基于LIC的海流动态模拟与可视化
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摘要
线积分卷积(LIC)方法是一种针对矢量场数据的可视化技术,本文主要研究了LIC方法应用于海洋流场的可视化质量改进问题。主要包括以下几点改进:根据海流运动方向改变稀疏背景噪声的指向以使流线变得更加细长明亮;针对稀疏噪声中海流变化剧烈的区域流线会出现分叉的问题,采用忽略稀疏背景噪声流线追踪时非主流线部分的纹理点的积分计算方法来解决此问题,同时可以省去不必要纹理点的积分计算的开支,加快显示速度;采用赋予海流随机的初始相位的方法来解决稀疏噪声循环动画突兀的问题;通过流线的运动速度快慢或者流线的颜色来表示海流速度大小;通过对海流数据进行插值并改善边界流线追踪条件的方法可形成完整细致的全球海流图像。实验结果表明,该方法可以生成纹理对比强烈、细节清晰、动画连贯的高质量海流运动图像,具有良好的可视化效果。
Line integral convolution(LIC) is a visualization technique for vector data. This paper mainly studies the visual quality improvement when LIC is applied to the ocean current field. Several improvements are made: the direction of background sparse noise is changed according to the direction of vector field in order to make the streamline more clear and bright; the pixels which the main streamlines do not pass are ignored to avoid the confusion by the dispersed streamlines, it can also save a lot of extra calculation of unnecessary pixels to speed up the operation; random initial phase for every streamline is provided to avoid the pulsation effect when using sparse noise as background noise during animation; the velocity is encoded in the speed of almost the same length streamline animation in order to express flow rate; moreover,display the velocity is displayed by the color of streamlines; interpolate ocean data and improve boundary streamline tracking conditions to form a complete and detailed global current image. The experimental results show that this method can generate high-quality ocean current images with strong texture contrast, animation continuity and clear details, and has good visual effects.
Line integral convolution(LIC) is a visualization technique for vector data. This paper mainly studies the visual quality improvement when LIC is applied to the ocean current field. Several improvements are made: the direction of background sparse noise is changed according to the direction of vector field in order to make the streamline more clear and bright; the pixels which the main streamlines do not pass are ignored to avoid the confusion by the dispersed streamlines, it can also save a lot of extra calculation of unnecessary pixels to speed up the operation; random initial phase for every streamline is provided to avoid the pulsation effect when using sparse noise as background noise during animation; the velocity is encoded in the speed of almost the same length streamline animation in order to express flow rate; moreover,display the velocity is displayed by the color of streamlines; interpolate ocean data and improve boundary streamline tracking conditions to form a complete and detailed global current image. The experimental results show that this method can generate high-quality ocean current images with strong texture contrast, animation continuity and clear details, and has good visual effects.
引文
Allendes Osorio R S,Brodlie K W,2009.Uncertain Flow Visualization using LIC.Proceeding.7th Theory and Practice of Computer Graphics(the 27th Conference organized by the Eurographics Association Eurographics UK Chapter),17-19,Cardiff University,Eurographics Association,215-222.
Arthur Okada,David Lane,1997.Enhanced Line Integral Convolution with Flow Feature Detection.Proc.SPIE 3017,Visual Data Exploration and Analysis IV,206.
Berger S,Gr?ller E,et al,2000.Color-Table Animation of Fast Oriented Line Integral Convolution for Vector Field Visualization.WSCG'2000:Conference proceeding:The 8th International Conference in Central Europe on Computers Graphics,Visualization and Interactive Digital Media′2000 in cooperation with EUROGRAPHICS and IFIP WG 5.10:University of West Bohemia,Plzen,Czech republic,February 7-10,2000,p.4-11.
Brian Cabral,1993.Imaging vector fields using line integral convolution.Proceeding SIGGRAPH′93 Proceedings of the 20th annual conference on Computer graphics and interactive techniques Pages,263-270.
Detlev Stalling,Hans-Christian Hege,1995.Fast and Resolution Independent Line Integral Convolution.Proceeding SIGGRAPH′95 Proceedings of the 22nd annual conference on Computer graphics and interactive techniques Pages 249-256 ACM New York,NY,USA1995.
Han W S,David L K,1997.A Line Integral Convolution Algorithm for Visualizing Unsteady Flows.Proceeding VIS'97 Proceedings of the8th conference on Visualization′97 Pages 317-ff.IEEE Computer Society Press?Los Alamitos,CA,USA.
Hege H C,Stalling D,1998.Fast LIC with Piecewise Polynomial Filter Kernels.In:Hege HC,Polthier K.(eds)Mathematical Visualization.1998 Springer,Berlin,Heidelberg.
Jarke J,Van Wijk,1991.Spot Noise:Texture Synthesis For Data Visualization.Computer Graphics,25(4):309-318.
Ming-Hoe Kiu,David C.Banks,1996.Multi-frequency Noise for LIC.Proceeding VIS'96Proceedings of the 7th conference on Visualization′96 Pages 121-126.IEEE Computer Society Press Los Alamitos,CA,USA.
Quan Wang,Xiaoan Tang,Junda Zhang,et al,2014.An approach of vector field texture visualization based on field driven strength,International Conference of Information and Communications Technologies,486-490,Nanjing,China.
Wegenkittl R,Groller E,1997.Purgathofer.Animating Flow Fields:Rendering of Oriented Line Integral Convolution.Published in Computer Animation′97,Date of Conference:5-7,Date Added to IEEE Xplore:06 August 2002.
Zhanping Liu,Robert J.Moorhead Ⅱ,2005.Accelerated Unsteady Flow Line Integral Convolution.Published in IEEE Transactions on Visualization and Computer Graphics(Volume:11,Issue:2,).
陈丁,万刚,王龙,等,2015.基于GPU的二维矢量场LIC算法研究.测绘工程,(3):26-30.
李宗民,黄晶慧,李华,2006.基于三角形滤波卷积核的快速线积分卷积算法.工程图学学报,27(1):105-109.
刘健,姜晓轶,范湘涛,2014.海洋环境信息可视化研究进展.海洋通报,33(2):235-240.
刘占平,2000.矢量场可视化若干关键问题的研究.北京:北京大学.
朱宏玮,姜国华,王宝智,2010.矢量场可视化线积分卷积方法研究与系统设计.计算机应用与软件,27(4):203-206.
詹芳芳,2013.二维LIC矢量场可视化算法的研究及改进.计算机科学,40(9):257-261.
张清波,2002.矢量场可视化技术研究及其在海洋数据处理上的应用,青岛:中国海洋大学.
Arthur Okada,David Lane,1997.Enhanced Line Integral Convolution with Flow Feature Detection.Proc.SPIE 3017,Visual Data Exploration and Analysis IV,206.
Berger S,Gr?ller E,et al,2000.Color-Table Animation of Fast Oriented Line Integral Convolution for Vector Field Visualization.WSCG'2000:Conference proceeding:The 8th International Conference in Central Europe on Computers Graphics,Visualization and Interactive Digital Media′2000 in cooperation with EUROGRAPHICS and IFIP WG 5.10:University of West Bohemia,Plzen,Czech republic,February 7-10,2000,p.4-11.
Brian Cabral,1993.Imaging vector fields using line integral convolution.Proceeding SIGGRAPH′93 Proceedings of the 20th annual conference on Computer graphics and interactive techniques Pages,263-270.
Detlev Stalling,Hans-Christian Hege,1995.Fast and Resolution Independent Line Integral Convolution.Proceeding SIGGRAPH′95 Proceedings of the 22nd annual conference on Computer graphics and interactive techniques Pages 249-256 ACM New York,NY,USA1995.
Han W S,David L K,1997.A Line Integral Convolution Algorithm for Visualizing Unsteady Flows.Proceeding VIS'97 Proceedings of the8th conference on Visualization′97 Pages 317-ff.IEEE Computer Society Press?Los Alamitos,CA,USA.
Hege H C,Stalling D,1998.Fast LIC with Piecewise Polynomial Filter Kernels.In:Hege HC,Polthier K.(eds)Mathematical Visualization.1998 Springer,Berlin,Heidelberg.
Jarke J,Van Wijk,1991.Spot Noise:Texture Synthesis For Data Visualization.Computer Graphics,25(4):309-318.
Ming-Hoe Kiu,David C.Banks,1996.Multi-frequency Noise for LIC.Proceeding VIS'96Proceedings of the 7th conference on Visualization′96 Pages 121-126.IEEE Computer Society Press Los Alamitos,CA,USA.
Quan Wang,Xiaoan Tang,Junda Zhang,et al,2014.An approach of vector field texture visualization based on field driven strength,International Conference of Information and Communications Technologies,486-490,Nanjing,China.
Wegenkittl R,Groller E,1997.Purgathofer.Animating Flow Fields:Rendering of Oriented Line Integral Convolution.Published in Computer Animation′97,Date of Conference:5-7,Date Added to IEEE Xplore:06 August 2002.
Zhanping Liu,Robert J.Moorhead Ⅱ,2005.Accelerated Unsteady Flow Line Integral Convolution.Published in IEEE Transactions on Visualization and Computer Graphics(Volume:11,Issue:2,).
陈丁,万刚,王龙,等,2015.基于GPU的二维矢量场LIC算法研究.测绘工程,(3):26-30.
李宗民,黄晶慧,李华,2006.基于三角形滤波卷积核的快速线积分卷积算法.工程图学学报,27(1):105-109.
刘健,姜晓轶,范湘涛,2014.海洋环境信息可视化研究进展.海洋通报,33(2):235-240.
刘占平,2000.矢量场可视化若干关键问题的研究.北京:北京大学.
朱宏玮,姜国华,王宝智,2010.矢量场可视化线积分卷积方法研究与系统设计.计算机应用与软件,27(4):203-206.
詹芳芳,2013.二维LIC矢量场可视化算法的研究及改进.计算机科学,40(9):257-261.
张清波,2002.矢量场可视化技术研究及其在海洋数据处理上的应用,青岛:中国海洋大学.