Dai, QiangWang, JiapingLiu, YimingSnyder, JohnWu, EnhuaGuo, Baining2015-02-232015-02-2320091467-8659https://doi.org/10.1111/j.1467-8659.2009.01570.xWe present a new model, called the dual-microfacet, for those materials such as paper and plastic formed by a thin, transparent slab lying between two surfaces of spatially varying roughness. Light transmission through the slab is represented by a microfacet-based BTDF which tabulates the microfacet s normal distribution (NDF) as a function of surface location. Though the material is bounded by two surfaces of different roughness, we approximate light transmission through it by a virtual slab determined by a single spatially-varying NDF. This enables efficient capturing of spatially variant transparent slices. We describe a device for measuring this model over a flat sample by shining light from a CRT behind it and capturing a sequence of images from a single view. Our method captures both angular and spatial variation in the BTDF and provides a good match to measured materials.10.1111/j.1467-8659.2009.01570.x1917-1925