Behavior Tree Editor

VS Code behavior tree visual editor for game AI workflows.

Features

• Visual canvas editor (drag, connect, organize nodes)
• Built-in inspector panel for node/tree properties
• Custom node definitions via .b3-setting
• One-click build command in editor title bar
• Optional expression validation for node args
• Auto theme adaptation (dark/light)

Quick Start

Open a tree file

• Right-click a tree .json file in Explorer
• Select Open With → Behavior Tree Editor

Create a new project

• Right-click a folder in Explorer
• Run Behavior Tree: Create Project

Configure nodes

Create a .b3-setting file in workspace:

{
  "nodes": [
    {
      "name": "MyAction",
      "type": "Action",
      "desc": "Does something useful",
      "args": [
        { "name": "duration", "type": "float", "desc": "Duration in seconds" }
      ]
    }
  ]
}

Build

Click Build in the editor title bar.

Build Script (.b3-workspace)

settings.buildScript supports ESM scripts:

• JavaScript: .js, .mjs
• TypeScript: .ts, .mts (runtime transpile, no type-check)

Example:

{
  "settings": {
    "checkExpr": true,
    "buildScript": "scripts/build.ts"
  }
}

All build hooks receive env:

• env.fs: Node fs
• env.path: full path helper object (all methods exposed)
• env.workdir: resolved workspace directory
• env.nodeDefs: loaded node definitions map
• env.logger: log/debug/info/warn/error

Use a Hook class. The extension constructs it once with env, then calls methods:

• constructor(env)
• onProcessTree(tree, path, errors)
• onProcessNode(node, errors)
• onWriteFile(path, tree)
• onComplete(status)

For compatibility:

• .ts / .mts: must export a class via named Hook or default
• .js / .mjs: support class export and legacy function-style exports

For TypeScript authoring hints, see:

• sample/scripts/build-script.d.ts
• sample/scripts/build.ts

Extension Settings

Inspector

Inspector is embedded on the right side of the tree editor.

• Select a node to edit node fields (args, input, output, desc, debug, disabled)
• Click empty canvas to edit tree fields (name, desc, vars, import, group)

Keyboard Shortcuts

Development

• Output logs: View → Output → channel Behavior3
• Webview logs are also available in DevTools

Requirements

• VS Code 1.85.0+

License

MIT