关键词: 关键词：三维仿真, R树, LOD模型, 实时渲染

Abstract: Abstract: In recent years， with the deepening research of manned spaceflight， the complexity and reliability requirements of space missions have been increasing. Real-time position calculation of massive targets and scene rendering are the key and difficult points of real-time rendering of space targets. To take advantage of the hierarchical detail model （LOD） in dynamic rendering， a real-time rendering method for massive space targets is proposed， which focuses on optimizing the traditional batch LOD model into an R-tree-based LOD model. When constructing the R-tree-based LOD model， there are issues such as index space overlap， low query efficiency， and LOD model texture mutation. Therefore， a node-based depth adjustment strategy is proposed to eliminate index space overlap， a fast pruning algorithm is adopted to improve query efficiency， and the shader-based alpha testing technique is used to achieve smooth transitions between LOD models. Through the collaborative processing of these three optimization algorithms， the optimized LOD model has improved in scene rendering time， space occupancy rate， frame rate， and other aspects.

Key words: Key words: 3D simulation, R-tree, LOD model, real-time rendering