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.