The unique and visually mesmerizing appearance of pearlescent materials has made them an indispensable ingredient in a diverse array of applications including packaging, ceramics, printing, and cosmetics. In contrast to their natural counterparts, such synthetic examples of pearlescence are created by dispersing microscopic interference pigments within a dielectric resin. The resulting space of materials comprises an enormous range of different phenomena ranging from smooth lustrous appearance reminiscent of pearl to highly directional metallic gloss, along with a gradual change in color that depends on the angle of observation and illumination. All of these properties arise due to a complex optical process involving multiple scattering from platelets characterized by wave-optical interference. This article introduces a flexible model for simulating the optics of such pearlescent 3D microstructures. Following a thorough review of the properties of currently used pigments and manufacturing-related effects that influence pearlescence, we propose a new model which expands the range of appearance that can be represented, and closely reproduces the behavior of measured materials, as we show in our comparisons. Using our model, we conduct a systematic study of the parameter space and its relationship to different aspects of pearlescent appearance. We observe that several previously ignored parameters have a substantial impact on the material's optical behavior, including the multi-layered nature of modern interference pigments, correlations in the orientation of pigment particles, and variability in their properties (e.g. thickness). The utility of a general model for pearlescence extends far beyond computer graphics: inverse and differentiable approaches to rendering are increasingly used to disentangle the physics of scattering from real-world observations. Our approach could inform such reconstructions to enable the predictive design of tailored pearlescent materials.

中文翻译：

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珠光材料的通用框架

珠光材料独特而迷人的外观使其成为包装、陶瓷、印刷和化妆品等各种应用中不可或缺的成分。与它们的天然对应物相比，这种珠光的合成例子是通过将微观干涉颜料分散在介电树脂中而产生的。由此产生的材料空间包含大量不同的现象，从让人联想到珍珠的光滑光泽外观到高度定向的金属光泽，以及取决于观察和照明角度的颜色渐变。所有这些特性都是由于复杂的光学过程而产生的，该过程涉及以波光干涉为特征的血小板的多次散射。本文介绍了一种用于模拟这种珠光 3D 微结构的光学的灵活模型。在对当前使用的颜料的特性和影响珠光的制造相关效果进行彻底审查之后，我们提出了一种新模型，该模型扩大了可以表示的外观范围，并密切再现了测量材料的行为，正如我们在我们的比较。使用我们的模型，我们对参数空间及其与珠光外观不同方面的关系进行了系统研究。我们观察到几个以前被忽略的参数对材料的光学行为有重大影响，包括现代干涉颜料的多层性质、颜料颗粒取向的相关性以及它们特性（例如厚度）的可变性。珠光通用模型的效用远远超出了计算机图形学：渲染的逆向和可微分方法越来越多地用于将散射物理与现实世界的观察分开。我们的方法可以为此类重建提供信息，以实现定制珠光材料的预测设计。