Core Concepts
NeRF-XL is a principled algorithm that enables the training and rendering of Neural Radiance Fields (NeRFs) with arbitrarily large capacity by efficiently distributing the NeRF parameters across multiple GPUs.
Abstract
The paper introduces NeRF-XL, a novel approach for scaling up Neural Radiance Fields (NeRFs) to handle large-scale and high-detail scenes by leveraging multiple GPUs.
Key highlights:
- Revisits existing multi-GPU approaches that train independent NeRFs on different spatial regions, and identifies fundamental issues that hinder quality improvements as more GPUs are used.
- Proposes a joint training approach where each GPU handles a disjoint spatial region of the NeRF, eliminating redundancy in model capacity and the need for blending during rendering.
- Introduces a novel distributed training and rendering formulation that minimizes communication between GPUs, enabling efficient scaling to arbitrarily large NeRF models.
- Demonstrates consistent quality and speed improvements as more GPUs are used, revealing the multi-GPU scaling laws of NeRFs for the first time.
- Evaluates the approach on a diverse set of datasets, including the largest open-source dataset to date (MatrixCity with 258K images covering 25 km^2).
The key innovation of NeRF-XL is its principled approach to distributing NeRF parameters across multiple GPUs, which allows the training and rendering of NeRFs with arbitrarily large capacity, in contrast to prior methods that struggle to leverage additional computational resources effectively.
Stats
The MatrixCity dataset contains 258,003 images covering a 25 km^2 area.
The Building dataset contains 1,940 images.
The University4 dataset contains 939 images.
The Mexico Beach dataset contains 2,258 images.
The Laguna Seca dataset contains 27,695 images.
The Garden dataset contains 161 images.
Quotes
"NeRF-XL remedies these issues and enables the training and rendering of NeRFs with an arbitrary number of parameters by simply using more hardware."
"Our work contrasts with recent approaches that utilize multi-GPU algorithms to model large-scale scenes by training a set of independent NeRFs [9, 15, 17]. While these approaches require no communication between GPUs, each NeRF needs to model the entire space, including the background region. This leads to increased redundancy in the model's capacity as the number of GPUs grows."
"We demonstrate the effectiveness of NeRF-XL on a wide variety of datasets, including the largest open-source dataset to date, MatrixCity [5], containing 258K images covering a 25km2 city area."