Light Field Networks: Neural Scene Representations with Single-Evaluation Rendering
Channel: Vincent Sitzmann
Date: 2021-06-07

Light Field Networks are the first fully implicit neural scene representation that enables real-time rendering.

--Project Page--
https://vsitzmann.github.io/lfns

--arXiv preprint--
https://arxiv.org/abs/2106.02634

--Abstract--
Inferring representations of 3D scenes from 2D observations is a fundamental problem of computer graphics, computer vision, and artificial intelligence. Emerging 3D-structured neural scene representations are a promising approach to 3D scene understanding. In this work, we propose a novel neural scene representation, Light Field Networks or LFNs, which represent both geometry and appearance of the underlying 3D scene in a 360-degree, four-dimensional light field parameterized via a neural implicit representation. Rendering a ray from an LFN requires only a *single* network evaluation, as opposed to hundreds of evaluations per ray for ray-marching or volumetric based renderers in 3D-structured neural scene representations. In the setting of simple scenes, we leverage meta-learning to learn a prior over LFNs that enables multi-view consistent light field reconstruction from as little as a single image observation. This results in dramatic reductions in time and memory complexity, and enables real-time rendering. The cost of storing a 360-degree light field via an LFN is two orders of magnitude lower than conventional methods such as the Lumigraph. Utilizing the analytical differentiability of neural implicit representations and a novel parameterization of light space, we further demonstrate the extraction of sparse depth maps from LFNs.

--Authors--
Vincent Sitzmann*, Semon Rezchikov*, William T. Freeman, Joshua B. Tenenbaum, Frédo Durand