Unreal Neural Director

Quick Start

Get up and running with Unreal Neural Director in minutes

This guide walks you through installing Unreal Neural Director, configuring your first AI provider, and sending your first autonomous prototyping request.

Prerequisites

  • Unreal Engine 5.7
  • The Python Editor Script Plugin enabled (Edit > Plugins > search "Python" > enable Python Editor Script Plugin, restart the editor)
  • An API key from at least one supported provider: Anthropic (Claude), OpenAI-compatible, or Google Gemini

The plugin also depends on StateTree and GameplayStateTree engine plugins, but these are declared in the .uplugin file and will be enabled automatically when you first load the project with UND installed.

Installation

  1. Copy the plugin -- Place the UnrealNeuralDirector/ folder into your project's Plugins/ directory:

    YourProject/
  Plugins/
    UnrealNeuralDirector/
      UnrealNeuralDirector.uplugin
      Source/
      Content/
      ...

  2. Regenerate project files -- Right-click your .uproject file and select Generate Visual Studio project files.

  3. Build the project -- Open the solution in Visual Studio and build, or launch the Unreal Editor directly (it will compile the plugin on first load).

UND is an editor-only plugin. It loads during the PostEngineInit phase and does not ship with packaged builds.

First Launch

Once the editor finishes loading, open the UND panel:

Window > Neural Director > Unreal Neural Director

The panel opens as a dockable tab. You can drag it to any location in the editor layout and it will persist across sessions.

Configuring a Provider

Before you can send messages, you need to connect an AI provider. UND supports two methods for providing API keys — pick whichever is easier for you.

When UND first loads, it creates a template configuration file at:

{YourProject}/Saved/UND/apikeys.cfg

Open this file in any text editor and uncomment the line for your provider, replacing the placeholder with your actual key:

# Uncomment and fill in the keys for the providers you use:
 
ANTHROPIC_API_KEY=sk-ant-your-key-here
# OPENAI_API_KEY=sk-your-key-here
# GEMINI_API_KEY=your-key-here
# XAI_API_KEY=xai-your-key-here
# DEEPSEEK_API_KEY=sk-your-key-here

Save the file. UND reads it fresh on every request, so no editor restart is needed — your key takes effect immediately.

The apikeys.cfg file is inside the Saved/ directory, which is excluded from version control by default. Your keys stay local and are never committed to your repository.

Method 2: Environment Variables

Alternatively, set the API key as a system environment variable:

Windows:

  1. Open Start > search "Environment Variables" > click Edit the system environment variables
  2. Click Environment Variables > under User variables, click New
  3. Variable name: ANTHROPIC_API_KEY (or OPENAI_API_KEY, GEMINI_API_KEY)
  4. Variable value: your API key
  5. Click OK, then restart the Unreal Editor (environment variables are read at process start)

macOS/Linux: Add to your shell profile (~/.bashrc, ~/.zshrc, or similar):

export ANTHROPIC_API_KEY="sk-ant-your-key-here"

Then restart your terminal and the Unreal Editor.

Selecting the Provider

  1. In the UND panel, click the Settings view at the top.
  2. Expand Provider Profiles and select the default profile, or create a new one.
  3. Choose your provider type: Anthropic, OpenAI-Compatible, or Gemini.
  4. Set the API Key Env Var field to the environment variable name that holds your key (e.g., ANTHROPIC_API_KEY). This must match the variable name in your apikeys.cfg or system environment.
  5. Switch to the Chat view — the status bar at the bottom should show the provider as connected.

API keys are never stored in UE config files. UND reads them from apikeys.cfg or environment variables at runtime.

Sending Your First Message

  1. Switch to the Chat view.
  2. Select your provider profile and agent profile from the bottom bar. The default agent is Coder, which is suitable for most tasks.
  3. Type a message in the input area at the bottom and press Enter or click Send.

Try something simple to verify everything works:

Create a new Blueprint actor called BP_RotatingCube that has a static mesh
component with a cube and rotates continuously on the Z axis.

UND will stream the AI response in real-time, call tools to create the Blueprint, and present you with the result.

Understanding the Workflow

A typical UND session follows this pattern:

  1. Describe what you want -- Write a natural language description of the game system, mechanic, or asset you need. Be as specific or as general as you like.

  2. The AI plans and executes -- UND breaks down your request, calls built-in tools (Python scripting, file I/O, Blueprint helpers, compilation), and iteratively builds what you asked for. The agent can make up to 100 tool-call round-trips per message by default.

  3. Review tool calls -- Depending on your approval mode, UND may ask you to approve destructive operations before executing them. You can set auto-approval rules for tools you trust.

  4. Iterate -- If the result is not exactly right, describe what needs to change. UND maintains full conversation context and can refine its work.

What Can UND Build?

UND has 31 built-in tools covering the full range of Unreal Editor operations:

  • Blueprints -- Create actors, components, functions, variables, event graphs, and wire them together
  • C++ code -- Write and edit source files, trigger Live Coding or Hot Reload
  • Materials -- Create material instances, set parameters, assign to meshes
  • Levels -- Place actors, configure lighting, set up gameplay areas
  • UI -- Build UMG widgets, HUDs, and menus
  • GAS -- Set up Gameplay Ability System abilities, effects, and attributes
  • Input -- Configure Enhanced Input actions and mappings
  • AI behavior -- Create behavior trees, state trees, and AI controllers
  • Project inspection -- Query the UE reflection system, search code, browse assets

The key to all of this is the execute_python tool, which provides full access to the Unreal Editor Python API via import unreal. Every operation the editor can perform is available through this tool.

Troubleshooting

"Provider is not configured" or no response

  • Verify your API key is set correctly: check Saved/UND/apikeys.cfg or your system environment variable
  • Make sure the API Key Env Var field in Settings matches the variable name exactly (e.g., ANTHROPIC_API_KEY)
  • If using environment variables, restart the Unreal Editor after setting them
  • Check the Output Log (Window > Developer Tools > Output Log) and filter by UND for detailed error messages

"PythonScriptPlugin module is not loaded"

The execute_python tool requires the Python Editor Script Plugin. Enable it via Edit > Plugins > search "Python" > enable Python Editor Script Plugin, then restart the editor.

Plugin fails to compile

  • Ensure you are using Unreal Engine 5.7. UND is not compatible with earlier engine versions.
  • Regenerate project files after adding the plugin (right-click .uproject > Generate Visual Studio project files)
  • If you get linker errors about StateTree, make sure the StateTree and GameplayStateTree plugins are enabled

The AI creates Blueprints but they break after editor restart

This happens when the AI creates C++ classes via Live Coding and then parents Blueprints to them. Live Coding patches are session-only — the classes disappear on restart, breaking any Blueprints that depended on them. UND now warns about this, but if you encounter it:

  1. Restart the editor
  2. Ask UND: "Check for broken Blueprints and fix them"
  3. The AI will detect broken parent classes and reparent the Blueprints to a valid engine class

Next Steps

  • Architecture -- Understand how UND processes requests internally
  • Settings -- Configure providers, agents, and plugin behavior
  • Panels & Views -- Learn the full UND interface