Implementation And Optimization Of Spatial Data Volume Rendering Algorithm Based On WebGL

Among all the rendering methods for spatial data,volume rendering is one of the most important methods due to its advantages of high accuracy and dynamic display of the internal structure of data.Because of the high performance requirements of the volume rendering,most of the previous applications are in the C/S architecture program.However,with the continuous improvement of computer hardware performance and the development of web browser function,there is a mature technology foundation to achieve some advanced rendering technology such as image rendering in B/S architecture application.The whole implementation process of Web GL based volume rendering algorithm is quite different from that of Open GL platform.and it is also worth exploring for web browser performance and display effect optimization.In view of the demand of 3D radar echo data display,this paper focuses on how to make the volume rendering flow smoothly on the browser platform.Besides,there is also the problem of how to display the 3D radar echo data on the earth carrier effectively and accurately.This paper studies the algorithm implementation and optimization of spatial data volume rendering based on Web GL,and deeply studies the optimization method of rendering results and the bottom design of the earth visualization platform.The specific research content and innovation are as follows:1)research and actualize a real-time ray-cast algorithm based on Web GL.The implementation of ray-cast algorithm on Web GL is given.The key points to be paid attention to in the process of volume rendering algorithm for Web GL version feature are discussed.After the experiment,the feasibility of realizing the ray-cast algorithm on the Web platform is proved.The complexity of the algorithm are also analyzed.2)starting from the ease and accuracy of improving the volume rendering results of the atmospheric data in the display of the three-dimensional earth ratio.An optimization scheme for volume rendering and display effect based on body data block deformation algorithm is proposed.And the implementation process of the block deformation algorithm is also given.Then the advantages and disadvantages of this method to the rendering effect are analyzed by experiments.3)in order to improve the performance and display effect,the drawing scheme of spherical carrier is put forward.At the same time,the optimization scheme is put forward for the problem of too many sampling steps of the spherical carrier,and the space skipping plus octree invalid voxel culling scheme.In addition,an algorithm for the establishment of a voxel compact encircling box using octree is proposed.Through the experimental analysis,this method can significantly improve the rendering performance and display effect.4)from the demand of this research work,this paper has studied and realized the earth visualization platform based on Web GL.The construction of the platform,the design scheme and the design process of the whole platform are explained in detail.And the implementation of the core functions of the platform is given a specific process.And the implementation and introduction of the Web platform for the specific rendering of the platform from the rendering process from the module of the program.This paper bases on Web GL to achieve volume rendering algorithm,designs,actualizes and optimizes the whole process of volume rendering algorithm for 3D radar echo data,and provides a reference for the application of volume rendering in the web browser platform.