Surface Rendering Technology Based On GPU Projected Grid And Application In Aircraft Flight Real-time Simulation System

Aircraft Flight Real-time Simulation System mainly uses the visualizations of flight data to simulate the real flight state dynamically in the three-dimensional form, and to show all kinds of integrated information comprehensively. So the existed problems in flight can be effectively identified and analyzed as a reliable basis for further flight tests. Thus, the research in Real-time Flight Simulation System has great value in application. However, Aircraft Flight Real-time Simulation System needs to deal with large-scale mesh data, such as large amounts of terrain mesh data. Therefore, how to effectively prevent data block or "splash", and accelerate running speed on computer, has become an important research subject in the field of real-time flight simulation system.In recent years, with the rapid development of graphics cards hardware, next-generation graphics hardware, the programmable Graphics Processing Unit (GPU), has come into being. As one special graphics processor, GPU takes advantage of parallel processing and the system architecture of focusing on computation, accelerating the whole graphics rendering pipeline on hardware and with complete function such as geometric transformation, illumination and texture calculation. Therefore, effective application the up-to-date graphics programmable GPU technology to accelerate, on GPU hardware, the processing of large-scale mesh data in real-time simulation system has become a research hotspot in the field of computer graphics and real-time simulation. The traditional surface rendering methods have such shortcomings as poor interactive performance, large run-time computing cost, light aliasing, etc.. In order to overcome such deficiencies, this paper implements view-dependent surface rendering technology based on GPU Projected Grid , taking advantage of GPU programmability and highly parallel computing ability and applies this rendering technique to the terrain rendering in Aircraft Flight Real-time Simulation System as an effective way to process large-scale topographic mesh data.The surface rendering technology based on GPU Projected Grid has following merits: to begin with, with the compact consistency of the method, all calculations are done on GPU, accelerating computation speed and thus greatly reducing the CPU burden; secondly, the projected rays passing through Projected Grid will generate surface mesh of different levels of detail(LOD) in an automatic way, without pre-set-up the structure of the level of detail on CPU, and real-time update the levels of detail of the mesh with the dynamic movement of the view point; thirdly, in each frame, only the triangles of Projected Grid are rendered, thus the whole rendering process has stable frame-rate and generates view-dependent surface. All these advantages are attributed to the increasing GPU parallel computing processing ability. Therefore, this rendering technique has good user real-time interaction, with broad prospects in engineering application.As specific application examples, this paper introduces Bezier surface rendering and terrain rendering based on the frame of GPU Projected Grid. At the same time, in the end of this paper, the overall architecture of ARJ 21 aircraft Flight Real-time Simulation System is described.