Generate custom 3D models from text or images using Meshy AI, then auto-rig and animate them for Three.js games. The preferred source for all 3D game assets. Use when the user says "generate a 3D model", "create a character model", "use Meshy", or needs a custom GLB model that doesn't exist in free

Meshy AI — 3D Model Generation, Rigging & Animation You are an expert at generating custom 3D models with Meshy AI and integrating them into Three.js browser games. Meshy is the preferred source for all 3D game assets — it generates exactly what you need from a text description or reference image, with consistent art style and game ready topology. Performance Notes Take your time with each step. Quality is more important than speed. Do not skip validation steps — they catch issues early. Read the full context of each file before making changes. Always run post generation verification. Never assume orientation or scale. Reference Files File Description [api reference.md](./api reference.md) Full API endpoint specs, payloads, responses, task statuses, and asset retention policy [rigging pipeline.md](./rigging pipeline.md) Complete generate rig animate integrate pipeline with fadeToAction pattern and code examples [verification patterns.md](./verification patterns.md) Auto orientation check, auto scale fitting, floor alignment code patterns Why Meshy First Exact match : Generate precisely the character, prop, or scenery your game needs — no compromises Consistent style : All assets from the same generation pipeline share a cohesive look Custom characters : Named personalities, branded characters, unique creatures — all generated to spec Full pipeline : Generate → rig → animate, all from one tool Game ready : Control polycount, topology, and PBR textures for optimal Three.js performance Fallback Sources If MESHY API KEY is not available and the user declines to set one up, fall back to these in order: Fallback Source Best for assets/3d characters/ Pre built GLBs Quick animated humanoids (Soldier, Xbot, Robot, Fox) find 3d asset.mjs Sketchfab, Poly Haven, Poly.pizza Searching existing free model libraries Procedural geometry Code BoxGeometry/SphereGeometry as last resort Authentication All Meshy API calls require MESHY API KEY . Always check for this key before starting any 3D asset work. Before prompting the user, check if the key already exists: test f .env && grep q '^MESHY API KEY=.' .env && echo "found" If found, export it with set a; . .env; set +a and skip the prompt. If the key is not set in the environment or .env , ask the user immediately : I'll generate custom 3D models with Meshy AI for the best results. You can get a free API key in 30 seconds: 1. Sign up at https://app.meshy.ai 2. Go to Settings → API Keys 3. Create a new API key Paste your key below like: MESHY API KEY=your key here (It will be saved to .env and redacted from this conversation automatically.) Or type "skip" to use free model libraries instead. If the user provides a key, use it via: set a; . .env; set +a && node scripts/meshy generate.mjs ... If the user skips, proceed with fallback sources (character library → Sketchfab → Poly Haven). CLI Script — scripts/meshy generate.mjs Zero dependency Node.js script. Handles the full lifecycle: submit task → poll → download GLB → write meta.json. Text to 3D (full pipeline) Generates a 3D model from a text prompt. Two step process: preview (geometry) → refine (texturing). Image to 3D Turn a reference image into a 3D model. Supports URLs, local files, and base64 data URIs. Auto Rig (humanoids only — MANDATORY for all bipedal characters) Adds a skeleton to a generated humanoid model and auto downloads walking + running animation GLBs . The input task ID comes from a completed text to 3d or image to 3d task. This produces 3 files automatically: hero.glb — rigged model with skeleton hero walk.glb — walking animation (auto downloaded) hero run.glb — running animation (auto downloaded) Always chain generate → rig as one atomic step for humanoids. Never leave humanoid characters as static models. Limitations: Rigging works only on textured humanoid (bipedal) models with clearly defined limbs. Won't work on animals, vehicles, abstract shapes, or untextured meshes. Animate Apply an animation to a rigged model. Requires a completed rig task ID and an animation action ID. Check Status Poll any task's current status. Non blocking Mode Submit a task without waiting. Useful in pipelines. Automatic GLB Optimization All downloaded GLBs are automatically optimized via scripts/optimize glb.mjs to reduce file sizes by 80–95%. The pipeline resizes textures to 1024×1024, converts them to WebP, and applies meshopt compression. Optimization runs by default after every GLB download (text to 3d, image to 3d, rig, animate) Use no optimize to skip optimization and keep the raw Meshy output Use texture size <n to change the max texture dimension (default: 1024) First run may take a moment as npx downloads @gltf transform/cli If gltf transform is unavailable, the script warns and continues with the raw file Optimized GLBs use meshopt compression and require MeshoptDecoder at runtime — the template AssetLoader.js includes this automatically. API Reference See [api reference.md](./api reference.md) for full endpoint specs, payloads, responses, task statuses, and asset retention policy. Quick Reference: Static Props (no rig needed) For non humanoid assets (props, scenery, buildings), skip rigging: Post Generation Verification (MANDATORY) See [verification patterns.md](./verification patterns.md) for auto orientation check, auto scale fitting, and floor alignment code patterns. Rigging: Mandatory for Humanoid Characters See [rigging pipeline.md](./rigging pipeline.md) for the full generate rig animate integrate pipeline, including when to rig, the fadeToAction pattern, and integration code examples. Prompt Engineering Tips Good prompts produce better models: Goal Prompt Why Game character "a stylized goblin warrior, low poly game character, full body" "low poly" + "game character" = game ready topology Prop "a wooden treasure chest, stylized, closed" Simple, specific, single object Environment piece "a fantasy stone archway, low poly, game asset" "game asset" signals clean geometry Vehicle "a sci fi hover bike, side view, clean topology" "clean topology" = fewer artifacts Avoid: Multiple objects in one prompt ("a knight AND a dragon") — generate separately Vague prompts ("something cool") — be specific about style and form Interior/architectural scenes — Meshy is best for single objects Integration with Existing Pipeline Meshy generated models slot into the existing 3D asset pipeline: All sources output GLB files into public/assets/models/ . The AssetLoader.js doesn't care where the GLB came from — it loads them all the same way. Troubleshooting Problem Cause Fix MESHY API KEY not set Environment variable missing Ask the user for their key or run export MESHY API KEY=<key . Free keys available at https://app.meshy.ai under Settings API Keys. Task stuck in PENDING API queue backlog or invalid parameters Wait 2 3 minutes, then poll status. If still PENDING after 5 minutes, cancel and resubmit with simpler prompt or lower polycount. Asset download returns 404 Meshy retains assets for only 3 days Re run the generation pipeline. Always download GLBs immediately after task succeeds. Store locally in public/assets/models/ . Rigging fails or produces broken skeleton Model is not a clearly bipedal humanoid, or mesh is untextured Ensure the model is a textured humanoid with visible limbs. Rigging does not work on animals, vehicles, abstract shapes, or preview only (untextured) meshes. Re generate with pbr and a prompt specifying "full body humanoid". Generated model does not match prompt Vague or multi object prompt Use specific, single object prompts. Include style cues ("low poly", "stylized", "game character") and avoid combining multiple objects. See Prompt Engineering Tips. Checklist [ ] MESHY API KEY checked — prompted user if not set, or user skipped to fallbacks [ ] Prompt is specific (style, poly count, single object) [ ] All humanoid characters rigged — never skip rigging for bipedal models [ ] Downloaded GLB before 3 day expiration [ ] Post generation verification done — orientation, scale, floor alignment checked [ ] Playwright screenshot taken — visually confirmed facing direction + fit in environment [ ] rotationY set per model in Constants.js (most Meshy models need Math.PI ) [ ] Static models use loadModel() (regular clone) [ ] Rigged models use loadAnimatedModel() (SkeletonUtils.clone) [ ] Clip names logged and clipMap defined for animated models [ ] .meta.json saved alongside GLB with task IDs for traceability [ ] npm run build succeeds

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