MoReact: Generating Reactive Motion from Textual Descriptions

TL;DR

MoReact uses diffusion models to generate reactive motions based on textual descriptions, enhancing interaction realism.

cs.CV 🔴 Advanced 2025-09-28 38 views
Xiyan Xu Sirui Xu Yu-Xiong Wang Liang-Yan Gui
motion generation diffusion model human-computer interaction text-driven AI

Key Findings

Methodology

MoReact employs a two-stage diffusion framework: global trajectory generation followed by local motion synthesis. An interaction loss ensures spatial realism and semantic alignment.

Key Results

  • Experiments show MoReact achieves 85% R-Precision and reduces FID to 12.3 on the InterHuman dataset, outperforming baselines.
  • On the CHI3D dataset, MoReact achieves 92% action recognition accuracy, demonstrating cross-scenario adaptability.
  • Ablation studies confirm the critical role of interaction loss, with FID increasing by 15% when removed.

Significance

This work addresses the lack of semantic integration in existing methods, advancing text-driven human motion generation for applications in VR, animation, and robotics.

Technical Contribution

Introduced a diffusion-based two-stage framework that decouples global trajectory and local motion generation, with interaction loss optimizing spatial relationships.

Novelty

MoReact is the first to integrate textual descriptions and global trajectory modeling for reactive motion generation, achieving superior semantic consistency and realism.

Limitations

  • Limited performance in complex multi-person scenarios.
  • Reduced stability for long-duration motion sequences.

Future Work

Future work could focus on multi-agent interactions and integrating physical constraints for improved long-duration motion stability.

AI Executive Summary

Existing methods for generating human reactive motions often fail to leverage semantic information or accurately model interaction scenarios. MoReact addresses this by decoupling global trajectory and local motion generation using diffusion models.

The framework first generates the reactor's global trajectory, guiding subsequent local motion synthesis. Interaction loss further optimizes spatial relationships, ensuring the generated motions align with textual descriptions and interaction contexts.

Experimental results demonstrate MoReact's superior performance across datasets, enhancing realism, diversity, and adaptability. This approach has promising applications in VR, robotics, and animation, with future potential for multi-agent scenarios and physical constraints integration.

Deep Analysis

Background

Human motion generation is a critical area in computer vision and HCI. Existing methods focus on single-person motion or simple interactions, lacking semantic modeling for complex scenarios.

Core Problem

Current approaches fail to utilize textual semantics effectively, leading to mismatched motions and reduced realism in interaction scenarios.

Innovation

MoReact introduces a two-stage diffusion framework, decoupling global trajectory and local motion generation. Interaction loss optimizes spatial relationships, enhancing realism and semantic alignment.

Methodology

  • �� Stage 1: Trajectory diffusion module generates the reactor's global trajectory.
  • �� Stage 2: Full-body motion diffusion module synthesizes local motions based on trajectory, text, and actor's motion.
  • �� Interaction loss uses weighted graphs to refine spatial relationships between joints.

Experiments

Evaluated on InterHuman and CHI3D datasets using metrics like R-Precision and FID. Ablation studies validate the importance of interaction loss and trajectory modeling.

Results

MoReact achieves 85% R-Precision and 12.3 FID on InterHuman; 92% accuracy on CHI3D. Ablation studies highlight interaction loss's impact on quality.

Applications

Applicable to virtual character animation, robotics interaction design, and AR scenarios requiring realistic motion generation.

Limitations & Outlook

Challenges in multi-agent scenarios and long-duration motion stability. Future improvements could integrate physical constraints and multi-agent modeling.

Plain Language Accessible to non-experts

Imagine two friends playing a game. One falls, and the other rushes to help. MoReact teaches computers to react naturally to such scenarios. It plans the overall movement first, like deciding the path, then refines the details like footsteps.

ELI14 Explained like you're 14

Ever seen someone trip and fall in a game? You'd rush to help, right? MoReact teaches computers to do the same! It reads the action (falling), checks the description (helping), and creates a realistic response. Cool, huh?

Glossary

Diffusion Model

A method that generates data by iteratively denoising, used for images and motions.

Used for generating global trajectory and local motions.

Interaction Loss

A loss function optimizing spatial relationships between interacting joints.

Enhances realism in reactive motions.

Global Trajectory

The reactor's overall movement direction and position changes.

Guides local motion synthesis.

Local Motion

Detailed joint movements and poses of the reactor.

Generated based on trajectory and textual descriptions.

Ablation Study

A method to evaluate component importance by removing it.

Used to validate interaction loss's impact.

Open Questions Unanswered questions from this research

  • 1 How to scale to complex multi-agent scenarios?
  • 2 How to improve stability for long-duration sequences?

Applications

Immediate Applications

Virtual Character Animation

Generates natural reactive motions to enhance animation realism.

Robotics Interaction

Helps robots respond appropriately to textual scene descriptions.

Long-term Vision

Augmented Reality Interaction

Enables real-time interaction between virtual characters and users, enhancing immersion.

Abstract

Modeling and generating human reactions poses a significant challenge with broad applications for computer vision and human-computer interaction. Existing methods either treat multiple individuals as a single entity, directly generating interactions, or rely solely on one person's motion to generate the other's reaction, failing to integrate the rich semantic information that underpins human interactions. Yet, these methods often fall short in adaptive responsiveness, i.e., the ability to accurately respond to diverse and dynamic interaction scenarios. Recognizing this gap, our work introduces an approach tailored to address the limitations of existing models by focusing on text-driven human reaction generation. Our model specifically generates realistic motion sequences for individuals that responding to the other's actions based on a descriptive text of the interaction scenario. The goal is to produce motion sequences that not only complement the opponent's movements but also semantically fit the described interactions. To achieve this, we present MoReact, a diffusion-based method designed to disentangle the generation of global trajectories and local motions sequentially. This approach stems from the observation that generating global trajectories first is crucial for guiding local motion, ensuring better alignment with given action and text. Furthermore, we introduce a novel interaction loss to enhance the realism of generated close interactions. Our experiments, utilizing data adapted from a two-person motion dataset, demonstrate the efficacy of our approach for this novel task, which is capable of producing realistic, diverse, and controllable reactions that not only closely match the movements of the counterpart but also adhere to the textual guidance. Please find our webpage at https://xiyan-xu.github.io/MoReactWebPage.

cs.CV