Desktop Vr Technology And Its Application In The Rail System In The Satellite,

The background of this thesis is the research of On-Orbit Satellites Display System Based on Desktop VR. It studies some technologies as follows: Data Organization technology based on tri-layer data model, Virtual Scene Organization based on the scene tree, structured satellites modeling and non-structured point-cloud rebuilding, and Object-Oriented view-port interaction technology.The VR node in this system must transmit data in a high speed reliably, as well as organize simulation and graphic data to build real-time virtual scene in the mean time. So a data organization system named tri-layer data organization architecture is deigned, which has a core of data transmission layer, data pre-processing layer and data application layer. This architecture provides a stable and reliable data exchange to support fast virtual scene building. As a mount of 3D models of satellites and stars are embedded in the virtual scene, a method to organize these models is needed. This thesis uses Scene Graph method for reference, and design a hierarchy structure to manage virtual scene, whose core is named as management entity. This method can express virtual scene of clarity.Also these 3D models should be created when the system is running. And they are divided in two part: one is structured and other is not. To set up 3D model of structured entities, a mixed method which relies on 3D modeling software and Graph API is presented in the thesis, and a basic system is developed to manage them. To set up 3D model of non structured entities, especially points-cloud object, this thesis enhances an algorithm based on grids for non-structured points-cloud rebuilding which improves the data structure and search method. By choosing appropriate parameters, the algorithm can give a triangle-net with high quantity rapidly.View-port interaction is the mayor interaction way in desktop VR. The thesis studies Object-Oriented Interaction Model, and design view-port interaction module in detail. And then gives out a method to realize virtual target camera to realize view-point transmission, and the method has a useful application in virtual camera on a satellite.At last, the thesis accomplishes the On-Orbit Satellites Display System Based on Desktop VR with the support of such trhese technologies. The final experiments and analysis prove that the main performance measurement and system error are both in a reasonable range.