Adaptive refinement for terrain rendering on GPU

In order to meet the requirement of more realistic and efficient rendering in a flight monitoring system, we present an interactively adaptive terrain rendering algorithm on GPU in this paper. By the algorithm, a two-pass GPU acceleration technique is designed for each frame. In the first pass, stream computing is applied to a coarse sampled mesh generated by persistent grid mapping. Then the refinement level for each triangle in the coarse mesh is calculated based on the complexity of the surface topography. In the second pass, terrain rendering is made according to the refinement level of each triangle, and the coarse sampled mesh is tessellated using different mesh refinement patterns which are updated and stored in the vertex buffers in the initialization stage. In order to eliminate the problem of T-junction, a matching process for various refinement patterns is implemented in the vertex shader. At last, elevation data and the corresponding satellite images are combined together to generate more realistic terrain in real time. The algorithm proposed has been applied to a flight monitoring system to support the flight test of advanced regional jet.