high performance computing on graphics processing units: hgpu.org

This paper demonstrates the simple yet effective usage of height fields for interactive landscape visualizations using a ray casting approach implemented in the pixel shader of modern graphics cards. The rendering performance is output sensitive, i.e., it scales with the number of pixels rather than the complexity of the landscape. Given a height field of a terrain and a topographic map or similar data as input, the vegetation cover is extracted and stored on top of the height field in a preprocess, enhancing the terrain with forest canopies or other mesostructure. In addition, enhanced illumination models like shadowing and ambient occlusion can be calculated at runtime with reasonable computational cost, which greatly enhances the scene realism. Finally, including the presented technique into existing rendering systems is relatively simple, mainly consisting of data preparation and pixel shader programming.