Practical multiple scattering for rough surfaces
Abstract
Microfacet theory concisely models light transport over rough surfaces. Specular reflection is the result of single mirror reflections on each facet, while exact computation of multiple scattering is either neglected, or modeled using costly importance sampling techniques. Practical but accurate simulation of multiple scattering in microfacet theory thus remains an open challenge. In this work, we revisit the traditional V-groove cavity model and derive an analytical, cost-effective solution for multiple scattering in rough surfaces. Our kaleidoscopic model is made up of both real and virtual V-grooves, and allows us to calculate higher-order scattering in the microfacets in an analytical fashion. We then extend our model to include nonsymmetric grooves, allowing for additional degrees of freedom on the surface geometry, improving multiple reflections at grazing angles with backward compatibility to traditional normal distribution functions. We validate the accuracy of our model against ground-truth Monte Carlo simulations, and demonstrate its flexibility on anisotropic and textured materials. Our model is analytical, does not introduce significant cost and variance, can be seamless integrated in any rendering engine, preserves reciprocity and energy conservation, and is suitable for bidirectional methods.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 04, 2018
- Source ID
- 10.1145/3272127.3275016
Entities
People
- Adrián Jarabo
- Daniel S. Jeon
- Diego Gutierrez
- Joo Ho Lee
- Min H. Kim
Organizations
- Defense Advanced Research Projects Agency
- European Research Council
- KAIST
- National Research Foundation of Korea
- Samsung Group
- University of Zaragoza