Extension method of stencil shadow volume
模板阴影体扩展方法

Stencil shadow volumes are the main 3D rendering method for vector maps. Basic geometric graphs, such as lines and polygons, are the main representation of map features. These representation forms were so simple that strictly limited map feature information had been transferred. Consequently, in order to enrich the 3D visualization styles of a vector map, an extended rendering method based on the stencil shadow volumes is presented, which realizes real-time symbol overlaying of a vector map on terrain. First, the basics of vector data visualization based on the stencil shadow volume theory are reviewed. Second, the extended method is introduced, which includes border smoothing with rounded caps, while dealing with outlines and overlaps. Finally, the experiment results show that a real-time display of vector maps on terrain can be achieved and that the visualization effects have been improved by cartographic symbolical overlay.