Research Of The Algorithms For Three-dimensional Terrain In Virtual Scene

Realistic graphics is always the frontiers of the computer graphics research field, Realisticgraphics are always playing an important role in virtual reality technology, visualization inscientific computing, multimedia teaching, stunt simulation in the film, computer gamesimulation, and many other aspects. 3D(Three Dimension) realistic terrain is the basiccomponent of virtual reality and visualization technology.Following with constant improvement of the people’s requirements to the realisticgraphics, there needs a highly realistic terrain, so it needs massive terrain data acquisition, butdata is unlimited, so the contradiction we face is the unlimited amount of data and the limitedlevel of hardware.First, in this paper，it realizes smooth transition between different texture by using linearinterpolation cross to the terrain texture. The entire texture is eventually formed by the texturemapping, the texture calculation and the elevation through the bilinear interpolation. In orderto avoid that a texture looks too smooth, by means of adding texture detail, the terrain effect ismore realistic and natural.Second, this discusses three types of terrain modeling technology, which are the grayvalue method, fault formation and midpoint displacement method, finally their terrain effectssuitable for different scenes by experiments.Third, the terrain elevation values in the terrain simulation are in one to onecorrespondence by the real world, at present, people generally used in the RSG belonging toDEM modeling, while the accuracy of these 3D terrain models grows with the developmentof Measuring Technique, the volume of their data sets grows even rapidly, so it must usesimplification technology to reach balance between the Realistic Terrain and rendering speed,since the Quad-tree and ROAM are the classic of terrain simplification, so this paper detailedanalysis them that the node evaluation mechanism of Quad-tree、optimization of terrainrendering、node error、rendering process based on ROAM and so on, finally complete experiment and meet customers’needs.Fourth, with daily applications of the computer such as Scene Simulation Technology, 3DGame, Military Simulation System posing grim challenge to the graphics simulation and datascheduling，GPU relatively CPU has obvious advantages in Mass Data Processing andmemory bandwidth, so this paper further studies four algorithms based on terrain rendering ofGPU block mode, and finally by summing up the predecessors’experiences, it puts forwardthe thought of seamless block mode based on ROAM.In conclusion, this paper carries out detailed research and improvement to algorithm of theterrain texture, terrain model, terrain simplification, optimization of terrain rendering andterrain structure block and so on, so that under the premise that does not affect the visualeffects, reduce the burden of the hardware maximally, which provides evidence and assitancefor the further studies about reslistic graphics.