Dissertation/Thesis/Essay title

Line sampling in participating media

Date of Award

Spring 6-2-2021

Document Type

Thesis (Master's)


Department of Computer Science

First Advisor

Wojciech Jarosz


Participating media, such as fog, fire, dust, and smoke, surrounds us in our daily life. Rendering participating media efficiently has always been a challenging task in physically based rendering. Line sampling has been derived to be an alternative method in direct lighting recently. Since line sampling takes visibility into account, it could reduce variance in the same render time compared to point sampling. We leverage the benefits of line sampling in the context of evaluating direct lighting in participating media. We express the direct lighting as a three-dimensional integral and perform line sampling in any one of them. We show how to apply multiple importance sampling (MIS) with common point samples, improving the robustness of estimators. We also show the drawbacks of MIS between different directions of lines. We demonstrate the efficiency of line sampling in participating media and discuss the results with different setups, such as different phase functions and occluder size.