Design And Implementation Of 3D Visualization Platform For Real-time Ocean Water Quality Data

Ocean is a huge and complex time-varying system which various factors influence each other and many processes interact with each other.It is clear that China has a vast ocean area.The ocean has a wealth of marine resources,including marine life,minerals and oil deposits on the seabed,and energy generated by seawater movements.However,with the changes in the marine water quality,the society’s level of economic development will surely be affected.To a certain extent,the display and monitoring of ocean water quality information can not only control and improve China’s marine environment,but also have great significance to the management of marine ecological environment.The dissertation designed a 3D visualization platform,which was discussed mainly from three aspects: ocean water rendering,buoys merging and heat map drawing.In addition,the platform was used to process and display real-time ocean water quality data.The main important works in this thesis as follow:(1)For ocean water rendering,a method based on the statistical wave model was used to simulate the fluctuation of the sea surface.In order to simulate the reality of the sea surface,we first used the model based on physical BRDF illumination to achieve the illumination effect.Then,with the illumination,we presented the realistic rendering effect of 3D seawater combining the reflected color,the refraction color of the sea according to the Fresnel Effect.(2)In view of the phenomenon of overlap of buoys in the 3D visualization platform,this thesis proposed a buoy merging method based on view change.We first proposed the merging rules of overlapping buoys,and then transformed the problem into connected sub graph.Next,we classified and merged buoys by improved algorithm.Finally,a new buoy icon was generated and the number of overlapped buoys was displayed.(3)For the results of the water quality evaluation of the sea area corresponding to the buoy,we generated and drew a thermodynamic diagram on the virtual earth surface.In terms of the shape of the thermodynamic map,based on the Delaunay triangulation algorithm,a newDelaunay triangulation algorithm based on boundary constraints was proposed in this dissertation.As for the color of the thermodynamic map,the water quality data was first mapped to the HSV color space,and then converted to the RGB color space.When each vertex was given a color and each triangle was filled with graduated color background,a thermodynamic diagram of the evaluation value information was formed.In the process of system design and implementation,we got the marine water quality data of the database with the database connection pool and displayed the water quality data with the graph.Finally,we visualized the data on the basis of the established evaluation model.