# PBR Texture Set Export (glTF, Unreal, Unity)

> Export a procedural material as a named PBR texture set for glTF, Unreal or Unity HDRP. Render a Material Nodes preset or your own graph at up to 1024 px and download a ZIP named for your engine: base color, normal in the right Y convention, a packed ORM or HDRP mask map, separate roughness, metallic and occlusion maps, 8- and 16-bit height, the editable graph and a manifest that lists channels and color spaces.

Part of usefulweb.app (https://usefulweb.app/). Part of [Renderloom](https://renderloom.usefulweb.app/) (ownerApp: renderloom). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://renderloompbrexport.usefulweb.app/ (interactive tool at https://renderloompbrexport.usefulweb.app/tool)
- JSON API: POST https://renderloompbrexport.usefulweb.app/api/v1/calculate with a JSON object of inputs (schema: https://renderloompbrexport.usefulweb.app/api/v1/tool)
- OpenAPI: https://renderloompbrexport.usefulweb.app/openapi.json
- MCP (Streamable HTTP): https://renderloompbrexport.usefulweb.app/mcp - tool `renderloom_pbr_export`

## Inputs
- preset (select): Material graph
- graph (textarea): Graph JSON (for a custom graph) - Format renderloom-material-graph version 1 (schema at /static/apps/renderloom/material-graph.schema.json). Copy it from Renderloom → Material Nodes.
- size (integer): Texture size (px)
- seed (integer): Graph seed (−1 keeps the graph’s seed)
- convention (select): Target engine
- height16 (boolean): Include a 16-bit height PNG

## Method
- The graph is evaluated with the same engine as the Material Nodes dialog at the chosen size. Parameters are fractions of the tile, so a 1024 px export matches the 256 px preview in look.
- glTF 2.0 / Blender / Godot: +Y (OpenGL-style) normal and an occlusion-roughness-metallic PNG — the glTF metallicRoughness texture reads roughness from G and metallic from B; the occlusion texture reads R, so the same ORM file can serve both.
- Unreal Engine: the same ORM packing with a −Y (DirectX-style) normal; the green channel is inverted (255 − value).
- Unity HDRP: +Y normal and a mask map with R = metallic, G = ambient occlusion, B = detail mask set to 0 (no detail map) and A = smoothness = 1 − roughness, as documented by Unity.
- Every package adds separate roughness, metallic, occlusion and height PNGs (8-bit RGBA), an optional 16-bit grayscale height PNG, the editable graph and export-manifest.json with the channel and color-space list.

## Limits
- Check the import settings of your engine: base color is sRGB, all other maps are linear data. The maps come from a procedural graph and are not scanned materials.