A Rubik’s Cube is a 3-D puzzle designed to be enjoyed for 15 minutes, loathed 30 more minutes, and then placed in a drawer and forgotten. This is because the utility of a solved Rubik’s Cube is less than the utility of an unsolved Rubik’s Cube, so there is simply no motivation to solve it.
But imagine if you could turn any object whatsoever into a puzzle that needs to be solved before you can use it. That would be fun, right? Sure it would, if by “fun” you mean “the worst.” So let’s do it!
Two computer science students from Columbia University have developed a method that allows people who have no idea what they're doing to create twisting 3D puzzles from arbitrary 3D models. Once you have the model in a computer, you can select your own rotation planes, and an algorithm will munch through everything, adjusting your model to prevent collisions and then 3D printing all the bits and pieces so that they interlock and rotate properly:
At the moment, this method works best with 3D models that have a large spherical component to their design, although the researchers are working on generalizing their technique. They’re also experimenting with ways of allowing some pieces to block the rotation of other pieces, which would allow for more rotational axes while also potentially enhancing the difficulty of the puzzle. From the sound of things, the biggest source of frustration has been the 3D printing itself, which makes assembly tricky and leaves the puzzles a bit fragile. So other potential improvements would be automatic generation of assembly instructions along with optimization of joint design for robustness.
Computational Design of Twisty Joints and Puzzles, by Timothy Sun and Changxi Zheng from Columbia University, will be presented at SIGGRAPH 2015 in Los Angeles, but you can read the full-length paper ahead of time here.