Study Of Real-time Embedded Environment Of 3d Gis Roaming

This thesis mainly discussed the real-time 3D GIS work through application for embeddedsystems based on the prototype development of a portable car navigation system.Firstly to solve the massive data accessing problem, the dynamic loading schema based onout-of-core paging algorithm was improved by adding motion prediction. In the mean time,multi-thread loading is used also to achieve the balanced performance.And then how to express the different GIS information is described from the algorithm tointegrate dynamic loading and ROAM algorithm. How to display 2D vector graphics and 3Dgeographic objects are also included. The method we used to integrate ROAM to dynamicscene is using a two-level index tree to accelerate the accessing of pre-computed Roam's errordata.At last the Scene Graph based scene management and its related traversal operations arecovered as well as the pipeline structure in the detail of how to be adapted to the data we useand the other specific environments.All the algorithms and optimizations mentioned in this thesis are valuable engineeringpractices.