Research On Key Technology Of Multidimensional Battlefield Environment Situation Visualization

With the rapid development of computer hardware and software technology,data and information visualization technology has been integrated into all aspects of society,and multidimensional battlefield situation in the digital battlefield is one of very important applications.Visualization technology is the most important expression form of the battlefield environment,and it is also the most important means used by commanders to recognize the environment.The multidimensional battlefield environment situation visualization is to use battlefield environment situation information,based on the consistent spatial datum,employed spatial geographic information as visual carrier,superimposed display various battlefield environment elements,introduced the computer graphics,cartography and geographic information science etc.in,to realize the visualization expression of battlefield environment situation by means of various interactive tools.The modern war is gradually tending to diversification and globalization,and the battlefield environment situation coverage is also more and broader.It not only includes traditional situation information such as route of march,force disposition of both side,combat entity state and so on,but also includes natural battlefield environment such as topography and geomorphology,hydrology and water conservancy,meteorology,which is increasingly becoming valued in recent years,humanistic environment,economic environment in the battlefield and so on.While with the gradual expansion of the battlefield scale,the rapid development of information acquisition technology,such as sensor technology,data quantity of various information resources is growing explosively,which leads various kinds of environment situation visualization to appearing many problems such as low efficiency,visual confusion,poor resolution and so on.And the paper will research on this kind of problems.First of all,to solve the scheduling problem with long time resulted by too many terrain blocks in the large-scale terrain visualization,the basis of the digital battlefield visualization,an enumeration quadtree algorithm was proposed.It merges adjacent nodes in the quadtree according to the type,uses some composite types of terrain blocks instead of those with single type,which effectively reduces the number of terrain blocks and speeds up the scheduling efficiency in the viewpoint changing process on the premise of unchanged final rendering effect.Considering the crack problem between terrain blocks with different resolutions,a vertex offset algorithm based on the tangent function was presented.It realizes the vertex offset in the T junction without additional judgment,which effectively solves the problem of cracks.Secondly,for the uneven grid distribution and the long and narrow triangles at earth's poles generated while extending terrain visualization to the global scale,the hexagon discrete grid system was introduced to achieve the density unification of global grid.On the basis of hexagon subdivision with the aperture of 4,a diamond block based hexagon grid quadtree algorithm was designed.Comparing with the grid with single resolution,it can realize viewpoint related visualization of hexagon with multi-resolution in the situation that the precision of visual perception is not affected,which improves the rendering efficiency effectively.To solve the crack problems between triangulated diamond blocks,four kinds of basic triangle strips were designed to conduct real time scheduling according to the adjacent relationship in the rendering process so as to implement the crack repairment.Then,on the visualization of battlefield natural environment data field,the research mainly focuses on the large-scale 3D scalar field and spherical flow field.In the ray casting algorithm for large volume date field,the spherical shell arc-shaped hexahedron is treated as proxy geometry instead of traditional hexahedron.To solve the high redundancy and the distortion of visualization effect in the polar regions while storing volume data according to longitude and latitude,the hexagon grid with single resolution was used as data storage topology to achieve the fast sampling of ray in the spherical space by means of fast look-up table of hexagon units and triangular prism interpolation algorithm.The final rendering mode was divided into three kinds according to different application scenarios,and the mode was determined in real time by view reference in the visualization to maximally improve volume rendering efficiency.For the problem that the time of streamline integral is too long in the large-scale vector field visualization,the geometry shader was employed to generate streamlines in parallel.It only needs to transfer a small amount of seed points to graphics pipeline,which saves the bandwidth of graphics pipeline substantially.Meanwhile,the viewpoint related quadtree algorithm was introduced in seed distribution process,which makes the streamline distribution density change according to the viewpoint.It improves the rendering frame rate and also optimizes the visual effect at the same time,prevents line confusion.Finally,we also carried out research on battlefield entity track graph visualization and optimization.In order to solve the line confusion of point-line graph,the land transportation information was integrated in,the original graph edge was replaced by the smooth curve composed by several Bessel curve,which achieves effective bound of related tracks and also reflects the general path information at the same time,improves the definition and the information content of the graph.The battlefield environment situation visualization algorithm mentioned above will be finally set into a same visualization platform,and most of the research results have been used in the relevant 863 topics.