UniPhysGen: Unified Physical Grounding for Simulation-Ready 3D Assets

2026-07-15

AI Summary

Existing 3D assets commonly lack consistent physical semantics—such as articulated motion and intrinsic physical properties—hindering their use in high-fidelity robotic simulation. This work proposes UniPhys, a novel framework that, for the first time, enables unified physical semantic modeling of heterogeneous 3D assets. UniPhys mitigates geometric shortcut biases arising from part decomposition discrepancies through a geometry-robust joint grounding mechanism and employs a joint modeling architecture to end-to-end infer both articulation semantics and physical attributes. Leveraging this approach, we introduce UniPhys-40K, a large-scale dataset, and UniPhys-Bench, a comprehensive benchmark. We also develop UniPhysGen, which achieves state-of-the-art performance in joint grounding and physical property estimation, producing assets directly deployable in robotic simulators for realistic physical interactions.

Abstract

Physically grounded 3D assets are increasingly important for embodied AI and robotic simulation. However, most existing 3D assets lack unified physical semantics, including articulation semantics and intrinsic physical properties, required for realistic interaction. Current approaches either treat these semantics independently or rely on canonicalized object structures, limiting robustness across heterogeneous 3D assets. We present UniPhys, a scalable framework for automatically transforming raw 3D assets into simulation-ready assets with unified physical semantics. Based on UniPhys, we construct UniPhys-40K, a large-scale physically grounded dataset, together with UniPhys-Bench, a carefully verified benchmark for unified physical grounding evaluation. We further introduce UniPhysGen, a unified physical grounding model that jointly reasons over articulation semantics and intrinsic physical properties. UniPhysGen incorporates geometry-robust articulation grounding to mitigate geometric shortcut bias under heterogeneous part decompositions. Extensive experiments demonstrate state-of-the-art performance across articulation grounding and intrinsic physical property estimation tasks, while the resulting assets can be directly deployed in robotic simulation environments for realistic physical interaction. Our code and dataset will be available at https://github.com/breezexian/UniPhysGen.

Problem

• physical grounding
• 3D assets
• articulation semantics
• intrinsic physical properties
• robotic simulation

Innovation

• unified physical grounding
• articulation semantics
• intrinsic physical properties
• simulation-ready 3D assets
• geometry-robust grounding