Livny,Y., Kogan,Z., El-Sana,J.
Abstract:
In this paper we present a novel approach for interactive rendering of large terrain datasets. Our approach is based on subdividing the terrain into rectangular patches at different resolutions. Each patch is represented by four triangular tiles and four strips. The four strips are used to stitch the four tiles, that can be at different resolutions, in a seamless manner. As a result, our scheme maintains the resolution changes within patches and not across patches as in previous approaches. At runtime the terrain patches are used to construct the appropriate level of detail based on view-parameters. The selected level of detail does not include any geometry, instead it includes the layout of the patches and the resolutions at the boundary edges. The resulted mesh does not include any cracks or degenerate triangles because adjacent patches agree on the resolution of the common edges. The GPU generates the meshes of the tiles by using scaled instances of cached tiles and assigns elevation and color for each vertex from the cached textures. To enable the rendering of large terrain datasets, we provide external memory support that caches the necessary elevation maps and color textures in video memory. Our algorithm manages to achieve quality images at high frame rates while providing seamless transition between different levels of detail.