Dual-Matrix Sampling for Scalable Translucent Material Rendering

Abstract

Abstract-This paper introduces a scalable algorithm for rendering translucent materials with complex lighting. We represent the light transport with a diffusion approximation by a dual-matrix representation with the Light-to-Surface and Surface-to-Camera matrices. By exploiting the structures within the matrices, the proposed method can locate surface samples with little contribution by using only subsampled matrices and avoid wasting computation on these samples. The decoupled estimation of irradiance and diffuse BSSRDFs also allows us to have a tight error bound, making the adaptive diffusion approximation more efficient and accurate. Experiments show that our method outperforms previous methods for translucent material rendering, especially in large scenes with massive translucent surfaces shaded by complex illumination.

State of the Art in Efficient Translucent Material Rendering with BSSRDF

“…Using only surrounding samples may result in the loss of contributions from other areas. A better solution is clustering, which uses hierarchical structures to organize all samples [JB02, AWB08, WLLC14, MBG*19]. In the following, we discuss these Patch and clustering techniques in detail:…”

“…The hierarchical tree is not the only structure employed in clustering approaches. The matrix format is another useful choice for storing contributions from light sources and surface points, as it can directly estimate the final pixel intensity using matrix multiplication [WLLC14]. This matrix representation is convenient for both clustering and estimation, but it needs more memory to represent extra connections among samples.…”