Papers › Mega-NeRF: Scalable Construction of Large-Scale NeRFs for Virtual Fly-Throughs

Mega-NeRF: Scalable Construction of Large-Scale NeRFs for Virtual Fly-Throughs

20 Dec 2021CVPR 2022 1arXiv:2112.10703archive 2025-07-28

Haithem Turki, Deva Ramanan, Mahadev Satyanarayanan

We use neural radiance fields (NeRFs) to build interactive 3D environments from large-scale visual captures spanning buildings or even multiple city blocks collected primarily from drones. In contrast to single object scenes (on which NeRFs are traditionally evaluated), our scale poses multiple challenges including (1) the need to model thousands of images with varying lighting conditions, each of which capture only a small subset of the scene, (2) prohibitively large model capacities that make it infeasible to train on a single GPU, and (3) significant challenges for fast rendering that would enable interactive fly-throughs. To address these challenges, we begin by analyzing visibility statistics for large-scale scenes, motivating a sparse network structure where parameters are specialized to different regions of the scene. We introduce a simple geometric clustering algorithm for data parallelism that partitions training images (or rather pixels) into different NeRF submodules that can be trained in parallel. We evaluate our approach on existing datasets (Quad 6k and UrbanScene3D) as well as against our own drone footage, improving training speed by 3x and PSNR by 12%. We also evaluate recent NeRF fast renderers on top of Mega-NeRF and introduce a novel method that exploits temporal coherence. Our technique achieves a 40x speedup over conventional NeRF rendering while remaining within 0.8 db in PSNR quality, exceeding the fidelity of existing fast renderers.

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get_ray_directions cmusatyalab/mega-nerf/mega_nerf/ray_utils.py official repository unverified MIT (permissive) · 84756d2240f13bad · report
get_rays cmusatyalab/mega-nerf/mega_nerf/ray_utils.py official repository unverified MIT (permissive) · 1b116bab88f79f31 · report
get_rays_batch cmusatyalab/mega-nerf/mega_nerf/ray_utils.py official repository unverified MIT (permissive) · b790eb12bdae0333 · report
lpips cmusatyalab/mega-nerf/mega_nerf/metrics.py official repository unverified MIT (permissive) · 319aa49a91d20d8d · report
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psnr cmusatyalab/mega-nerf/mega_nerf/metrics.py official repository unverified MIT (permissive) · 03c2d8f719caf048 · report
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