PhiZero：围绕物理语言构建的世界模型

摘要

我们提出PhiZero——一个围绕物理语言构建的物理世界模型，其中物理语言是世界状态转移的一种紧凑离散表示。现有的物理世界模型通常直接在像素空间中预测未来视频，使底层世界动态隐含在高维视觉预测器中。受人类能够从视觉经验中抽象出预测结构、并将其组织为自然语言以进行显式推理的能力启发，我们通过自监督方式从野外视频中学习物理语言，并利用它显式推理物理世界如何演化。据此，PhiZero采用先推理后渲染的范式：它首先将未来世界演化推断为物理语言序列，再将推断出的转移渲染为视频。在生成与理解基准上的大量实验验证了PhiZero对物理一致的世界演化进行建模的能力。我们进一步展示了其在逼真且交互式世界建模、细粒度动作条件模拟以及零样本运动迁移方面的潜力。

English

We introduce PhiZero, a physical world model built around physical language, a compact discrete representation of world-state transitions. Existing physical world models typically predict future videos directly in pixel space, leaving the underlying world dynamics implicit within high-dimensional visual predictors. Motivated by humans' ability to abstract predictive structure from visual experience and organize it in natural language for explicit reasoning, we learn physical language from in-the-wild videos through self-supervision and use it to explicitly reason about how the physical world evolves. Accordingly, PhiZero adopts a reason-then-render paradigm: it first infers future world evolution as a physical-language sequence and then renders the inferred transitions into videos. Extensive experiments across generation and understanding benchmarks validate the ability of PhiZero to model physically coherent world evolution. We further show its potential for realistic and interactive world modeling, fine-grained action-conditioned simulation, and zero-shot motion transfer.