The document discusses an algorithm called the Architectonic Style Area (ASA) algorithm for procedurally generating 3D buildings in virtual worlds based on architectural styles of real-world areas. The ASA algorithm uses statistical descriptions of architectural elements to automatically create realistic building facades without manually modeling each one. Modelers define common building templates for an area along with statistical values for architectural parameters of each template. The algorithm then procedurally generates buildings by sampling from these parameters to assemble realistic facade textures. This allows large virtual areas to be populated with diverse, culturally authentic buildings efficiently.