We study the problem of folding a given polyomino $P$ into a polycube~$Q$, allowing faces of $Q$ to be covered multiple times. First, we define a variety of folding models according to whether the folds (a)~must be along grid lines of $P$ or can divide squares in half (diagonally and/or orthogonally), (b)~must be mountain or can be both mountain and valley, (c)~can remain flat (forming an angle of $180^), and (d)~whether the folding must lie on just the polycube surface or can have interior faces as well. Second, we give all inclusion relations among all models that fold on the grid lines of~$P$. Third, we characterize all polyominoes that can fold into a unit cube, in some models. Fourth, we give a linear-time dynamic programming algorithm to fold a tree-shaped polyomino into a constant-size polycube, in some models. Finally, we consider the triangular version of the problem, characterizing which polyiamonds fold into a regular tetrahedron.
|Number of pages||30|
|Journal||International Journal of Computational Geometry and Applications|
|Publication status||Published - 2018|
Fields of Expertise
- Information, Communication & Computing