Abstract
The LEGO brick system is one of the most popular toys in the world. It can stimulate one's creativity while being lots of fun. It is however very hard for the naive user to assemble complex models without instructions. In this work, we propose a method that converts 3D polygonal models into LEGO brick building instructions automatically. The most important part of the conversion is that the connectivity between the bricks should be assured. For this, we introduce a graph structure named "legograph" that allows us to generate physically sound models that do not fall apart by managing the connections between the bricks. We show some experimental results and evaluation results. These show that the 3D brick models generated following the instructions generated by our method do not fall apart and that one can learn how to efficiently build 3D structures from our instructions.
