基于虚拟现实技术的地球太空环境仿真

描述了一种地球太空环境的仿真,采用几何计算构建地球形状模型,将地球划分为128块（经线方向16块和纬线方向8块）,计算得到每块区域顶点坐标,法向量,纹理坐标;使用MipMap技术根据视点与每块区域距离变化选择不同精度纹理粘贴;实时判断该区域的可见性,剔除不可见区域减少绘制开销;并采用cg和NormalMap技术将normal图与地球纹理图进行处理,实现地球表面的轮廓凹凸效果,同时添加云层纹理,得到了由地球纹理,云层纹理及NormalMap的多层混合纹理,达到比较逼真的效果;另外采用Billboard技术和纹理融合技术实现地球大气层光晕效果,使用了LensFlare技术实现太阳照射效果,最后采用skybox技术实现星空背景效果。

Abstract：

A simulation of earth and space environment was describedr.The whole earth was cut into 128 parts,16 in longitude,8 in latitude,and the position of vertices,normal vectors,texture coordinate were computed by geometry.Different resolutions of texture were chosen according to the distance from the eye to the area presented by the technique MipMap.The unvisible parts were eliminated by judging the parts’ visibility in realtime.Using the techniques of Cg,NormalMap and the mixture of the textures of the earth,the clouds and the multi-layered clouds,the relatively vivid result for representing the surface of the earth was achieved.Moreover,the technique of Billboard,Lensflare,SkyBox and texture blending were used to show the shine of atmosphere,sunshine,and the background of space.

VR-based Earth-Space Environment Simulation

A simulation of earth and space environment was describedr.The whole earth was cut into 128 parts,16 in longitude,8 in latitude,and the position of vertices,normal vectors,texture coordinate were computed by geometry.Different resolutions of texture were chosen according to the distance from the eye to the area presented by the technique MipMap.The unvisible parts were eliminated by judging the parts’ visibility in realtime.Using the techniques of Cg,NormalMap and the mixture of the textures of the earth,the clouds and the multi-layered clouds,the relatively vivid result for representing the surface of the earth was achieved.Moreover,the technique of Billboard,Lensflare,SkyBox and texture blending were used to show the shine of atmosphere,sunshine,and the background of space.