Research On Key Technologies Of Virtual Simulation Experiment System For Geomorphologic Evolution Of Taiwan Strait

Geomorphology is a discipline that studies the morphological characteristics,genesis,distribution and evolution of the earth's surface.It has strong perception,practicality and comprehensiveness.However,the on-site experimental environment is subject to the limitations of time and space dynamics,and it is impossible to obtain the effect of situational learning in depth.Based on the complementary construction of on-site experimental support conditions,this paper builds a comprehensive and collaborative geographic experimental environment of "combination of virtual and real".According to the teaching goals and experimental needs in geomorphology,taking the Taiwan Strait as an example,we have conducted in-depth research on how to describe the evolution of the Taiwan Strait from static description to three-dimensional dynamic simulation,from result research to process restoration since the last glacial maximum.Finally,based on the game engine Unity 3D,a virtual simulation experiment system for the evolution of the Taiwan Strait geomorphology was designed.The research perspective has shifted from the geographical cognition in the "Evolution of the Taiwan Strait" to the various scenarios that occur in the "virtual environment".Incorporate its complex,ambiguous,diverse geographic space,geographic process and geographic mechanism into the virtual space-time reference frame for visual expression and analysis.Therefore,three key research technologies are studied:(1)Research on the 3D visualization method of seabed topography.This paper combines the water depth points,isobaths and coastline data extracted from the S-57 standard electronic chart data to compare different submarine topographic interpolation methods.The Kriging method that integrates the mainland edge with better interpolation effect and relatively high interpolation accuracy is selected to generate the submarine digital elevation model of the Taiwan Strait to supplement the water depth points.Combining with GIS technology,in Unity 3D,the optimization of the traditional point-by-point interpolation algorithm in the Delaunay triangulation algorithm combined with the isobath and the minimum standard deviation criterion is realized,and the real seabed topography of the Taiwan Strait is constructed.(2)Real-time and realistic rendering of the three-dimensional sea surface.The fast Fourier transform algorithm based on the ocean statistical model is used to construct a three-dimensional sea surface dynamic grid,and the parallel processing of the Computer Shader is used to accelerate the FFT algorithm.At the same time,the Unity Shader technology is used to render optical effects such as the reflection,refraction and Fresnel effect of the three-dimensional sea surface,and realize the effects of sea surface foam and folds,and further improve the realism of the three-dimensional sea surface of the Taiwan Strait.(3)Simulation of the geomorphological evolution process of the Taiwan Strait since the last glacial maximum.Based on sedimentological methods,this paper uses sea level markers and borehole data to fit the sea level change curve of the Taiwan Strait since the last glacial maximum.The results are imported into Unity 3D to realize the dynamic simulation of the landform evolution process of the Taiwan Strait since the last glacial maximum,revealing the changes of sea and land and the spatial distribution of ancient coastlines.This paper fully combines the characteristics of the geography major,uses multi-disciplinary theory and technology,and highlights the comprehensive observation and analysis of geographic objects and geographic processes.The virtual simulation experiment system designed for the evolution of the Taiwan Strait geomorphology provides a new guarantee and platform for cultivating college geography undergraduates.