Voxel-Based Interactive Rendering of Translucent Materials under Area Lights Using Sparse Samples

Abstract

Interactive rendering of translucent materials in virtual worlds has always proved to be challenging. In our work, we develop a voxel illumination framework for translucent materials illuminated by area lights. Our voxel illumination framework consists of two voxel structures. They are the Enhanced Subsurface Light Propagation Volumes (ESLPV), which handles the local translucent material appearance and the Light Propagation Volumes (LPV), which handles indirect illumination for the entire scene. Using a set of sparsely distributed Poisson disk samples in the ESLPV and LPV, illumination can be gathered from area lights. A uniform set of Poisson disk samples on the translucent objects is resampled and chosen as Translucent Planar Lights (TPLs) and is used to distribute lighting from translucent objects into the LPV by an additional gathering process. Our technique allows for direct and indirect illuminations from highly scattering translucent materials to be rendered interactively under area lighting at good quality. We can achieve similar effects, such as scattered light illumination from translucent materials, when compared to offline renderers without precomputations.