Procedural building generator for Unreal Engine workflows.
Shape a building or city upstream in the browser, export real geometry, then continue materials, lighting, interaction and optimisation in Unreal Engine. Metropolygonia is a companion design tool, not an Unreal Engine plug-in.
- RecommendedGLB for a compact, self-contained building handoff
- ScaleMetric model dimensions; begin with import scale 1.0
- MaterialsNamed groups, embedded image textures and UV coordinates
- UV convention2 × 2 m base coverage for tiled material workflows
Generate the structured base, finish the experience
Metropolygonia is designed for the stage before final scene authoring. Use explicit parameters to establish massing, floor structure, façades, openings, optional interiors and the surrounding road layout. Export when the proportions and systems are useful, then treat the result as an asset entering your Unreal Engine pipeline.
Inside Unreal Engine you retain the work that belongs there: replace or refine materials, establish collisions and LOD strategy, light the scene, add gameplay or simulation, profile performance and make the final artistic decisions. A generated model is a production starting point, not a promise that every project-specific requirement has already been solved.
GLB into Unreal Engine
Finish the building state
Check dimensions, floor count, openings and whether interiors should be included. Remove systems that the target scene does not need before export.
Export GLB
GLB stores the glTF scene, binary geometry and referenced image data in one file, reducing the chance that a texture or sidecar file is separated during handoff.
Import through Interchange
Use Unreal Engine's current Interchange-based asset import workflow. Begin at scale 1.0, keep the generated material slots, and review the import options appropriate to your project.
Validate before duplication
Compare a known doorway or storey height against an Unreal measurement, inspect normals and UVs, and confirm material-slot assignment before placing many instances.
Build the final material layer
Assign your production PBR materials, adjust UV tiling where required and configure collision, Nanite, LODs or lightmap strategy according to the target platform.
For exact importer behaviour and version-specific options, use Epic's current documentation for importing assets with Interchange and glTF format support.
Choose the handoff, not just the extension
| Output | Use in this workflow | Material behaviour |
|---|---|---|
| GLB | Recommended first choice for a compact building handoff. | Can carry named materials and embedded image textures with the geometry. |
| glTF | Useful when an open, inspectable JSON scene description suits the pipeline. | The Metropolygonia export embeds binary and image data as data URIs in one .gltf file; other glTF tools may create sidecar resources. |
| OBJ + MTL | Compatibility route for DCC exchange or an intermediate cleanup pass. | MTL and image files are sidecars. The relationship is simpler than a modern PBR graph. |
| STL | Geometry-only proxy, collision or fabrication-oriented use. | No UV or material handoff should be expected. |
| City ZIP | Organised transfer of a city rather than one combined opaque mesh. | Separate buildings, the road mesh and a manifest support independent placement and review. |
See the complete export format guide before choosing OBJ or STL for a material-sensitive project.
UV-ready now; native PBR authoring is coming soon
Generated surfaces use a consistent metric UV convention with a 2 × 2 metre base tile at multiplier 1. That gives tiled materials a predictable starting density across differently sized building elements and makes it easier to apply libraries such as Megascans without re-unwrapping the entire model.
Exported image textures and named material groups help preserve the visual organisation of the generated model. They are not a replacement for a project-specific Unreal material graph. Native PBR material export is still in development and is explicitly coming soon; do not plan a production handoff around an unreleased feature.
The 2 × 2 m UV guide explains the base convention and a practical tiled-material setup.
Keep buildings and roads manageable
A city export packages buildings as separate files rather than forcing the complete design into one inseparable asset. The road geometry and manifest sit alongside them. This structure makes it possible to replace, transform, optimise or stream assets independently after import.
- Use stable names before exporting so assets remain recognisable after import.
- Import and validate one representative building first.
- Preserve separate assets when independent placement, culling or optimisation matters.
- Decide collision, LOD, Nanite and material-instance strategy in Unreal Engine based on camera distance and target hardware.
For a focused handoff checklist, continue to the Unreal Engine export guide.