Technology Research Of 3D Modeling And Visualization Of Geological Body

The simulation and expression of the traditional geological information mainly use the following ways such as:planar graph,profile and 3D perspective drawing etc.While these methods can not show complex natural geological phenomena,can not make people understand the underground geological structure thoroughly,and can not satisfy the demands for engineers.3D Geosciences Modeling System(3DGMS) makes use of the visualization technology of computer to understand and express the geological body and environment from the 3D digital space in order to make up the shortcomings and deficiencies of the traditional geological information.In this paper the geological body is a geological object which is a lamellar distribution in the gross and has faults,folds,and strata inversion in the local.It mainly refers to the rock and lithosphere within 2000 meters depth underneath the ground.The data which express the geological body,is various and extensive.Therefore utilizing the information of drilling,roadway,and geophysical and geochemical exploration,and constructing irregular geological model to actualize the three-dimensional reconstruction and visualization,make us understand the geology regularity and orebody spatial distribution completely,make out objective and scientific exploration and mining proposals.Geological body 3D visualization modeling is a kind of technology which applies the modern spatial information theory to study formation and formation processing, data organization,spatial modeling and digital express,and utilizes the visualized technique to reappear the real 3D for stratum and environment information.In this paper we studied the 3D spatial data models in detail,Delaunay triangulated irregular network,all kinds of generation algorithms,some implementation tools of visualization,and gave the thinking and process of constructing,and developed 3D modeling and visualization of geological body based on the contour line of coal seam floor. At last,real data of the contour line of coal seam floor was taken as an example to test the experimental system. Main research conclusions as follows:(1) Through the research of 3D spatial models,TIN model is chosen to construct the geological body in this paper since it can use less data to express the model,overcome the data redundancy for flat areas and avoid the data interpolation required by Grid model.At the same time TIN model can also consider the characteristic of model,and express the fluctuant change.(2) Through the comparison and analysis to incremental insertion algorithms,four TIN constructing algorithms,we found that the triangle growing law is the easiest one, because it needs low memory and has good spatial performance.It can operate easily,so this method is chosen to design corresponding data structure.(3) Through the comparison to Direct3D,VRML and Java3D,we found the application of the Graph Library function of OpenGL has inimitableness advantage in visualization of 3D geological body.(4) VB 6.0 programming code is used and the experimental system of 3-dimenssion modeling and visualizing is established by applying the Graph Library function of OpenGL and the contour line of coal seam floor.The experimental system is divided into three parts:digital elevation and discrete points extraction(generation) module, Delaunay triangulated irregular network module and OpenGL 3-dimension display module.(5) In order to test the practicality of the 3D modeling and visualization experimental system established,the contour line of the second coal seam in Shandong is used as an example.It shows that the implementation method of the 3-demension model and experimental system in this paper is feasible through processing.3D modeling and visualization of geological body is a new type subject and technology which deal with geology exploration,geophysics,mine survey,GIS,graphic and iconology,and scientific visualization etc.The implementation method of 3D modeling and visualization of geological body in this paper has some feasibility and uniqueness,and further provides some beneficial enlightenment for the large software development of the geological body's 3D visualization.