Geometry-based Mapping and Rendering of Vector Data over LOD Phototextured 3D Terrain Models

Abstract

Interactive three-dimensional (3D) visualization of very large-scale grid digital elevation models coupled with corresponding high-resolution remote-sensing phototexture images is a hard problem. The graphics load must be controlled by an adaptive view-dependent surface triangulation and by taking advantage of different levels of detail (LODs) using multiresolution modeling of terrain geometry. Furthermore, the display of vector data over the level of detail terrain models is a challenging task. In this case, rendering artifacts are likely to occur until vector data is mapped consistently and exactly to the current level-of-detail of terrain geometry. In our prior work, we have developed a view-dependent dynamic block-based LOD mesh simplification scheme and out-ofcore management of large terrain data for real-time rendering on desktop PCs. In this paper, we have proposed a new rendering algorithm for the combined display of multiresolution 3D terrain and polyline vector data representing the geographical entities such as roads, state or country boundaries etc. Our algorithm for multiresolution modeling of vector data allows the system to adapt the visual mapping without rendering artifacts to the context and the user needs while maintaining interactive frame rates. The algorithms have been implemented using Visual C++ and OpenGL 3D API and successfully tested on different real-world terrain raster and vector data sets.