LIC纹理可视化技术在流场中的研究与应用

发布时间：2018-03-04 18:46

本文选题：纹理可视化　切入点：线性积分卷积　出处：《西南科技大学》2016年硕士论文　论文类型：学位论文

【摘要】：流场可视化技术运用计算机图形学和图像处理等技术表达流场特性,为自然流动规律研究和重大工程决策提供有力工具。特别是纹理可视化技术兼具形状和色彩,能够细腻的表现流场特征而被广泛应用。但该技术计算量大、渲染效率低,且扩展到三维流场时,存在严重遮挡和视觉混乱现象。本文针对这些问题和不足开展研究,主要贡献如下:针对颜色增强二维LIC纹理可视化算法,在流场属性值分布不均时,传统线性颜色映射生成图像,整体颜色分布集中无法表达流场细节特征的现象。本文提出一种基于分层聚类的颜色映射算法,该算法从属性场全局特性出发,进行全局采样、邻近聚类、等比例映射颜色域。模拟风场数据和Isabel飓风截面数据测试表明,本文算法生成图像鲜明细腻,可有效解决颜色聚集现象。针对传统Volume LIC算法应用于三维流场时出现的遮挡问题,本文提出基于稀疏噪声Volume LIC GPU加速绘制技术。该技术使用基于Hilbert空间填充曲线的稀疏噪声生成算法生成均匀稀疏噪声代替原始稠密噪声有效减少空间遮挡。同时设计GPU+GLSL硬件加速算法,优化算法复杂性,提高算法执行效率。Tornado龙旋风数据和Isabel飓风模拟数据测试结果表明,相比于传统Volume LIC,本文算法在时间上和可视化效果上都有明显提升。设计一个三维流场纹理可视化原型系统,该系统集成上述算法研究成果,并具有数据特征拓扑展示、二维流场纹理可视化、三维流场纹理可视化等主要功能。使用多种数据集对系统功能和交互进行测试,表明本系统运行流畅、可视化效果优异。
[Abstract]:The flow field visualization technology uses computer graphics and image processing to express the flow field characteristics, which provides a powerful tool for the study of natural flow law and important engineering decision, especially the texture visualization technology has both shape and color. It is widely used to represent the characteristics of flow field in detail. However, this technique has the advantages of large computation, low rendering efficiency and serious occlusion and visual confusion when it is extended to 3D flow field. In this paper, we study these problems and shortcomings. The main contributions are as follows: for the color enhancement two-dimensional LIC texture visualization algorithm, the traditional linear color mapping generates images when the flow field attribute values are unevenly distributed. In this paper, a color mapping algorithm based on hierarchical clustering is proposed. The test results of simulated wind field data and Isabel hurricane section data show that the algorithm can effectively solve the color aggregation phenomenon because of the sharp and fine images generated by this algorithm. In view of the occlusion problem in 3D flow field, the traditional Volume LIC algorithm is applied to the 3D flow field. In this paper, an accelerated rendering technique based on sparse noise Volume LIC GPU is proposed, which uses sparse noise generation algorithm based on Hilbert space filling curve to generate uniform sparse noise instead of original dense noise to effectively reduce spatial occlusion. Design GPU GLSL hardware acceleration algorithm, The complexity of the algorithm is optimized, and the efficiency of the algorithm is improved. The test results of tornado cyclone data and Isabel hurricane simulation data show that, Compared with the traditional Volume algorithm, the algorithm in this paper has a significant improvement in time and visualization effect. A 3D flow field texture visualization prototype system is designed, which integrates the research results of the above algorithms and has a data feature topology display. The main functions of two-dimensional flow field texture visualization and 3D flow field texture visualization are analyzed. The system function and interaction are tested by using various data sets, which shows that the system runs smoothly and the visualization effect is excellent.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TP391.41

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