Bidirectional Autoregressive Motion Model (BAMM): A Novel Framework for Generating High-Quality and Editable Text-Driven Human Motions

Core Concepts

BAMM is a novel text-to-motion generation framework that unifies generative masked modeling and autoregressive modeling to capture rich and bidirectional dependencies among motion tokens, while learning a direct probabilistic mapping from textual inputs to motion outputs with dynamically-adjusted motion sequence length.

Abstract

The paper introduces Bidirectional Autoregressive Motion Model (BAMM), a novel text-to-motion generation framework. BAMM consists of two key components:

Motion Tokenizer: This component encodes raw 3D human motion into discrete tokens in the latent space using a Vector Quantized Variational Autoencoder (VQ-VAE).

Conditional Masked Self-attention Transformer: This component learns to autoregressively predict randomly masked motion tokens by adopting a hybrid attention masking strategy. It utilizes both unidirectional and bidirectional causal masks to capture rich dependencies among motion tokens and enable dynamic prediction of motion sequence length.

By unifying generative masked modeling and autoregressive modeling, BAMM can simultaneously achieve high-quality motion generation with enhanced usability and built-in motion editability. During inference, BAMM employs a cascaded motion decoding approach, where it first generates a coarse-grained motion sequence using unidirectional autoregressive decoding, and then refines it through bidirectional autoregressive decoding.
Extensive experiments on the HumanML3D and KIT-ML datasets demonstrate that BAMM outperforms current state-of-the-art text-to-motion generation methods in both qualitative and quantitative measures. BAMM also supports various motion editing tasks, such as inpainting, outpainting, prefix prediction, and suffix completion, without requiring specialized training for these tasks.

Stats

The total frames of the motion sequences in Fig. 1(a) are 196 and 124.

Quotes

"Generating human motion from text has been dominated by denoising motion models either through diffusion or generative masking process. However, these models face great limitations in usability by requiring prior knowledge of the motion length."
"To address these challenges, we propose Bidirectional Autoregressive Motion Model (BAMM), a novel text-to-motion generation framework."
"By unifying generative masked modeling and autoregressive modeling, BAMM captures rich and bidirectional dependencies among motion tokens, while learning a direct probabilistic mapping from textual inputs to motion outputs with dynamically-adjusted motion sequence length."

Key Insights Distilled From

BAMM

by Ekkasit Piny... at arxiv.org 03-29-2024

https://arxiv.org/pdf/2403.19435.pdf

Deeper Inquiries

How can BAMM's bidirectional autoregressive modeling be extended to other domains beyond text-to-motion generation, such as video synthesis or audio generation

BAMM's bidirectional autoregressive modeling can be extended to other domains beyond text-to-motion generation by adapting the framework to suit the specific requirements of video synthesis or audio generation. For video synthesis, the model can be modified to predict sequential frames in a video by treating each frame as a "token" and using bidirectional autoregressive modeling to generate realistic and coherent video sequences. This approach would involve encoding video frames into latent tokens and using a masked self-attention transformer to predict the next frames in both directions. By capturing dependencies between video frames bidirectionally, the model can generate high-quality and contextually consistent video content.
Similarly, for audio generation, BAMM's bidirectional autoregressive modeling can be applied to predict audio samples sequentially. By treating audio samples as tokens and leveraging the masked self-attention transformer, the model can generate realistic audio sequences that align with textual descriptions or other input prompts. This approach would enable the generation of diverse and high-fidelity audio content, such as music, speech, or sound effects, based on the provided input.

What are the potential limitations of BAMM's approach, and how could it be further improved to handle more complex or diverse motion sequences

While BAMM offers significant advancements in text-to-motion generation, there are potential limitations to consider. One limitation is the complexity and diversity of motion sequences that the model can handle. To improve this aspect, BAMM could be further enhanced by incorporating more sophisticated motion tokenization techniques to capture finer details and nuances in motion sequences. Additionally, the model could benefit from incorporating hierarchical structures or multi-scale representations to better represent complex motions with varying levels of granularity.
Furthermore, to handle more diverse motion sequences, BAMM could be improved by integrating domain-specific knowledge or constraints into the modeling process. By incorporating domain-specific information or constraints, the model can generate motions that are more contextually relevant and realistic. Additionally, exploring ensemble modeling techniques or incorporating feedback mechanisms for iterative refinement could help enhance the model's ability to generate diverse and complex motion sequences.

Given the model's ability to generate high-quality motions from text, how could this technology be leveraged to enhance virtual reality, gaming, or other interactive experiences

The technology of generating high-quality motions from text using BAMM can be leveraged to enhance virtual reality, gaming, and other interactive experiences in various ways. In virtual reality applications, BAMM's capability to generate realistic and contextually aligned motions can enhance the immersion and realism of virtual environments. By incorporating BAMM-generated motions into virtual reality experiences, users can interact with virtual characters or environments in a more natural and intuitive manner.
In gaming, BAMM's text-to-motion generation can be utilized to create dynamic and responsive character animations based on in-game events or player inputs. By integrating BAMM into game development pipelines, developers can easily generate lifelike animations that adapt to different gameplay scenarios, enhancing the overall gaming experience. Additionally, BAMM's motion generation technology can be used to create interactive storytelling experiences where users can influence the narrative through their actions or choices, leading to more engaging and personalized gameplay.