A Scaleable Approach to Visualization of Large Virtual Cities

Visualization of large urban complexes on the web is highly demanding task both from the networking and computational point of view. The whole threedimensional model of a city is mostly too big to be downloaded in a reasonable time and to be stored in a memory of commonly used computers. This paper presents a scaleable approach for subdividing an urban model into smaller parts. Dynamic loading and unloading data allows theoretically unlimited extension of a model with constant network and computation load. Further requirements specific to presentation of virtual cities are also discussed. Theoretical considerations are followed by a practical implementation utilizing VRML language for modeling historical city of Prague.