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RESEARCH SERIES

Generative
World Models.

Construct worlds. Ground them in reality. Learn through interaction.

We build controllable, reality-aligned 3D environments and evaluate how agents understand, edit, and act within them.

WORLD CONSTRUCTION

From evidence to environments.

Controllable generation, real-world grounding, and editable 3D assets.

INTERACTIVE EVALUATION

From understanding to action.

Spatial reasoning, scene correction, and closed-loop refinement in 3D worlds.

01
CONTROLLABLE WORLD GENERATION

UrbanWorld

UrbanWorld: An Urban World Model for 3D City Generation

Preprint 2024.07

Create customizable urban environments.

UrbanWorld combines flexible urban layouts, multimodal scene design, texture generation, and iterative refinement to create customizable 3D cities from text and image prompts.

Controllable environments provide a setting for agent perception, navigation, and simulation.

UrbanWorld framework: urban layouts, scene design, asset rendering, and scene refinement.
UrbanWorld framework: urban layouts, scene design, asset rendering, and scene refinement. SourceClick the figure to view full size.
02
REALITY-ALIGNED CITY GENERATION

UrbanWorld2.0

UrbanWorld2.0: A Multimodal Agentic Framework for Reality-Aligned 3D World Generation at City-Scale

ACM MM 2026

Ground generated worlds in real places.

UrbanWorld2.0 uses a multimodal agent to coordinate planning, perception, generation, and refinement, grounding city-scale 3D worlds in real geospatial and visual evidence.

This connects real-world observations with editable 3D environments, bringing visual, geometric, and semantic structure together.

UrbanWorld2.0 framework: agentic generation of reality-aligned 3D cities.
UrbanWorld2.0 framework: agentic generation of reality-aligned 3D cities. SourceClick the figure to view full size.
03
COMPOSITIONAL IMAGE-TO-3D GENERATION

CityLift

CityLift: Compositional 3D Urban Generation from a Single Image

Preprint 2026.10

Turn an urban image into editable 3D assets.

CityLift turns a single urban image into a coherent scene of individually editable building meshes, combining scene-level spatial structure with detailed building generation.

The compositional representation preserves building placement while allowing individual assets to be edited and recombined.

CityLift produces editable building meshes while maintaining a coherent urban scene.
CityLift produces editable building meshes while maintaining a coherent urban scene. SourceClick the figure to view full size.
04
INTERACTIVE SPATIAL EVALUATION

SpatialAct

SpatialAct: Probing Spatial Reasoning-to-Action Capabilities of VLM Agents in 3D Scenes

Preprint 2026.05

Test how spatial understanding becomes action.

SpatialAct evaluates whether vision-language model agents can turn spatial understanding into reliable actions in 3D scenes, from basic reasoning to error correction and multi-turn refinement.

Interactive evaluation closes the loop between world construction, agent understanding, and scene refinement.

SpatialAct task hierarchy, spanning spatial reasoning, scene correction, and interactive refinement.
SpatialAct task hierarchy, spanning spatial reasoning, scene correction, and interactive refinement. SourceClick the figure to view full size.
RESEARCH OUTLOOK

Questions we are exploring next.

How can generated worlds preserve real-world structure while remaining editable, interactive, and useful for evaluating agent behavior? We connect environment quality with spatial reasoning and action through feedback.

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