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Learning Motion Priors for 4D Human Body Capture in 3D Scenes (LEMO)

Official Pytorch implementation for 2021 ICCV (oral) paper "Learning Motion Priors for 4D Human Body Capture in 3D Scenes"

[Project page] [Video] [Paper]

Installation

The code has been tested on Ubuntu 18.04, python 3.8.5 and CUDA 10.0. Please download following models:

• SMPL-X models: version 1.0
• VPoser model: version 1.0 (source code included in the our repo, human_body_prior folder)

If you use the temporal fitting code for PROX dataset, please install following packages:

• Chamfer Pytorch
• (optional) Mesh Packages: for contact / depth term
• (optional) PyTorch Mesh self-intersection: for self-interpenetration term
  • Download the per-triangle part segmentation: smplx_parts_segm.pkl

Then run pip install -r requirements.txt to install other dependencies. It is noticed that different versions of smplx and VPoser might influece results.

Datasets

• PROX
• AMASS

Trained Prior Models

The pretrained models are in the runs.

• Motion smoothness prior: in runs/15217
• Motion infilling prior: in runs/59547

The corresponding preprocessing stats are in the preprocess_stats

• For motion smoothness prior: preprocess_stats/preprocess_stats_smooth_withHand_global_markers.npz
• For motion infilling prior: preprocess_stats/preprocess_stats_infill_local_markers_4chan.npz

Motion Prior Training

Train the motion smoothness prior model with:

python train_smooth_prior.py --amass_dir PATH/TO/AMASS --body_model_path PATH/TO/SMPLX/MODELS --body_mode=global_markers

Train the motion infilling prior model with:

python train_infill_prior.py --amass_dir PATH/TO/AMASS --body_model_path PATH/TO/SMPLX/MODELS --body_mode=local_markers_4chan

Fitting on AMASS

Stage 1: per-frame fitting, utilize motion infilling prior (e.x., on TotalCapture dataset, from first motion sequence to 100th motion sequence, optimize a motion sequence every 20 motion sequences)

python opt_amass_perframe.py --amass_dir=PATH/TO/AMASS --body_model_path=PATH/TO/SMPLX/MODELS --body_mode=local_markers_4chan --dataset_name=TotalCapture --start=0 --end=100 --step=20 --save_dir=PATH/TO/SAVE/RESULUTS

Stage 2: temporal fitting, utilize motion smoothness and infilling prior (e.x., on TotalCapture dataset, from first motion sequence to 100th motion sequence, optimize a motion sequence every 20 motion sequences)

python opt_amass_tempt.py --amass_dir=PATH/TO/AMASS --body_model_path=PATH/TO/SMPLX/MODELS --body_mode=local_markers_4chan --dataset_name=TotalCapture --start=0 --end=100 --step=20 --perframe_res_dir=PATH/TO/PER/FRAME/RESULTS --save_dir=PATH/TO/SAVE/RESULTS

Make sure that start, end, step, dataset_name are consistent between per-frame and temporal fitting, and save_dir in per frame fitting and perframe_res_dir in temporal fitting are consistent.

Visualization of fitted results:

python vis_opt_amass.py --body_model_path=PATH/TO/SMPLX/MODELS --dataset_name=TotalCapture --start=0 --end=100 --step=20 --load_dir=PATH/TO/FITTED/RESULTS

Set --vis_option=static will visualize a motion sequence in static poses, and set --vis_option=animate will visualize a motion sequence as animations. The folders res_opt_amass_perframe and res_opt_amass_temp provide several fitted sequences of Stage 1 and 2, resp..

Fitting on PROX

Stage 1: per-frame fitting, utilize fitted params from PROX dataset directly

Stage 2: temporal consistent fitting: utilize motion smoothness prior

cd temp_prox
python main_slide.py --config=../cfg_files/PROXD_temp_S2.yaml --vposer_ckpt=/PATH/TO/VPOSER --model_folder=/PATH/TO/SMPLX/MODELS --recording_dir=/PATH/TO/PROX/RECORDINGS --output_folder=/PATH/TO/SAVE/RESULTS

Stage 3: occlusion robust fitting: utilize motion smoothness and infilling prior

cd temp_prox
python main_slide.py --config=../cfg_files/PROXD_temp_S3.yaml --vposer_ckpt=/PATH/TO/VPOSER --model_folder=/PATH/TO/SMPLX/MODELS --recording_dir=/PATH/TO/PROX/RECORDINGS --output_folder=/PATH/TO/SAVE/RESULTS

Visualization of fitted results:

cd temp_prox/
cd viz/
python viz_fitting.py --fitting_dir=/PATH/TO/FITTED/RESULTS --model_folder=/PATH/TO/SMPLX/MODELS --base_dir=/PATH/TO/PROX/DATASETS 

Fitted Results of PROX Dataset

The temporal fitting results on PROX can be downloaded here. It includes 2 file formats:

• PROXD_temp: PROX format (consistent with original PROX dataset). Each frame fitting result is saved as a single file.
• PROXD_temp_v2: AMASS format (similar with AMASS dataset). Fitting results of a sequence are saved as a single file.
• convert_prox_format.py converts the data from PROXD_temp format to PROXD_temp_v2 format and visualizes the converetd format.

Additional Data

We utilize LEMO code to fit initialized motion sequences for RoHM (but only use per-frame fitting, without the temporal term or the scene collision terms). We provide a sample sequence here.

Citation

When using the code/figures/data/video/etc., please cite our work

@inproceedings{Zhang:ICCV:2021,
  title = {Learning Motion Priors for 4D Human Body Capture in 3D Scenes},
  author = {Zhang, Siwei and Zhang, Yan and Bogo, Federica and Pollefeys Marc and Tang, Siyu},
  booktitle = {International Conference on Computer Vision (ICCV)},
  month = oct,
  year = {2021}
}

Acknowledgments

This work was supported by the Microsoft Mixed Reality & AI Zurich Lab PhD scholarship. We sincerely thank Shaofei Wang and Jiahao Wang for proofreading.

Relevant Projects

The temporal fitting code for PROX is largely based on the PROX dataset code. Many thanks to this wonderful repo.