Research On Seamless Rendering Technology Of Large Scale Terrain Based On Curve Fitting And GPU

As a hot technology in the field of virtual reality visualization,the real-time rendering technology of large-scale terrain scene has been widely used in military trench simulation,intelligent city terrain modeling,game and entertainment scene simulation.In order to adapt to the rapid development of virtual reality technology better,it has become a research hotspot how to optimize the rendering effect of large-scale terrain and how to improve the rendering speed of large-scale terrain.The Level Of Detail model is used to separate the terrain blocks from top to bottom,left to right in large-scale terrain real-time rendering.So that there is a phenomenon of hierarchy inconsis-tency between adjacent grids,which leads to cracks between adjacent tiles and inside of tiles.The problem of cracks is the key factor of image quality.A reasonable crack processing algorithm is helpful to improve the real-time rendering effect of terrain.At the same time,the complex computation of massive data has a great impact on the real-time performance of terrain rendering.An algorithm that can guarantee both image quality and rendering speed is particularly important.The curve fitting model combines the collected data points into appropriate curves and avoids the cracks by controlling the migration of the topographic grid vertices.The method is simple and accurate.The algorithm of motion prediction based on viewpoint is simple and accurate,too.According to the judgment of view point,the real-time scheduling of terrain blocks in visible range is carried out,which greatly saves memory space and improves the rendering speed of GPU.Based on this,the existing curve fitting function method,viewpoint motion prediction method and related crack processing algorithm are studied in this paper.The advantages and disadvantages of existing methods are analyzed.The crack processing method based on curve fitting function is combined with the algorithm based on viewpoint motion prediction.At the same time,the radius of the bounding sphere constructed by the terrain block is considered while the error control range is calculated.The main work is as follows:1.The real-time rendering technology of large-scale terrain scene is studied.Existing algorithms and related research results are analyzed deeply.The specific application of large-scale terrain seamless rendering is understand further.Combined with crack processing algorithm,GPU acceleration algorithm and texture mapping algorithm,this paper can improve the quality of terrain rendering and accelerate the speed of terrain rendering.2.A seamless terrain rendering algorithm based on curve fitting function and GPU acceleration is proposed combined with the Hermitian interpolationalgorithm based viewpoint motion prediction.The curve fitting function is constructed by the least square method.The layout of grid vertices is controlled by curve function at different levels,so that the cracks caused by the level of detail changese are liminated.At the same time,a pyramid model with different resolutions is build according to the Hermitian interpolation based viewpoint motion prediction algorithm.The lossy compression or lossless compression is used to terrain area of different levels of detail.The amount of data storage and transmission can be reduced.The time of data transmission can be shortened.The processing speed of computer can be improved,and a higher frame rate can be ensured.3.A texture seamless mapping method of multi-resolution based on error control is proposed.According to the current viewpoint position and the direction of sight,the bounding sphere based on the terrain block is constructed,and the visual cone is clipped.The radius of the bounding sphere is taken into account in the calculation of the texture error to ensure the accuracy of the error control.At the same time,the view motion prediction based on Hermitian,the weighting of angle and distance are used.The multi-parameter texture pixel information is generated to ensure the convergence of terrain texture and complete the seamless rendering of terrain texture.