Inference-time Physics Alignment of Video Generative Models with Latent World Models
TLDR
Using latent world models as rewards to improve physics plausibility of video generation at inference time, achieving first place in PhysicsIQ Challenge.
Reasoning
Strengths: novel inference-time alignment approach, strong empirical results including competition win and human preference study. Weaknesses: reliance on a specific latent world model (VJEPA-2), limited discussion of limitations or generalization.
Read-first score
Read-first score 67.8, weighted from topical fit, citation, graph, method, reproducibility, and recency signals. Original total remains 44.
Field roles
Rank sensitivity
Stability: volatile; rank range: 200.
Keyword Scores
Deep Analysis
Innovations
- Identifying that physics plausibility shortfall in video generation is due to suboptimal inference strategies, not just pre-training
- Introducing WMReward, an inference-time alignment method that uses a latent world model as a reward to search and steer multiple candidate denoising trajectories
- Demonstrating that scaling test-time compute via latent world model guidance improves physics plausibility across diverse generation settings
Methodology
The authors treat improving physics plausibility as an inference-time alignment problem. They leverage the strong physics prior of a latent world model (VJEPA-2) as a reward to search and steer multiple candidate denoising trajectories, enabling scaling test-time compute for better generation performance. Evaluation is conducted across image-conditioned, multiframe-conditioned, and text-conditioned generation settings, with validation from human preference study and the ICCV 2025 Perception Test PhysicsIQ Challenge.
Key Results
The approach substantially improves physics plausibility across multiple generation settings, validated by human preference study. In the ICCV 2025 Perception Test PhysicsIQ Challenge, it achieves a final score of 62.64%, winning first place and outperforming the previous state of the art by 7.42%.