Overview
Field: Computer Vision (CV) Authors: Alexander Pondaven, Ziyi Wu, Igor Gilitschenski Published: 2025-04-01 arXiv: 2504.01264
Abstract (translated)
Recent advances in video diffusion have enabled the development of "world models" capable of simulating interactive environments. However, these models are largely restricted to single-agent settings, failing to control multiple agents simultaneously in a scene. In this work, the authors tackle a fundamental issue of *action binding* in existing video diffusion models, which struggle to associate specific actions with their corresponding subjects.
To address this, they propose ActionParty, an action-controllable multi-subject world model for generative video games. Key ideas:
- Subject state tokens: latent variables that persistently capture the state of each subject in the scene.
- Spatial biasing mechanism: state tokens and video latents are jointly modeled, disentangling global video frame rendering from per-subject action control.
- Extends video-diffusion world models from single-agent to multi-agent control.
- Solves the action-binding problem (correctly pairing an action with its actor).
- Enables interactive multi-player generative video game simulation with identity-consistent tracking over time.
ActionParty is evaluated on the Melting Pot benchmark, demonstrating the first video world model capable of simultaneously controlling up to seven players across 46 diverse environments. Results show significantly improved action-following accuracy and identity consistency, along with robust autoregressive subject tracking during complex interactions.