Procedural modeling of round building geometry

Creation of procedural 3D building models can significantly lessen the costs of modeling, since it allows generating a variety of similar shapes from one procedural description. The common field of application for procedural modeling is modeling of straight building facades, which are very well suited for shape grammars - a special kind of procedural modeling system. In order to generate round building geometry, we present a way to setup different coordinate systems in shape grammars. Besides Cartesian, these are primarily cylindrical and spherical coordinate systems for generation of structures like towers or domes, that can procedurally adapt to different dimensions and parameters. The users can apply common splitting idioms from shape grammars in their familiar way, for creating round instead of straight geometry.