Walk through Paintings: Egocentric World Models from Internet Priors
About
What if a video generation model could not only imagine a plausible future, but the correct one -- accurately reflecting how the world changes with each action? We answer this by presenting the Egocentric World Model (EgoWM), a simple, architecture-agnostic method that transforms any pre-trained video diffusion model into an action-conditioned world model, enabling precisely controllable future prediction. Rather than training from scratch, we repurpose the rich world priors of Internet-scale video models by injecting appropriately compressed motor commands through lightweight conditioning layers. This allows our model to follow actions faithfully while preserving generalization and realism. Our approach scales naturally across embodiments and action spaces -- from 3-DoF mobile robots to 25-DoF humanoids, where predicting egocentric joint-angle-driven dynamics is substantially more challenging. The model produces coherent rollouts for both navigation and manipulation, requiring only modest fine-tuning. To evaluate physical correctness independent of appearance, we introduce the Structural Consistency Score (SCS), which measures whether stable scene elements evolve consistently with the provided actions. Our method improves SCS by up to 65\% over the prior state of the art, Navigation World Models; applies seamlessly to three different video diffusion model architectures; and effectively utilizes Internet priors to generalize to unseen environments, including navigation and manipulation inside paintings. Finally, we demonstrate the applicability of EgoWM to robotic planning.