ArXiv

PhiZero: A World Model Built Around Physical Language

2026-07-30 · 17:59 UTC ·Shuyao Shang, Yuqi Wang, Ruopeng Gao... ·1 min read
Authors
Shuyao Shang, Yuqi Wang, Ruopeng Gao...
Categories
cs.CV
arXiv
https://arxiv.org/abs/2607.28624v1
PDF
https://arxiv.org/pdf/2607.28624v1

Brief

PhiZero is a physical world model that learns a compact discrete "physical language" from in-the-wild video via self-supervision. It employs a reason-then-render paradigm—predicting future world-state sequences in this language before rendering pixels—enabling explicit, interpretable modeling of dynamics. Experiments on generation and understanding benchmarks validate physically coherent predictions and demonstrate applications such as action-conditioned simulation and zero-shot motion transfer.

Why it matters

PhiZero (Shuyao Shang et al., arXiv:2607.28624v1, 2026-07-30) introduces "physical language," a compact discrete representation of world-state transitions learned from in-the-wild videos via self-supervision.

Key details

  • PhiZero uses a reason-then-render pipeline: it first predicts future world evolution as a physical-language sequence and then renders those inferred transitions into video; experiments across generation and understanding benchmarks validate its ability to produce physically coherent world evolution and enable interactive world modeling, fine-grained action-conditioned simulation, and zero-shot motion transfer.
Source evidence

Abstract

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.

Comment: Project page: https://phi-zero.github.io/