CHS: Small: Developing and Validating a Physically Accurate Light-Scattering Model for the Rendering of Bird and Other Dinosaur Feathers

虽然计算机图形学已经成为科学可视化(以及许多其他领域，如医学、工业、教育和通信)的重要工具，但仍然迫切需要对自然世界进行更真实、更精细的表示。渲染是计算机图形学的核心组成部分，它使用光和材质相互作用的模型来生成当今最逼真的图像，但在这方面还需要对许多真实世界的材质进行基础研究。例如，在鸟类学和古生物学中，研究人员继续研究羽毛的微结构，以努力发现这些微结构是如何产生颜色和彩虹的，并揭示现代鸟类和已灭绝恐龙的羽毛之间的异同，但到目前为止，还没有足够复杂的模型来描述光与羽毛亚结构的复杂、多尺度的相互作用。这个跨学科的项目将导致第一个专门为羽毛开发的计算机图形外观模型，通过收集和建立生物物理数据来设计一种生物逼真的渲染方法。其他广泛的影响将来自项目成果，有助于与鸟类和其他恐龙有关的教育活动，同时改变渲染能力，为科学可视化、插图、纪录片和互动图形创建逼真的羽毛和羽毛生物图像。真实世界羽毛解剖的出现是光线与不同规模的复杂图案结构相互作用的结果。目前，为了方便起见，哺乳动物的毛发和毛皮的纤维着色模型经常被使用，尽管它们的结构和机械性能截然不同；因此，本质上，这样的模型不能准确地再现羽毛的散射特性。此外，结构着色，一种在纤维阴影模型中根本没有表现出来的波动光学特性，在许多羽毛中都存在。为了解决这些不足，将通过收集和观察来自羽毛的不同尺度的物理数据来开发新的材料模型。广泛的分类学采样将使鸟类之间的重要差异变得明显，并有助于对各种各样的微观结构进行成像。将记录光散射数据，以开发和验证新的物理材料模型。更好地理解这些多尺度光相互作用以及结构着色的复杂现象有可能推动几个领域的前景。活体鸟类羽毛和非鸟类恐龙化石之间的可视化和比较将增加对羽毛进化的理解，适用于鸟类学中配偶选择的信号和进化研究，并提高计算机图形中光纤和波光模型的复杂性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Although computer graphics has become a crucial tool for scientific visualization (and many other fields such as medicine, industry, education, and communication), more realistic, fine-scale representations of the natural world are still sorely needed. Rendering, a core component of computer graphics, uses models of light and material interaction to generate today's most photorealistic images, but there are many real-world materials yet to be fundamentally studied in this regard. In ornithology and paleontology, for example, researchers continue to investigate feather micro-structures in an effort to discover how these produce color and iridescence, and to reveal the similarities and differences between feathers of modern birds and those of extinct dinosaurs, but to date no sufficiently sophisticated model has been developed to represent the complex, multi-scale interaction of light with feather sub-structures. This interdisciplinary project will lead to the first computer-graphics appearance model specifically developed for feathers, by collecting and building on biophysical data to design a biologically realistic rendering method. Additional broad impacts will derive from the project outcomes contributing to educational activities related to birds and other dinosaurs while transforming rendering capabilities to create photorealistic images of feathers and feathered creatures for scientific visualization, illustration, documentaries, and interactive graphics. The appearance of real-world feather anatomy is the result of light interactions with complex, patterned structures of varying scale. Currently, fiber-shading models of mammalian hair and fur are often used for convenience, despite their quite different structural and mechanical properties; inherently, therefore, such models do not accurately recreate the scattering properties of feathers. Furthermore, structural coloration, a wave-optics property not represented at all in fiber-shading models, is present in many feathers. To address these deficiencies, novel material models will be developed by collecting and observing physical data of varying scales from feathers. Broad taxonomic sampling will make manifest important variation among birds and facilitate imaging of a wide variety of microscopic structures. Light-scattering data will be recorded to develop and validate the new physical material models. Greater understanding of these multi-scale light interactions as well as the complex phenomenon of structural coloration holds potential to advance perspectives in several fields. Visualizations and comparisons between living-bird feathers and non-avian dinosaur fossils will increase understanding of feather evolution, be applicable to studies of signaling and evolution of mate choice in ornithology, and improve sophistication of fiber and wave-optics models in computer graphics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.