/ Machine Learning

Point-Voxel CNN for Efficient 3D Deep Learning

Point-Voxel CNN for Efficient 3D Deep Learning

pvcnn

[NeurIPS 2019, Spotlight] Point-Voxel CNN for Efficient 3D Deep Learning.

@inproceedings{liu2019pvcnn,
  title={Point-Voxel CNN for Efficient 3D Deep Learning},
  author={Liu, Zhijian and Tang, Haotian and Lin, Yujun and Han, Song},
  booktitle={Advances in Neural Information Processing Systems},
  year={2019}
}

pvcnnd

pvcnnz

pvcnn

Overview

We release the PyTorch code of the Point-Voxel CNN.
Overview

Prerequisites

The code is built with following libraries:

For point data pre-processing, you may need plyfile.

Data Preparation

S3DIS

We follow the data pre-processing in PointCNN.
The code for preprocessing the S3DIS dataset is located in scripts/s3dis/.
You should first download the dataset from here, then run

python scripts/s3dis/prepare_data.py -d [path to unzip dataset dir]

Code

This code is based on PointCNN and Pointnet2_PyTorch.
We modified the code for PyTorch-style data layout.
The core code to implement PVConv is modules/pvconv.py. Its key idea costs only a few lines of code:

    voxel_features, voxel_coords = voxelize(features, coords)
    voxel_features = voxel_layers(voxel_features)
    voxel_features = trilinear_devoxelize(voxel_features, voxel_coords, resolution)
    fused_features = voxel_features + point_layers(features)

Pretrained Models

Here we provide some of the pretrained models. The accuracy might vary a little bit compared to the paper, since we re-train some of the models for reproducibility.

S3DIS

We compare the 3D-UNet and PointCNN performance reported in the following table.
The accuracy is tested following here. The list is keeping updating.

Overall Acc mIoU
3D-UNet 85.12 54.93
PVCNN 86.16 56.17
PointCNN 85.91 57.26
PVCNN++ 87.14 58.33

Testing Pretrained Models

For example, to test the downloaded pretrained models on S3DIS, you can run

python train.py [config-file] --devices [gpu-ids] --evaluate --configs.train.best_checkpoint_path [path to your models]

For instance, if you want to evaluate PVCNN on GPU 0,1 (with 4096 points on Area 1-4 & 6), you can run

python train.py configs/s3dis/pvcnn/area5.py --devices 0,1 --evaluate --configs.train.best_checkpoint_path s3dis.pvcnn.area5.pth.tar

Training

We provided several examples to train PVCNN with this repo:

  • To train PVCNN on S3DIS holding out Area 5, you can run
python train.py configs/s3dis/pvcnn/area5.py --devices 0,1
  • To train PVCNN++ on S3DIS holding out Area 5, you can run
python train.py configs/s3dis/pvcnnpp/area5.py --devices 0,1

In general, to train a model, you can run

python train.py [config-file] --devices [gpu-ids]

To evaluate trained models, you can do inference by running:

python train.py [config-file] --devices [gpu-ids] --evaluate

GitHub

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