Discussion On3D Modeling Method And The Geological Spatial Surface Reconstructon

In order to process the scattered data points for engineering geological space and numerous geological objects information, useing multi-layer B-spline interpolation method and NURBS method, based on the theory of engineering geology, and combined with database technology and data structure technology, a system which integrates database management and data processing of geological information is further improved in this paper. According to the law of the geological structure, the system can rebuild the interface of terrain, stratum, weathering, unloading boundaries and groundwater table, achieve3D visualization, build a three-dimensional geological model through the interactive user interface, and with an example to verify the validity and reasonableness of the surface reconstruction method. The main reaserch contents as following:(1) According to the current geological research results of3D visualization, Through the existing vector topographic map, the field exploration observation data and remote sensing system for the3D discrete points data of geological objects. Using the multi-layer B-spline interpolation method after comparison of spatial interpolation methods to interpolate or approximate the irregular scattered data points of engineering geology by encrypting or sparsing grids. It improves the precision and smooth of3D geological model through controlling the interpolation layer and the grid step length.(2) Based on the laws of geological structure and the classification method of rock weathering and unloading, Using the NURBS surface fitting and OpenGL technology to rebuild the geological object surface with effective control points which were processed by the multi-layer B-spline interpolation method. The visualization of three-dimensional geological interface of topography, stratigraphy, unloading, weathering and groundwater in the area of engineering geology is achieved. In order to make the three-dimensional geological object model more realistic, based on graphical display principle to rotate the model, clipping, smooth and blanking, texture mapping and other operations. (3) Further to complete the3D visualization system VisualDRM3D of engineering geology information. The system mainly includes three big function module:data management,3D geological modeling and engineering application, which integrates database management, data processing and3D visualization. It uses the related data structures and the effective application of database module, couples multivariate geological data, interplates the original irregular scattered data, realizes the interface reconstruction of geological objects and the3D visualization.So it can establishes the three-dimensional geological modelling, which fully reflects the intelligent of three-dimensional geological modeling.(4) Based on the engineering geological theory,3D modeling method is proposed above and the characteristics of the scattered data of engineering geology, taking Maerdang hydropower station in Qinghai province as an example, the geological spatial data interpolation and3D Modeling is discussed, which provided an effective approach for scattered data points in the actual project, and the effective application of the interface reconstruction of geological objects and3D visualization provides a foundation to three-dimensional modeling and geological analysis later.