Topological relations embodied in a generalized tri-prism (GTP) model for a 3D geoscience modeling system

摘要

3D geoscience modeling system (3D GMS) embodied with topological relations is of extreme importance for Geosciences. This paper presents a universal 3D model, generalized tri-prism (GTP) for 3D GMS and real-3D GIS, which is a modification and improvement of former presented analogous tri-prism (ATP) model and is the common model of pyramid model, tetrahedron model and tri-prism (TP) model. The GTP model takes the divergent drill holes, rather than triangulation network after interpolation or vertical parallel drill holes after projection transformation, as its direct data source. Hence, the reliability and quality of the 3D model is maximatily ensured. The GTP component is comprised of six primitives as node, TIN-edge, side-edge, TIN-face, side-face and GTP. Besides, three intermediary diagonal lines in each GTP component are temporary applied for spatial operations. Six groups of topological relations between the six primitives are carefully designed for geo-spatial inquiry and geo-spatial analysis. The mechanisms of chipping, dynamic updating and local refining operations of so constructed 3D geological model are introduced. A real-3D software platform, GeoMo(3D@), developed with VC++, OPGL and SQL server, demonstrates most of the 3D geospatial operations including clipping, separating, uncovering and geo-fence diagram generating based on an actual 3D geological model of a coal mine, Tangshan, P.R. China. (C) 2004 Elsevier Ltd. All rights reserved.