Building volumetric appearance models of fabric using micro CT imaging
Building volumetric appearance models of fabric using micro CT imaging
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DOI：
10.1145/1964921.1964939
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发表时间：
2011-07
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影响因子：
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通讯作者：
Shuang Zhao;Wenzel Jakob;Steve Marschner;Kavita Bala
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文献类型：
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作者：
Shuang Zhao;Wenzel Jakob;Steve Marschner;Kavita Bala
纺织品等复杂厚材料的外观由其3D结构决定，仅通过表面反射模型无法完全描述。虽然体散射可以产生这种材料的高度逼真的图像，但创建所需的体密度模型是困难的。程序方法需要程序员的努力和直觉来为每种材料设计专用算法。此外，由此产生的模型缺乏真实的材料的视觉复杂性及其自然产生的不规则性。本文提出了一种新的方法来获取体积模型，密度数据的基础上，从X射线计算机断层扫描（CT）扫描和外观数据的照片下不受控制的照明。为了对材料建模，进行CT扫描，从而产生标量密度体积。处理该3D数据以提取方向信息并去除噪声。所得到的密度和方向字段中使用的外观匹配过程中定义的体积中的散射特性，当渲染，产生与匹配的照片的纹理统计的图像。正如我们的研究结果所示，这种方法可以很容易地产生具有极端细节的体积外观模型，并且在更大的尺度上，一系列非常不同的织物（如缎子和天鹅绒）的独特纹理和亮点会自动出现-所有这些都仅仅基于精确的中尺度几何形状。
The appearance of complex, thick materials like textiles is determined by their 3D structure, and they are incompletely described by surface reflection models alone. While volume scattering can produce highly realistic images of such materials, creating the required volume density models is difficult. Procedural approaches require significant programmer effort and intuition to design specialpurpose algorithms for each material. Further, the resulting models lack the visual complexity of real materials with their naturally-arising irregularities. This paper proposes a new approach to acquiring volume models, based on density data from X-ray computed tomography (CT) scans and appearance data from photographs under uncontrolled illumination. To model a material, a CT scan is made, resulting in a scalar density volume. This 3D data is processed to extract orientation information and remove noise. The resulting density and orientation fields are used in an appearance matching procedure to define scattering properties in the volume that, when rendered, produce images with texture statistics that match the photographs. As our results show, this approach can easily produce volume appearance models with extreme detail, and at larger scales the distinctive textures and highlights of a range of very different fabrics like satin and velvet emerge automatically---all based simply on having accurate mesoscale geometry.