  We present a tool for exploring the design space of shaders using an
interactive evolutionary algorithm integrated with the Unity editor, a
well-known commercial tool for video game development. Our framework leverages
the underlying graph-based representation of recent shader editors and
interactive evolution to allow designers to explore several visual options
starting from an existing shader. Our framework encodes the graph
representation of a current shader as a chromosome used to seed the evolution
of a shader population. It applies graph-based recombination and mutation with
a set of heuristics to create feasible shaders. The framework is an extension
of the Unity editor; thus, designers with little knowledge of evolutionary
computation (and shader programming) can interact with the underlying
evolutionary engine using the same visual interface used for working on game
scenes.
