  Designers increasingly rely on procedural generation for automatic generation
of content in various industries. These techniques require extensive knowledge
of the desired content, and about how to actually implement such procedural
methods. Algorithms for learning interpretable generative models from example
content could alleviate both difficulties. We propose SIGI, a novel method for
inferring shapes and inducing a shape grammar from grid-based 3D building
examples. This interpretable grammar is well-suited for co-creative design.
Applied to Minecraft buildings, we show how the shape grammar can be used to
automatically generate new buildings in a similar style.
