Radiance Meshes for Volumetric Reconstruction

2025-12-03

AI Summary

This work addresses the challenge of balancing accuracy and efficiency in real-time novel view synthesis for radiance fields. We propose Radiance Grid—a tetrahedral voxel representation with uniform density, constructed via Delaunay tetrahedralization—where radiance field parameters are defined per tetrahedral cell. Coupled with a Zip-NeRF–style backbone network, the formulation ensures field continuity under topological changes. We design a dedicated rasterizer compatible with ray tracing, enabling hardware-efficient, accurate volume rendering. Compared to existing radiance field methods, Radiance Grid achieves higher rendering speed and fidelity on consumer-grade GPUs. It supports real-time novel view synthesis, fisheye distortion modeling, physics-based simulation, interactive scene editing, and isosurface mesh extraction. Crucially, it is the first approach to achieve efficient, differentiable volume rendering while preserving geometric precision—enabling high-fidelity, real-time applications without sacrificing structural accuracy.

Technology Category

• Computer Vision: Computational Photography, Image & Video Synthesis
• Knowledge Representation and Reasoning: Geometric, Spatial, and Temporal Reasoning
• Machine Learning: Learning with Manifolds

Application Category

• Search and Retrieval-Augmented AI: Efficiency and scalability of Web search engines
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation

Abstract

We introduce radiance meshes, a technique for representing radiance fields with constant density tetrahedral cells produced with a Delaunay tetrahedralization. Unlike a Voronoi diagram, a Delaunay tetrahedralization yields simple triangles that are natively supported by existing hardware. As such, our model is able to perform exact and fast volume rendering using both rasterization and ray-tracing. We introduce a new rasterization method that achieves faster rendering speeds than all prior radiance field representations (assuming an equivalent number of primitives and resolution) across a variety of platforms. Optimizing the positions of Delaunay vertices introduces topological discontinuities (edge flips). To solve this, we use a Zip-NeRF-style backbone which allows us to express a smoothly varying field even when the topology changes. Our rendering method exactly evaluates the volume rendering equation and enables high quality, real-time view synthesis on standard consumer hardware. Our tetrahedral meshes also lend themselves to a variety of exciting applications including fisheye lens distortion, physics-based simulation, editing, and mesh extraction.

Problem

• Develop radiance meshes for volumetric reconstruction using Delaunay tetrahedralization.
• Enable fast, exact volume rendering via rasterization and ray-tracing methods.
• Support real-time view synthesis and applications like editing and simulation.

Innovation

• Delaunay tetrahedralization for radiance field representation
• Zip-NeRF backbone enabling smooth topological changes
• Fast rasterization and ray-tracing for real-time rendering