Methodologies and tools for large-scale, real-world, virtual environments: a prototype to enhance the understanding of historic Newcastle upon Tyne

There is a growing demand for comprehensive 3D infomlation, for improved inventory, analysis , prediction, simulation and visualization , Increasing attention is heing given to the requirements of comprehensive information systems, such as Geographical Information Systems (GIS) , to move from the utilization of predominantly 2D digital mapped data sets to those that are fully 3D, Most commercially available GIS still cannot handle true 3D data, but most Computer Aided Design (CAD) systems can, These CAD systems have all the required functionality for manipulating the data, but have restricted data structure (Kraak, 1 989). Some recent GIS , developed by major CAD vendors, have overcome this direction problem. A CAD product by such a vendor is used in this work to construct the initial 3D model.