PhysEditWorld: A Large-Scale Dataset Toward Physics-Editable World Models

Game world models can generate visually plausible gameplay, yet controlling how motion responds to changes in physical parameters remains challenging. Studying this capability requires comparable observations in which a physical parameter varies while the scene and interaction remain fixed. We introduce PhysEditWorld, a multimodal dataset for physics-editable game world modeling, together with our open-source UE5 DataFactory plugin. The current release focuses on gravity. The plugin replays recorded interactions under different gravity settings while preserving the scene, initial state, action trace, controller configuration, and camera policy. This design produces matched motion sequences with explicit gravity labels and synchronized visual, action, camera, and engine-state annotations. PhysEditWorld spans 12 authored UE5 scenes, 100+ hours of gameplay interactions, and 60M+ rendered frames. Fine-tuning on PhysEditWorld strengthens gravity-dependent motion responses in video generation and improves Qwen3-VL-8B gravity-class accuracy from 24.71% to 95.29% on held-out scenes. The publicly released dataset and plugin support controlled data collection, training, and evaluation of game world models under explicit physics edits.