On an alternative framework for building virtual cities: supporting urban contextual modelling on demand

For various purposes, virtual city applications have been developed around the globe to provide users with online resources and services over the Internet. Following our research on the Sheffield Urban Contextual Databank (SUCoD) project, this paper presents an alternative framework for building virtual cities, which goes beyond conventional static urban modelling. A three-tier system framework is described in conjunction with the design and implementation of the SUCoD prototype. We demonstrate SUCoD's novel functionalities by showing that complex urban contextual information sets, including three-dimensional interactive models, multilayer interactive maps, and hypermedia documents, can be retrieved dynamically by user-specified urban contextual attributes, spatial locations, and boundaries. The three-tier framework also facilitates system development in an extensible way, allowing continuous parallel extensions of system functionalities, user-interface components, and contextual data resources. SUCoD's dynamic capabilities are considered crucial in its future uses for urban contextual modelling on demand in relation to the past, present, and future of the City of Sheffield.