find-3d-assets

name	find-3d-assets
description	Find, download, and integrate low-poly 3D models (GLB/GLTF) for web projects. Use when the user needs 3D assets, furniture models, game assets, or asks about KayKit, poly.pizza, Kenney, Sketchfab, or Three.js models.

Finding 3D Assets for Web Projects

Search Strategy

When looking for a specific 3D model, follow this priority order:

1. Check Local Models First

Look in modules/web-app/public/models/ — the model (or something close) might already exist. See the Current Project Models table at the bottom.

2. Search Sketchfab (Largest Library, API Download)

Sketchfab is the primary source for high-quality downloadable 3D models. It has API-based download which makes it the most automatable option when the user has a SKETCHFAB_API_TOKEN.

Finding models — web search:

site:sketchfab.com [object name] low poly downloadable free
sketchfab [object name] CC0 OR CC-BY download

Finding models — direct Sketchfab search URL:

https://sketchfab.com/search?q=[keyword]&downloadable=true&sort_by=-likeCount

Finding models — Sketchfab Search API:

# Search without auth (public models)
curl -s "https://api.sketchfab.com/v3/search?type=models&q=standing+desk&downloadable=true&sort_by=-likeCount&count=5" \
  | python3 -c "
import sys, json
data = json.load(sys.stdin)
for r in data.get('results', []):
    print(f\"{r['name']} by {r['user']['displayName']} — {r['faceCount']} tris — {r['license']['label']}\"
          f\"  https://sketchfab.com/3d-models/{r['slug']}-{r['uid']}\")
"

Filters to use when searching:

• downloadable=true — only models with download enabled
• sort_by=-likeCount — most popular first (usually highest quality)
• license=by for CC-BY, license=cc0 for CC0
• max_face_count=20000 — keep it web-friendly

Sketchfab Download Workflow (Automated)

Requires: SKETCHFAB_API_TOKEN environment variable (stored in .env, loaded by direnv). Get one at: https://sketchfab.com/settings/password → "API Token" section.

MODEL_ID="65a7f4b06a5f4954a0d43eb8812dd165"   # hex ID from the model URL
OUTPUT="standingDesk.glb"                       # target filename

# Step 1 — Get signed download URLs (expires in 5 min)
DOWNLOAD_JSON=$(curl -s \
  -H "Authorization: Token $SKETCHFAB_API_TOKEN" \
  "https://api.sketchfab.com/v3/models/$MODEL_ID/download")

# Step 2 — Extract the GLB URL (preferred) or fall back to GLTF zip
GLB_URL=$(echo "$DOWNLOAD_JSON" | python3 -c "import sys,json; d=json.load(sys.stdin); print(d.get('glb',{}).get('url',''))")
GLTF_URL=$(echo "$DOWNLOAD_JSON" | python3 -c "import sys,json; d=json.load(sys.stdin); print(d.get('gltf',{}).get('url',''))")

if [ -n "$GLB_URL" ]; then
  # Direct GLB — no conversion needed
  curl -L -o "/tmp/${OUTPUT}" "$GLB_URL"
else
  # GLTF zip — download, unzip, convert
  curl -L -o /tmp/model.zip "$GLTF_URL"
  unzip -o /tmp/model.zip -d /tmp/model_tmp/
  npx gltf-pipeline -i /tmp/model_tmp/scene.gltf -o "/tmp/${OUTPUT}"
  rm -rf /tmp/model.zip /tmp/model_tmp/
fi

# Step 3 — Optimize (MANDATORY — see "Post-Download Optimization" section)
# Sketchfab GLBs are typically 5-30MB; this pipeline gets them to 100-500KB.
npx gltf-transform resize "/tmp/${OUTPUT}" /tmp/opt-s1.glb --width 256 --height 256
npx gltf-transform simplify /tmp/opt-s1.glb /tmp/opt-s2.glb --ratio 0.05 --error 0.02
npx gltf-transform webp /tmp/opt-s2.glb /tmp/opt-s3.glb
npx gltf-transform prune /tmp/opt-s3.glb /tmp/opt-s4.glb
npx gltf-transform draco /tmp/opt-s4.glb "modules/web-app/public/models/${OUTPUT}"
rm -f /tmp/opt-s*.glb "/tmp/${OUTPUT}"

# Step 4 — Generate gzip sidecar for nginx gzip_static
node -e "
const fs=require('fs'),zlib=require('zlib');
const p='modules/web-app/public/models/${OUTPUT}';
const d=fs.readFileSync(p);
fs.writeFileSync(p+'.gz',zlib.gzipSync(d,{level:9}));
console.log('${OUTPUT}:',(d.length/1024).toFixed(0)+'KB →',(fs.statSync(p+'.gz').size/1024).toFixed(0)+'KB gzipped');
"

API response format (all four formats may be available):

{
  "glb":    { "url": "https://...standing_desk.glb?...",  "size": 2300908, "expires": 300 },
  "gltf":   { "url": "https://...standing_desk.zip?...",  "size": 6265725, "expires": 300 },
  "usdz":   { "url": "https://...Standing_Desk.usdz?...", "size": 1893909, "expires": 300 },
  "source": { "url": "https://...standing-desk.zip?...",  "size": 13136219, "expires": 300 }
}

• Prefer glb (single binary, ready to use)
• Fall back to gltf (zip with scene.gltf + textures, needs conversion)
• source is the original upload format (often large, avoid)
• URLs expire in 5 minutes — download immediately after requesting

Sketchfab Manual Download

If API isn't available:

1. Open the model page in browser
2. Click "Download 3D Model"
3. Choose Autoconverted format (glTF) — this gives a zip
4. Unzip, find scene.gltf inside
5. Convert: npx gltf-pipeline -i scene.gltf -o model.glb

Sketchfab URL Anatomy

https://sketchfab.com/3d-models/standing-desk-65a7f4b06a5f4954a0d43eb8812dd165
                                 ^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                                 slug           model ID (use this for API calls)

• Model metadata: GET https://api.sketchfab.com/v3/models/{id}
• Download links: GET https://api.sketchfab.com/v3/models/{id}/download (requires auth)
• Search: GET https://api.sketchfab.com/v3/search?type=models&q={query}&downloadable=true

3. Search poly.pizza (Fast Aggregator)

poly.pizza aggregates models from Google Poly archive, Sketchfab, and community uploads. Good for quick keyword searches when you don't need API automation.

Web search pattern:

site:poly.pizza [object name] low poly
poly.pizza [object name] 3D model free download

Direct URL pattern: https://poly.pizza/search/[keyword]

• Results include GLB direct download links — no conversion needed
• Most models are CC-BY (attribution required) or CC0
• Filter by "Animated" if you need animations
• Each model page shows triangle count, vertex count, and a 3D preview

4. Search Kenney (Game-Focused, CC0)

Kenney provides complete asset packs, not individual models. Great for consistent art style.

Web search pattern:

site:kenney.nl [category] assets
kenney.nl [furniture/vehicle/nature] 3D

Direct URL: https://kenney.nl/assets?q=3d

• All CC0 — no attribution needed
• Consistent low-poly style across packs
• Downloads are zip files with multiple formats (GLTF included)

5. Search GitHub for Asset Packs

Many free asset packs live on GitHub, including KayKit.

Web search pattern:

github [object type] 3D model gltf CC0 free
github low-poly [category] asset pack
KayKit-Game-Assets github [pack name]

6. General Web Search

When the above sources don't have what you need:

Web search patterns:

[object name] 3D model free download gltf glb low poly
[object name] 3D asset CC0 free commercial use
[object name] game ready 3D model free

Additional sources to check:

• Quaternius (quaternius.com) — CC0 low-poly packs
• OpenGameArt (opengameart.org) — CC0/CC-BY game assets
• Turbosquid (turbosquid.com) — filter by Free + GLTF
• CGTrader (cgtrader.com) — filter by Free + Low Poly
• itch.io — search "3D assets" (many free/cheap packs)

7. AI-Generated / Procedural (Last Resort)

If no model exists, consider:

• Building it from primitives in Three.js (boxes, cylinders, spheres)
• Using Meshy.ai or similar AI 3D generators
• Commissioning from itch.io creators

---

KayKit by Kay Lousberg

Free CC0-licensed low-poly 3D asset packs. Single gradient atlas texture (1024x1024).

Packs & GitHub Repos

Pack	Content	GitHub
Furniture Bits	50+ furniture, desks, chairs, beds, shelves	KayKit-Game-Assets/KayKit-Furniture-Bits-1.0
Furniture Bits EXTRA	+20 computer/gaming setup items (monitor, keyboard, mouse, laptop, desk chair)	Paid ($3.95+) on itch.io
Character Pack	Low-poly characters	KayKit-Game-Assets/KayKit-Adventurers-1.0
Mini Game Kit	Props, nature, buildings	KayKit-Game-Assets/KayKit-Mini-Game-Kit-1.0
Prototype Bits	64+ generic shapes/props	KayKit-Game-Assets/KayKit-Prototype-Bits-1.0

File Structure in Repos

addons/kaykit_*/Assets/
├── gltf/       ← Use these (.gltf + .bin pairs)
├── fbx/
├── obj/
└── texture/    ← Atlas texture (furniturebits_texture.png)

KayKit Download Workflow

1. Browse the GitHub repo's Assets/gltf/ directory for model names
2. Download the .gltf + .bin pair (both required)
3. Convert to .glb (single binary) for web: npx gltf-pipeline -i model.gltf -o model.glb
4. Place in modules/web-app/public/models/
5. Use with useGLTF('/models/model.glb') from @react-three/drei

---

File Format Priority

Format	When to Use	Conversion
.glb	Preferred — single binary, fastest to load	Use directly
.gltf + .bin	Common in asset packs	npx gltf-pipeline -i input.gltf -o output.glb
.gltf + .bin (Draco)	Smaller files	npx gltf-pipeline -i input.gltf -o output.glb -d
.fbx	Some Sketchfab models	Convert with Blender or online tools
.obj	Last resort — no PBR	Convert with Blender

---

Post-Download Optimization (MANDATORY)

Every model downloaded from Sketchfab or other external sources MUST be optimized before use. Sketchfab GLBs are typically 5-30MB with 1024x1024 textures and 100K+ vertices — far too heavy for a web scene. The optimization pipeline below routinely achieves 80-96% file size reduction with no visible quality loss at typical viewing distances.

Inspect Before Optimizing

Always inspect the model first to understand what's eating space:

npx gltf-transform inspect public/models/myModel.glb

Key things to look for:

• Texture resolution — 1024x1024 or 2048x2048 is overkill for desk-scale objects; 256-512 is plenty
• Texture format — PNG textures are often 3-5x larger than WebP; JPEG is better but WebP wins
• Vertex count — >50K vertices for a desk ornament is excessive; simplify to 5-10K
• Extra attributes — TEXCOORD_1, TEXCOORD_2, TANGENT add significant data; prune if unused
• Texture count — baseColor + normal + metallicRoughness + specular = 4 textures that compress differently

The Optimization Pipeline

Run these steps in order using separate commands (not gltf-transform optimize, which uses its own defaults and can produce worse results):

MODEL="electricPiano"
ORIGINAL="/tmp/${MODEL}-original.glb"
DEST="modules/web-app/public/models/${MODEL}.glb"

# Step 1 — Resize textures (256 for small objects, 512 for hero objects)
npx gltf-transform resize "$ORIGINAL" /tmp/${MODEL}-s1.glb --width 256 --height 256

# Step 2 — Simplify geometry (ratio = target fraction, error = allowed deviation)
npx gltf-transform simplify /tmp/${MODEL}-s1.glb /tmp/${MODEL}-s2.glb --ratio 0.05 --error 0.02

# Step 3 — Convert textures to WebP (much smaller than PNG/JPEG)
npx gltf-transform webp /tmp/${MODEL}-s2.glb /tmp/${MODEL}-s3.glb

# Step 4 — Prune unused accessors, textures, materials
npx gltf-transform prune /tmp/${MODEL}-s3.glb /tmp/${MODEL}-s4.glb

# Step 5 — Draco mesh compression (ALWAYS last — decode is lossy if re-run)
npx gltf-transform draco /tmp/${MODEL}-s4.glb "$DEST"

# Step 6 — Generate gzip sidecar for nginx gzip_static
node -e "
const fs=require('fs'),zlib=require('zlib');
const data=fs.readFileSync('$DEST');
fs.writeFileSync('${DEST}.gz', zlib.gzipSync(data, {level:9}));
console.log('${MODEL}.glb:', (data.length/1024).toFixed(1)+'KB →',
  (fs.statSync('${DEST}.gz').size/1024).toFixed(1)+'KB gzipped');
"

# Clean up
rm -f /tmp/${MODEL}-s*.glb /tmp/${MODEL}-original.glb

Optimization Guidelines by Object Role

Role	Texture Size	Simplify Ratio	Expected Output
Background/room	256x256	0.1	<100 KB
Desk-scale object (keyboard, mouse, plant)	256x256	0.05-0.1	<50 KB
Hero object (desk, piano)	512x512	0.05	100-500 KB
Detailed prop (headset) with palette texture	Skip resize	0.1	200-300 KB

Real-World Results

Model	Source Size	After Pipeline	Wire (gzip)	Reduction
standingDesk.glb	1.8 MB	87 KB	80 KB	96%
electricPiano.glb	13.5 MB (Sketchfab GLB)	500 KB	390 KB	97%
gamingHeadset.glb	717 KB	239 KB	235 KB	67%

Common Pitfalls

• Do NOT use gltf-transform optimize --compress draco as a single step. It runs its own simplify/weld/join pipeline with different defaults and can produce larger files than the step-by-step approach, especially on models that were already Draco-compressed.
• Draco is always the LAST step. If you need to re-optimize, start from the original (pre-Draco) file. Decoding and re-encoding Draco is lossy and often inflates the result.
• Keep the original download until you've verified the optimized version renders correctly.
• Sketchfab GLBs often have 1024x1024 textures even for small objects. These are the biggest size offender — resizing to 256x256 can cut 50-80% of file size alone.
• Some models have redundant UV channels (TEXCOORD_1, TEXCOORD_2) that prune will strip if no material references them.

Checking Licenses

Before using any model, verify the license:

License	Attribution?	Commercial?	Modify?
CC0	No	Yes	Yes
CC-BY	Yes (credit author)	Yes	Yes
CC-BY-SA	Yes + share-alike	Yes	Yes (same license)
CC-BY-NC	Yes	No	Yes

For this project, prefer CC0 or CC-BY. Add attribution in a comment or credits page for CC-BY models.

All Sources (Quick Reference)

Source	URL	License	API?	Best For
Sketchfab	sketchfab.com	Varies (filter CC0/CC-BY)	Yes (token)	Largest library, API download
poly.pizza	poly.pizza	CC-BY (mostly)	Yes (free)	Quick keyword search, direct GLB
KayKit	github.com/KayKit-Game-Assets	CC0	No	Consistent low-poly game style
Kenney	kenney.nl/assets	CC0	No	Complete themed packs
Quaternius	quaternius.com	CC0	No	Low-poly themed packs
OpenGameArt	opengameart.org	CC0/CC-BY	No	Game-ready assets
itch.io	itch.io	Varies	No	Indie asset packs
Three.js examples	github.com/mrdoob/three.js	MIT	No	Reference/test models

Integration Pattern (React Three Fiber)

import { useGLTF } from '@react-three/drei';

function Model({ url, ...props }) {
  const { scene } = useGLTF(url);
  return <primitive object={scene.clone()} {...props} />;
}

// Preload for instant display
useGLTF.preload('/models/myModel.glb');

Debugging Model Dimensions

import { Box3, Vector3 } from 'three';

const box = new Box3().setFromObject(scene);
const size = new Vector3();
box.getSize(size);
console.log(`Size: ${size.x} × ${size.y} × ${size.z}`);

Non-Uniform Scaling

KayKit models are often small. Scale them up, and use non-uniform scale={[x, y, z]} to change proportions (e.g., make a square desk into a wide desk).

---

Environment Variables

Variable	Purpose	Where to Get
SKETCHFAB_API_TOKEN	Download models via Sketchfab API	sketchfab.com/settings/password → API Token

Add to .env.example and .env per the env-vars workspace rule.

---

Current Project Models

Located in modules/web-app/public/models/:

File	Size (wire)	Source	License	Used For
desk.glb	~2 KB	KayKit Furniture EXTRA	CC0	Wide desk (non-uniform scaled)
chairDesk.glb	~3 KB	KayKit Furniture EXTRA	CC0	Office chair
computerScreen.glb	~1 KB	KayKit Furniture EXTRA	CC0	Monitor
computerKeyboard.glb	~1 KB	KayKit Furniture EXTRA	CC0	Keyboard
computerMouse.glb	~1 KB	KayKit Furniture EXTRA	CC0	Mouse
laptop.glb	~1 KB	KayKit Furniture EXTRA	CC0	Laptop
speakerSmall.glb	~2 KB	KayKit Furniture EXTRA	CC0	Speaker
pottedPlant.glb	~2 KB	KayKit Furniture Bits	CC0	Plant
lampRoundTable.glb	~1 KB	KayKit Furniture Bits	CC0	Table lamp
emptyRoom.glb	~1 KB	KayKit Furniture Bits	CC0	Room shell
standingDesk.glb	80 KB	Sketchfab (Ryan_Nein)	CC-BY	Standing desk (optimized: 1.8MB→87KB)
electricPiano.glb	390 KB	Sketchfab (Mateusz Woliński)	CC-BY	Electric piano (optimized: 13.5MB→500KB)
gamingHeadset.glb	235 KB	Sketchfab	CC-BY	Gaming headset (optimized: 717KB→239KB)

Note: KayKit models are already tiny (<5KB) since they use a shared palette texture. Sketchfab models need the full optimization pipeline (see above) — their raw downloads are 10-100x larger.