Research On Automatic,Interactive And Implicit Regional 3D Geological Modeling And Cutting Analysis

The rapid and automatic 3D geological modeling and spatial cutting analysis based on the actual material map and drilling data of regional geological survey is of great significance for improving the expression level of regional geological survey results and assisting analysis and decision-making.Compared with the traditional explicit 3D geological modeling method,implicit 3D modeling has the advantages of high degree of automation,smooth surface and easy updating,which has become a research hotspot in the field of 3D geological modeling.However,the interactivity of implicit modeling,divide and conquer modeling and the matching implicit cutting analysis method are still unsolved problems.In this paper,the interaction and partition of regional geological bodies are studied.The main research contents are as follows:(1)Interaction modeling and divide and conquer modeling method.According to the interactive requirements of implicit modeling process,the corresponding data structure and modeling algorithm are designed to realize the interactive modeling process supporting backtracking and composition,which improves the flexibility of modeling process;For the modeling area with large range and large amount of data.the idea of "divide and rule" is adopted.The research area is divided into blocks for modeling,and the multithreading technology is introduced to improve the processing speed of modeling,and the topological consistency maintenance of the whole model is realized.(2)The combined cutting algorithm of 3D geological model based on dynamic quadtree index.Aiming at the problem that the time efficiency of continuous sectioning is not high for the model with large amount of data,the dynamic quadtree index method is introduced to quickly locate the triangular patches in the influence area of sectioning,and quickly generate the outline polygon set of the section according to the position relationship of intersection lines.Then,the geological section map is formed by polygon triangulation,which improves the efficiency of fence sectioning,continuous arc sectioning,cross-section and so on The speed of complex combination cutting and continuous cutting analysis functions such as step cutting and excavation analysis.(3)Based on HRBF implicit function and moving tetrahedron,an implicit method for 3D geological body cutting is proposed.In view of the problem that the traditional explicit cutting method relies on the 3D geological body model established in advance,which is easy to lead to the intersection of cavities due to the topology problem of the model,this paper introduces the implicit function to express various types of cutting planes,sets a reasonable cutting operation order,and the explicit operation and attribute definition method of the cutting plane mesh based on the moving tetrahedron,In this paper,a new implicit method of generating geological section plane directly from geological survey source data is proposed,which has the advantages of supporting multiple types of section plane and controllable depth and surface accuracy.Based on the above research,a series of 3D geological modeling and spatial analysis algorithms are designed,implemented and improved,and an automatic and interactive 3D Geological Modeling Visualization and spatial analysis software prototype system is developed.The modeling and spatial analysis experiments of several regional geological survey cases show that the modeling and analysis process and method proposed in this paper improve the interaction of 3D geological modeling and the efficiency of 3D geological body cutting analysis,and provide a new idea and reference for implicit 3D geological modeling and visual analysis theory.