Solution of an Inverse Problem in Rendering Metallic and Pearlescent Appearance
نویسندگان
چکیده
Physically based rendering of metallic and pearlescent appearance requires knowledge of the composition of paint or coating. However, sometimes composition is not available, while the Bi-directional Reflectance Distribution Function (BRDF) is measured from an actual sample. Such a situation invokes the inverse problem to find a paint composition from a given BRDF. We solve this problem based on a two-layer paint model, where two basic kinds of pigments, flakes and microparticles, are separated in different layers. Because of this, appearance attributes such as gloss, glitter, shade are directly connected to the physical parameters of our model. Therefore, solution of the inverse problem can serve as a starting point for subsequent paint design that is done in appearancerelated rather than physical terms. Our solution involves two consecutive optimizations, which are calculated in real time on a contemporary PC.
منابع مشابه
Rendering Pearlescent Appearance Based On Paint-Composition Modelling
We describe a new approach to modelling pearlescent paints based on decomposing paint layers into stacks of imaginary thin sublayers. The sublayers are chosen so thin that multiple scattering can be considered across different sublayers, while it can be neglected within each of the sublayers. Based on this assumption, an efficient recursive procedure of assembling the layers is developed, which...
متن کاملEfficient Resampling, Compression and Rendering of Metallic and Pearlescent Paint
An interesting class of materials are metallic and pearlescent paints. They pose serious challenges to computer graphics since they have high frequencies in both angular and spatial domain, have a complex, pure stochastic spatial structure and angular dependent color shifts. Hybrid approaches that combine model and image-based representations have proven to faithfully reproduce metallic and pea...
متن کاملSimulation of sparkles in metallic paints
Metallic and pearlescent paints contain flakes and exhibit strong texture (spatial fluctuations of luminance) and sparkles (rare, extremely bright tiny points). We present an algorithm for calculating these texture and sparkles during image rendering.
متن کاملSOLUTION OF AN INVERSE PARABOLIC PROBLEM WITH UNKNOWN SOURCE-FUNCTION AND NONCONSTANT DIFFUSIVITY VIA THE INTEGRAL EQUATION METHODS
In this paper, a nonlinear inverse problem of parabolic type, is considered. By reducing this inverse problem to a system of Volterra integral equations the existence, uniqueness, and stability of the solution will be shown.
متن کاملThe use of inverse quadratic radial basis functions for the solution of an inverse heat problem
In this paper, a numerical procedure for an inverse problem of simultaneously determining an unknown coefficient in a semilinear parabolic equation subject to the specification of the solution at an internal point along with the usual initial boundary conditions is considered. The method consists of expanding the required approximate solution as the elements of the inverse quadrati...
متن کامل