HoloPathTracer: Fast and Accurate Wave Path Tracing for Holography

2026-06-12

AI Summary

This work addresses the limitations of conventional computer-generated holography, which decouples radiance estimation from wave propagation and thus fails to reproduce continuous depth and view-dependent cues as well as physically based material effects such as specular reflections and refractions. The paper presents the first unified rendering framework that integrates path tracing with wave optics, simultaneously solving the rendering equation and the Rayleigh–Sommerfeld diffraction integral via Monte Carlo integration to encode full 3D visual information into phase-only holograms. By introducing an environment radiance cache and a Path Reuse strategy, the method achieves an order-of-magnitude acceleration in convergence and supports temporally multiplexed, efficient hologram generation. Experiments on spatial light modulators demonstrate high-fidelity holographic reconstruction of complex visual phenomena, including depth-of-field blur and view-dependent highlights.

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. Existing CGH paradigms decouple radiance estimation from wave propagation by pre-rendering radiance on discretized scene sectors. This separation between radiometric and wave-optical computation inherently limits the range of focus cues and visual effects that can be faithfully reproduced, including depth- and view-continuity, and physically based material behaviors such as glossy or mirror-like reflection and refraction. We present a physically accurate yet computationally efficient wave optics rendering framework leveraging path tracing to encode full 3D visual cues into phase holograms. Specifically, we employ a Monte Carlo method to solve both the rendering equation and the Rayleigh--Sommerfeld integral simultaneously. Our algorithm is fully compatible with modern graphics techniques and can generate multiple time-multiplexed random holograms with minimal additional time cost via Path Reuse. By employing a fast approximation with an ambient radiance cache, we realize an order of magnitude convergence speed improvement. The resulting coherent wave fields that inherently encode comprehensive visual effects are converted into phase-only holograms under complex-amplitude supervision. Through extensive simulations and experimental validations on a spatial light modulator-based display prototype, we demonstrate faithful holographic reconstructions of natural 3D cues and complex materials, including realistic defocus blur, view-dependent effects, as well as appearance highlights and reflections.

Problem

• computer-generated holography
• wave optics
• visual realism
• focus cues
• material appearance

Innovation

• wave path tracing
• computer-generated holography
• Rayleigh-Sommerfeld diffraction
• phase-only hologram
• physically based rendering