Advanced Volume Visualization Techniques

先进的体积可视化技术PI：查尔斯·汉森，犹他州大学计算学院UtahDirect大学的体绘制已经被证明是一种有效和灵活的可视化方法，用于交互式探索和分析3D标量场。分析三维体数据集的能力对于大规模模拟的成功至关重要。这项研究将通过更忠实的渲染方法来增加对体积数据的分析和理解，这些方法考虑了光与体积本身的相互作用。这项研究将探索一种新的交互式体积着色方法，该方法结合了全局照明效果，并且对于体积材质的照明是健壮的。虽然直接体绘制在可视化应用中被广泛使用，但是这些应用中的大多数(如果不是全部的话)渲染由Phong局部表面着色模型近似照亮的(半透明)表面。此着色模型可渲染此类曲面，但它不能提供足够的照明特性来实现良好的空间敏锐度。为了改进用于体绘制的光照模型，有必要使用体阴影技术来研究对全局光照的近似。这项研究是在一个有效的模型中进行的，该模型捕获了分类的体积数据的物理效果，例如后向散射、表面间/表面内照明和更好的前向散射。该项目的成功是通过将新技术应用于计算燃烧、生物电场模拟、多模式医学成像以及用于无损检测的扫描多模式数据等领域的多场可视化来衡量的，其中通过直接体绘制进行分析是一种合适的可视化方法。这些新方法的有效性将通过用户研究来测试，用户研究将包括熟悉计算机图形学感知测试的感知心理学家和领域科学家。

Advanced Volume Visualization TechniquesPI: Charles Hansen, School of Computing, University of UtahCo-PI: Sarah Creem-Regehr, Dept. of Psychology, University of UtahDirect volume rendering has proven to be an effective and flexible visualization method for interactive exploration and analysis of 3D scalar fields. The ability to analyze 3D volumetric data sets is crucial to the success of large-scale simulation. This research will increase the analysis and understanding of volumetric data through more faithful rendering methods that take into consideration the interaction of light with the volume itself. The research will investigate a new interactive volume shading method that incorporates global illumination effects and is robust for lighting of volumetric materials. Such an illumination model will more effectively bring out data characteristics for analysis and will be more effective for multi-field visualization than current shading methods.While direct volume rendering is widely used in visualization applications, most, if not all, of these applications render (semi-transparent) surfaces lit by an approximation to the Phong local surface shading model. This shading model renders such surfaces but it does not provide sufficient lighting characteristics for good spatial acuity. To improve an illumination model for volume rendering, it is necessary to investigate approximations to global illumination using novel volumetric shading techniques. This investigation is producing in an effective model that captures physical effects of classified volumetric data such as back-scattering, inter/intra-surface illumination, and better forward scattering. The success of this project is being measured by applying the new techniques to multi-field visualization in the areas of computational combustion, bio-electric field simulation, multi-modal medical imaging, and scanned multi-modal data for non-destructive testing in which analysis through direct volume rendering is an appropriate visualization methodology. The effectiveness of these new methods will be tested through user studies that will include both perceptual psychologists familiar with perception testing in computer graphics and domain scientists.