基于GPU的大规模深海海浪泡沫的实时模拟研究

发布时间：2018-02-04 12:56

本文关键词： 深海模拟泡沫模拟 GPU CUDA　出处：《燕山大学》2014年硕士论文　论文类型：学位论文

【摘要】：海浪泡沫是海洋中一种常见的自然现象，在虚拟现实应用、计算机游戏以及电影特效中，泡沫效果极大地影响着用户的真实感体验。近年来，随着计算机硬件设备的不断更新和相关技术的快速发展，大规模海洋场景的绘制越来越受到计算机图形学研究者的关注。泡沫作为海浪最生动的体现，，其逼真度对海洋模拟起到很重要的作用。本文针对海浪泡沫不真实和不完善的问题，提出一种改进海浪泡沫模拟的新方法。首先，为了构建动态海浪，利用Phillips频谱计算海浪频域的振幅值，通过快速傅立叶逆变换(IFFT)将频域的振幅值转换到空间域的高度值，从而构建海面高度场。由于Phillips频谱是从真实海洋中得到的统计数据，从而能够模拟出高真实感的深海海浪。其次，在快速傅立叶变换反演海浪谱计算生成高度场的基础上，使用CUDA对频域振幅值进行多线程并行运算，节省FFT算法的计算时间。对构建好的海面网格进行GPU渲染，计算每个像素的颜色值，得到不同光照环境下海洋场景的模拟。再次，为了降低波涛汹涌的海浪上泡沫的重复性，生成真实感较强的海洋效果，提出一种修正函数得到基于全局坐标的动态阈值条件来控制泡沫生成，并降低其周期重复性的方法。在海洋模拟中使用平铺的小补丁构造深海海洋表面能够减少计算量。但是这种方法导致海洋表面的泡沫有明显的重复性，严重影响了模拟效果的逼真度和真实感。针对这一问题，设计了一个动态阈值条件用于决定是否在海面的某像素点上显示泡沫从而减少泡沫的重复性。最后，利用OSG开源图形库、图形架构CUDA和OpenGL高级着色语言GLSL设计实现了深海海浪及泡沫的仿真系统。
[Abstract]:Wave foam is a common natural phenomenon in the ocean. In the application of virtual reality, computer games and movie special effects, the bubble effect greatly affects the user's real experience in recent years. With the continuous updating of computer hardware and the rapid development of related technology, large-scale ocean scene rendering has been paid more and more attention by computer graphics researchers. Foam is the most vivid embodiment of ocean waves. The fidelity plays an important role in ocean simulation. In this paper, a new method to improve the simulation of ocean wave foam is proposed to solve the problem of unreality and imperfection of ocean wave foam. Firstly, in order to construct dynamic wave, the amplitude value of frequency domain is calculated by using Phillips spectrum, and the amplitude value of frequency domain is converted to the height value of space domain by inverse Fourier transform (FFT). Because the Phillips spectrum is the statistical data obtained from the real ocean, it can simulate the deep-sea waves with a high sense of reality. Secondly, on the basis of fast Fourier transform (FFT) inversion of wave spectrum to generate height field, CUDA is used to perform multithreading parallel computation of amplitude in frequency domain. The computation time of FFT algorithm is saved, and the constructed sea surface mesh is rendered by GPU, the color value of each pixel is calculated, and the simulation of ocean scene under different illumination environment is obtained. Thirdly, in order to reduce the repeatability of the foam on the rough waves and to produce a realistic ocean effect, a modified function is proposed to obtain the dynamic threshold condition based on the global coordinates to control the foam generation. The method of reducing its cycle repeatability. The use of small patches in ocean simulation to construct deep ocean surface can reduce the computational burden. But this method leads to the foam of ocean surface has obvious reproducibility. In order to solve this problem, a dynamic threshold condition is designed to determine whether to display the foam at a pixel point on the sea surface to reduce the foam repeatability. Finally, the simulation system of deep sea wave and foam is designed and implemented by using OSG open source graphics library, graphic architecture CUDA and OpenGL advanced coloring language GLSL.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P731.2;TP391.41

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