WorldAct: Activating Monolithic 3D Worlds into Interactive-Ready Object-Centric Scenes
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| Authors | Jichen Hu et al. |
| Year | 2026 |
| HF Upvotes | 1 |
| arXiv | 2605.15843 |
| Download | |
| Code | https://github.com/SJTU-DeepVisionLab/WorldAct |
Abstract
Recent 3D world modeling systems based on generative scene synthesis, such as Marble, can create coherent and explorable 3D environments, yet their outputs are typically static monolithic assets with limited editability and physical interaction. This restricts their use in immersive content creation and embodied simulation, where generated worlds must be actively modified and manipulated. To tackle this challenge, we present WorldAct, a framework that converts static generated 3D worlds into editable and interaction-ready scenes. WorldAct uses a multimodal agent to guide scene decomposition, identify actionable objects, reconstruct geometrically aligned object-level meshes for interaction, and restore the residual background via 3D inpainting. The resulting scenes support object-level editing, collision-aware manipulation, and embodied task execution while preserving global scene coherence. Experiments show that WorldAct enables richer interaction scenarios than the original generated scenes, suggesting a practical path toward editable and interactive 3D world models.
Engineering Breakdown
Plain English
WorldAct takes static 3D worlds generated by systems like Marble and converts them into interactive, editable scenes where individual objects can be manipulated. The framework uses a multimodal agent to decompose the monolithic scene into separate objects, reconstruct aligned meshes for each, and fill in the background—enabling these AI-generated worlds to support real interaction and editing rather than just viewing.
Key Engineering Insight
The core technical challenge is decomposing a single fused 3D representation into discrete, interaction-ready objects without ground truth annotations. WorldAct solves this via a multimodal agent that guides segmentation and reconstruction, which is pragmatically important because it avoids expensive supervised training while producing usable output geometry.
Why It Matters for Engineers
Generated 3D environments are only useful in production if creators can actually edit and modify them—right now they're locked monolithic assets. This work bridges the gap between what generative systems output and what game engines, VR platforms, and simulation tools actually need: object-centric scenes with physics bodies and collision geometry.
Research Context
Previous generative 3D systems (Marble, etc.) solved coherent world creation but left the scene in a single undifferentiated mesh. WorldAct advances the pipeline by adding a critical post-processing stage that makes generated worlds production-ready for content creation workflows, extending generative 3D from 'render-only' to 'fully-editable-and-interactive.'
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