A semantic approach to patch-based procedural generation of urban road networks

A road network is one of the core elements of urban environments, strongly defining their layout. Procedural modeling has been increasingly used to create such road networks. However, many procedural methods are complex and difficult to master by non-experts, often have a limited and hard-to-control expressive range, and require a variety of specialized input data to generate a complex road network. To mitigate this, some methods proposed to use stochastic data on road patches extracted from example maps to design a road network following a given urban style. We propose a novel patch-based method that uses the semantics of individual patches to help guiding the procedural generation. Our approach combines the advantages of patch-based generation with those of conventional parametric methods. Due to the intuitive character of semantic parameters and tags, our approach provides for an easy customization of fictive road network creation, allowing a user to easily define various types of road network styles, containing only the desired features and structures of real-world road networks.