View-dependent massive terrain data scheduling algorithm

In order to meet the demand of real-time transmission of the terrain data and efficient display, based on the different view field of high altitude and surface, firstly, a general(efficient to both surface and high altitude) view field algorithm is proposed. This algorithm promotes the traditional vision clipping algorithm, efficiently determining the visibility of the view field. the LODs of the key nodes and previsible region when position of the vision moves. Pre-scheduling method is used to keep the calculation in order. Then progressive transmission strategy is adopted to transmit the processed data. Finally, the validity of the algorithm is approved by experiment.