Use the 2 × 2 m UV convention.

What the numbers mean

A UV tile describes how a two-dimensional texture repeats across a three-dimensional surface. In Metropolygonia the base density is tied to world size: a multiplier of 1 maps one repeat across a 2 metre by 2 metre area. The same convention is used as a predictable starting point rather than fitting one image uniquely to every wall or slab.

The base is a scale convention, not a claim that every material physically covers two metres. A brick surface, large concrete panel and fine plaster all need different visual frequency. Use the multiplier to match the real size represented by the chosen material.

Set texture scale by surface

1. Choose the surface category

   Work with the material assignment for the wall, roof, ground or other available surface rather than applying one density indiscriminately to the complete building.

2. Select a representative texture

   Choose or randomise a preview texture close to the intended material family. The preview is useful for judging scale and continuity, not a substitute for the destination shader.

3. Match physical pattern size

   Use the texture-scale control to change the resulting tile size. Judge a known element such as a door or storey beside the surface so the material does not appear miniature or oversized.

4. Inspect corners and horizontal surfaces

   Orbit the building and check transitions, roofs, slab edges and recessed areas. A convincing front elevation alone does not establish a sound material handoff.

5. Export the checked model

   GLB or glTF preserves UV coordinates. OBJ can preserve UVs with MTL and PNG sidecars, while STL is geometry-only and should not be selected for this workflow.

Apply a tiled PBR material

Import the model and keep its UV channel. Create or use a material that samples the colour, normal and packed surface maps with the same UV coordinates and tiling value. A material instance with an exposed scalar is a practical way to tune the repeat without editing the source mesh.

1. Apply a neutral checker first and compare the tile against a known 2 metre reference.
2. Assign the Megascans or other tiled material to the corresponding imported material slot.
3. Use one shared UV multiplier for all maps in that material so colour, normal and roughness remain aligned.
4. Adjust only enough to match the library asset's documented physical size and the scene's art direction.
5. Inspect from the real gameplay or camera distance, not only close to the surface.

UV-ready does not mean final PBR-ready

Metropolygonia currently exports geometry, UV coordinates, named material groups and supported image textures. These pieces reduce setup work and keep the building organised in the destination tool.

Native PBR material export is in progress and coming soon. Until that feature is released and documented, expect to assemble the final PBR material graph in Unreal Engine or your DCC. That includes channel packing, normal-map handling, displacement decisions, blend layers, macro variation and any project-specific optimisation.

This boundary is often useful: the procedural source controls the structure and mapping convention, while the production project controls expensive shader features and visual consistency across the whole environment.

If the surface still looks wrong

The pattern is too large or too small

Confirm the physical size represented by the source texture, then adjust the shared material multiplier. Avoid changing individual map scales independently.

The maps drift apart

Feed colour, normal, roughness and other packed maps through the same UV transform. Different tiling values make a physically based material internally inconsistent.

A unique graphic repeats

Logos, signs and murals are not tiled materials. Give them a dedicated mesh, decal or custom unwrap rather than forcing them through the base building convention.

STL has no material

That is expected. Use GLB, glTF or OBJ for a UV-aware handoff, as described in the export format reference.