Flying with Photons: Rendering Novel Views of Propagating Light
This work addresses the challenge of visualizing light propagation in scenes for applications in computer graphics and imaging, representing a novel method rather than an incremental improvement.
The authors tackled the problem of synthesizing videos of light propagation from novel viewpoints by introducing an ultrafast imaging setup and a neural volume rendering framework based on transient fields, achieving picosecond-level temporal resolution and rendering complex effects like scattering and diffraction.
We present an imaging and neural rendering technique that seeks to synthesize videos of light propagating through a scene from novel, moving camera viewpoints. Our approach relies on a new ultrafast imaging setup to capture a first-of-its kind, multi-viewpoint video dataset with picosecond-level temporal resolution. Combined with this dataset, we introduce an efficient neural volume rendering framework based on the transient field. This field is defined as a mapping from a 3D point and 2D direction to a high-dimensional, discrete-time signal that represents time-varying radiance at ultrafast timescales. Rendering with transient fields naturally accounts for effects due to the finite speed of light, including viewpoint-dependent appearance changes caused by light propagation delays to the camera. We render a range of complex effects, including scattering, specular reflection, refraction, and diffraction. Additionally, we demonstrate removing viewpoint-dependent propagation delays using a time warping procedure, rendering of relativistic effects, and video synthesis of direct and global components of light transport.