The Styria Flyover-LOD management for huge textured terrain models

With the Styria Flyover one can virtually fly over Styria, a province of Austria. The countryside is characterized by a mixture of rather flat regions in the south east and mountains up to 3000 m in the north west. The digital model covers Styria and parts of its adjoining provinces (30,000 km/sup 2/); it is based on a DTM consisting of more than 23 million triangles and on 50 Mbyte texture data (satellite images). The framework combines an R-tree data structure with efficient LOD management (automatic mesh refinement), progressive rendering and dynamic performance adjustment. On a SGI O2 it delivers more than 8 frames per second. The authors' approach demonstrates that efficient algorithms make a fast 3D GIS user interface possible without spending a fortune on hardware. The paper focuses on techniques and data structures to maximize the performance of visualization.