  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.
