Overall Design And Implementation Techniques For GeoModel, A 3D Geo-object Modeling And Visualization System

3D geo-object modeling and visualization technology is the leading edge field of geosciences as well as an important part of 3D-GIS, the study of which can supplement the basic theory of 3D-GIS, widen its application area, and also promote the development of quantitative geology. As the advanced stage and practical application of 3D modeling and visualization technology, true 3D subsurface modeling software can provide technical support for geologic prospecting, mine development management, and underground safety as well as give core solutions for mine informatization. In fact, the research is of both theoretical and practical significances. Through exploring the history and actuality of the advanced 3D mining software in western countries as well as analyzing the basic theories of visualization technology and spatial modeling techniques, a 3D mine modeling and visualization system called GeoModel was designed and its key implementation technologies were discussed. Based on HOOPS/3dAF, the system integrated spatial database techniques, 2D constrained/unconstrained triangulation techniques, 3D constrained triangulation techniques, techniques of forming a closed surface from several open surfaces, grid modeling techniques based on different interpolation methods, fault modeling techniques based on a projection method, regular solid modeling techniques based on parameterization, and irregular solid modeling techniques based on linear octree coding. The original ideas of the research are as follows: 1) A 3D geo-object modeling and visualization system called GeoModel was designed, which consists of HOOPS/3dAF, a 3D spatial geologic database, an integrated solution for surface modeling, and a solid modeling scheme. 2) A geo-object concept model suitable for 3D geo-object modeling and visualization was established, in which geo-objects were divided into six categories ( point, string, open surface, close surface, regular solid, and irregular solid), and corresponding computer graphics representations were given to the six categories. 3) Aiming at the complexity of geo-object surface, an integrated surface modeling solution was put forward, which consists of grid modeling based on various interpolation methods, 2D constrained / unconstrained triangulation, 3D constrained triangulation, and the technique of forming a closed surface from several open surfaces. 4) Through exploring fault modeling, a fault modeling solution dominated by a projection method was invented. 5) In the paper a linear octree modeling method based Gargantini coding was introduced into solid modeling. The encoding and decoding, compression, set...