European Conference on Computer Vision 2024

Length-Aware Motion Synthesis via Latent Diffusion

Alessio Sampieri*, Alessio Palma*, Indro Spinelli, and Fabio Galasso

Sapienza University of Rome, Italy

[Paper]

Abstract

The target duration of a synthesized human motion is a critical attribute that requires modeling control over the motion dynamics and style. Speeding up an action performance is not merely fast-forwarding it. However, state-of-the-art techniques for human behavior synthesis have limited control over the target sequence length.

We introduce the problem of generating length-aware 3D human motion sequences from textual descriptors, and we propose a novel model to synthesize motions of variable target lengths, which we dub ``Length-Aware Latent Diffusion'' (LADiff). LADiff consists of two new modules: 1) a length-aware variational auto-encoder to learn motion representations with length-dependent latent codes; 2) a length-conforming latent diffusion model to generate motions with a richness of details that increases with the required target sequence length. LADiff significantly improves over the state-of-the-art across most of the existing motion synthesis metrics on the two established benchmarks of HumanML3D and KIT-ML.

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Create the environment

conda create python=3.10 --name ladiff
conda activate ladiff

Install the packages in requirements.txt and install PyTorch 1.12.1

cd src
pip install -r requirements.txt

Run the scripts to download dependencies:

bash prepare/download_smpl_model.sh
bash prepare/prepare_clip.sh
bash prepare/download_t2m_evaluators.sh

Put datasets in the datasets folder, please refer to HumanML3D for setup.

We tested our code on Python 3.10.9 and PyTorch 1.12.1.

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Pretrained model

Download the checkpoints trained on HumanML3D from the Google Drive, and place them in the experiments/ladiff folder.

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Train your own model

For the stage 1 (LA-VAE) please first check the parameters in configs/config_vae_humanml3d.yaml, e.g. NAME,DEBUG.

Then, run the following command:

python -m train --cfg configs/config_vae_humanml3d.yaml --cfg_assets configs/assets.yaml --batch_size 64 --nodebug

For the stage 2 (LA-DDPM) please update the parameters in configs/config_ladiff_humanml3d.yaml, e.g. NAME,DEBUG,PRETRAINED_VAE (change to your latest ckpt model path in previous step)

Then, run the following command:

python -m train --cfg configs/config_ladiff_humanml3d.yaml --cfg_assets configs/assets.yaml --batch_size 128  --nodebug

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Evaluate the model

Please first put the trained model checkpoint path to TEST.CHECKPOINT in configs/config_ladiff_humanml3d.yaml.

Then, run the following command:

python -m test --cfg configs/config_ladiff_humanml3d.yaml --cfg_assets configs/assets.yaml

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Citation

If you find our code or paper helpful, please consider citing us.

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Acknowledgements

Thanks to MLD, our code is borrowing from them. Please visit their page for more instructions.