CFD非结构化网格流场体可视化方法研究
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摘要
体可视化是目前公认的3D标量场可视化的最重要途径。它通过“重采样”与“图像合成”等步骤,直接将由离散的3D数据场生成屏幕图像,能够使用户看穿数据体,深入了解数据场的全局状态和内部细节,在流场可视化中的地位举足轻重。与结构化网格相比,非结构化网格拓扑结构复杂,导致体可视化算法设计和实现困难,时空复杂性高。尤其是,对于CFD数值模拟产生的3D非结构化网格流场数据,还具有数据格式多样、物理特征复杂以及非定常(时变)等特点。复杂的数据对象使已有的体可视化技术在精确性、有效性、实时性等方面面临严峻挑战。本课题面向CFD领域的实际应用需求,针对已有非结构化网格体可视化方法存在的不足之处,深入研究了格心格式数据的高精度绘制、重要物理特征的准确绘制、非结构化网格体数据的清晰绘制、非定常流场体数据的高效绘制等目前流场体可视化中的多个热点和难点问题。所完成的主要工作和创新成果有:
     1.针对已有可视化方法只能对CFD非结构化网格格心格式数据完成“间接”绘制而导致的精度和矛盾问题,提出一种非结构化网格格心格式数据直接体可视化方法。该方法直接基于原始格心数据完成数据重构,避免了外推计算,能够获得精度较高的绘制数据;在此基础上,结合迎风型FVM求解思想和Roe平均方法,设计了一种基于双控制体的采样点间断态重构方法,将数值解中的“流间断”信息传递给绘制数据,解决已有可视化方法与数值计算方法的矛盾问题。误差分析和实验结果表明,该方法能明显提高数据重构精度,使绘制结果与数值计算结果更为一致。同时,该方法的有效性并不局限于体绘制,对于其他可视化方法(如等值面提取、流线跟踪等)也同样适用。
     2.针对已有3D激波特征提取方法准确性、有效性和适应性差的问题,提出一种非结构化网格流场3D激波特征体可视化方法。该方法利用激波物理特性,结合光线投射体绘制算法优势,基于两级采样计算完成3D激波检测和噪声过滤;在激波检测时,基于压力梯度计算一级采样点处流场的正则马赫数,有效排除了接触间断特征;在此基础上,通过比较二级采样点处流场速度在激波切面上的分量大小来实现噪声的自动识别与过滤,使过滤的有效性不依赖于数据集本身;针对拓扑复杂的3D非结构化网格数据,设计实现了基于GPU的激波特征高效体绘制算法。实验结果表明,该方法具有良好的有效性和适应性,即便对包含多激波特征的复杂流场数据,也具有很高的准确性。
     3.针对3D非结构化网格数据采样点梯度计算复杂而导致体光照算法设计和实现困难、实时性差的问题,提出一种高效的非结构化网格数据体光照计算与实现方法。该方法基于格林公式和反转距离外推(或体积加权外推)计算非结构化网格顶点梯度,对于不同类型的非结构化网格单元都具有较高的准确性和良好的适应性;在此基础上,采用单元梯度张量计算采样点梯度,有效降低了计算开销;设计了纹理数据结构,实现了基于GPU的实时体光照算法。实验结果表明,所提出的3D非结构化网格数据体光照方法,能够更加清晰地表现3D流场的局部细节和层次结构;且对较大规模非结构化网格体数据,绘制性能可达到实时交互。
     4..针对3D非结构化网格时变流场数据时空一致性不能有效利用而导致动态体绘制时空效率较差的问题,提出一种基于时空一致性的非结构化网格时变流场高效体绘制方法。该方法在分析非结构化网格单元和顶点数据时间一致性的基础上,建立单元和顶点数据时间表,充分利用时间表中的时间一致性信息降低动态采样计算开销;考虑面相邻单元数据的空间一致性,加速光线在数据体中的穿越过程;设计了一种单元和顶点数据相分离的GPU纹理结构以及一种小巧的单元梯度矩阵,明显降低了显存开销;设计了以16步时变数据为单位的数据分组与调度策略,既有效了避免绘制停顿,又使显存纹理结构更为紧致、高效。空间分析和实验表明,该方法不仅明显提高了绘制效率,而且具有更优显存空间利用率,能实现更大网格规模的非结构化网格时变流场体绘制。
Volume visualization, which plays an important role in flow visualization, hasbeen taken as the leading and preferred method to visualize 3D scalar fields. It producesthe final image from the discrete 3D fields by re-sampling and synthesizing, makingusers gain a direct insight into the whole state and the details of the fields. Compared tostructured-grid data, unstructured-grid data with complicated topology result indifficulties in designing and implementing the volume visualization algorithms,especially for the 3D unstructured-grid flow fields from the CFD simulation. It is achallenging work to achieve the accurate, available and real-time visualization of the 3Dunstructured-grid flows with different formats, complicated physical features andunsteady behaviors. To overcome the deficiencies of the existing volume visualizationmethods for the 3D unstructured-grid flows, this dissertation focuses on the followingissues in the practical CFD applications: high-accuracy visualization of the cell-centereddata, exact extraction of the important physical features, volume illumination of the 3Dunstructured-grid data and efficient rendering of the unsteady flows. The majorcontributions of this paper are as follows.
     1. To visualize unstructured cell-centered data, the existing methods can onlyperform indirect visualization, which depress the rendering accuracy and violate thediscontinuity constraint. To solve the problems, this paper proposes a direct method tovisualize unstructured cell-centered data. High accuracy is achieved via datareconstruction performed directly on the original cell-centered data. To keep thediscontinuity, the field at a sample is reconstructed using the double control volumesand the Roe-average computation inspired by an Upwind-FVM solver. Analysis andexperiments demonstrate that the proposed approach gains a high-accuracyreconstruction which is more accordant with the numerical solution. In addition, theidea of direct reconstruction is not only fit for volume rendering, but also can be appliedto other visualization methods (such as isosurface extraction and streamline tracking)and helps render high-accuracy images for CFD simulation.
     2. To deal with the accuracy, availability and adaptability deficiency of the existingmethods on extracting the 3D shocks in flows, a two-level sampling method ispresented for shock detection and noise filtering based on the shock attributes with theaid of ray casting. The normal Mach at the first-level sample is computed with thepressure gradient to detect the shock and the contact discontinuity feature is eliminatedaccordingly. To identify and filter the noise, the velocity magnitude at the second-levelsample is projected on the tangent of the shock to evaluate the noise, which isindependent of the data set. This work is performed on GPU for the 3D unstructuredgriddata with complicated topology. Experimental results show that the approach can automatically filter the noise. The adaptability and accuracy are much better than theexisting methods even for the multi-shock flows.
     3. It is difficult to estimate the sample gradient for unstructured-grid volumeillumination due to the complicated topology, which makes the real-time volumeillumination be hardly achieved because of the computation complexity and thedifficulty of implementation on GPU. This paper proposes an efficient illuminationcomputation and implementation approach for unstructured-grid volume. The vertexgradient is accurately estimated using the Green-Gauss theorem and the inverse-distanceextrapolation (or the volume-weighted extrapolation), which can be applied to theunstructured cells with various shapes. Furthermore, the sample gradient is obtained byan efficient method based on the cell gradient tensor and the computation cost islowered consequently. With the aid of a well-designed data structure, the real-timeperformance of the algorithm can be achieved on GPU even for the large data sets.Experiments show that this approach can lead to a clear insight into the details andstructures of the 3D flows.
     4. Although the temporal and spatial coherence plays an essential role invisualizing unstructured time-varying fields, the existing approaches do not pay enoughattention to it and thus depresses the performence. This paper presents an efficientapproach for volume rendering of unstructured time-varying flows by utilizing thetemporal and spatial coherence. The temporal coherence of both the cell and the vertexdata is analyzed to build the temporal tables, which is used to accelerate the dynamic resampling.The spatial coherence between the face-adjacencies is exploited to speed upthe ray traversal. We also design a novel texture structure that separates the vertex datafrom the cell data and a smart gradient matrix to reduce the pressure of GPU memory. Abasic unit containing 16-step data is used in data compression and management to avoidrendering stalls and lead to a compact and efficient storage. Analysis and experimentsdemonstrate that the approach gains a much lower cost of both time and space than theexisting methods, which allows rendering time-varying data on a larger mesh scale inreal time.
引文
[1] McCormick B. H., DeFanti T. A., Brown M. D.. Visualization in ScientificComputing[J]. Computer Graphics, 1987, 1(2): 99-108.
    [2] McLoughlin, T., Laramee, R. S., Peikert, R., Post, F., Chen, M., Over twodecades of integration-based, geometric flow visualization[J]. Computer GraphicsForum, 2010,29(6): 1807-1829.
    [3] Max, N., Correa, C., Muelder, C., Yan, S., Chen, C.-K., Ma, K.-L. Flowvisualization in science and mathematics[J]. Journal of Physics, 2009, 180(1):012087–012096.
    [4]王福军.计算流体动力学分析—CFD软件原理与应用[M].北京:清华大学出版社,2004.
    [5]阎超.计算流体力学方法及应用[M].北京:北京航空航天大学出版社,2006.
    [6] Kwan-Liu Ma.Parallel Visualization of Large-Scale AerodynamicsCalculations:A Case Study on the Cray T3E[C], IEEE Parallel Visualization andGraphics Symposium 1999, San Francisco, CA,1999: 15– 115.
    [7]唐泽圣.三维数据场可视化[M].北京:清华大学出版社,1999.
    [8]白晓征.包含运动界面的爆炸流场数值模拟方法及其应用[D].长沙:国防科技大学博士学位论文,2009.
    [9] CFD General Notation System Example Files [EB/OL].http://cgns.sourceforge.net/CGNSFiles.html.
    [10]刘儒勋,舒其望.计算流体力学的若干新方法[M].北京:科学出版社,2003.
    [11] John D. Anderson著,吴颂平、刘赵淼译.计算流体力学基础及其应用.北京:机械工业出版社,2007.
    [12] Nielson G M, Hamann B. The Asymptotic Decider: Resolving theAmbiguity in Marching Cubes[C]. IEEE proceedings of visualization, 1991:83-91.
    [13] Chen M, Tang Z, Tang L, Generting Grouping Isosurfaces from Multiresolution3D Data sets[C]. In Proceedings of CAD & Graphics 97, 262-267.
    [14] Mattausch O, Theussl T, Hauser H, et al. Strategies for InteractiveExploration of 3D Flow Using Evenly-Spaced Illuminated Streamlines[C]. InProceedings of the 19th Spring Conference on Computer Graphics, New York: ACMPress, 2003: 213~222.
    [15] Laramee R S, Hauser H. Geometric Flow Visualization Techniques for CFDSimulation Data[C]. In Proceedings of the 21st Spring Conference on ComputerGraphics, New York: ACM Press, 2005: 213~216.
    [16] Levoy M.. Display of surfaces from volume data[J]. IEEE computergraphics and application, 1988,8(3): 29-37.
    [17] Levoy M. Volume Rendering by Adaptive Refinement[R]. UNC TechnicalReport 88030, 1988.
    [18] Cheng L, Yu C. An efficient volume-rendering algorithm with an analyticapproach[J]. The Visual Computer, 1996. 12(10): 515–526.
    [19] Garrity, M. P., Raytracing irregular volume data[C]. In Proceedings of the1990 Workshop on Volume Visualization, San Diego, California, IEEE ComputerSociety, 1990,24(5): 35–40.
    [20] Bunyk, P., Kaufman, A., Silva, C. T., Simple, fast, and robust ray casting ofirregular grids[C]. In Proceedings of IEEE Visualization 1997, Phoenix, Arizona, IEEEComputer Society, 1997: 30–36.
    [21] Wilhelms J, Gelder V. A coherent projection approach for direct volumerendering[J]. Computer Graphics. 1991, 25(4): 275-281.
    [22] Martin Kraus, Thomas Ertl, Cell-Projection of Cyclic Meshes[C]. IEEEVisualization 2001, San Diego, CA, 2001: 215– 559.
    [23] Ma Kwan-Liu, Thomas W. Crockett, A Scalable Parallel Cell-ProjectionVolume Rendering Algorithm for Three-Dimensional Unstructured Data[C]. IEEESymposium on Parallel Rendering 1997, 1997: 95– 104.
    [24] Shirley P., Tuchman A. A polygonal approximation to direct scalar volumerendering[C]. In Proceedings of San Diego Workshop on Volume Visualization, 1990,24(5): 63–70.
    [25] Shen. H.-W. Isosurface extraction in time-varying fields using a temporalhierarchical index tree[C]. In Proceedings of IEEE Visualization 1998, ResearchTriangle Park, North Carolina: IEEE Computer Society, 1998: 159–166.
    [26] Vapor (Visualization & Analysis Platform) general gallery [EB/OL].http://www.vapor.ucar.edu/gallery/index.php.
    [27] David Ellsworth, Bryan Green, Patrick Moran. Interactive Terascale ParticleVisualization[C]. IEEE Visualization 2004, Austin, Texas, 2004: 353-360.
    [28]徐华勋,曾亮,蔡勋,李思昆.GPU加速3D流场特征提取与多分辨率绘制[J].计算机辅助设计与图形学学报,2009,21(7):893-899.
    [29] Falk M, Weiskopf D. Output-Sensitive 3D Line Integral Convolution. IEEETransactions on Visualization and Computer Graphics. 2008, 14(4):820~834.
    [30] Silva, C. T., Comba, J. L. D., Callahan, S.P., Bernardon, F. F.. A survey ofgpu-based volume rendering of unstructured grids[J]. Brazilian Journal of Theoretic andApplied Computing. 2005, 12(2): 9–29.
    [31] Garth C, Gerhardt F, Tricoche X, et al. Efficient Computation andVisualization of Coherent Structures in Fluid Flow Applications[J]. IEEE Transactionson Visualization and Computer Graphics, 2007, 13(6): 1464~1471.
    [32] Correa, C. D., Hero, R., Ma, K.-L., A comparison of gradient estimationmethods for volume rendering on unstructured meshes[J]. IEEE Transaction onVisualization and Computer Graphics, 2009,15(6): 1-15.
    [33] Garth C, Tricoche X, Scheuermann G. Tracking of Vector FieldSingularities in Unstructured 3D Time-Dependent Datasets[C]. In Proceedings IEEEVisualization, Los Alamitos, CA: IEEE Computer Society Press, 2004:329–335.
    [34]蔡勋,岳凯,徐华勋.基于冷暖光照模型的矢量场稀疏纹理绘制.计算机辅助设计与图形学学报, 2010,22(12):2083-2088.
    [35] Wei Li, Mueller, K., Kaufman, A., Empty Space Skipping and OcclusionClipping for Texture-based Volume Rendering[C]. IEEE Visualization, 2003. 2003:317-324.
    [36] Kwan-Liu Ma, Aleksander Stompel.Visualizing Very Large-ScaleEarthquake Simulations[C]. IEEE Conference on Supercomputing, 2003. 2003: 48-58.
    [37] Kwan-Liu Ma. Ultra Scale Visualization[C]. In Proceedings ofTransdisciplinary Fluid Integration 2006. 2006: 7-14.
    [38] Klaus Engel, Markus Hadwiger, Joe M. Kniss, Aaron E. Lefohn, ChristofRezk Salama, Daniel Weiskopf, Real-Time Volume Graphics[Z], Course Notes ofsiggraph2004, New York, ACM press,2004.
    [39] Fan-Yin Tzeng, Eric Lum, Kwan-Liu Ma. A novel interface for higher-Dimensional Classification of volume data[C]. In proceedings of IEEE Visualization2003 Conference, 2003: 505-512.
    [40] Woodring, Jonathan, Shen Han-Wei. Incorporating highlighting animationsinto static visualizations[C]. In Proceedings of the SPIE 2007, 2007: 649503-649514.
    [41] Stegmaier S, Ertl T. A Graphics Hardware-Based Vortex Detection andVisualization System [C]. In Proceedings IEEE Visualization, Los Alamitos, CA: IEEEComputer Society, 2004: 195–202.
    [42] Mahrous K M, Bennett J C, Hammann B, et al. Improving TopologicalSegmentation of Three-dimensional Vector Fields [C]. In Proceedings of the JointEurographics - IEEE TCVG Symposium on Visualization, Aire-la-Ville, Switzerland:Eurographics Association Press, 2003: 203–212.
    [43] Mahrous K, Bennett J C, Scheuermann G, et al. Topological Segmentationin Three-dimensional Vector Fields [J]. IEEE Transactions on Visualization andComputer Graphics, 2004, 10(2):198–205.
    [44] Wischgoll T, Scheuermann G. Locating Closed Streamlines in 3D VectorFields [C]. In Proceedings of the Joint Eurographics - IEEE TCVG Symposium onVisualization, Aire-la-Ville, Switzerland: Eurographics Association Press, 2002:227–280.
    [45] Weinkauf T, Sahner J, Gunther B, et al. Feature-based Analysis of a MultiParameter Flow Simulation [C]. In Proceedings of Simulation and Visualization, Airela-Ville, Switzerland: Eurographics Association Press, 2008:237-252.
    [46] Christoph P, Jens K, Steffen P. Hierarchical Vortex Regions in SwirlingFlow. Computer Graphics Forum, 2009, 28(3):863~870.
    [47] Markus Hadwiger, Patric Ljung, Christof Rezk Salama, Timo Ropinski,Advanced Illumination Techniques for GPU-Based Volume Raycasting[Z], CourseNotes of siggraph2009, New York, ACM press,2009.
    [48] Popinski, T., Rezk, C., Hadwiger, M., Ljung, P. GPU-based volume raycastingwith advanced illumination[EB/OL]. http://vis.computer.org/visweek2008/session. [2009–9–21].
    [49] Eric Lum, Kwan-Liu Ma. Lighting Transfer Function Using GradientAlgned Sampling[C]. In proceedings of IEEE Visualization 2004 Conference, 2004:289-296.
    [50] van Wijk J J. Spot Noise-Texture Synthesis for Data Visualization. InProceedings of ACM SIGGRAPH, New York : ACM Press, 1991: 309~318.
    [51] Cabral B, Leedom L. Imaging Vector Fields Using Line IntegralConvolution. In Proceedings of ACM SIGGRAPH, New York : ACM Press, 1993:263–272.
    [52] Jobard B, Erlebacher G, Hussaini M. Lagrangian-Eulerian Advection forUnsteady Flow Visualization. IEEE Transactions on Visualization and ComputerGraphics, 2002, 8(3):211-222.
    [53] van Wijk J J. Image Based Flow Visualization. ACM Transactions onGraphics, 2002, 21(3):745–754.
    [54] Roger A. Crawfis, Han-Wei Shen, Nelson Max, Flow visualizationtechniques for CFD using volume rendering[C]. The 9th international symposium onflow visualization, 2000: 64_1- 64_10.
    [55] Li G S. Bordoloi U, Shen H W. Chameleon: An Interactive Texture-basedRendering Framework for Visualizing Three-dimensional Vector Fields[C]. InProceedings of IEEE Visualization, Los Alamitos, CA: IEEE Computer Society Press,2003: 241~248.
    [56] Westover L. Footprint Evaluation for volume rendering[J]. ComputerGraphics, 1990, 24(4): 367-376.
    [57] Cameron G G, Undrill P E. Rendering Volumetric Medical Image Data on aSIMD-architecture Computer[C]. In Proceedings of the third Eurographics Workshopon Rendering, 1992: 135-145.
    [58] Philippe Lacroute and Marc Levoy, Fast Volume Rendering Using a Shear-Warp Factorization of the Viewing Transformation[C]. In Proceedings of SIGGRAPH'94, Orlando, Florida, 1994: 451-458.
    [59] Cabral B., Cam N., Foran J.. Accelerated volume rendering and tomographicreconstruction using texture mapping hardware[C]. Processing of IEEE Symposium onVolume Visualization, 1994: 91–98.
    [60] Lefohn A. E., Kniss J. M., Hansen C. D., Whitaker R. T.. A streamingnarrow-band algorithm: Interactive computation and visualization of level sets[J]. IEEETransactions on Visualization and Computer Graphics, 2004, 10(4):422–433.
    [61] Rezk-Salama C., Engel K., Bauer M., Greiner G., Ertl T.. InteractiveVolume Rendering on Standard PC Graphics Hardware Using Multi-Textures andMulti-Stage Rasterization[C]. In Proceedings of SIGGRAPH/Eurographics Workshopon Graphics Hardware 2000, 2000: 145-155.
    [62] Engel K., Kraus M., Ertl T.. High-quality pre-integrated volume renderingusing hardware-accelerated pixel shading[C]. In Proceedings of the EG/SIGGRAPHWorkshop on Graphics hardware, 2001: 9–16.
    [63] Krueger J., Westermann R.. Acceleration Techniques for GPU-basedVolume Rendering[C]. In Proceedings of IEEE Visualization'03, 2003: 287–292.
    [64] Roettger S., Guthe S., Weiskopf D., Ertl T.. Smart Hardware-AcceleratedVolume Rendering[C]. Procceedings of EG/IEEE TCVG Symposium on VisualizationVisSym '03, 2003: 231–238.
    [65] LaMar E., Hamann B., Joy K.I.. Multiresolution Techniques for InteractiveTexture-Based Volume Visualization[C]. In Proceedings of IEEE Visualization'99,1999: 355–361.
    [66] Ropinski T. Accelerating Volume Raycasting using Occlusion Frustum[C].In Proceedings of the joint IEEE/EG International Symposium on Volume and PointbasedGraphics, Aire-la-Ville, Switzerland: Eurographics Association Press, 2008:147~154.
    [67] Stegmaier, S., Strengert M, Klein T., Ertl T. A Simple and Flexible VolumeRendering Framework for Graphics-Hardware-based Ray Casting[C]. In Proceedings ofthe International Workshop on Volume Graphics'05, 2005: 187-195
    [68] Weiler, M., Kraus, M., Merz, M., Ertl, T.. Hardware-based ray casting fortetrahedral meshes[C]. The 14th IEEE Visualization 2003 Conference, Seattle,Washington, IEEE Computer Society, 2003: 333–340.
    [69] Bernardon, F.F., Pagot, C.A., Comba, J.L.D., Silva, C.T., Gpu-based tiledraycasting using depth peeling[J]. Journal of Graphics Tools, 2006, 11(4): 1–16.
    [70] Muigg, P., Hadwiger, M., Doleisch, H., Hauser, H., Scalable hybridunstructured and structured grid raycasting[J]. IEEE Transaction on Visualization andComputer Graphics, 2007, 13(6): 1592–1599.
    [71] Callahan S. P., Ikits M., Comba J. L. D., Silva C. T.. Hardware-assistedvisibility ordering for unstructured volume rendering[J]. IEEE Transactions onVisualization and Computer Graphics, 2005,11(3):285–295.
    [72] Steven P. Callahan, Jo?ao L.D. Comba, Peter Shirley, Cl′audio T. Silva.Interactive Rendering of Large Unstructured Grids Using Dynamic Level-of-Detail.IEEE Visualization’05, 2005: 199—206.
    [73] Callahan S. P., Ikits M., Comba J. L. D., Silva C. T.. Hardware-AssistedVisibility Sorting for Unstructured Volume Rendering[J]. IEEE Transactions onVisualization and Computer Graphics, 2005, 11(3): 285–295.
    [74] Reed D. M., Yagel R., Law A., Shin P.-W., Shareef N.. Hardware assistedvolume rendering of unstructured grids by incremental slicing[C]. IEEE VolumeVisualization 1996, 1996:55 - 62, 101.
    [75] Stein C., Becker B., Max N.. Sorting and hardware assisted rendering forvolume visualization[C]. In Proceedings of IEEE Symposium on Volume Visualization,1994: 83–89.
    [76] Bernardon F. F., Callahan S. P., Comba J. L. D., Silva C. T.. Volumerendering of time-varying scalar fields on unstructured meshes[R]. Technical ReportUUSCI-2005-006, SCI Institute, 2005.
    [77] Barth, T.J., Jespersen, D.C.: The design and application of upwind schemeson unstructured meshes[C]. The 27th Aerospace Sciences Meeting, 1989, AIAA-89-0366.
    [78] Wang C.-L., Yu H.-F., Ma K.-L.. Application-driven compression forvisualizing large-scale time-varying data[J]. IEEE Computer Graphics and Application,2010, 30 (1): 59-69.
    [79] Callahan, S. P., Silva, C. T., Accelerating unstructured volume renderingwith joint bilateral upsampling[J]. Journal of Graphics, GPU & Game Tools, 2009,14(1): 1-15
    [80] Frink, N. T. Upwind scheme for solving the Euler equations on unstructuredtetrahedral meshes[J]. AIAA Journal. 1992, 30(1):70–77.
    [81] Mitchell, C. R. Improved reconstruction schemes for the Navier-Stokesequations on unstructured meshes[C] AIAA Aerospace Sciences Meeting and Exhibit1994, AIAA-94-0642.
    [82] Lovely D., Haimes R. Shock detection from computational fluid dynamicsresults[C]. In Proceedings of the 14th AIAA Computational Fluid DynamicsConference, 1999: AIAA 99-3285.
    [83] Dale A. Lawrence, Christopher D. Lee, Lucy Y. Pao. Shock and vortexvisualization using a combined visual/haptic interface[C]. In Proceedings of IEEEVisualization 2000, Salt Lake City, UT, 2000: 131-137.
    [84] Frits H. Post, Benjamin Vrolijk, Helwig Hauser. State of the art in flowvisualization: feature extraction and tracking[J]. Computer Graphics Forum, 2004, 22(4): 775-792.
    [85] Ming Jiang, Tat-Sang Choy, Sameep Mehta. Feature Mining Paradigms forScientific Data[C]. In Proceedings of Third SIAM International Conference on DataMining 2003. San Francisco, CA, 2003: 13-24.
    [86] Pagendarm, H-G., Seitz, B. An algorithm for detection and visualization ofdiscontinuities in scientific data fields applied to flow data with shock waves. ScientificVisualization– Advanced Software Techniques, 1993: 161-177.
    [87] Hesselink L., Levy Y., Batra Rajesh. Automatic flow feature extraction foruse in computational steering of aerodynamic design processes[EB/OL]. http:// wwwleland.stanford.edu/rbatra/ics/ics.html.,2010.
    [88] Ledergerber, C., Guennebaud, G., Meyer, M., Bacher, M., Pfister, H.Volume mls ray casting[J]. IEEE Transaction on Visulization and Computer Graphics,2008, 14(6):1539–1546.
    [89] Mavriplis, J. Revisiting the least-squares procedure for gradientreconstruction on unstructured meshes[C] Processing of AIAA Computational FluidDynamics Conference 2003, AIAA 2003-3986.
    [90] Cignoni, P., Montani, C., Scopigno, R.: Tetrahedra based volumevisualization[J]. Mathematical Visualization, 1998: 3–18.
    [91] Bernardon F.F., Callahan S.P., Silva C.T.. An adaptive framework forvisualizing unstructured grids with time-varying scalar fields[J]. Parallel Computing2007, 33(6):391-405.
    [92] Schneider J., Westermann R.. Compression domain volume rendering[C]. InProceedings of IEEE Visualization 2003. Seattle, Washington, IEEE Computer Society,2003: 293-300.
    [93] K.-L. Ma. Visualizing time-varying volume data[J]. Computing in Scienceand Engineering, 2003, 5(2): 34–42.
    [94] Ellsworth D., Chiang L.-J., Shen H.-W. Accelerating time-varying hardwarevolume rendering using tsp trees and color-based error metrics[C]. In Proceedings ofVolume Visualization Symposium 2000, New York, ACM Press, 2000: 119–128.
    [95] Ma K.-L., Shen H.-W.. Compression and accelerated rendering of timevaryingvolume data[C]. In Proceedings of 2000 International Computer Symposium onComputer Graphics and Virtual Reality, 2000: 82–89.
    [96] Newell M., Newell R., Sancha T.. A solution to the hidden surfaceproblem[C]. In Proceedings of ACM Annual Conference, 1972: 443–450.
    [97] Williams P. L.. Visibility-ordering meshed polyhedra[J]. ACM Transactionson Graphics, 1992,11(2):103–126.
    [98] ATI. Radeon 9500/9600/9700/9800 OpenGL programming and optimizationguide[EB/OL], http://www.ati.com, 2003.
    [99] Comba J. L. D., Klosowski J. T., Max N., Mitchell J. S. B., Silva C. T.,Williams P. L.. Fast polyhedral cell sorting for interactive rendering of unstructuredgrids[J]. Computer Graphics Forum, 1999,18(3):369–376.
    [100] Comba J. L. D., Mitchell J. S. B., Silva C. T.. On the convexification ofunstructured grids from a scientific visualization perspective[Z]. Scientific Visualization:Extracting Information and Knowledge from Scientific Datasets. 2005: 17-34.
    [101] Cook R., Max N., Silva C. T., Williams P.. Efficient, exact visibilityordering of unstructured meshes[J]. IEEE Transactions on Visualization and ComputerGraphics, 2004,10(6):695–707.
    [102] Kraus M., Ertl T.. Cell-projection of cyclic meshes[C]. In Proceedings ofIEEE Visualization 2001, 2001: 215–222.
    [103] Silva C. T., Mitchell J.S., and Williams P.L.. An exact interactive timevisibility ordering algorithm for polyhedral cell complexes[C]. In Proceedings of IEEESymposium on Volume Visualization, 1998: 87–94.
    [104] Carpenter L.. The A-buffer, an antialiased hidden surface method[J].Computer Graphics, 1984, 7(18): 103–108.
    [105] Everitt C.. Interactive order-independent transparency[Z]. White paper,NVIDIA Corporation, 1999.
    [106] Jouppi N. P., Chang C.-F. Z3: an economical hardware technique for highqualityantialiasing and transparency[C]. Procceedings of ACMSIGGRAPH/Eurographics Workshop on Graphics Hardware, 1999: 85–93.
    [107] Krishnan S., Silva C. T., Wei B. A hardware-assisted visibility-orderingalgorithm with applications to volume rendering of unstructured grids[C]. Procceedingsof EG/IEEE TCVG Symposium on Visualization VisSym 2001, 2001: 233–242.
    [108] Mammen A. Transparency and antialiasing algorithms implemented withthe virtual pixel maps technique[J]. IEEE Computer Graphics, 1989, 9(4):43–55.
    [109] Wittenbrink C. R-Buffer: A pointerless a-buffer hardware architecture[C].In Proceedings of ACM SIGGRAPH/Eurographics Workshop on Graphics Hardware,2001: 73–80.
    [110] Comba J. L. D., Klosowski J. T., Max N., Mitchell J. S. B., Silva C. T.,Williams P. L.. Fast polyhedral cell sorting for interactive rendering of unstructuredgrids[J]. Computer Graphics Forum, 1999,18(3):369–376.
    [111] Cook R., Max N., Silva C. T., Williams P. Efficient, exact visibilityordering of unstructured meshes. IEEE Transactions on Visualization and ComputerGraphics, 2004,10(6):695–707.
    [112] Kraus M., Ertl T.. Cell-projection of cyclic meshes[C]. In Proceedings ofIEEE Visualization 2001, 2001: 215–222.
    [113] Silva C. T., Mitchell J. S., Williams P. L.. An exact interactive timevisibility ordering algorithm for polyhedral cell complexes[C]. In Proceedings of IEEESymposium on Volume Visualization, 1998: 87–94.
    [114] King D., Wittenbrink C., Wolters H.. An architecture for interactivetetrahedral volume rendering[C]. In Proceedings of IEEE TVCG/EurographicsInternational Workshop on Volume Graphics, 2001: 101–110.
    [115] Kraus M., Qiao W., Ebert D. S.. Projecting tetrahedra without renderingartifacts[C]. In Proceedings of IEEE Visualization 2004, 2004: 27–34.
    [116] Rottger, S., Kraus, M., Ertl, T., Hardware-accelerated volume andisosurface rendering based on cell-projection[C]. In Proceedings of IEEE Visualization2000, Salt Lake City, Utah, IEEE Computer Society, 2000: 109–116.
    [117] Wylie B., Moreland K., Fisk L. A., Crossno P.. Tetrahedral projectionusing vertex shaders[C]. In Proceedings of IEEE/ACM Symposium on VolumeGraphics and Visualization, 2002: 7–12.
    [118] Stein C., Becker B., Max N.. Sorting and hardware assisted rendering forvolume visualization[C]. In Proceedings of IEEE Symposium on Volume Visualization,1994: 83–89.
    [119] Riguer, G. Performance Optimization Techniques for ATI GraphicsHardware with DirectX 9.0. [EB/OL] http://mirror.ati.com/developer/techpapers.html.2002.
    [120] Mammen A. Transparency and Antialiasing Algorithms Implemented withthe Virtual Pixel Maps Technique[J]. IEEE Computer Graphics, 1989, 9(4):43–55.
    [121] Lorensen WE, Cline H E. Marching Cube: A high resolution 3D surfaceconstruction algorithm[J]. Computer Graphics, 1987,21(4): 163-169.
    [122] Doi A, Koide A. An efficient method of triangulating equi-valued surfacesby using tetrahedral cells[J]. IEICE Transactions, 1991, E74(1): 214-224.
    [123] Mallinson G.D. The Calculation of the lines of a Three Dimensional VectorField[Z]. Computational Fluid Mechanism, North Holland. 1988: 525-534.
    [124] Mebarki A, Alliez P, Devillers O. Farthest Point Seeding for EfficientPlacement of Streamlines[C]. In Proceedings IEEE Visualization, Los Alamitos, CA:IEEE Computer Society Press, 2005:479-486.
    [125] Li L, Hsien H H, Shen H. W. Illustrative Streamline Placement andVisualization[C]. In Proceedings of IEEE Pacific Visualization Symposium, LosAlamitos, CA: IEEE Computer Society Press, 2008: 79-86.
    [126] Marchesin S. Chen C. K, Ho C. View-Dependent Streamlines for 3DVector Fields[J]. IEEE Transactions on Visualization and Computer Graphics, 2010,16(6): 1578-1586.
    [127] Frink, N. T., Parikh, P., Pirzadeh, S. A fast upwind solver for the Eulerequations on three-dimensional unstructured meshes[R]. Technical Report, 1991,AIAA-91-0102.
    [128] Roe, P. L., Approximate Riemann solvers, parameter vectors, anddifference schemes[J]. Journal of Computational Physics, 1981, 43(2): 357–372.
    [129] Godunov S K. A Difference Scheme for Numerical ComputationDiscontinuous Solution of Hydrodynamic Equations[J]. Matematicheskii Sbornik,1959,47(3): 271–306.
    [130] Schneider, P. J., Eberly, D. H. Geometric tools for computer graphics[M].Morgan Kaufmann, 2003: 9–16.
    [131] Ma K.-L., van Rosendale J., Vermeer W. 3D shock wave visualization onunstructured grids[C]. In Proceedings Symposium on Volume Visualization, 1996:87–94.
    [132] (加)施特罗托特等著,叶修梓,万华根,张引译.非真实感图形学——造型、绘制与动画技术(国外计算机科学教材系)[M].北京:电子工业出版社,2004.
    [133] Phong B. T.. Illumination for Computer Generated Pictures[J].Communications of the ACM, 1975,18(6): 311-317.
    [134] Bruce A G, Gooch B, Shirley P. A Non-Photorealistic Lighting Model forAutomatic Technical Illustration[C]. In Proceedings of ACM SIGGRAPH, New York :ACM Press, 1998: 447~452.
    [135] Banks D C. Illumination in Diverse Codimensions[C]. In Proceedings ofACM SIGGRAPH, New York: ACM Press, 1994:327~334.
    [136] Zockler M, Stalling D, Hege H C. Interactive Visualization Of 3D-VectorFields Using Illuminated Stream Lines[C]. In Proceedings of IEEE Visualization, LosAlamitos, CA, IEEE Computer Society Press , 1996:107~113.
    [137] Mallo O, Peikert R, Sigg C, et al. Illuminated Lines Revisited [C]. InProceedings of IEEE Visualization, Los Alamitos, CA, IEEE Computer Society Press,2005, 2005: 19~26.
    [138] Blinn. James F. Models of Light Reflection for Computer SynthesizedPictures[J]. Computer Graphics, 1977, 11(2): 192~198.
    [139]同济大学数学系编,工程数学:线性代数(第五版)[M].北京:高等教育出版社,2007.
    [140] Livnat Y., Shen H.-W., Johnson C. R.. A near optimal isosurface extractionalgorithm using the span space[J]. IEEE Transactions on Visualization and ComputerGraphics, 1996, 2(1): 73-84.
    [141] Thompson Joe F., Soni B. K., Weatherill N. P. Handbook of gridgeneration[M], CRC Press, Boca Raton, London, New York and Washington, D.C.1999.
    [142] Shen H.-W., Hansen C. D., Livnat Y., Johnson C. R.. Isosurfacing in spanspace with utmost efficiency[C]. In Proceedings of IEEE Visualization 1996, SanFrancisco, CA, IEEE Computer Society, 1996: 287–294.
    [143] Dimitri J. Mavriplis. Unstructured-mesh discretizations and solvers forcomputational aerodynamics[J]. AIAA Journal, 2008, 46(6): 1281-1298.
    [144] Lurig C., Grosso R., Ertl T.. Implicit Adaptive Volume Ray Casting[C]. InProceedings of the International Conference on Computer Graphics and Visualization1997, Plzen, Czech Republic, 1997: 114–120.

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