Three-dimensional R-tree index expansion structure-based three-dimensional city model adaptive method

Abstract

The invention relates to a three-dimensional R-tree index expansion structure-based three-dimensional city model adaptive method. The method comprises the following steps of: expanding a three-dimensional R-tree index expansion structure to ensure that an intermediate node can manage a target model; generating a multi-level of detail (LOD) target model from a leaf node layer to a root node layer,namely from bottom to top layer by layer, wherein different R-tree layers represent different LODs; a target in the leaf node layer is the highest LOD model; a father node of the leaf node layer is an LOD model of a second detail; and the LOD is gradually lowered upwards in turn, and the root node layer has the lowest LOD; defining multi-LOD definition parameters which comprise the number of layers, the farthest action range of the highest LOD, and the interlayer times; and in a real-time visual process, modifying the multi-LOD definition parameter in real time according to the current performance so as to quantitatively adjust the scene complexity of a three-dimensional city model.

Description

technical field [0001] The invention belongs to the technical field of geographic space information systems, and in particular relates to a three-dimensional city model adaptive method based on a three-dimensional R-tree index expansion structure. Background technique [0002] With the development of geospatial data acquisition methods such as photogrammetry and laser scanning technology, the acquisition accuracy and modeling speed of 3D model data have been continuously improved. complexity, and increase the volume of data. The development speed of hardware technology in 3D display can no longer meet the growing needs of data volume, even the computer with the best hardware level cannot display all the data in real time; the development of hardware technology makes various hardware terminals appear continuously, The performance characteristics of these terminals are different, and even the same type of terminals will have different performances. In realistic 3D applicatio...

AI Technical Summary

Problems solved by technology

[0002] With the development of geospatial data acquisition methods such as photogrammetry and laser scanning technology, the acquisition accuracy and modeling speed of 3D model data have been continuously improved. complexity, and make the data volume explode

The development speed of hardware technology in 3D display can no longer meet the growing needs of data volume, even the computer with the best hardware level cannot display all the data in real time; the development of hardware technology makes various hardware terminals appear continuously, The performance characteristics of these terminals are different, even for the same type of terminals, there will be performance differences

Existing popular general-purpose rendering platforms such as Vega, OSG, and OpenGVS are still unable to meet the requirements of gigabit-level scene complexity, and the recently developed massive graphics rendering systems are generally research prototype systems, usually in a new key Integrate other system modules based on the algorithm, such as GigaWalk of the University of North Carolina, Far Voxels of the Italian CRS4 Visual Computing Group, iWalk of Princeton University, vLOD of Hopkins University, etc.

These systems require a lot of preprocessing and are not well adaptable to 3D urban scenes with different complex types and hardware conditions

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