Spherical Gaussian‐based Lightcuts for Glossy Interreflections

Abstract

It is still challenging to render directional but non‐specular reflections in complex scenes. The SG‐based (Spherical Gaussian) many‐light framework provides a scalable solution but still requires a large number of glossy virtual lights to avoid spikes as well as reduce clamping errors. Directly gathering contributions from these glossy virtual lights to each pixel in a pairwise way is very inefficient. In this paper, we propose an adaptive algorithm with tighter error bounds to efficiently compute glossy interreflections from glossy virtual lights. This approach is an extension of the Lightcuts that builds hierarchies on both lights and pixels with new error bounds and new GPU‐based traversal methods between light and pixel hierarchies. Results demonstrate that our method is able to faithfully and efficiently compute glossy interreflections in scenes with highly glossy and spatial varying reflectance. Compared with the conventional Lightcuts method, our approach generates lightcuts with only one‐fourth to one‐fifth light nodes therefore exhibits better scalability. Additionally, after being implemented on GPU, our algorithms achieve a magnitude of faster performance than the previous method.

Morphological Anti-Aliasing Method for Boundary Slope Prediction

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Extension: Adaptive Sampling with Implicit Radiance Field

“…The multi-light rendering framework is an important rendering framework outside the path tracing algorithm. Its basic idea is to simplify the simulation of the complete light path illumination transmission after multiple refraction and reflection to calculate the direct illumination from many virtual light sources, and provide a unified Mathematical framework to speed up this operation [5], including how to efficiently process virtual point lights and geometric data in external memory [25], how to efficiently integrate virtual point lights using sparse matrices and compressed sensing [11], and how to handle virtual line light data in translucent media [10], use spherical Gaussian virtual point lights to approximate indirect reflections on glossy surfaces [9], and more.…”

A Virtual Point Light Generation Method in Close-Range Area

“…The multi-light rendering framework is an important rendering framework outside the path tracing algorithm. Its basic idea is to simplify the simulation of the complete light path illumination transmission after multiple refraction and reflection to calculate the direct illumination from many virtual light sources, and provide a unified Mathematical framework to speed up this operation [4], including how to efficiently process virtual point lights and geometric data in external memory [26], how to efficiently integrate virtual point lights using sparse matrices and compressed sensing [11], and how to handle virtual line light data in translucent media [10], use spherical Gaussian virtual point lights to approximate indirect reflections on glossy surfaces [9], and more.…”