Object3D

Base class for most scene objects. Provides transform hierarchy, visibility, and serialization.

Extends EventDispatcher.

Constructor

const obj = new Object3D()

Properties

• id — Auto-incrementing integer ID (readonly)
• uuid — UUID string (readonly)
• name — Optional name string
• type — Type string ('Object3D')
• parent — Parent Object3D (or null)
• children — Array of child Object3Ds
• up — Up direction vector (default (0, 1, 0))
• position — Local position (Vector3)
• rotation — Local rotation as Euler (syncs with quaternion)
• quaternion — Local rotation as Quaternion (syncs with rotation)
• scale — Local scale (Vector3, default (1, 1, 1))
• matrix — Local transform matrix (Matrix4)
• matrixWorld — World transform matrix (Matrix4)
• matrixAutoUpdate — Auto-compute local matrix each frame (default true)
• matrixWorldAutoUpdate — Auto-compute world matrix (default true)
• matrixWorldNeedsUpdate — Force world matrix update this frame
• visible — Whether to render (default true)
• castShadow, receiveShadow — Shadow flags (default false)
• renderOrder — Override render sorting (default 0)
• animations — Array of AnimationClips
• userData — Custom data object

Static

• Object3D.DEFAULT_UP — Default up vector (0, 1, 0)
• Object3D.DEFAULT_MATRIX_AUTO_UPDATE — Default true
• Object3D.DEFAULT_MATRIX_WORLD_AUTO_UPDATE — Default true

Methods

Transform

• applyMatrix4(matrix) — Apply matrix, decompose into position/rotation/scale
• applyQuaternion(q) — Apply rotation
• setRotationFromAxisAngle(axis, angle), setRotationFromEuler(euler), setRotationFromMatrix(m), setRotationFromQuaternion(q)
• rotateOnAxis(axis, angle) — Rotate in local space
• rotateOnWorldAxis(axis, angle) — Rotate in world space
• rotateX(angle), rotateY(angle), rotateZ(angle)
• translateOnAxis(axis, distance) — Translate along local axis
• translateX(d), translateY(d), translateZ(d)
• lookAt(x, y, z) or lookAt(vector3) — Face a point in world space

Space Conversion

• localToWorld(vector) — Local → world
• worldToLocal(vector) — World → local

Hierarchy

• add(object, ...) — Add child(ren)
• remove(object, ...) — Remove child(ren)
• removeFromParent() — Remove self from parent
• clear() — Remove all children
• attach(object) — Add child while preserving world transform

Search

• getObjectById(id), getObjectByName(name)
• getObjectByProperty(name, value) — First match
• getObjectsByProperty(name, value, result?) — All matches

World State

• getWorldPosition(target), getWorldQuaternion(target), getWorldScale(target), getWorldDirection(target)

Traversal

• traverse(callback) — Visit all descendants
• traverseVisible(callback) — Visit visible descendants only
• traverseAncestors(callback) — Visit all ancestors

Matrix

• updateMatrix() — Recompute local matrix from position/rotation/scale
• updateMatrixWorld(force?) — Recompute world matrices for this and descendants
• updateWorldMatrix(updateParents?, updateChildren?) — Selective update

Serialization

• toJSON(meta?) — Serialize to JSON
• clone(recursive?) — Deep copy
• copy(source, recursive?) — Copy values from another Object3D

Events

• added — Fired when added to a parent
• removed — Fired when removed from a parent
• childadded — Fired on parent when a child is added
• childremoved — Fired on parent when a child is removed