Rendering 3d Vector Data Using the Theory of Stencil Shadow Volumes

In geographical information systems vector data has important applications in the analysis and management of virtual landscapes. Therefore, methods that allow combined visualization of terrain and geospatial vector data are required. Such methods have to adapt the vector data to the terrain surface and to ensure a precise and efficient mapping. In this paper, a rendering method based on the stencil shadow volumes theory is presented, which allows high-quality real-time overlay of vector data on virtual landscapes. The method includes three steps which are the generation of the vector data polyhedra, creation of the mask in stencil buffer and the application of the mask to the scene to render the vector data. The research and experiment show that our approach is a screen-space algorithm and is of pixel-level precision. Since it does not suffer from aliasing artifacts like texture-based techniques and independent of the complexity of the terrain data set, it can achieve good performance for the rendering of 3D vector data.