# AI ProBuilder — Unity Extension

AI ProBuilder (com.ivanmurzak.unity.mcp.probuilder) — Procedural mesh modeling — create shapes, extrude / bevel / bridge faces, set face materials, and merge meshes. An AI Game Developer extension for Unity that adds 4 capabilities through RQL (no extra MCP tools).

_Last updated: 2026-10-17_

## At a glance

| Field | Value |
| --- | --- |
| Capabilities | 4 capabilities |
| Version | 2.0.0 |
| Package id | com.ivanmurzak.unity.mcp.probuilder |
| Engine | Unity · Unity 2022.3+ |
| Base plugin | com.ivanmurzak.unity.mcp |
| Wraps | com.unity.probuilder |
| Repository | https://github.com/IvanMurzak/Unity-MCP/blob/main/extensions/ProBuilder/README.md |
| RQL sources | probuilder |
| RQL functions | probuilder.facing, probuilder.edges, probuilder.openEdges, probuilder.vertices |
| RQL types | ProBuilderMesh |

## How it works

Adds no MCP tools: it contributes an RQL module with the probuilder source, the probuilder.facing, probuilder.edges, probuilder.openEdges, probuilder.vertices functions and adapters for ProBuilderMesh. That powers 4 capabilities the agent reaches through rql-query / rql-mutate.

- Create ProBuilder shapes — Create editable shapes (cube, cylinder …) and extruded polygon shapes, or merge several meshes into one. RQL: `probuilder | call CreateShape("Cube", "Crate", "(2, 1, 2)", "(0, 0.5, 0)")`
- Inspect meshes — Read face, vertex and edge counts, bounds and materials, list faces with their direction, and pick faces by direction (up, down, left …). RQL: `probuilder | get meshes | where gameObject.name == "Crate" | select faceCount vertexCount edgeCount bounds materials`
- Edit meshes — Extrude faces; bevel, bridge, connect and subdivide edges; delete faces, flip normals and move the pivot. Every edit is validated and undoable. RQL: `probuilder | get meshes | where gameObject.name == "Crate" | call Extrude(probuilder.facing($, "Up"), 0.5)`
- Face materials — Assign a material to chosen faces of a ProBuilder mesh. RQL: `probuilder | get meshes | where gameObject.name == "Crate" | call SetFaceMaterial(probuilder.facing($, "Up"), "Assets/Materials/Grass.mat")`

## Install

Requires the base plugin com.ivanmurzak.unity.mcp. After installing, the RQL module loads with the package — the agent sees it in rql-schema.

```bash
openupm add com.ivanmurzak.unity.mcp.probuilder
```

## When to ask the AI for it

Ask for blockout / greybox geometry and in-editor mesh editing without leaving Unity.

Not sure if it's installed? Ask the agent to run rql-schema — the probuilder source only exists when the package is present.

## Example prompts

1. Create a ProBuilder cube 4×3×4 at the origin and name it `Room`.
2. Extrude the top face of `Room` up by 2 units, then assign the `Concrete` material to it.

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Source (HTML): https://ai-game.dev/docs/extensions/unity/probuilder