Efficient Modeling and Rendering of Iridescence from Cholesteric Liquid Crystals

We introduce a novel approach to the efficient modeling and rendering of Cholesteric Liquid Crystals (CLCs), materials known for producing colorful effects due to their helical molecular structure. CLCs reflect circularly-polarized light within specific spectral bands, making their accurate simulation challenging for realistic rendering in Computer Graphics. Using the two-wave approximation from the Photonics literature, we develop a piecewise spectral reflectance model that improves the understanding of how light interact with CLCs for arbitrary incident angles. Our reflectance model allows for more efficient spectral rendering and fast integration into RGB-based rendering engines. We show that our approach is able to reproduce the unique visual properties of both natural and man-made CLCs, while keeping the computation fast enough for interactive applications and avoiding potential spectral aliasing issues.