Hybrid Level of Detail Algorithm for Real-Time Rendering of Large-Scale Terrain

Hybrid level of detail (LOD) (HLOD) algorithm based on discrete LOD and continuous LOD is presented for real-time rendering of large-scale terrains. There are n HLOD models created off-line, which form a pyramid with n layers. Each of these models contains countless versions of the model at various levels of detail. When rendering, the corresponding models in some layer will be chosen. As the viewer's moves, either the continuous LOD algorithm will be applied to the selected models, or the visible models in another layer will be selected. An experiment on a triangular irregular network(TIN) terrain model was performed respectively using discrete LOD, continuous LOD and HLOD. The experimental results show that the HLOD algorithm exceeds the other two kinds of LOD in frame rate without reduction of terrain's fidelity.