Please again remember that CGtalk renders [link] and DeviantART [link] renders are not allowed to be cut or used in anything you make. If your not sure if it came from CGtalk or DA then don't render it there are many other things you can render that look just as good. Gamewallpapers is not looked down apon because it is commercial art and is allowed to be used, same for most wallpapers found on gaming sites or anime sites. (to whoever moved this into non-gaming. I posted it here because there is not a topic about it here and apearently people don't know about cgtalk renders. Moved it back hope you dont mind )
Understood ... Even though I don't agree with it. (Since some of the work on their is rip offs of other peoples work .. AKA. Drawings of Yoda/Goku/Others. Which is no different then what we do.) But I won't render or feature any of them in my sigs since I was asked not too.
Damn it , LOL , I didn't even know sorry , Let me find another... See same person did this: http://www.deviantart.com/view/4246936/ Now how can someone who uses others peoples "work" (Gordon Freeman) , Be pissed at someone who uses theres? Sure he drew it the the idea wasn't his. Don't get me wrong his/her work is awesome. But its just how I see things.
If you have explicit consent from the creator, then you're allowed to render the image. Make sure when you post the render, you give a link to the persons DA/pieces and include the proof that you're allowed to render the image.
This has alot to do with copyright (gotta love them legal things). The character is copyright of whoever holds it, but the artwork is copyright of the creator (unless given to someone else). On dA the people who post their things hold the copyright of the artwork itself. That means that you need explicit permission to edit it in any way. Legally, GR could be sued if they allowed everyone to take random artwork and edit it. GR would be encouraging it and distributing it. So that's a huge reason to ban images supplied from those websites (dA specifically speaks about copyright, so no one can claim ignorance). I think stock images should be okay, so long as the source, on dA, is posted and permission is granted in the description. They are there for manipulating and sharing, after all. Just make sure to link back to the image (and be extra careful to read their terms, since they tend to vary quite a bit).