Software to Construct Everything with Legos

If you remain a big kid at heart or, more practically speaking, if you enjoy architectural challenges, an algorithm developed by Romain Testuz should enable all your artistic fantasies through the famous small Lego pieces. This graduate work has received particular attention since its inception and has now been made public at a conference.

The software automatically transforms a three-dimensional image into bricks and simplifies the challenge of construction by proposing a comprehensive plan of the parts to be used on each floor. With it, any shape is possible. The only requirement is that the parts fit together.

As a student of the Laboratory for Computer Graphics and Geometrics (LGG), Romain Testuz chose this semester project because he loves to combine the virtual with the real: “The first challenge was to find research that had been conducted on this subject and to understand what wasn’t working in pursuit of a better solution.” He then spent the next several months with pockets full of Legos to resolve these problems and confirm the new model.

Construction: manual
After making his own 3D object or finding one on the internet, it is subjected to the software that transforms it. It begins by proposing the bricks smaller than 1/1. At this stage, this building is only realizable on the computer screen. The algorithm then uses trial and error to include the largest bricks in its realization: “It’s at this stage that we find the strength or weaknesses of the object,” explains the young developer, “because if the bricks don’t fit, your actual model collapses.”

To overcome structural weaknesses, Romain Testuz, along with his supervisor, Yuliy Schwartzburg, used graph theory. Representing each piece by a top – a red dot – and each connection by an edge – a blue line, it is possible to detect where the structure is fragile and needs to be repaired—all automatically.

A Gentleman 30 Floors High
Some additional features have been implemented to make the software even better. It can offer several construction solutions based on available materials, and it also allows the user to choose the color of the model or any specific part of it.
A man 30 stories tall – about 30 cm – now stands on Romain’s desk as a trophy of his finished work.

Next year Romain will continue his research at LGG in the field of caustics. In the meantime he is thinking about notifying LEGO of his research. In fact, the Danish company has put forth the challenge twice already to the scientific community to tackle the complexities of planning and construction by using their famous bricks.

Conference website: http://lgg.epfl.ch/publications.php