Somewhat inspired by some of Robert Lang’s recent work, this model has a twist that transitions from a 16-sided ‘circle’ to a square. Interestingly, the bottom edges of the square tube are approximately parabolic segments. The center doesn’t quite collapse cleanly, but it’s close enough for practical purposes. This twist is a bit more challenging to fold than the ones I’m used to. I might try incorporating some multi-shape twists like these into some of my more complex models.
