Efficient Multiresolution Models for progressive Terrain Rendering (Effiziente Multiresolutionsmodelle für progressives Terrain Rendering)

This paper deals with the problem of simplifying, transmitting and rendering large textured terrain models. The terrain is rendered from a hierarchy of quadratic tiles of geometry. Each of these tiles has a corresponding texture with a constant number of texels, e.g. 64x64, in each resolution level. Therefore, the ratio between the needed geometric accuracy within a tile and the texel size is a constant, independent of the level of detail, e.g. one texel (1/64 of the width of the tile). This observation allows us to create an efficient new multiresolution model for terrain data where not only the number of vertices is adapted to the level of detail but also the relative accuracy of the coordinates. Although we do not use a pure quadtree data structure due to its known problems with the representation of not axis aligned geometric features, our data structure is very compact and avoids redundant transmission of coordinates.