Power Foam: Unifying Real-Time Differentiable Ray Tracing and Rasterization

2026-04-27

AI Summary

This work proposes a differentiable 3D representation that unifies real-time ray tracing and rasterization by addressing a key limitation of existing foam-based representations: their unbounded cells hinder tile-based rasterization. To resolve this, we replace traditional Voronoi foams with bounded power diagrams, effectively constraining cell extents while preserving efficient ray traversal. We further introduce an oriented explicit surface to model the interface between interior and exterior regions and embed differentiable textures to decouple geometry from appearance. This approach generalizes foam structures into controllable, bounded power diagrams without requiring expensive Delaunay triangulation during training. The resulting method matches the rasterization performance of 3D Gaussian Splatting (3DGS) while maintaining state-of-the-art ray tracing efficiency, offering a unified and practical framework for real-time differentiable rendering.

Abstract

We introduce a differentiable 3D representation that unifies the ray tracing capabilities of foam-based ray tracing with the efficiency of modern rasterization pipelines. While prior foam representations enable constant-time ray traversal through an explicit volumetric partition of space, their potentially unbounded cells hinder efficient tile-based rasterization. We address this limitation by generalizing Voronoi foams to bounded power diagrams with controllable cell extents, enabling spatially bounded primitives without requiring expensive Delaunay triangulations during training. We further introduce an oriented surface formulation that explicitly models interfaces between interior and exterior regions, and decouple geometry from appearance by embedding differentiable texture directly on these surfaces. Together, these contributions yield a representation that preserves state-of-the-art ray tracing efficiency while achieving rasterization performance competitive with current generation 3DGS, providing a practical path toward unified real-time differentiable rendering.

Problem

• differentiable rendering
• ray tracing
• rasterization
• foam representation
• real-time rendering

Innovation

• Power Diagrams
• Differentiable Rendering
• Ray Tracing
• Rasterization
• 3D Representation