An amalgamated 3D spatial data model for city modelling

Abstract

3D spatial data models for city modelling have seen great improvement and most cities around the globe are now attempting to create virtual 3D models of their cities. The current city Earth surface is actually an amalgamation of natural and man - made objects above, on and below the city terrain surface. 3D modelling of subsurface objects and their integration with the surface and above surface objects has not seen much progress and the attempt at viewing above surface and subsurface man - made objects for Earth realism not achieved. Level of Details (LoD) for spatial objects has not been extended to man - made features below the surface. LoD0 maps for surface and subsurface integration exist for most city centres but this does not exist for 3D city models. Hence the need for a 3D data model suitable for above and below surface man - made constructions. This paper discusses 3D spatial data models currently in existence for the integration of surface and subsurface models. A suitable geometric and topological 3D object oriented model (3DOOM) is proposed using the 3D TIN as the base model. A vector approach using implicit geometry is used within a Mi crosoft Visual C plus plus 2010 programming environment with OpenGL libraries to create 3D spatial objects for the above and below surface man - made constructions. The simulation of an integrated 3D spatial model is presented.A stand - alone above and below 3D spatial models for man - made constructions is assessed up to LoD4 for the subsurface and LoD3 for the above surface in an integrated model.