Realistic 3d Terrain Modeling And Visualization

3D terrain has extensive application fields, such as Geographic Information System,digital city, digital earth, virtual reality, games and entertainment. At present, how torealize fine modeling and three dimension visualization of large scale complicate 3Dterrain based on great data is hot topic and difficulty of research. The followingstudies have been done around the problem.·After analyzing features of digital couture map that is very popular, a kind ofinterpolation method based on experience has been proposed, which is fast and highquality.·A method of semiautomatic user-dependent elevation identification has beenproposed, which is reliable and decrease dramatically user's interaction comparedwith other methods.·According to contour feature(A point on couture line, except for its (x,y,z) value, hascharacteristic that it maybe locate on the same line with other points.), elevationvalues of mesh points are computed through their neighbors.·A method of interpolating 3D regular data field has been proposed. Free-curvesurface constructed by the method has its feature-boundary curves connecting eachtwo patches are c1 continuous.·A new kind of method has been proposed which first gets dynamic partition fromgrid and then in patch predigests terrain complexity through view-dependent bi-treebased on multi-resolution. It has proved smooth frame.·After the structural features of several data model of digital elevation model havebeen compared, dynamic partition and pre-reading algorithm experience-dependentbased on grid has been proposed. It has proved that this algorithm can solve real-timebrowse problem of large scale 3D terrain.·The comparison of quadric-tree with bi-tree predigesting adapting algorithmintroduces an amelioration of real-time optimally adapting mesh, which optimizesscreen space distortion computing, resolution of patch of grid in view frustum, nodeculling in frustum, triangle split and merge and mesh construction between frames.