The widely used ambient occlusion (AO) technique provides an approximation of some global illumination effects and is efficient enough for use in real-time applications. Because it relies on computing the visibility from each point on a surface, AO computation is expensive for dynamically deforming objects, such as characters in particular. In this paper, we describe an algorithm for producing high-quality dynamically changing AO for characters. Our fundamental idea is to factorize the AO computation into a coarse-scale component in which visibility is determined by approximating spheres, and a fine-scale component that leverages a skinning-like algorithm for efficiency, with both components trained in a regression against ground-truth AO values. The resulting algorithm accommodates interactions with external objects and generalizes without requiring carefully constructed training data. Extensive comparisons illustrate the capabilities and advantages of our algorithm.
Preprint - To be presented at I3D 2019
Binh Huy Le, Henrik Halen, Carlos Gonzalez-Ochoa, and JP Lewis. 2019. High-Quality Object-Space Dynamic Ambient Occlusion for Characters using Bi-level Regression. In Symposium on Interactive 3D Graphics and Games (I3D ’19), May 21–23, 2019, Montreal, QC, Canada. ACM, NewYork, NY, USA, 10 pages. https://doi.org/10.1145/3306131.3317029
You can download the (preprint) paper here: PDF (21.5MB)