HyRF: Hybrid Radiance Fields for Memory-efficient and High-quality Novel
  View Synthesis
Authors: name: Zipeng Wang, name: Dan Xu

Recently, 3D Gaussian Splatting (3DGS) has emerged as a powerful alternative
to NeRF-based approaches, enabling real-time, high-quality novel view synthesis
through explicit, optimizable 3D Gaussians. However, 3DGS suffers from
significant memory overhead due to its reliance on per-Gaussian parameters to
model view-dependent effects and anisotropic shapes. While recent works propose
compressing 3DGS with neural fields, these methods struggle to capture
high-frequency spatial variations in Gaussian properties, leading to degraded
reconstruction of fine details. We present Hybrid Radiance Fields (HyRF), a
novel scene representation that combines the strengths of explicit Gaussians
and neural fields. HyRF decomposes the scene into (1) a compact set of explicit
Gaussians storing only critical high-frequency parameters and (2) grid-based
neural fields that predict remaining properties. To enhance representational
capacity, we introduce a decoupled neural field architecture, separately
modeling geometry (scale, opacity, rotation) and view-dependent color.
Additionally, we propose a hybrid rendering scheme that composites Gaussian
splatting with a neural field-predicted background, addressing limitations in
distant scene representation. Experiments demonstrate that HyRF achieves
state-of-the-art rendering quality while reducing model size by over 20 times
compared to 3DGS and maintaining real-time performance. Our project page is
available at https://wzpscott.github.io/hyrf/.