If I may interject - I know this comes post-issue, but I feel a lot of GDSE users are misguided in that they don't believe 3D graphic design falls under this SE.
My Reasoning - Just because a lot of current GDSE users might not necessarily know how to answer 3D design questions doesn't mean this isn't the place for it. The whole premise of Stack Exchange is to help people, so why are we turning away people that need help?
I agree that this is not a site for 'How-To' and tech support but by the same respect, most GDSE questions are 'How-To'. If you scroll down your feed it's mostly 'How do I do x'
There is an Area 51 subforum for 3D graphic design - http://area51.stackexchange.com/proposals/86368/3d-graphics-modeling-animation
However, I don't believe that is the place for it since it is Graphic Design. By definition Graphic Design is the process of visual communication through the use of images and space - that I believe includes the 3D spectrum. Photoshop has the ability to do minimal 3D renderings, does that mean I should go to a different forum to ask my question?
Take for example StackOverflow. If it is a question regarding code, it doesn't matter what program you are using, it is still a valid question.
We should embrace these 3D design questions, and have them tagged as such. People who are active in the 3D graphic design world also probably know a decent amount of photoshop and other GD topics - they could be a great addition to the GDSE community. Why would we not want to grow GDSE? - I understand with limited moderation it can be difficult to scale up, but I think you are missing the overall idea of Stack Exchange.
Instead of dispersing all 3D questions elsewhere on the internet, making GDSE even less capable of answering 3D questions, we migrate those questions here. Build the 3D community and those who don't know how to answer the questions don't need to think about it.