应用薄膜干涉模型进行蝴蝶彩色效果物理绘制

Physical Rendering of Butterfly Iridescence Applying Film Interference Model

针对当前蝴蝶彩色效果绘制方法的真实感问题,提出一种应用薄膜干涉模型的真实感绘制方法.首先根据蝴蝶表面脊突结构构造多层薄膜模型;然后利用多层薄膜干涉原理模拟光在薄膜内部的多次反射、透射形成的混合散射特性,其中,菲涅尔公式被引入以解释反射或透射波的幅值变化,微表面散射因子被创造性地引入来模拟蝴蝶粗糙表面的各向异性特性;最后通过全波长光谱建模增强干涉效果,在此基础上还将该算法与光线追踪渲染框架相结合,构建了可应用于光线追踪器的波动双向散射分布函数干涉模型,以精确地模拟光的幅值和相位变动.实验结果表明,该模型能够有效地绘制出较为逼真的蝴蝶彩色效果.

To address the problems in realistic rendering of butterfly iridescences in computer graphics, this paper proposes a photorealistic simulation method, based on the thin film interference model. The method firstly constructs the multilayer film model, according to the ridge microstructures on butterfly wings; then it applies the multilayer film interference principle to model the mixed scattering characteristics of multiple reflections and transmissions of light inside films; The Fresnel formulae is employed to explain the amplitude variations of reflected or transmitted wave, and the microfacet scattering factor is creatively incorporated to model the anisotropic properties of rough surfaces of butterflies; finally, we augment the interference effects by full wavelength spectrum modeling and further combine the method with a ray tracing framework to construct the wave bidirectional scattering distribution function interference model, to accurately render the amplitude and phase variations of light. The experimental results demonstrate that our method can efficiently model the photorealistic iridescent colors of butterflies.