Large-Scale Terrain Real-Time Rendering In Distributed Virtual Battlefield Based On The GPU And Layer Quad-Tree

Funding by the Nation"863"Projects"the space XXXX,"we studied"the large-scale terrain real-time rendering in distributed virtual battlefield based on the GPU and layer quad-tree". The large-scale terrain is an important part of the distributed virtual battlefield, for the real-time, realistic and interactive of elements required by Large-scale distributed virtual battlefield terrain, we studied the terrain data storage and paging, as well as rendering algorithm. This topic has very important significance on the establishment of efficient real-time distributed virtual battlefield system simulation.Firstly, by analyzing the typical terrain modeling methods and the most advanced terrain models, we considered the establishment of large-scale terrain LOD model related to vision as the key of real-time rendering. Therefore, the pyramid layer quad-tree structure was designed to store the terrain data, around addressing methods and GPU-based multi-threaded paging algorithms were introduced to speed up the rate of access to the terrain data.Secondly, in order to improve real-time and fidelity from the overall and local terrain rendering, we optimized the rendering progress based on the layer quad-tree. Our researches are as follows: in order to reduce the error of terrain mesh triangulation, roaming speed was introduced to rebuild the global LOD evaluation factor; Occlusion query algorithm were optimized by using check list method, which reduced the CPU and GPU idle time; Boundary Elevation style fitting algorithm was proposed to avoid cracks, which achieves the smooth and seamless transition between the different resolution terrain blocks.Then, Fast Texture construction method and dynamic pre-calculation method were proposed based on sample-based texture block and buffer pool, which can realize the detail texture between the different LOD terrain blocks composed in real-time.Finally, by using the"VC + OpenGL"programming tools on windows platform, a distributed virtual battlefield terrain simulation system was designed and realized. The experiment results show that, our system not only achieved a smooth and seamless transition in roaming scene, but also solved the real-time constraints to the battlefield environment by the terrain elementsOur researches on real time paging, controlling of LOD and the optimization of rendering speed are efficient. It is capable of meeting the real-time demands by distributed virtual battlefield. It is a useful exploration for large-scale battlefield terrain rendering.