HoloWorld Wants to Generate Entire Cities With Coherent Interiors and Exteriors

 

A new research framework tries to solve a major world-generation problem: making the inside of a building actually correspond to the city and exterior that contain it.

The missing link in generated worlds

AI systems can already generate outdoor scenes, building forms and interior layouts, but those outputs are often disconnected. A convincing street may contain buildings whose interiors were generated with no meaningful relationship to the façade, footprint or surrounding block.

HoloWorld, a new research framework posted on arXiv on August 6, attempts to treat the city as one continuously updated context rather than a collection of separate generation tasks.

From city plan to room

The framework starts from a user description and progressively represents information at different scales. It generates urban exteriors while maintaining context across neighboring blocks, grounds those exteriors in 3D building instances and footprints, and then uses the building geometry and appearance to condition indoor generation.

The authors describe HoloWorld as the first framework to unify indoor and outdoor generation within one coherent 3D urban world. In their experiments, they report a 7.68% improvement in average AQS over the compared state of the art for urban exterior generation, while also emphasizing indoor–outdoor correspondence and cross-block continuity.

Why architects and environment artists should watch this

The technical goal overlaps directly with architectural visualization, simulation and game environment production. A world generator becomes much more useful when a door on the street leads into a plausible interior that belongs to that exact building.

For professional workflows, the interesting future is not a button that replaces design. It is a system that can rapidly produce context — neighborhoods, massing alternatives, interior shells and spatial variations — while maintaining enough structural consistency to remain editable.

Sources & further reading

• arXiv — To See a World in a Living Context: Unified Indoor-Outdoor Urban World Generation