KMM: Key Frame Mask Mamba for Extended Motion Generation

 

1 Peking University 2 The Australian National University
3 Monash University 4 The University of Adelaide
5 The University of Sydney 6 McGill University

 

*Equal Contribution. Corresponding author.
Work done while being a visiting student researcher at Peking University.

Abstract

Human motion generation is a cut-edge area of research in generative computer vision, with promising applications in video creation, game development, and robotic manipulation. The recent Mamba architecture shows promising results in efficiently modeling long and complex sequences, yet two significant challenges remain: Firstly, directly applying Mamba to extended motion generation is ineffective, as the limited capacity of the implicit memory leads to memory decay. Secondly, Mamba struggles with multimodal fusion compared to Transformers, and lack alignment with textual queries, often confusing directions (left or right) or omitting parts of longer text queries. To address these challenges, our paper presents three key contributions: Firstly, we introduce KMM, a novel architecture featuring Key frame Masking Modeling, designed to enhance Mamba's focus on key actions in motion segments. This approach addresses the memory decay problem and represents a pioneering method in customizing strategic frame-level masking in SSMs. Additionally, we designed a contrastive learning paradigm for addressing the multimodal fusion problem in Mamba and improving the motion-text alignment. Finally, we conducted extensive experiments on the go-to dataset, BABEL, achieving state-of-the-art performance with a reduction of more than 57% in FID and 70% parameters compared to previous state-of-the-art methods.

Visualization

A person does a spinning dance, then takes a jump sideways to their right. (279)
A person raises their left hand above their head and moves downward, as if throwing an object toward the ground. The person walks forward, arms by their side. Someone raises their right leg and extends it then lowers it. Someone greeting while standing and raising hand. (415)
A person sidesteps back and forth then moves backward. The person flaps their arms, bending forward. The person is jumping up and down slightly on the spot. A person swam in free style. (525)
A person vaults over an obstacle. A man crouches, stands back up, scratches his head, and crouches again. (380)
A man walks slowly forwards, stepping widely to the left and right. Aarms flap up and down, then the body knees down with both hands on the ground. (307)
A person grabbed something and throw it away. A person who is standing with his hands by his sides takes one small step backwards and resumes his original stance. The person is walking in a clockwise circle. This person walks slowly frontwards. (478)
A person is practicing tennis moves. A person walks while touching something with his right hand. (271)
The person was laying down and then they got up backwards. A person jogging in place. (260)
A person pushes with his left leg and foot first in the floor and then pushes with his right leg and foot. A figure walks forward then turns on their heel to walk back where they came from. (325)
A person leans over, grabbing object with right hand. walk over and commences rubbing motion with right hand or arm. A person takes a small hop forward. (274)
A person stretching their left arm. A person walks using a handrail with his left hand. (184)
A person dances with someone. Crawling forward on his knees. (357)
A person picks up something on his left and sets it down on his right. A person walks turning to the left. A person waves their left hand repeatedly above their head. A person walks to the left holding object on head. (396)
A person is practicing tennis techniques. Someone jumps twice and looks down at the ground. (242)
A person waves with both arms above head. A person lowers to ground and walks on all fours. (293)

Methodology

 

 


This figure illustrates the architecture of the proposed Motion Mamba model. Each of encoder and decoder blocks consists of a Hierarchical Temporal Mamba block (HTM) and a Bidirectional Spatial Mamba (BSM) block, which possess hierarchical scan and bidirectional scan within SSM layers respectively. This symmetric distribution of scans ensure a balanced and coherence framework across the encoder-decoder architecture.


Performance

 

 


The figure illustrates that previous extended motion generation methods often struggle with directional instructions, leading to incorrect motions. In contrast, our proposed KMM, with enhanced text-motion alignment, effectively improves the model's understanding of text queries, resulting in more accurate motion generation.