Metropolygonia Open app
Documentation

Build deliberately. Export with context.

These guides cover the shortest reliable path from parameters to a usable 3D asset. Start with one building, understand what each format carries, then validate the result in the tool where final production happens.

Start here

Four guides, one practical path

01 / Quick start

Create your first procedural building

Set the envelope, refine the systems, choose interior detail and check the generated model before your first export.

 02 / Pipeline

Export to Unreal Engine

Use GLB or a city package, import at predictable scale and validate materials, UVs and geometry before scene-wide use.

 03 / Materials

Use the 2 × 2 m UV convention

Understand the base tile, adjust material scale and apply Megascans or other tiled PBR libraries without a complete re-unwrap.

 04 / Reference

Choose an export format

Compare what GLB, glTF, OBJ and STL preserve, what they omit and when a city ZIP is the more manageable handoff.
Quick start

The reliable first ten minutes

  1. Open the building editor

    Start with a building rather than a city. A single asset is faster to inspect and makes scale or material problems easier to isolate.

  2. Set real dimensions first

    Choose the footprint, storey height and floor count before adjusting decorative systems. Those values control the fundamental volume.

  3. Decide whether you need interiors

    Generate rooms and circulation for a walkthrough, or use an exterior shell when the asset will remain context or background geometry.

  4. Save the parameters

    Keep the preset and seed for any option you may need again. Procedural variation is valuable precisely because it remains reproducible.

  5. Export and validate one file

    GLB is the recommended first test for Unreal Engine. Check a known dimension, UV orientation and material slots before repeating the process at city scale.

The generated model is an upstream assetFinish project-specific materials, collision, lighting, simulation, topology cleanup and performance work in Unreal Engine or your chosen DCC tool.
At a glance

What each output is for

OutputBest first useImportant boundary
GLBCompact handoff to Unreal Engine or another modern 3D tool.Validate how the destination maps imported materials in your current version.
glTFOpen exchange where separate resources and inspectability are useful.Move the scene description, binary data and images together.
OBJ + MTLBroad compatibility and an intermediate DCC cleanup step.Material semantics are simpler and files remain linked sidecars.
STLMaterial-free geometry, proxies, collision or rapid prototyping.It does not carry the UV and material workflow.
City ZIPSeparate buildings, road geometry and a manifest for a larger layout.Import one representative asset before processing the full package.
Product state

What is ready and what is still in progress

The generator currently creates browser-based parametric building and city geometry, supports saved parameter workflows, and exports individual buildings as GLB, glTF, OBJ or STL. City projects can be packaged with separate buildings, road geometry and a manifest.

UV coordinates use a consistent 2 × 2 metre base convention, and supported model exports can carry the generated image textures. Native PBR material export is in development and coming soon. Until it ships and is documented here, build the final physically based material graphs in the destination tool.

Metropolygonia is not a BIM, engineering or code-compliance product. Dimensions help maintain a predictable 3D scale; they do not certify that a generated building is constructible, accessible or compliant with local regulations.

Terms

Small glossary

Procedural generation
Geometry assembled by programmed rules from explicit inputs. In this product it is not generative AI.
Seed
A value that makes controlled variation repeatable when the other parameters stay the same.
UV coordinates
Two-dimensional coordinates that tell a 3D surface how an image or tiled material should be mapped.
Material group or slot
A named assignment on the model that lets the destination tool target groups of surfaces with a material.
City package
A ZIP handoff containing separately manageable assets instead of only one merged city mesh.