The Future of VRML on Large Urban Models

Abstract: In this paper, the suitability and usability of VRML for urbanmodelling is discussed based on the experience gained by the creation ofurban models of varying sizes, level of detail and use. Areas where the currentVRML specification is failing to satisfy the needs of large-scale urbanmodelling are highlighted. Properties of a successful alternative or VRML3.0specification are suggested and briefly discussed.Keywords: VRML, virtual word design, digital urban models. 1. Background During the past six years a series of three-dimensional urban computer models have beendeveloped in the Centre for Advanced Studies in Architecture (CASA) at the University ofBath. Computer models were constructed in order to assist in making the planning anddevelopment control process more flexible by providing a means by which planningproposals could be visualised and alternative schemes for a site compared; allowing non-experts to comprehend the implications of proposed changes. Developments in the domainsof Virtual Reality (VR) and the Internet triggered a series of research projects carried out inCASA to tackle the issues of interactivity, structuring and management of large urbandatabases.In 1991 CASA received a grant to construct a 3D computer model of the city of Bath. Themodel was constructed from aerial photographs using photogrammetry, is accurate to lessthan half a metre and covers the whole historic city centre, an approximate area of 2.5x2.0