Run any Skill in Manus with one click

$pwd:

threejs

Name: Threejs
Author: benchflow-ai

// Three.js scene-graph parsing and export workflows: mesh baking, InstancedMesh expansion, part partitioning, per-link OBJ export, and URDF articulation.

Run Skill in Manus

$ git log --oneline --stat

stars:1,272

forks:307

updated:May 27, 2026 at 23:55

File Explorer

7 files

SKILL.md

readonly

name	threejs
description	Three.js scene-graph parsing and export workflows: mesh baking, InstancedMesh expansion, part partitioning, per-link OBJ export, and URDF articulation.

Three.js Scene Graph + Export

Quick start

Load the module, call createScene(), then updateMatrixWorld(true).
Treat named THREE.Group nodes as parts/links.
Assign each mesh to its nearest named ancestor.
Bake world transforms into geometry before export.
Export per-part OBJ (and optionally URDF) using deterministic ordering.

Scene graph essentials

Object3D (root)
├── Group (part)
│   ├── Mesh
│   └── Group (child part)
│       └── Mesh
└── Group (another part)
    └── Mesh

THREE.Scene / THREE.Object3D: containers
THREE.Group: logical part (no geometry)
THREE.Mesh: geometry + material

Part partitioning rules

Parts are named groups at any depth.
Each mesh belongs to the nearest named ancestor.
Nested named groups are separate parts; do not merge their meshes into parents.
Skip empty parts; sort part names for determinism.

function buildPartMap(root) {
  const parts = new Map();
  root.traverse((obj) => {
    if (obj.isGroup && obj.name) parts.set(obj.name, { group: obj, meshes: [] });
  });
  root.traverse((obj) => {
    if (!obj.isMesh) return;
    let parent = obj.parent;
    while (parent && !(parent.isGroup && parent.name)) parent = parent.parent;
    if (parent && parts.has(parent.name)) parts.get(parent.name).meshes.push(obj);
  });
  return Array.from(parts.values()).filter((p) => p.meshes.length > 0);
}

Mesh baking (world transforms)

Always bake transforms before export:

root.updateMatrixWorld(true);
let geom = mesh.geometry.clone();
geom.applyMatrix4(mesh.matrixWorld);
if (geom.index) geom = geom.toNonIndexed();
if (!geom.attributes.normal) geom.computeVertexNormals();

InstancedMesh expansion

const tempMatrix = new THREE.Matrix4();
const instanceMatrix = new THREE.Matrix4();
obj.getMatrixAt(i, instanceMatrix);
tempMatrix.copy(obj.matrixWorld).multiply(instanceMatrix);

Axis conversion (Y-up to Z-up)

const axisMatrix = new THREE.Matrix4().makeRotationX(-Math.PI / 2);
geom.applyMatrix4(axisMatrix);

Per-part OBJ export

Collect meshes owned by each part.
Do not traverse into child named groups when exporting a part.
Merge baked geometries per part and write <part>.obj.

Reference: references/link-export-rules.md.

Relation between Three.js and URDF articulation

Use named groups as links.
Parent is the nearest named ancestor link.
Joint type defaults to fixed unless evidence suggests revolute/prismatic.
Sort link and joint names for determinism.

References:

references/joint-type-heuristics.md
references/urdf-minimal.md

Scripts

InstancedMesh OBJ exporter: node scripts/export_instanced_obj.mjs
Per-link OBJ exporter: node scripts/export_link_objs.mjs --input <scene_js> --out-dir <dir>
URDF builder: node scripts/build_urdf_from_scene.mjs --input <scene_js> --output <file.urdf> --mesh-dir <mesh_dir>

Adjust inputs/outputs inside scripts as needed.

related-skills.json

same repository

fragmentation-aware-packing.md

from "benchflow-ai/skillsbench"

Choose placements that preserve useful residual capacity. Use for bin packing, GPU sharing, accelerator placement, and multi-resource scheduling where stranded capacity hurts future fit.

2026-05-301.3k

multi-resource-allocation-validation.md

from "benchflow-ai/skillsbench"

Validate and repair proposed resource allocations by replaying them against temporary capacity. Use when actions consume several resource dimensions such as CPU, memory, GPUs, or accelerators.

2026-05-301.3k

online-resource-scheduling.md

from "benchflow-ai/skillsbench"

Design deterministic online scheduling policies from current observations. Use when assigning arriving work to limited resources without seeing future requests.

2026-05-301.3k

pymatgen.md

from "benchflow-ai/skillsbench"

Materials science toolkit. Crystal structures (CIF, POSCAR), phase diagrams, band structure, DOS, Materials Project integration, format conversion, for computational materials science.

2026-05-211.3k

task-creator.md

from "benchflow-ai/skillsbench"

SkillsBench task authoring — walk a contributor from idea to submission-ready task following CONTRIBUTING.md and the task-implementation rubric. Use when the user wants to create a new SkillsBench task, scaffold a task from an existing workflow (notebook, Excel workbook, document, dataset), convert a prompt or a benchmark item into a SkillsBench task, write skills for a task, or prepare a SkillsBench PR. Pairs with `task-review` (run that as a self-check before submitting).

2026-05-051.3k

task-review.md

from "benchflow-ai/skillsbench"

SkillsBench task PR review — classifies the task track (standard / research / multimodal), runs static policy checks against the track-specific rubric, benchmarks the task across oracle plus Claude and Codex (with and without skills), audits trajectories for cheating and skill invocation, and produces a `pr-N-task-timestamp-run.txt` review report alongside a `prN.zip` bundle of trajectories. Use when reviewing a SkillsBench task PR (by number, branch, or local task path), when the user asks to review a task, run benchmarks on a PR, audit a submission, classify a task as research or multimodal track, or prepare a comment to post on a SkillsBench PR.

2026-05-051.3k

package.json

"author": "benchflow-ai"

"repository": "benchflow-ai/skillsbench"

View GitHub Repository View Creator Repositories

$ install --global

$ download --local

Run Skill in Manus

$ useful --forSOC

Software DevelopersComputer and Mathematical Occupations15-1252L4

name	threejs
description	Three.js scene-graph parsing and export workflows: mesh baking, InstancedMesh expansion, part partitioning, per-link OBJ export, and URDF articulation.

Three.js Scene Graph + Export

Quick start

Load the module, call createScene(), then updateMatrixWorld(true).
Treat named THREE.Group nodes as parts/links.
Assign each mesh to its nearest named ancestor.
Bake world transforms into geometry before export.
Export per-part OBJ (and optionally URDF) using deterministic ordering.

Scene graph essentials

Object3D (root)
├── Group (part)
│   ├── Mesh
│   └── Group (child part)
│       └── Mesh
└── Group (another part)
    └── Mesh

THREE.Scene / THREE.Object3D: containers
THREE.Group: logical part (no geometry)
THREE.Mesh: geometry + material

Part partitioning rules

Parts are named groups at any depth.
Each mesh belongs to the nearest named ancestor.
Nested named groups are separate parts; do not merge their meshes into parents.
Skip empty parts; sort part names for determinism.

function buildPartMap(root) {
  const parts = new Map();
  root.traverse((obj) => {
    if (obj.isGroup && obj.name) parts.set(obj.name, { group: obj, meshes: [] });
  });
  root.traverse((obj) => {
    if (!obj.isMesh) return;
    let parent = obj.parent;
    while (parent && !(parent.isGroup && parent.name)) parent = parent.parent;
    if (parent && parts.has(parent.name)) parts.get(parent.name).meshes.push(obj);
  });
  return Array.from(parts.values()).filter((p) => p.meshes.length > 0);
}

Mesh baking (world transforms)

Always bake transforms before export:

root.updateMatrixWorld(true);
let geom = mesh.geometry.clone();
geom.applyMatrix4(mesh.matrixWorld);
if (geom.index) geom = geom.toNonIndexed();
if (!geom.attributes.normal) geom.computeVertexNormals();

InstancedMesh expansion

const tempMatrix = new THREE.Matrix4();
const instanceMatrix = new THREE.Matrix4();
obj.getMatrixAt(i, instanceMatrix);
tempMatrix.copy(obj.matrixWorld).multiply(instanceMatrix);

Axis conversion (Y-up to Z-up)

const axisMatrix = new THREE.Matrix4().makeRotationX(-Math.PI / 2);
geom.applyMatrix4(axisMatrix);

Per-part OBJ export

Collect meshes owned by each part.
Do not traverse into child named groups when exporting a part.
Merge baked geometries per part and write <part>.obj.

Reference: references/link-export-rules.md.

Relation between Three.js and URDF articulation

Use named groups as links.
Parent is the nearest named ancestor link.
Joint type defaults to fixed unless evidence suggests revolute/prismatic.
Sort link and joint names for determinism.

References:

references/joint-type-heuristics.md
references/urdf-minimal.md

Scripts

InstancedMesh OBJ exporter: node scripts/export_instanced_obj.mjs
Per-link OBJ exporter: node scripts/export_link_objs.mjs --input <scene_js> --out-dir <dir>
URDF builder: node scripts/build_urdf_from_scene.mjs --input <scene_js> --output <file.urdf> --mesh-dir <mesh_dir>

Adjust inputs/outputs inside scripts as needed.

threejs

Three.js Scene Graph + Export

Quick start

Scene graph essentials

Part partitioning rules

Mesh baking (world transforms)

InstancedMesh expansion

Axis conversion (Y-up to Z-up)

Per-part OBJ export

Relation between Three.js and URDF articulation

Scripts

More from this repository

More from this repository

Three.js Scene Graph + Export

Quick start

Scene graph essentials

Part partitioning rules

Mesh baking (world transforms)

InstancedMesh expansion

Axis conversion (Y-up to Z-up)

Per-part OBJ export

Relation between Three.js and URDF articulation

Scripts