Temporally sliced photon primitives for time-of-flight rendering

1Dartmouth College

In Computer Graphics Forum (Proceedings of EGSR), 2022

We show a steady-state render (left) for this subsurface scattering scene and two rows of time-of-flight renders (right) at different times. The top row is rendered using only progressive transient photon beams, while the bottom row uses our unbiased MIS estimator. Each column corresponds to a different time. The time-of-flight renders include only volumetric transport for clarity and are each rendered at 1.5 minutes per frame.


We derive a class of new Monte Carlo estimators for volumetric time-of-flight rendering, generalizing prior work on transient photon points and beams Conceptually, our method starts with any steady-state photon primitive – like a photon plane, parallelepiped, or parallelotope – and slices it with a temporal wavefront, producing a primitive of one dimension lower. We show how different unbiased temporally sliced primitives arise by analytically integrating any four dimensions within a novel extended spatio-temporal path space formulation. The differences between these estimators reduce to the determinant of a 4 × 4 Jacobian matrix, with columns dictated by the chosen dimensions. We then show how to combine the relative strengths of different sliced primitives using multiple importance sampling. Finally, we implement several of the new estimators enabled by our theory and compare them to each other as well as previous techniques.



Video (full-quality)

Presentation slides video


This work was generously supported by NSF awards 1812796 and 1844538, and a Neukom Institute CompX faculty grant.


Yang Liu, Shaojie Jiao, Wojciech Jarosz. Temporally sliced photon primitives for time-of-flight rendering. Computer Graphics Forum (Proceedings of EGSR), 41(4), July 2022.
    author   = {Liu, Yang and Jiao, Shaojie and Jarosz, Wojciech},
    title    = {Temporally sliced photon primitives for time-of-flight rendering},
    journal  = {Computer Graphics Forum (Proceedings of EGSR)},
    year     = {2022},
    month    = jul,
    volume   = {41},
    number   = {4},
    issn     = {1467-8659},
    doi      = {10/jgzq},
    keywords = {photon surfaces, photon mapping, participating media, multiple importance sampling, MIS}
© The Author(s). This is the author's version of the work. It is posted here by permission of The Eurographics Association for your personal use. Not for redistribution. The definitive version is available at diglib.eg.org.