Key Techniques And System Development Of Slope Digital Geologic Logging In 3D Environment

With the fast development of computer technology and the computer analogue technology of geological information, the demands of engineering 3D visualization have been day and day exigent.Digital Geologic Logging Information System, which is based on photogrammetry, is a combination of close-range photogrammetry, digital image processing, and GIS techniques and has achieved the integration of geologic logging data acquisition, processing, management and analysis in hydroelectric project, which has upgraded specialty information and productivity level. Aiming at the shortages of the existing 3D modeling software, this paper has studied the 3D slope visualization technique for an excavated surface of a hydroelectric project, based on the data generated by digital geologic logging system, which are as follows:(1)The background terrain data is generated by the angle point coordinates of the slopes well, and the composite method of slopes and background terrain is discussed.the slopes and background models are built. Practical application indicates that this method can describe the spatial distribution and morphology of slope well,which meets the pratical requirements.(2)An approximate building the model of anomalous slope is put forwards and the surface image which can not be expanded on the spatial can be expanded.The expanding images are used to texture mapping. The technology of DEM is used to build the model of anomalous slope, and the horizontal projection image is used to texture mapping;(3)The technique of MIPMAP has to use up large numbers of EMS memory, therefore this paper put forwards the method throng the selective and feedback functions of OpenGL and the texture mapping, which combines the characteristic of 3D slope scene and the demands of logging. By this method, the scene can be established fleetly and the conflict between the drawing efficiency of large scene and the visual effect of analysis can also be resolved.(4) According to the technology of actual graphic drawing and the characteristic of slope scene, this paper has realized the dynamic and real-time browse in the slope scene. At the same time, the animated scene and the quickly position scene can also be realized. This method has satisfied the requirement of observation and analysis.(5)By learning from the pyramid method, the selective and feedback functions of OpenGL are improved to realize the precision selection. This method improves the efficiency and accuracy of the measurement and has been used in the 3D spatial query.(6)The methods of the primitive stereoscopic pair measurement and the true 3D aided measurement of analogue scene are used to improve the way of the analogue structural plane aided measurement.This method has resolved the problem which the linear geologic feature can not be digital logged and stored in 2D scene.(7)Based on the correlation research and combined the requirements of digital geologic logging, a practicable 3D slope visualization system of digital geologic logging has been designed and developed.