基于OpenCL的三维地形生成技术的研究与实现

发布时间：2018-04-01 08:46

本文选题：四叉树　切入点：OpenCL　出处：《中国科学院大学(中国科学院沈阳计算技术研究所)》2017年硕士论文

【摘要】：三维地形生成技术是虚拟现实领域中的重点研究方向,其主要应用于虚拟战场环境仿真、城市景观规划、虚拟旅游、飞行模拟器训练及3D游戏等众多领域。随着航空航天、卫星遥感技术的快速发展,地形数据的采样精度越来越高,数字高程数据和纹理数据量成倍增长,则大规模地形的实时绘制成为研究的难点问题。为了使渲染的地形更具有真实感和沉浸感,三维地形渲染仍然是一个值得深入研究的课题。本文取得如下研究成果:1.研究基于地形分块的动态调度和实时预取方案,针对大规模的DEM数据集,采用分块化的策略进行组织和管理;然后,根据当前视点的位置和运动方向,计算各个地形块的优先级,采用动态调度的方法把地形块动态调入内存,这种方法能够有效地提高内存的利用率。2.研究基于GPU的地形块并行简化算法。由于各个地形块的简化具有弱相关性,本文提出基于OpenCL的利用GPU并行简化地形块算法,采用四叉树和标记矩阵相结合的数据结构构建LOD模型,可有效降低地形块内裂缝消除的难度。3.研究基于GPU的地形块并行渲染方案。在地形块渲染之前,消除地形块内的裂缝,并把需要绘制的顶点批量送往OpenGL渲染流水线实现地形块的并行渲染。4.实现基于OpenCL的CPU-GPU协同处理的三维地形实时渲染系统。通过上述研究内容,本文最后实现了CPU-GPU协同处理的三维地形可视化系统,并对系统性能进行测试。本系统能够充分发挥CPU和GPU各自的优势,极大的降低CPU的工作负载,帧率稳定在90帧/秒左右,获得较高的渲染帧率和较好的渲染效果。
[Abstract]:3D terrain generation technology is an important research direction in the field of virtual reality. It is mainly used in many fields such as virtual battlefield environment simulation, urban landscape planning, virtual tourism, flight simulator training and 3D game. With the rapid development of satellite remote sensing technology, the sampling accuracy of topographic data is getting higher and higher, and the digital elevation data and texture data increase exponentially. In order to make the rendered terrain more realistic and immersive, the real-time rendering of large-scale terrain becomes a difficult problem. Three-dimensional terrain rendering is still a subject worthy of further study. In this paper, the following research results are obtained: 1. Dynamic scheduling and real-time prefetching schemes based on terrain partitioning are studied for large-scale DEM data sets. Then, according to the position and motion direction of the current viewpoint, the priority of each terrain block is calculated, and the dynamic scheduling method is adopted to dynamically transfer the terrain block into memory. This method can effectively improve the utilization of memory. 2. The parallel simplification algorithm of terrain block based on GPU is studied. Because the simplification of each terrain block has weak correlation, this paper proposes a parallel simplification algorithm based on OpenCL using GPU. Using the data structure of quadtree and label matrix to construct LOD model can effectively reduce the difficulty of eliminating cracks in terrain block. 3. The parallel rendering scheme of terrain block based on GPU is studied. Before terrain block rendering, the cracks in terrain block are eliminated. The vertex that needs to be drawn is sent to pipeline to realize the parallel rendering of terrain block. 4. The 3D terrain real-time rendering system based on CPU-GPU cooperative processing based on OpenCL is realized. Finally, a 3D terrain visualization system with CPU-GPU collaborative processing is implemented, and the performance of the system is tested. The system can give full play to the respective advantages of CPU and GPU, greatly reduce the workload of CPU, and the frame rate is stable at about 90 frames per second. Get high frame rate and good rendering effect.
【学位授予单位】：中国科学院大学(中国科学院沈阳计算技术研究所)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP391.9

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