基于kd-tree的分布式实时光线跟踪渲染技术研究

发布时间：2018-03-31 17:49

本文选题：虚拟现实　切入点：光线跟踪　出处：《哈尔滨工程大学》2013年硕士论文

【摘要】：随着信息技术的不断发展，越来越多的高新技术应用到社会的各个领域中来，而作为信息技术发展重要驱动力的虚拟现实技术也越来越多地应用到规划领域中来。虚拟现实对于城市规划设计、售楼促销、虚拟社区及娱乐和汇报展示等都具有很重要的意义，人们对虚拟现实中的画质要求也更高，要求画质更加的趋近真实以及更加流畅的画面。目前采用的光线跟踪技术可以很好的模拟光线的传播行为，包括环境光、漫反射光、镜面光、软阴影以及光的折射、反射，光线跟踪虽然可以生成较为真实的图形，但是这种算法的缺点是计算量太大，每计算一帧都需要花费大量的时间，所以这就限制了光线跟踪只能应用在电影、广告和CG动画等离线渲染中，而无法应用在像游戏和模拟驾驶等实时渲染应用程序中。本文以光线跟踪渲染为研究对象，首先根据光线跟踪计算方法的特点，分析算法中最消耗时间的步骤，在王征等人自适应八叉树算法的基础上，结合大规模室内场景中光源数量较多的特点，提出一种基于kd-tree的潜在可见光源集算法，提高不可见光源剔除的效率，从而提高大规模室内场景下的帧速；另一方面，在晋国涛的论文研究基础上，从分布式计算中的客户端计算机任务分配方面改进，，提出一种实时反馈任务分配算法，该算法根据各个客户端的时间消耗反馈来调整任务下发的策略，使各个客户端的平均帧速趋于相近，从而提高分布式光线跟踪计算中的有效渲染帧速。最后，根据改进的算法方案，结合OpenGL设计并实现出一个基于kd-tree的分布式实时光线跟踪渲染系统。
[Abstract]:With the continuous development of information technology, more and more high and new technologies are applied to various fields of society. Virtual reality technology, an important driving force for the development of information technology, is increasingly applied to the field of planning. Virtual community, entertainment and presentation are of great significance, and people have higher requirements for the quality of the picture in the virtual reality, which requires the quality of the picture to be closer to the real and more fluent picture. The current ray-tracing techniques can well simulate the propagation behavior of light, including ambient light, diffuse reflection light, specular light, soft shadow and refraction of light, reflection. But the drawback of this algorithm is that it takes a lot of time to compute a frame, so it limits the use of ray tracking in offline rendering, such as movies, ads and CG animations. Can not be used in real-time rendering applications such as games and simulated driving. In this paper, ray-tracing rendering is taken as the research object. Firstly, according to the characteristics of ray-tracing calculation method, the most time-consuming steps in the algorithm are analyzed, and based on the adaptive octree algorithm of Wang Zheng et al. Considering the large number of light sources in large scale indoor scene, a potential visible light source set algorithm based on kd-tree is proposed, which can improve the efficiency of invisible light source removal and improve the frame rate of large scale indoor scene. Based on the research of Jinguotao, a real-time feedback task assignment algorithm is proposed from the aspect of client computer task allocation in distributed computing. The algorithm adjusts the strategy of task sending according to the time consuming feedback of each client, makes the average frame rate of each client tend to be similar, thus improves the effective rendering frame rate in distributed ray tracing calculation. Finally, According to the improved algorithm and OpenGL, a distributed real-time ray tracing rendering system based on kd-tree is designed and implemented.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TP391.9

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