Yeah, everyone involved in FSF, CC, and content creators appears to agree that we (usually) want to interpret the combination of software and art as aggregation and thus being compatible In this case, though, we're talking about a composite of your art with someone else's GPLv2+ art in a single .png file, which I think we'd agree is a derived work of both art sources.
Oops, I did make a mistake in noting your license. I hope I can be forgiven in that I've been going through a *lot* of content verifying the licensing. And I totally understand requiring attribution.
I'm not a lawyer, but my understanding is that CC-BY-3 content can't be used in works derived under the GPLv2+. This comes from http://www.gnu.org/licenses/license-list.html saying that CC-BY-2 is definitely incompatible, and the wiki prepping for CC4 saying "it would really be nice to be unidirectionally GPLv3-compatible, because CC-BY and CC-BY-SA aren't currently", neither of which specifically answers the combination of GPLv2+ and CC-BY-3. I suspect, though, that if there was new GPL compatibility as of CC3, there would have been a lot more fanfare (like there was for the ability to mix CC-BY-3 with CC-BY-SA-3).
Yeah, everyone involved in FSF, CC, and content creators appears to agree that we (usually) want to interpret the combination of software and art as aggregation and thus being compatible In this case, though, we're talking about a composite of your art with someone else's GPLv2+ art in a single .png file, which I think we'd agree is a derived work of both art sources.
Oops, I did make a mistake in noting your license. I hope I can be forgiven in that I've been going through a *lot* of content verifying the licensing. And I totally understand requiring attribution.
I'm not a lawyer, but my understanding is that CC-BY-3 content can't be used in works derived under the GPLv2+. This comes from http://www.gnu.org/licenses/license-list.html saying that CC-BY-2 is definitely incompatible, and the wiki prepping for CC4 saying "it would really be nice to be unidirectionally GPLv3-compatible, because CC-BY and CC-BY-SA aren't currently", neither of which specifically answers the combination of GPLv2+ and CC-BY-3. I suspect, though, that if there was new GPL compatibility as of CC3, there would have been a lot more fanfare (like there was for the ability to mix CC-BY-3 with CC-BY-SA-3).