threejs-objects

Original：🇺🇸 English

Translated

three.js scene graph objects: Object3D transforms and hierarchy, Group, Mesh, InstancedMesh, SkinnedMesh, BatchedMesh, LOD, Line/LineLoop/LineSegments, Points, Sprite, Bone, Skeleton, ClippingGroup; interaction via Raycaster, Layers masks, and EventDispatcher patterns. Merges the former interaction scope—use for picking and layers; for pure vector math without scene graph use threejs-math; for playing skeletal clips use threejs-animation; for frustum culling internals see camera docs.

7installs

Sourcefull-stack-skills/threejs-skills

Added on2026-09-18

NPX Install

npx skill4agent add full-stack-skills/threejs-skills threejs-objects

SKILL.md Content

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When to use this skill

ALWAYS use this skill when the user mentions:

Parent/child relationships,

position/rotation/scale

,

matrixAutoUpdate

,

updateMatrixWorld

Choosing mesh types: static vs instanced vs skinned vs batched LOD
Picking:
```
Raycaster.setFromCamera
```
,
```
intersectObjects
```
, recursive flag, face/uv results
Layers: selective visibility for cameras/lights/objects

IMPORTANT: objects vs math

Need	Skill
Scene graph + picking	threejs-objects
Box/ray math only	threejs-math

Trigger phrases include:

"Object3D", "InstancedMesh", "SkinnedMesh", "Raycaster", "layers"
"父子节点", "射线拾取", "图层"

How to use this skill

Compose scenes with
```
Group
```
and transforms; minimize deep hierarchies where possible.
Instancing: set per-instance matrices; understand
```
count
```
and frustum culling behavior.
SkinnedMesh: bind skeleton; clips in threejs-animation; skinning material flags in threejs-materials.
Picking: normalize device coords, set ray from camera, filter by layers, sort intersections.
Events:
```
EventDispatcher
```
on custom objects—patterns only, not DOM frameworks.
Clipping:
```
ClippingGroup
```
usage per docs when user needs sectional cuts.
Dispose: geometries/materials/textures when removing objects permanently.

See examples/workflow-raycaster-pick.md.

Doc map (official)

Docs section	Representative links
Core	https://threejs.org/docs/Object3D.html
Objects	https://threejs.org/docs/Mesh.html
Objects	https://threejs.org/docs/InstancedMesh.html
Core	https://threejs.org/docs/Raycaster.html

Scope

In scope: Object3D graph, renderable object types, raycasting, layers, dispatcher basics.
Out of scope: Physics engines; XR input mapping (threejs-webxr).

Common pitfalls and best practices

Forgetting
```
updateMatrixWorld
```
before world-space ray tests on moved objects.
Raycaster without
```
layers
```
set picks unintended objects—set masks consistently on camera and objects.
InstancedMesh raycast hits need per-instance handling—check docs for your version.

Documentation and version

Object3D

, mesh types,

Raycaster

, and

Layers

are documented under Objects and Core in three.js docs. Behavior of picking and layers can shift slightly—link the exact page for the user’s three.js line.

Agent response checklist

When answering under this skill, prefer responses that:

Link

Object3D

,

Mesh

,

InstancedMesh

,

Raycaster

, or

Layers

as needed.

Pair skeletal animation with threejs-animation and skinned mesh setup.
Route pure linear-algebra questions without a scene graph to threejs-math.
Route XR input to threejs-webxr when sessions/controllers are involved.
Mention
```
dispose()
```
for geometries/materials when removing objects permanently.

References

Keywords

English: object3d, mesh, instancedmesh, skinnedmesh, raycaster, layers, scene graph, three.js

中文： 场景图、Object3D、Mesh、实例化、骨骼网格、射线拾取、图层、three.js