implicit-decoder

The tensorflow code for paper "Learning Implicit Fields for Generative Shape Modeling", Zhiqin Chen, Hao (Richard) Zhang.

project page | paper

Introduction

We advocate the use of implicit fields for learning generative models of shapes and introduce an implicit field decoder, called IM-NET, for shape generation, aimed at improving the visual quality of the generated shapes. An implicit field assigns a value to each point in 3D space, so that a shape can be extracted as an iso-surface. IM-NET is trained to perform this assignment by means of a binary classifier. Specifically, it takes a point coordinate, along with a feature vector encoding a shape, and outputs a value which indicates whether the point is outside the shape or not. By replacing conventional decoders by our implicit decoder for representation learning (via IM-AE) and shape generation (via IM-GAN), we demonstrate superior results for tasks such as generative shape modeling, interpolation, and single-view 3D reconstruction, particularly in terms of visual quality.

Citation

If you find our work useful in your research, please consider citing:

@article{chen2018implicit_decoder,
  title={Learning Implicit Fields for Generative Shape Modeling},
  author={Chen, Zhiqin and Zhang, Hao},
  journal={Proceedings of IEEE Conference on Computer Vision and Pattern Recognition (CVPR)},
  year={2019}
}

Dependencies

Requirements:

• Python 3.5 with numpy, scipy and h5py
• Tensorflow
• PyMCubes (for matching cubes)
• pycollada (for writing .dae files)
• OpenCV-Python (for reading and writing images)

Our code has been tested with Python 3.5, TensorFlow 1.8.0, CUDA 9.1 and cuDNN 7.0 on Ubuntu 16.04 and Windows 10.

Datasets and Pre-trained weights

The original voxel models and rendered views are from HSP. Since our network takes point-value pairs, the voxel models require further sampling. The sampling method can be found in our project page.

We provide the ready-to-use datasets in hdf5 format, together with our pre-trained weights. The weights for IM-GAN is the ones we used in our demo video. The weights for IM-SVR is the ones we used in the experiments in our paper.

• IMAE&IMGAN
• IMSVR

Backup links:

• IMAE&IMGAN
• IMSVR

Usage

For data preparation, please see directory point_sampling.

To train an autoencoder, go to IMGAN and use the following commands for progressive training. You may want to copy the commands in a .bat or .sh file.

python main.py --ae --train --epoch 50 --real_size 16 --batch_size_input 4096
python main.py --ae --train --epoch 100 --real_size 32 --batch_size_input 8192
python main.py --ae --train --epoch 200 --real_size 64 --batch_size_input 32768

The above commands will train the AE model 50 epochs in 16³ resolution (each shape has 4096 sampled points), then 50 epochs in 32³ resolution, and finally 100 epochs in 64³ resolution.

To train a latent-gan, after training the autoencoder, use the following command to extract the latent codes:

python main.py --ae

Then train the latent-gan and get some samples:

python main.py --train --epoch 10000
python main.py

You can change some lines in main.py to adjust the number of samples and the sampling resolution.

To train the network for single-view reconstruction, after training the autoencoder, copy the weights and latent codes to the corresponding folders in IMSVR. Go to IMSVR and use the following commands to train IM-SVR and get some samples:

python main.py --train --epoch 1000
python main.py

License

This project is licensed under the terms of the MIT license (see LICENSE for details).