StackBlock: block-shaped interface for flexible stacking

We propose a novel building-block interface called StackBlock that allows users to precisely construct 3D shapes by stacking blocks at arbitrary positions and angles. Infrared LEDs and phototransistors are laid in a matrix on each surface of a block to detect the areas contacted by other blocks. Contact-area information is transmitted to the bottom block by the relay of infrared communication between the stacked blocks, and then the bottom block sends all information to the host computer for recognizing the 3D shape. We implemented a prototype of StackBlock with several blocks and evaluated the accuracy and latency of 3D shape recognition. As a result, StackBlock could sufficiently perform 3D shape recognition for users' flexible stacking.