Instant Neural Surface Reconstruction

This repository contains a concise and extensible implementation of NeRF and NeuS for neural surface reconstruction based on Instant-NGP and the Pytorch-Lightning framework. Training on a NeRF-Synthetic scene takes ~5min for NeRF and ~10min for NeuS on a single RTX3090.

NeRF in 5min NeuS in 10 min
Rendering rendering-nerf rendering-neus
Mesh mesh-nerf mesh-neus


This repository aims to provide a highly efficient while customizable boilerplate for research projects based on NeRF or NeuS.

  • Acceleration techniques from Instant-NGP: multiresolution hash encoding and fully fused networks by tiny-cuda-nn, occupancy grid pruning and rendering by nerfacc
  • out-of-the-box multi-GPU and mixed precision training by PyTorch-Lightning
  • hierarchical project layout that is designed to be easily customized and extended, flexible experiment configuration by OmegaConf


Note: to utilize multiresolution hash encoding or fully fused networks provided by tiny-cuda-nn, you should have least an RTX 2080Ti, see for more details.


  • Install PyTorch>=1.10 here based the package management tool you used and your cuda version (older PyTorch versions may work but have not been tested)
  • Install tiny-cuda-nn PyTorch extension: pip install git+
  • pip install -r requirements.txt


Training on NeRF-Synthetic

Download the NeRF-Synthetic data here and put it under load/. The file structure should be like load/nerf_synthetic/lego.

Run the launch script with --train, specifying the config file, the GPU(s) to be used (GPU 0 will be used by default), and the scece name:

# train NeRF
python --config configs/nerf-blender.yaml --gpu 0 --train dataset.scene=lego tag=example

# train NeuS with mask
python --config configs/neus-blender.yaml --gpu 0 --train dataset.scene=lego tag=example
# train NeuS without mask
python --config configs/neus-blender.yaml --gpu 0 --train dataset.scene=lego tag=example system.loss.lambda_mask=0.0

The code snapshots, checkpoints and experiment outputs are saved to exp/[name]/[tag]@[timestamp], and tensorboard logs can be found at runs/[name]/[tag]@[timestamp]. You can change any configuration in the YAML file by specifying arguments without --, for exmaple:

python --config configs/nerf-blender.yaml --gpu 0 --train dataset.scene=lego tag=iter50k seed=0 trainer.max_steps=50000


The training precedure are by default followed by testing, which computes metrics on test data, generates animations and exports the geometry as triangular meshes. If you want to do testing alone, just resume the pretrained model and replace --train with --test, for example:

python --config path/to/your/exp/config/parsed.yaml --resume path/to/your/exp/ckpt/epoch=0-step=20000 --gpu 0 --test


All experiments are conducted on a single NVIDIA RTX3090.

PSNR Chair Drums Ficus Hotdog Lego Materials Mic Ship Avg.
NeRF Paper 33.00 25.01 30.13 36.18 32.54 29.62 32.91 28.65 31.01
NeRF Ours 34.80 26.04 33.89 37.42 35.33 29.46 35.22 31.17 32.92
NeuS Ours (with mask) 33.14 24.74 28.61 34.39 29.78 26.71 32.60 26.85 29.60
Training Time (mm:ss) Chair Drums Ficus Hotdog Lego Materials Mic Ship Avg.
NeRF Ours 04:34 04:35 04:18 04:46 04:39 04:35 04:26 05:41 04:42
NeuS Ours (with mask) 08:50 09:01 08:53 09:19 09:37 09:17 08:17 11:53 09:23


  • Support more dataset formats, like COLMAP outputs and DTU
  • Support background model based on NeRF++ or Mip-NeRF360
  • Support GUI training and interaction
  • More illustrations about the framework

Related Projects

  • ngp_pl: Great Instant-NGP implementation in PyTorch-Lightning! Background model and GUI supported.
  • Instant-NSR: NeuS implementation using multiresolution hash encoding.


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