Are 3D questions on-topic or off-topic? Into what extent?
It's computer graphics, but it isn't graphic design.
It might be used to create elements of a design, but then so might photography - and like photography, it's a whole subject in its own right.
NB, personally I have changed my mind on this: Should we rename the site to 'Graphic art and design'?
These are my humble views which are now edited after e100's insightful answer
Off-topic by a mile:
3D In my view is way more off topic than, ie, exporting a gif as a part of a design.
(Don't take me wrong, I love 3D, would love an StackExchange site about it: Is one of my most solid areas of expertise and I truly enjoy it (also animating in 3D). But IMO this definitely would require to state clearly (like is asked here) if the site is about "all graphic" (as I understood initially, and would have preferred), in the way a lot of people treat the term of "graphic design", or graphic design theory, or which specific area of design. Probably in the "what would be off-topic" kind of examples that was not clear enough, and that might have caused the confusion, but we're in time, still at beta stage. )
I must admit I'm surprised at this. Several years ago, 2D and 3D design were very separate disciplines performed by different people in different buildings working for different agencies using different software and hardware, but the gap between the two is coming down as the cost and technical barriers are coming down.
I'm a graphic designer and I'd never identify myself as a 3D person, but I've recently started doing light 3D work because it's sometimes the most appropriate way to meet a design brief, and because it's now practical in a way it wasn't until recently. I was wondering why I never saw 3D, z-brush, cinema 4D, Maya questions here and it never occurred to me that they might be forbidden.
The convergence between 2D and 3D methods and working seems to be coming in the other direction too. 3D work seems to be in some ways becoming more like 2D, with workflows in many cases starting with 2D vector designs, and software like ZBrush and Cinema4D are being consciously, deliberately pushed towards the graphic design community in everything from their interface design to compatibilities to marketing.
I really think that if we're dogmatic about this, we'll end up behind the times, rigidly defending what was once a hard, sharp line but which has become a fluid continuum.
I agree with e100 in saying we need to draw a line somewhere and it should be led by analogies to graphic design's relationship with other related but ultimately separate disciplines. However, I think we should be consistent in where we draw these lines: drawing them towards the far end of these continuums, at the point beyond which there are clearly no longer any transferable principles, not the near end, where there are some non-transferable principles but where we're also throwing out or blocking useful, potentially transferable, design-related knowledge.
Please flag up anything that is wrong below, I'm still learning about this site. This is where I understand we draw the line with other related disciplines:
Slightly off-topic but related: