Interactive Constrained MAP-Elites: Analysis and Evaluation of the Expressiveness of the Feature Dimensions

In this article, we propose the interactive constrained multidimensional archive of phenotypic elites (MAP-Elites), a quality-diversity solution for game content generation, implemented as a new feature of the evolutionary dungeon designer (EDD): a mixed-initiative co-creativity tool for designing dungeons. The feature uses the MAP-Elites algorithm, an illumination algorithm that segregates the population among several cells depending on their scores with respect to different behavioral dimensions. Users can flexibly and dynamically alternate between these dimensions anytime, thus guiding the evolutionary process in an intuitive way, and then incorporate suggestions produced by the algorithm in their room designs. At the same time, any modifications performed by the human user will feed back into MAP-Elites, closing a circular workflow of constant mutual inspiration. This article presents the algorithm followed by an in-depth evaluation of the expressive range of all possible dimension combinations in several scenarios and discusses their influence in the fitness landscape and in the overall performance of the procedural content generation in the EDD.