Research Of 3D Dynamic Emulation Technology On Geo-Process

Visualization of the 3D terrain and emulational technology of river routing and mountain upheaving on geo-process are main questions that are discussed in this thesis.Compared with some different denotations of digital terrain , the advantage of terrain modeling using regular reseau is better than using anomalistic trigonal reseaus. The basic theory of 3D terrain modeling and programming method based OpenGL is expatiated.The searching arithmetic that adapts to river routing is programmed through studying and comparing all kinds of searching arithmetics. In addition, the arithmetic of dynamic dispaying on the side of mountain upheaving is preseneted too.Visualization of the 3D terrain is realized in the course of researching. Visualization of the terrain is pivotal technique in GIS and VR, and it is also the pivotal thchnique of studying dynamic display on geo-process. 3D model can be founded in GIS, but it can be controlled rarely. 3D graphics can be protracted by using OpenGL, and 3D technique is offered in OpenGL. But the complicated graphics can not be protracted in OpenGL. We need a method to fall together the two technique. The pivotal technique to solve the problem is using GIS to found model and using technique of protracting graphics in OpenGL to realize 3D terrain realization.The foundation of digital geographic environment is building 3D terrain, and the resource of data is correlative space data that is managed by GIS. When 3D geographic environment of object' s region is founded, the imminent creating technique of graphics of rectangle reseau and triangle reseau is adopted to found emulational model. The 3D cooedinates of every data point are reproduced really in the terrain that is founded. In addition, the model is predigested to quicken the speed. The system adopts the technology of texture mapping, illumination, light reflection of colorful material etc, and the 3D terrain is presented really.The system is designed from founding space -time adaptive model and selecting boundary searching algorithm , ignoring secondary factors and simplifying boundary conditions. Analyzing the space-time adaptive relation of river routing and basin terrain and using the algorithm of breadth_first search, the searching model of the watercourse boundary and the realizing model of dynamic river routing are founded. The spontaneously searching function of the watercourse and overwhelmed area is realized. Dynamic simulation of river routing is based on computer graphics and VR technology and imitate the river' s propelling condition in the virtual situation of the computer. The river routing is reproduced according to given level of the water, and this is the foundation of reproducing river routing more really under the condition of thinking about water dynamics.Visual C++ is the programming flat of the dynamic 3D emulation system. The system realizes 3D visualization of object region, integrating the programming technique of GIS and OpenGL. Using the algorithm of breadth_f irst search, the system decides the adaptive relation of moving water and shape of basin channel and make thevisual effect of river routing true, mountain upheaving also is studied in the system. Visualization of the 3D terrain and emulational technology of river routing and mountain upheaving is effective.