Scene Management

import { Object3D, Vector3, Matrix4, Quaternion, Euler, Layers, AnimationClip, Material } from 'three';

/**
 * Base class for all 3D objects with transform, hierarchy, and event system
 */
class Object3D extends EventDispatcher {
  /** Unique identifier for the object */
  readonly id: number;
  
  /** UUID string identifier */
  readonly uuid: string;
  
  /** Optional name for the object */
  name: string;
  
  /** Object type string for serialization */
  readonly type: string;
  
  /** Reference to parent object in hierarchy */
  parent: Object3D | null;
  
  /** Array of child objects */
  children: Object3D[];
  
  /** Up direction vector (default is Y-up) */
  up: Vector3;
  
  /** Local position */
  position: Vector3;
  
  /** Local rotation as Euler angles */
  rotation: Euler;
  
  /** Local rotation as quaternion */
  quaternion: Quaternion;
  
  /** Local scale */
  scale: Vector3;
  
  /** Local transformation matrix */
  matrix: Matrix4;
  
  /** World transformation matrix */
  matrixWorld: Matrix4;
  
  /** Model-view matrix */
  readonly modelViewMatrix: Matrix4;
  
  /** Normal matrix for transforming normals */
  readonly normalMatrix: Matrix3;
  
  /** Auto-update local matrix from position/rotation/scale */
  matrixAutoUpdate: boolean;
  
  /** Auto-update world matrix */
  matrixWorldAutoUpdate: boolean;
  
  /** Force world matrix update on next render */
  matrixWorldNeedsUpdate: boolean;
  
  /** Layer membership for selective rendering */
  layers: Layers;
  
  /** Visibility flag */
  visible: boolean;
  
  /** Cast shadows flag */
  castShadow: boolean;
  
  /** Receive shadows flag */
  receiveShadow: boolean;
  
  /** Frustum culling enabled */
  frustumCulled: boolean;
  
  /** Rendering order override */
  renderOrder: number;
  
  /** Animation clips attached to object */
  animations: AnimationClip[];
  
  /** Custom depth material for shadow rendering */
  customDepthMaterial?: Material;
  
  /** Custom distance material for point light shadows */
  customDistanceMaterial?: Material;
  
  /** User data object */
  userData: Record<string, any>;
  
  /**
   * Constructor creates a new 3D object
   */
  constructor();
  
  /**
   * Apply transformation matrix to object
   * @param matrix - Transformation matrix to apply
   * @returns This object for chaining
   */
  applyMatrix4(matrix: Matrix4): this;
  
  /**
   * Apply quaternion rotation to object
   * @param quaternion - Quaternion to apply
   * @returns This object for chaining
   */
  applyQuaternion(quaternion: Quaternion): this;
  
  /**
   * Set rotation from axis and angle
   * @param axis - Rotation axis (normalized vector)
   * @param angle - Rotation angle in radians
   * @returns This object for chaining
   */
  setRotationFromAxisAngle(axis: Vector3, angle: number): this;
  
  /**
   * Set rotation from Euler angles
   * @param euler - Euler angles
   * @returns This object for chaining
   */
  setRotationFromEuler(euler: Euler): this;
  
  /**
   * Set rotation from rotation matrix
   * @param matrix - Matrix containing rotation
   * @returns This object for chaining
   */
  setRotationFromMatrix(matrix: Matrix4): this;
  
  /**
   * Set rotation from quaternion
   * @param quaternion - Quaternion rotation
   * @returns This object for chaining
   */
  setRotationFromQuaternion(quaternion: Quaternion): this;
  
  /**
   * Rotate around arbitrary axis in local space
   * @param axis - Rotation axis (normalized)
   * @param angle - Rotation angle in radians
   * @returns This object for chaining
   */
  rotateOnAxis(axis: Vector3, angle: number): this;
  
  /**
   * Rotate around arbitrary axis in world space
   * @param axis - World space rotation axis (normalized)
   * @param angle - Rotation angle in radians
   * @returns This object for chaining
   */
  rotateOnWorldAxis(axis: Vector3, angle: number): this;
  
  /**
   * Rotate around local X axis
   * @param angle - Rotation angle in radians
   * @returns This object for chaining
   */
  rotateX(angle: number): this;
  
  /**
   * Rotate around local Y axis
   * @param angle - Rotation angle in radians
   * @returns This object for chaining
   */
  rotateY(angle: number): this;
  
  /**
   * Rotate around local Z axis
   * @param angle - Rotation angle in radians
   * @returns This object for chaining
   */
  rotateZ(angle: number): this;
  
  /**
   * Translate along arbitrary axis
   * @param axis - Translation direction (normalized)
   * @param distance - Translation distance
   * @returns This object for chaining
   */
  translateOnAxis(axis: Vector3, distance: number): this;
  
  /**
   * Translate along local X axis
   * @param distance - Translation distance
   * @returns This object for chaining
   */
  translateX(distance: number): this;
  
  /**
   * Translate along local Y axis
   * @param distance - Translation distance
   * @returns This object for chaining
   */
  translateY(distance: number): this;
  
  /**
   * Translate along local Z axis
   * @param distance - Translation distance
   * @returns This object for chaining
   */
  translateZ(distance: number): this;
  
  /**
   * Transform local position to world coordinates
   * @param vector - Local position to transform
   * @returns World position
   */
  localToWorld(vector: Vector3): Vector3;
  
  /**
   * Transform world position to local coordinates
   * @param vector - World position to transform
   * @returns Local position
   */
  worldToLocal(vector: Vector3): Vector3;
  
  /**
   * Orient object to look at target position
   * @param target - Target position to look at
   * @param up - Up direction (optional, defaults to object.up)
   */
  lookAt(target: Vector3): void;
  lookAt(x: number, y: number, z: number): void;
  
  /**
   * Add child object to hierarchy
   * @param object - Child object to add
   * @returns This object for chaining
   */
  add(...objects: Object3D[]): this;
  
  /**
   * Remove child object from hierarchy
   * @param object - Child object to remove
   * @returns This object for chaining
   */
  remove(...objects: Object3D[]): this;
  
  /**
   * Remove this object from its parent
   * @returns This object for chaining
   */
  removeFromParent(): this;
  
  /**
   * Remove all child objects
   * @returns This object for chaining
   */
  clear(): this;
  
  /**
   * Attach object to new parent maintaining world transform
   * @param object - Object to attach
   * @returns This object for chaining
   */
  attach(object: Object3D): this;
  
  /**
   * Find child object by ID
   * @param id - Object ID to search for
   * @returns Found object or undefined
   */
  getObjectById(id: number): Object3D | undefined;
  
  /**
   * Find child object by name
   * @param name - Object name to search for
   * @returns Found object or undefined
   */
  getObjectByName(name: string): Object3D | undefined;
  
  /**
   * Find child object by property value
   * @param name - Property name
   * @param value - Property value to match
   * @returns Found object or undefined
   */
  getObjectByProperty(name: string, value: any): Object3D | undefined;
  
  /**
   * Find all child objects by property value
   * @param name - Property name
   * @param value - Property value to match
   * @returns Array of matching objects
   */
  getObjectsByProperty(name: string, value: any): Object3D[];
  
  /**
   * Get world position
   * @param target - Target vector to store result
   * @returns World position
   */
  getWorldPosition(target: Vector3): Vector3;
  
  /**
   * Get world quaternion
   * @param target - Target quaternion to store result
   * @returns World quaternion
   */
  getWorldQuaternion(target: Quaternion): Quaternion;
  
  /**
   * Get world scale
   * @param target - Target vector to store result
   * @returns World scale
   */
  getWorldScale(target: Vector3): Vector3;
  
  /**
   * Get world direction
   * @param target - Target vector to store result
   * @returns World direction
   */
  getWorldDirection(target: Vector3): Vector3;
  
  /**
   * Execute callback for this object and all descendants
   * @param callback - Function to execute
   */
  traverse(callback: (object: Object3D) => void): void;
  
  /**
   * Execute callback for all visible descendants
   * @param callback - Function to execute
   */
  traverseVisible(callback: (object: Object3D) => void): void;
  
  /**
   * Execute callback for all ancestors
   * @param callback - Function to execute
   */
  traverseAncestors(callback: (object: Object3D) => void): void;
  
  /**
   * Update local matrix from position/rotation/scale
   */
  updateMatrix(): void;
  
  /**
   * Update world matrix and children
   * @param updateParents - Update parent matrices first
   * @param updateChildren - Update child matrices
   */
  updateMatrixWorld(updateParents?: boolean): void;
  
  /**
   * Update world matrix
   * @param updateParents - Update parent matrices first
   * @param updateChildren - Update child matrices
   */
  updateWorldMatrix(updateParents: boolean, updateChildren: boolean): void;
  
  /**
   * Serialize object to JSON
   * @param meta - Metadata for serialization
   * @returns JSON representation
   */
  toJSON(meta?: any): any;
  
  /**
   * Clone object
   * @param recursive - Clone children recursively
   * @returns Cloned object
   */
  clone(recursive?: boolean): this;
  
  /**
   * Copy properties from another object
   * @param source - Source object to copy from
   * @param recursive - Copy children recursively
   * @returns This object for chaining
   */
  copy(source: Object3D, recursive?: boolean): this;
  
  /**
   * Called before shadow rendering
   * Override for custom shadow behavior
   */
  onBeforeShadow(
    renderer: any, 
    object: Object3D, 
    camera: any, 
    shadowCamera: any, 
    geometry: any, 
    depthMaterial: any, 
    group: any
  ): void;
  
  /**
   * Called after shadow rendering
   * Override for custom shadow behavior
   */
  onAfterShadow(
    renderer: any, 
    object: Object3D, 
    camera: any, 
    shadowCamera: any, 
    geometry: any, 
    depthMaterial: any, 
    group: any
  ): void;
  
  /**
   * Called before rendering
   * Override for custom render behavior
   */
  onBeforeRender(
    renderer: any, 
    scene: any, 
    camera: any, 
    geometry: any, 
    material: any, 
    group: any
  ): void;
  
  /**
   * Called after rendering
   * Override for custom render behavior
   */
  onAfterRender(
    renderer: any, 
    scene: any, 
    camera: any, 
    geometry: any, 
    material: any, 
    group: any
  ): void;
  
  /** Default up direction for all objects */
  static DEFAULT_UP: Vector3;
  
  /** Default matrix auto update setting */
  static DEFAULT_MATRIX_AUTO_UPDATE: boolean;
  
  /** Default matrix world auto update setting */
  static DEFAULT_MATRIX_WORLD_AUTO_UPDATE: boolean;
}

import { Object3D, Vector3, Quaternion } from 'three';

// Create basic object
const obj = new Object3D();
obj.position.set(1, 2, 3);
obj.rotation.x = Math.PI / 4;
obj.scale.setScalar(2);

// Hierarchy management
const parent = new Object3D();
const child = new Object3D();
parent.add(child);

// Find objects
const found = parent.getObjectByName('myObject');
const byId = parent.getObjectById(123);

// Transformations
obj.translateX(5);
obj.rotateY(Math.PI / 2);
obj.lookAt(new Vector3(0, 0, 0));

// World coordinates
const worldPos = obj.getWorldPosition(new Vector3());
const localPos = obj.worldToLocal(worldPos.clone());

// Traversal
parent.traverse((child) => {
  console.log(child.name, child.position);
});

import { Scene, Object3D, Color, Texture, Fog, FogExp2, Material } from 'three';

/**
 * Scene container for 3D content with environment settings
 */
class Scene extends Object3D {
  /** Type flag for scene detection */
  readonly isScene: true;
  
  /** Background color, texture, or cube map */
  background: Color | Texture | null;
  
  /** Environment map for all physical materials */
  environment: Texture | null;
  
  /** Fog effect for the scene */
  fog: Fog | FogExp2 | null;
  
  /** Background blur amount for cube map backgrounds (0-1) */
  backgroundBlurriness: number;
  
  /** Background intensity multiplier */
  backgroundIntensity: number;
  
  /** Background rotation in radians */
  backgroundRotation: Euler;
  
  /** Environment map intensity multiplier */
  environmentIntensity: number;
  
  /** Environment map rotation in radians */
  environmentRotation: Euler;
  
  /** Override material for all objects in scene */
  overrideMaterial: Material | null;
  
  /**
   * Create new scene
   */
  constructor();
  
  /**
   * Serialize scene to JSON
   * @param meta - Metadata object
   * @returns JSON representation
   */
  toJSON(meta?: any): any;
  
  /**
   * Copy properties from another scene
   * @param source - Source scene
   * @param recursive - Copy children recursively
   * @returns This scene for chaining
   */
  copy(source: Scene, recursive?: boolean): this;
}

import { Scene, Color, CubeTextureLoader, Fog } from 'three';

// Create scene with background
const scene = new Scene();
scene.background = new Color(0x87CEEB); // Sky blue

// Environment mapping
const loader = new CubeTextureLoader();
scene.environment = loader.load([
  'px.jpg', 'nx.jpg', 'py.jpg', 'ny.jpg', 'pz.jpg', 'nz.jpg'
]);

// Add fog
scene.fog = new Fog(0xcccccc, 10, 15);

// Background controls
scene.backgroundIntensity = 0.8;
scene.backgroundRotation.y = Math.PI / 4;

import { Group, Object3D } from 'three';

/**
 * Empty object for grouping other objects with shared transformations
 */
class Group extends Object3D {
  /** Type flag for group detection */
  readonly isGroup: true;
  
  /**
   * Create new group
   */
  constructor();
}

import { Group, Mesh, BoxGeometry, MeshBasicMaterial } from 'three';

// Create group for related objects
const buildings = new Group();
buildings.name = 'CityBuildings';

// Add multiple objects to group
for (let i = 0; i < 10; i++) {
  const building = new Mesh(
    new BoxGeometry(1, Math.random() * 3 + 1, 1),
    new MeshBasicMaterial({ color: Math.random() * 0xffffff })
  );
  building.position.x = i * 2;
  buildings.add(building);
}

// Transform entire group
buildings.position.y = 1;
buildings.rotation.y = Math.PI / 6;

// Add to scene
scene.add(buildings);

import { EventDispatcher } from 'three';

/**
 * Event system base class
 */
class EventDispatcher {
  /**
   * Add event listener
   * @param type - Event type string
   * @param listener - Event handler function
   */
  addEventListener(type: string, listener: (event: any) => void): void;
  
  /**
   * Check if has event listener
   * @param type - Event type string
   * @param listener - Event handler function
   * @returns True if listener exists
   */
  hasEventListener(type: string, listener: (event: any) => void): boolean;
  
  /**
   * Remove event listener
   * @param type - Event type string
   * @param listener - Event handler function
   */
  removeEventListener(type: string, listener: (event: any) => void): void;
  
  /**
   * Dispatch event to listeners
   * @param event - Event object with type property
   */
  dispatchEvent(event: { type: string; [key: string]: any }): void;
}

import { Object3D } from 'three';

// Custom event handling
const obj = new Object3D();

obj.addEventListener('customEvent', (event) => {
  console.log('Custom event fired:', event.data);
});

// Built-in hierarchy events
obj.addEventListener('added', () => {
  console.log('Object was added to parent');
});

obj.addEventListener('removed', () => {
  console.log('Object was removed from parent');
});

// Dispatch custom events
obj.dispatchEvent({
  type: 'customEvent',
  data: { message: 'Hello World' }
});

// Object3D static defaults
Object3D.DEFAULT_UP: Vector3; // (0, 1, 0)
Object3D.DEFAULT_MATRIX_AUTO_UPDATE: boolean; // true
Object3D.DEFAULT_MATRIX_WORLD_AUTO_UPDATE: boolean; // true

import { Layers } from 'three';

/**
 * Layer membership system for selective rendering
 */
class Layers {
  /** Layer mask as 32-bit integer */
  mask: number;
  
  /**
   * Set single active layer (0-31)
   * @param layer - Layer number
   */
  set(layer: number): void;
  
  /**
   * Enable specific layer
   * @param layer - Layer number
   */
  enable(layer: number): void;
  
  /**
   * Enable all layers
   */
  enableAll(): void;
  
  /**
   * Toggle layer state
   * @param layer - Layer number
   */
  toggle(layer: number): void;
  
  /**
   * Disable specific layer
   * @param layer - Layer number
   */
  disable(layer: number): void;
  
  /**
   * Disable all layers
   */
  disableAll(): void;
  
  /**
   * Test if layer is enabled
   * @param layer - Layer number
   * @returns True if enabled
   */
  test(layer: number): boolean;
  
  /**
   * Test if any layers match between objects
   * @param layers - Other layers object
   * @returns True if any layers match
   */
  isEnabled(layers: Layers): boolean;
}

import { Raycaster, Vector3, Camera, Object3D, Intersection } from 'three';

/**
 * Raycaster for 3D ray casting and intersection testing
 */
class Raycaster {
  /** The ray used for raycasting */
  ray: Ray;
  
  /** Near distance for intersection testing */
  near: number;
  
  /** Far distance for intersection testing */  
  far: number;
  
  /** Camera used for coordinate transformations */
  camera: Camera;
  
  /** Layers to test against */
  layers: Layers;
  
  /** Line threshold for line intersection testing */
  linePrecision: number;
  
  /** Point threshold for point intersection testing */  
  pointPrecision: number;
  
  /**
   * Create raycaster
   * @param origin - Ray origin point
   * @param direction - Ray direction (normalized)
   * @param near - Near clipping distance
   * @param far - Far clipping distance
   */
  constructor(origin?: Vector3, direction?: Vector3, near?: number, far?: number);
  
  /**
   * Set ray from camera and mouse coordinates
   * @param coords - Normalized device coordinates (-1 to 1)
   * @param camera - Camera for ray calculation
   */
  setFromCamera(coords: Vector2, camera: Camera): void;
  
  /**
   * Set ray from origin and direction
   * @param origin - Ray origin point
   * @param direction - Ray direction (normalized)
   */
  set(origin: Vector3, direction: Vector3): void;
  
  /**
   * Test intersection with single object
   * @param object - Object to test
   * @param recursive - Test child objects recursively
   * @returns Array of intersections
   */
  intersectObject(object: Object3D, recursive?: boolean): Intersection[];
  
  /**
   * Test intersection with array of objects
   * @param objects - Objects to test
   * @param recursive - Test child objects recursively
   * @returns Array of intersections
   */
  intersectObjects(objects: Object3D[], recursive?: boolean): Intersection[];
}

interface Intersection {
  /** Distance from ray origin to intersection */
  distance: number;
  
  /** Intersection point in world coordinates */
  point: Vector3;
  
  /** Surface normal at intersection */
  normal?: Vector3;
  
  /** UV coordinates at intersection */
  uv?: Vector2;
  
  /** Face index (for geometry intersections) */
  faceIndex?: number;
  
  /** Object that was intersected */
  object: Object3D;
}