Procedural Physically based BRDF for Real‐Time Rendering of Glints

Abstract

microfacet density ρ exp(20) exp(35) ∞ Figure 1: Left: Sponza scene with sparkling fabrics and stones is rendered on an NVIDIA GeForce RTX 2080 (3.0 ms/frame). Right: A sparkling plane perpendicular to the camera with specular microfacet density increasing from left to right. Top right: our physically based BRDF (2.5 ms/frame) converges to Cook and Torrance's BRDF (0.4 ms/frame), which assumes an infinite number of microfacets. Bottom right: the state-of-the-art method [ZK16] (1.3 ms/frame) is not physically based and does not converge to the BRDF of Cook and Torrance.

Real-Time Geometric Glint Anti-Aliasing with Normal Map Filtering

“…In this paper, we draw from these works and use the geometric specular anti-aliasing method of . We convolve the glinty SDF of Chermain et al [2020] with a slope kernel. We also estimate the derivatives in the projected half vector space [Tokuyoshi and Kaplanyan 2019].…”

“…In this paper, we focus on reflectance modeling of sparkling surfaces combined with normal map filtering and geometric specular anti-aliasing.Sparkling materials are very common in our environment: sand, snow, ice, ocean, glittery materials, etc., but they are challenging to render because their reflectance distributions contain high frequencies and have hundreds of sharp lobes. Methods exist to render these kinds of materials Yan et al 2016], and some of them provide means to do so in real-time [Chermain et al 2020;Zirr and Kaplanyan 2016]. Although these methods handle high-frequency lobes (glints), some of these lobes are missed when the surface is strongly curved (especially normal mapped surfaces) and when the number of pixel samples is low.…”

“…CARSTEN DACHSBACHER, Institute for Visualization and Data Analysis, Karlsruhe Institute of Technology, Germany [Chermain et al 2020] + Geometric glint anti-aliasing + Normal map filtering Reference Real-time geometric specular anti-aliasing is required when using a low number of pixel samples and highfrequency specular lobes. Several methods have been proposed for mono-lobe bidirectional reflection distribution functions (BRDFs), but none for multi-lobe BRDFs, e.g., a glinty BRDF.…”

“…It eliminates most of the inconsistent appearing and disappearing of glints on surfaces with significant curvatures during animations. The technique uses the glinty BRDF of Chermain et al [2020] and leverages hardware GPU-filtering of textures to filter slope distributions on the fly. We also improve this glinty BRDF by adding a correlation factor of slope.…”

A Multiscale Microfacet Model Based on Inverse Bin Mapping

“…Zirr et al[ZK16] presented a real-time approach capable of rendering sparkling flakes and parallel scratches. Later, Chermain et al[CSJD20] developed a real-time approach to render glitter that additionally converges to the microfacet BRDF for high flake densities. Methods specialized for efficient rendering of scratches have been recently developed [RGB16; WVJH17; VWH18].…”