...
    /**
     * List of custom tags for a node.
     */
    std::map<std::string, std::string>* _tags;

    /**
     * Pointer to the Camera attached to the Node.
     */
    Camera* _camera;

    /**
     * Pointer to the Light attached to the Node.
     */ 
    Light* _light;

    /**
     * Pointer to the Model attached to the Node.
     */
    Model* _model;
    
    /**
     * Pointer to the Form attached to the Node.
     */
    Form* _form;
    
    /**
     * Pointer to the AudioSource attached to the Node.
     */
    AudioSource* _audioSource;
    
    /**
     * Pointer to the ParticleEmitter attached to the Node.
     */
    ParticleEmitter* _particleEmitter;
    
    /**
     * Pointer to the PhysicsCollisionObject attached to the Node.
     */
    PhysicsCollisionObject* _collisionObject;
    
    /**
     * Pointer to the AI agent attached to the Node.
     */
    AIAgent* _agent;

    /**
     * World Matrix representation of the Node.
     */
    mutable Matrix _world;
...