Building a Three.js Editor Extension: Architecture and Implementation Advice

Your project to extend the Three.js editor with TypeScript and additional features sounds promising. Based on your requirements and the context of Three.js addons, here's some advice on architecture and implementation:

Overall Architecture Approach

1. Modular Architecture: Separating the editor library from the demo application is an excellent approach. Consider using a monorepo structure with packages for:

   • Core editor library
   • UI components
   • Command system
   • File handling
   • Demo application

2. TypeScript Integration: Converting to TypeScript will provide better type safety and documentation. Start by:

   • Creating proper interfaces for all Three.js objects
   • Defining command types and parameters
   • Using generics for reusable components

3. Plugin System: Consider implementing a plugin architecture to allow for extensibility without modifying the core code.

Specific Implementation Recommendations

Command System

Retain the existing command system but enhance it with TypeScript:

TYPESCRIPTCopied
// Command interface
interface EditorCommand {
  execute(): void;
  undo(): void;
  toJSON(): object;
}

// Command factory
class CommandFactory {
  static createAddObjectCommand(editor: Editor, object: THREE.Object3D): EditorCommand {
    return new AddObjectCommand(editor, object);
  }
  // Other command creators
}

Scene Description

For maintaining compatibility with existing scene.json files:

TYPESCRIPTCopied
interface SceneDescription {
  metadata: {
    version: number;
    type: string;
    generator: string;
  };
  project: {
    shadows: boolean;
    vr: boolean;
    // other project settings
  };
  objects: {
    [uuid: string]: ObjectDescription;
  };
  // other scene properties
}

// Parser for scene files
class SceneParser {
  static fromJSON(json: string, editor: Editor): void {
    // Parse and load scene
  }
}

Feature Integration

For your additional features:

1. Custom Labels:

   TYPESCRIPTCopied
   class LabelSystem {
     addLabel(position: THREE.Vector3, text: string, options?: LabelOptions): Label;
     updateLabel(id: string, properties: Partial<LabelProperties>): void;
     removeLabel(id: string): void;
   }

2. Line Drawing:

   • Leverage the Line2, LineGeometry, and LineMaterial from Three.js addons
   • Create a drawing system with different line styles and interactions

3. Physics Integration:

   • Consider using an existing physics library like Ammo.js, Cannon.js, or Rapier
   • Create a physics manager that handles the synchronization between Three.js objects and physics bodies

AI Command Interface

For future AI control:

TYPESCRIPTCopied
interface AICommandInterface {
  executeCommand(commandName: string, parameters: object): Promise<CommandResult>;
  getSceneState(): SceneState;
  registerCustomCommand(name: string, handler: CommandHandler): void;
}

Development Strategy

1. Start with Core Components:

   • Begin by converting the basic editor structure to TypeScript
   • Implement the command system and scene serialization
   • Create the separation between library and demo app

2. Add Features Incrementally:

   • Once the core is stable, add one feature at a time
   • Write tests for each feature before moving to the next

3. Use Existing Addons:

   • Leverage Three.js addons like OrbitControls, TransformControls, etc.
   • Use BufferGeometryUtils for geometry operations

4. Documentation:

   • Document your API thoroughly
   • Create examples for each feature

Collaboration Considerations

1. API Design: Create clear, consistent APIs that are well-documented
2. Component Boundaries: Define clear boundaries between components
3. Event System: Implement a robust event system for communication between components
4. Version Control: Use semantic versioning and maintain a changelog

Learning from Existing Projects

The projects you referenced (Online3DViewer and nunuStudio) have good architectural patterns:

1. From Online3DViewer:

   • Clean separation of model and view
   • Efficient file handling and format conversion

2. From nunuStudio:

   • Component-based architecture
   • Extensible editor UI

By combining the strengths of these projects with the Three.js addon ecosystem, you can create a powerful and flexible 3D editor.

Would you like more specific advice on any particular aspect of the architecture or implementation?