SIGGRAPH 2026 (Journal Track)

HoloPathTracer: Fast and Accurate Wave Path Tracing for Holography

Wenbin Zhou1,* Xiangyu Meng1,* Jiankai Xing1,2 Xin Liu1 Suyeon Choi3,4 Yifan Peng1
1The University of Hong Kong 2Tsinghua University 3Stanford University 4Seoul National University

* Equal contribution

Paper Supplement ACM Code
HoloPathTracer-Full focal sweep reconstruction.
Natural Defocus
HoloPathTracer-Full clockwise view-dependent reconstruction.
View-dependent
Near Far

HoloPathTracer creates holograms from path tracing scenes with physically accurate visual cues encoded, including (curved-surfaces) reflection and refraction, glossy materials, global illumination, natural defocus, and continuous view-dependent effects.

Abstract

Holography offers unique advantages for delivering perceptual realism while preserving compact form factors in VR/AR. Its perceptual quality, however, hinges on encoding rich wavefronts of photorealistic scenes into interference patterns and then incoherently multiplexing the resulting wave fields for perception.

We present a physically accurate yet computationally efficient wave optics rendering framework leveraging path tracing to encode full 3D visual cues into phase holograms. Our Monte Carlo method solves the rendering equation and the Rayleigh-Sommerfeld integral simultaneously, generates multiple time-multiplexed random holograms with minimal additional cost through path reuse, and accelerates convergence with an ambient radiance cache.

Extensive simulations and experimental validations on a spatial light modulator-based display prototype demonstrate faithful holographic reconstructions of natural 3D cues and complex materials, including realistic defocus blur, view-dependent effects, highlights, and reflections.

Motivation & Overview

Motivation

Method Overview

Wave Path Tracing Pipeline

The method traces coherent plane-wave bundles through a physically based scene, evaluates BSDF events, samples random phases in hologram space, and accumulates complex amplitudes on a recording plane. Coherent interactions preserve optical path length for correct depth and view consistency, while diffuse and glossy components are handled through randomized wave facets for efficient time-multiplexed holography.

Nine-stage HoloPathTracer processing pipeline.
HoloPathTracer decomposes light transport into coherent and incoherent components, sharing traced geometry, amplitudes, and optical path lengths across multiple hologram frames.

Wave Facets

Angular-amplitude distributions are formed by combining path-traced amplitudes with phase information, supporting material-dependent scattering and variable-frame multiplexing.

Angular amplitude on wave facets.

Random Phase Sampling

Gaussian random fields are sampled in hologram space to keep effective phase bandwidth tied to the SLM recording plane.

Gaussian random field sampling in UV and hologram spaces.

Captured Display Results

A phase-only SLM prototype reconstructs focal stacks from optimized holograms. Captured results show sharper in-focus details and more natural defocus than a representative focal stack baseline.

Acquired display results comparing HoloPathTracer with focal stack.

Efficiency

Runtime

Runtime ablation on CGH frameworks.
Runtime ablation across representative CGH frameworks under 1, 3, 8, and 24 time-multiplexed frames. Since only the random phase term changes across frames, traced geometry, amplitudes, and optical path lengths are shared, allowing HoloPathTracer to generate multiple frames with only marginal overhead.

Convergence

Convergence behavior of wave field rendering schemes.
Convergence comparison between direct hologram-plane rendering, the proposed two-stage wave-recording-plane to SLM propagation, and the texture-baked fast variant. Rendering first to a nearby wave recording plane substantially reduces sampling demand, with dashed lines marking 80% of the PSNR reached at 107 spp.

Interactive Results

Interactive holographic reconstruction.

Drag the eye to change the view. Drag focus point or scroll grid to focus.

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Eye Focusing

BibTeX

@article{zhou2026holopathtracer,
  author  = {Zhou, Wenbin and Meng, Xiangyu and Xing, Jiankai and Liu, Xin and Choi, Suyeon and Peng, Yifan},
  title   = {HoloPathTracer: Fast and Accurate Wave Path Tracing for Holography},
  journal = {ACM Transactions on Graphics},
  volume  = {45},
  number  = {4},
  article = {39},
  year    = {2026},
  doi     = {10.1145/3811351}
}