NAADF: Globally Illuminated Voxel Worlds Accelerated with Nested Axis-Aligned Distance Fields
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Date
2026
Journal Title
Journal ISSN
Volume Title
Publisher
The Eurographics Association and John Wiley & Sons Ltd.
Abstract
Achieving realistic rendering of 3D scenes in real time using path tracing is challenging due to the high sample count required, with ray tracing as the bottleneck. Focusing on voxels as a geometry representation offers significant opportunities for optimizations, especially for tracing the rays. We propose a multilayered spatial structure augmented with in-cell axis-aligned distance fields (AADF) operating as caches. Our nested cell structure accelerates ray tracing 3–5× compared to dense spatial structures such as directed acyclic graphs. Using AADFs constructed while rendering inside the cells doubles ray throughput again. As an application, nested AADFs allow doubling the speed of global illumination computations while reducing artifacts such as flickering, blurring, ghosting, and aliasing. We adapt temporal antialiasing to retain the last 32 frames rather than a single history buffer to generate the final image. Global illumination sampling is optimized by compressing and separating lit and unlit samples and applying spatial resampling using a reservoir-based spatiotemporal importance resampling method (ReSTIR). Our NAADF structure supports editing with fast updates, overlays of dynamic geometry, and extensions for transform-aware compression or large-scale scans.
Description
@article{10.1111:cgf.70413,
journal = {Computer Graphics Forum},
title = {{NAADF: Globally Illuminated Voxel Worlds Accelerated with Nested Axis-Aligned Distance Fields}},
author = {Ulschmid, Annalena and Macho, Jonas and Ott, Marvin and Wimmer, Michael and Ohrhallinger, Stefan},
year = {2026},
publisher = {The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {10.1111/cgf.70413}
}