Research On 3D Visual Simulation Of Seabed Environment

With the development of computer visualization technology,seabed environment simulation has always been a research hotspot in computer graphics.It is time-consuming and laborious to render the seabed environment in real-time due to the complex seabed terrain,large amount of data and the complex interaction between seawater,terrain and light.The existing rendering methods have poor rendering effects,slow speed,and lack of systematicness.At the same time,the real-time performance puts a challenge on the speed of graphics generation.The emergence of Graphics Processing Unit(GPU)eases this problem.Replacing part of the work of the CPU by the GPU,liberating the CPU,can greatly improve the real-time rendering capability of the computer.The rendering method of multi-element fusion studied in this paper.By creating a three-dimensional dynamic seabed scene,comprehensively rendering various visible elements such as terrain,caustics,shafts,scattering and bubbles in the seabed environment.Then through the mouse and keyboard interaction,to achieve the navigation of the entire undersea environment.This method can not only realize the dynamic rendering of the real-time seabed environment,but also improve the rendering efficiency and the rendering effect.The main research work of the thesis is as follows:(1)The terrain data acquisition and modeling rendering methods is studied.The OBJ file model is established by extracting the digital elevation data based on remote sensing image data in this paper.The model is combined with the image texture obtained by the side-scan sonar,and the terrain is realized by normal transformation and texture mapping.The pre-processing and simplified operation of the OBJ file model speed up the rendering speed.It can be loaded during the terrain loading in seconds,and the loading efficiency is significantly improved.(2)Caustics and shafts rendering based on caustics map and ray marching algorithm is included in high-fidelity real-time rendering of marine environment.The caustics texture is obtained through the caustics map algorithm,and then the caustics technology and the timer are combined to realize the dynamic rendering of the caustics.By drawing shafts through the ray marching algorithm,GPU rendering greatly eases the CPU's operating pressure.The experimental results show that the method is feasible and effective.(3)The three-dimensional dynamic visualization of real data is studied in a virtual environment.Open GL is used to achieve three-dimensional dynamic scene construction.First,the basic system interface is built,and then combined with the multi-element fusion rendering method proposed in this article,integrated terrain rendering,dynamic caustics and shafts rendering,plus the rendering of bubbles and scattering through the particle system.The dynamic simulation of the sea surface is realized by the high dynamic range technology,and the construction of the dynamic seabed scene is realized.Finally,the technology of mouse and keyboard interaction is used to realize the underwater navigation.The overall rendering speed can reach 18 fps,which can meet the real-time rendering requirements.