Procedural Physically based BRDF for Real‐Time Rendering of Glints. (24th November 2020)

• Record Type: Journal Article
• Authors: Chermain, X.; Sauvage, B.; Dischler, J.‐M.; Dachsbacher, C.
• Is Part Of: Computer graphics forum. Volume 39:Number 7(2020)
• Page Start: 243
• Page End: 253
• Publication Date: 2020-11-24
• Subjects: CCS Concepts -- Computing methodologies → Reflectance modeling; Computer graphics -- Periodicals; 006.605
• DOI: 10.1111/cgf.14141
• Languages: English
• ISSNs: 0167-7055

Abstract

Abstract: Physically based rendering of glittering surfaces is a challenging problem in computer graphics. Several methods have proposed off‐line solutions, but none is dedicated to high‐performance graphics. In this work, we propose a novel physically based BRDF for real‐time rendering of glints. Our model can reproduce the appearance of sparkling materials (rocks, rough plastics, glitter fabrics, etc.). Compared to the previous real‐time method [ZK16], which is not physically based, our BRDF uses normalized NDFs and converges to the standard microfacet BRDF [CT82] for a large number of microfacets. Our method procedurally computes NDFs with hundreds of sharp lobes. It relies on a dictionary of 1D marginal distributions: at each location two of them are randomly picked and multiplied (to obtain a NDF), rotated (to increase the variety), and scaled (to control standard deviation/roughness). The dictionary is multiscale, does not depend on roughness, and has a low memory footprint (less than 1 MiB).