3D Interlocking Puzzles


3D Interlocking puzzles are very challenging geometric problems with the fascinating property that once we solve one by putting together the puzzle pieces, the puzzle pieces interlock with one another, preventing the assembly from falling apart. One has to identify and follow certain orders to assemble the puzzle pieces into the target shape.


Please click the icon of each puzzle in the table to download the 3D models, e.g., for 3D printing.

K = 4 K = 6 K = 8 K = 10 K = 12 K = 14


Puzzles.   Each puzzle in the above table is recursive interlocking, meaning that the assembly of puzzle pieces (with at least three pieces) remains an interlocking puzzle after the (sequential) removal of pieces. Here, the number of pieces in each puzzle is denoted as K.

Assembly.   For each interlocking puzzle with K pieces, the OBJ models of the puzzle pieces are named as Piece_i.obj (i = {1, ..., K}), where i represents the assembly order of the piece; i.e., Piece_1.obj is the first piece to assemble and Piece_K.obj is the last piece to assemble (i.e., the key piece).

Visualization.   The downloaded puzzle pieces can be visualized with MeshLab, and their assembly procedure can be assisted by showing/hiding certain puzzle pieces in the software.


The interlocking puzzles are generated based on the methods proposed in the following paper:
  • Peng Song, Chi-Wing Fu, and Daniel Cohen-Or. Recursive Interlocking Puzzles . ACM Transactions on Graphics (SIGGRAPH Asia), 31(6), Article No. 128, 2012.