Research Of Large-Scale Ocean Waves 3D Visualization

The demands for research of ocean development and naval operations drive the development of 3D visualization of ocean waves.Large-scale ocean wave area contains varieties of waves,such as deep ocean waves and shallow ocean waves,and the intersection between the ocean and coast.At present,the research is not deep enough in the transition zone between the distant view and close view of deep ocean,the transition zone between deep ocean waves and shallow ocean waves,the visualization of interaction between ocean waves and coast terrain and the uniformity of the screen pixel projected from ocean wave mesh.This paper is supported by the fund “Research on visualization of composable and self-correcting ocean XX” and the advanced research project “Virtual XX environment modeling,simulation and visualization platform” to carry out the research.And the paper has researched on the fusion modeling method of multi-ocean waves in the visualization of large-scale ocean waves,real-time interaction between ocean waves and coast and the generation of large-scale ocean waves mesh based on pixel.The main research results and innovation points are as follows:1)According to the modeling problem that the transition wave between far and near waves in deep ocean,the transition zone between deep and shallow ocean etc,a adaptive fusion modeling method of deep waves from far to near and transition between deep and shallow ocean waves is proposed.The inconsistent problem of visualizations details of deep waves is solved by using a nonlinear function to interpolate the deep ocean waves between far and near area.By considering the influence of depth,terrain etc.on the waves,a self-correcting transition algorithm is put forward to smooth the transition from the deep ocean to shallow ocean according to the depth of ocean.In order to adapt to the integration of deep and shallow waves,an improved shallow ocean model is given by dynamically adjusting the parameters of Fournier model.Then the waves including calm wave and rolling wave are visualized by using the improved model.The experimental results show that the method proposed in this paper can quickly obtain virtual large-scale ocean waves,including the transition of deep ocean and shallow ocean,which improve the fidelity of visualization of ocean waves.2)In order to solve the crack existed in the transition between ocean waves and coast,loss of details in crossing area,wave refraction calculation and real-time interactive,an interactive visualization method is put forward by given the magnetic vertices algorithm,dynamic wave line tracking algorithm and multilayer dynamic texture mapping technology.Considering the volatility of ocean waves,the magnetic vertices method is designed to generate dynamic coast line.In the process of calculation of wave refraction,the wave line tracking algorithm is improved to dynamically generate new wave lines to solve the missing problem of wave refraction details.Then a multilayer dynamic texture mapping method of sea shore interaction is given to simulate the spray and foam.The experimental results show that the proposedmethod can realize dynamic coastlines,including wave refraction and dynamic interaction effect of nearshore waves off the coast of the waves of the sea scene,which improved the nearshore waves under the requirement of real-time visual fidelity scene.3)In view of the present large scale terrain based multi-resolution grid waves are difficult to realize the reasonable distribution of visual graphic details after projection,this paper proposes a massive waves multi-resolution grid generation method based on pixels by considering human visual,intuitive image pixel as parameters.The degree of mesh segmentation is determined after calculating the projection grid after small footprint image pixel values.An automatic cutting algorithm is given to cut the grid out of the viewpoint.Screen pixels of wave grid are uniformly distributed.And the expression of massive waves is enhanced.The library of boundary grid and inner grid is established,then a grid stitching algorithm based on indexing technology is designed.So the splicing crack problems of the different level of detail grids can be solved.In the nearshore aspect,an automatically adjusted algorithm is designed.A culling method is given to cull the grid covered by coastal terrain.The experimental results show that the proposed method can quickly realize the waves of the grid generation and splicing,could improve the ability of multi-resolution grid to express the details of the waves.4)In order to embed the visualization software into different visual application system,a generalization of the massive waves visualization software with general design,general interface and general drawing process is proposed.An optimization method of massive waves drawing is given through a height map editing method based on the Shader and a dynamic mesh update policy based on viewpoints.The acceleration platform,CUDA,is embedded and dynamic lights and fog effect of the ocean surface are drew.With these methods,the real-time scene rendering can be improved.The sense of reality can be enhanced.In order to verify the validity of the waves visualization methods,the ship swaying and ship stem are visualized.Finally,a typical virtual ocean battlefield environment is realized based on OSG rendering engine.The experimental results show that the developed visualization software can be quickly embedded as the node of sea waves in visualization system,which can generate realistic sea environment,and also satisfy with the real-time requirements.