, to which i am licensed distribution of the runtime, but not licensed the abilty to distribute (or even access) the source code of that runtime. so the technological measures of the cc-by license would be violated by my inability to allow other users to edit the actual graphics file that is used by the runtime, i could include the stolengun.png file in my distribution and give attribution, but that solengun.png file would not be the ACTUAL image that was displayed by the runtime.

i know this all seems like splitting hairs and making mountains out of molehills. in a way it is. copyright law and fair use is a gray area all over the internet, and fair use doesn't come into play with the files on this site because it is dedicated to "free" and "copylefted" artworks.

great discussion though

No, it's about money, not prisons. Suing isn't free. If I release something under restrictive license and you steal it, I simply won't be able to do much about it, unless you make a lot of money with it and then, may be, if I have a chance to get that money from you and it's bigger than expenses, then yeah, there will be a reason to sue you. Otherwise we will both lose and the court will be the only winner.

"at least in Russia, at the beginning of the trial, the judge says: "guided by the law and COMMON SENSE." By your logic, if I take a picture of a black square on the screen, will it cease to be a derivative? where is the logic? if none of those present can tell me something that I do not know, let me speculate. to understand whether a file is derivative or not, we need some features of the original that make it different from most. in this case it is: the shape and color of the handle, and the folded stock. accordingly, if these characteristics of the source file are absent, then these are 2 different projects, albeit made in the same style.

Hmm. It seems like you are moving the goalposts after the game has started, my dude. The original (paraphrased) question was:

"what constitutes a derivative, according to copyright law?"

Now it seems to have changed into:

"what could someone get away with in court, despite copyright law?"

What is true and what can be proven in court are two different things. (Because OGA is a US-based site, you can always safely assume any license discussion on OGA is about US law by default unless stated otherwise)

The truth is if you use any part of someone else's work to create your work, it is a derivative of that other person's work. 

What can be proven is ... well, not much if the derivative looks nothing like the original. It doesn't change the fact that a 1x1 pixel black square is a derivative of a 32x32 pixel gun which is a derivative of a 256x256 2D rendition derived from a 3D model, but like you say, the Judge is going to say "according to COMMON SENSE, there is no evidence this is a derivative. Case dismissed!". However, if you discussed on the internet about using a particular 3D model of a gun to make a black square, then there IS a way to prove that it's a derivative; that internet discussion can be used as evidence.

Common sense works both ways, though. As in my hypothetical scenario about rrodg84 creating a door that, by REMARKABLE COINCIDENCE is exactly the same as a Legend of Zelda door, even though he didn't use any of Nintendo's assets as references or guides, the judge is going to say "according to COMMON SENSE, this is a derivative. In fact, its a blatant rip-off copy!" even if that's not actually true.

"...By your logic, if I take a picture of a black square on the screen, will it cease to be a derivative?..."

No, that is not what I was trying to say. If you took a picture of a black square on the screen, then it would indeed be a derivative; You used someone else's work (the black square on the screen) to make a different asset (the picture you took). That particular scenario tends to fall under Fair Use, so it doesn't matter much, but the other scenarios we've been discussing would not be so forgiven by Fair Use.

... to understand whether a file is derivative or not, we need some features of the original that make it different from most. in this case it is: the shape and color of the handle, and the folded stock. accordingly, if these characteristics of the source file are absent, then these are 2 different projects, albeit made in the same style."

Nope. Sorry, that isn't what makes something a derivative or not. Yes they would be two different projects, but one would still be a derivative of the other, and therefore subject to the original copyright. The uniqueness of the original asset, nor the absence of such unique features in the new asset, are irrelevant to it being a derivative or not. Those things tend to make it easier to prove, though. If you used any part of someone else's work as a base, a guide, a shape reference, whatever, in the process of making your new asset, then your new asset is a derivative of it. It doesn't matter if the new asset looks nothing alike, though that does make it difficult to prove.

I have no idea why you would bother using another asset to make some new asset that looks nothing like it. It would be easier to just start from scratch at that point. Never-the-less, the truth is, it's a derivative, even if it's too difficult to prove that in court. Which is why buttons is right as well. It's usually about money, not the truth. The chances of actually getting in trouble for failing to attribute a derivative are shockingly slim.