Modeling and Editing Isotropic BRDF

Reflectance properties of real-world opaque materials can be represented by bidirectional reflectance distribution function (BRDF). Non-parametric BRDF becomes the main aspect nowadays because of its verisimilitude and generality. This paper introduces our BRDF capture equipment and a new compact non-parametric model based on curves for isotropic BRDF. 3D isotropic BRDF data are captured and assembled into a 2D matrix, then decomposed to several 1D curves through twice matrix decomposition, each curve has its own feature, such as specular shape curve, diffuse color curve, etc. The data are compressed effectively, and then reconstructed by these 1D curves during real-time rendering. More important, artist can edit the captured reflectance by adjusting one or more meaningful 1D curve intuitively. Experimental results show that, our method can capture the reflectance data, model and edit BRDF effectively.