Three-Dimension Visualization Query Method Based on R-Tree

Since k nearest neighbor(KNN) query which adopts relative conditions has more strict demands,this paper proposes a new KNN query algorithm,which adopts breadth traversal and optimal ordering principle and can fit different distributions of spatial features very well.Aiming at multi-scale phenomenon in 3D visualization,this paper presents a LOD feature query method.Experiments show that these spatial query methods have high efficiency and can retrieve focused features precisely.Moreover,LOD function can be realized to simplify 3d scene on the premise of guaranteeing rendering precision,which can satisfy current requirement of 3D GIS.