This is the eleventh installment of the Monthly Topic Challenges with topics suggested and voted on here. This month's topic is "Now in 3D" (suggested by Jafe) and will span from the 1st of June to the 30th of June. During this period, we will compile the list of relevant questions and post it as an answer to this question.
In the meantime, please go and propose and vote on future challenges!
Everyone have fun, and happy puzzling!
Link to other Monthly Topic Challenges.
NOTE
The suggestion is copied to this post for posterity.
Now in 3D
The three-dimensional tag can bring a nice twist to a variety of puzzle types. We've seen paper folding, grid deduction, crosswords, mazes and even pencil-and-paper game puzzles use the extra dimension to great effect. While presenting 3D things in a 2D environment brings some challenges to both setters and solvers, the added dimension offers a nice opportunity to produce some real mind benders when done right. Creativity is encouraged – the only requirement here is that the puzzle somehow make use of three-dimensional space.