Three.js 3D Generator

Purpose

Create production-oriented 3D assets, then prepare them for Three.js games. This is the Three.js game system's 3D-generation layer; it uses Tripo as the provider for text-to-3D, image-to-3D, texturing, rigging, retargeting, stylization, conversion, and downloadable GLB/FBX outputs.

Resolve <this-skill-dir> in the commands below in this order: ~/.claude/skills/threejs-3d-generator, ~/.codex/skills/threejs-3d-generator, ~/.agents/skills/threejs-3d-generator, or repo skills/threejs-3d-generator.

API Key

Never store API keys in skill files or client-side game code, and never paste a key value into a report. The script reads --api-key or TRIPO_API_KEY.

Step 0, before declaring the key unavailable: run this skill's own probe and paste its literal output into the report.

python3 <this-skill-dir>/scripts/threejs_3d_asset.py probe   # prints TRIPO_API_KEY=SET|MISSING

TRIPO_API_KEY=MISSING is only a valid skip/blocker reason when this output is shown. Keys defined only in a shell profile can be absent from the process env; if the plain probe prints MISSING unexpectedly, wrap it: zsh -lc 'source ~/.zprofile 2>/dev/null || true; source ~/.zshrc 2>/dev/null || true; python3 <this-skill-dir>/scripts/threejs_3d_asset.py probe'. When the director skill is loaded, prefer threejs-game-director/scripts/probe_asset_credentials.sh, which probes all three asset keys at once.

Generated model download URLs expire quickly, so download outputs immediately after successful tasks.

Tool Script

Reference gate:

• Load references/api-notes.md before provider API work, endpoint/task decisions, model-version choices, polling, postprocess, conversion, rigging, animation, or download handling.
• Load references/threejs-integration.md before importing Tripo outputs into a browser game or advising GLB/FBX integration.
• Load references/image-generator-workflows.md before pairing threejs-image-generator with this skill for 2D concepts, texture references, UI art, logos, decals, or image-to-3D inputs.

Track required references in a reference ledger with yes/no, path, and failure reason. Do not mark an asset pipeline complete while a required reference is skipped.

Run from the user's current project directory:

python3 <this-skill-dir>/scripts/threejs_3d_asset.py --help

Common Commands

Recommended premium game hero model:

python3 <this-skill-dir>/scripts/threejs_3d_asset.py text \
  --prompt "game-ready [hero asset], strong readable silhouette, layered hard-surface detail, PBR materials, clean topology for browser game, centered pivot, 3/4 view, no text" \
  --model-version v3.1-20260211 \
  --texture-quality detailed \
  --geometry-quality detailed \
  --wait --download --out-dir assets/models/hero

Text to 3D:

python3 <this-skill-dir>/scripts/threejs_3d_asset.py text \
  --prompt "game-ready sci-fi hover bike, sleek armored panels, readable silhouette, PBR, front facing" \
  --model-version v3.1-20260211 \
  --texture-quality detailed \
  --geometry-quality detailed \
  --wait --download --out-dir assets/models/hover-bike

Image to 3D from a local threejs-image-generator concept:

python3 <this-skill-dir>/scripts/threejs_3d_asset.py image \
  --image assets/concepts/hover-bike-front.png \
  --model-version v3.1-20260211 \
  --enable-image-autofix \
  --texture-alignment original_image \
  --texture-quality detailed \
  --wait --download --out-dir assets/models/hover-bike

Status and download:

python3 <this-skill-dir>/scripts/threejs_3d_asset.py status TASK_ID
python3 <this-skill-dir>/scripts/threejs_3d_asset.py download TASK_ID --out-dir assets/models

Texture, rig, animate, or convert:

python3 <this-skill-dir>/scripts/threejs_3d_asset.py postprocess \
  --type texture_model --original-task-id TASK_ID \
  --texture-prompt "brushed gunmetal, orange hazard decals, worn edges" \
  --wait --download --out-dir assets/models/retextured

python3 <this-skill-dir>/scripts/threejs_3d_asset.py postprocess \
  --type animate_prerigcheck --original-task-id TASK_ID --wait

# Rig version is routed by --rig-type: biped -> v1.0-20240301 (the v2.x rigger
# fails on humanoids), other body plans -> v2.5-20260210. Only pass
# --model-version to override that routing.
python3 <this-skill-dir>/scripts/threejs_3d_asset.py postprocess \
  --type animate_rig --original-task-id TASK_ID --rig-type biped --spec tripo --wait

# animate_retarget takes the RIG task ID, not the generation task ID.
# Pass the same --rig-type used for the rig so the version routing matches
# (biped rigs use the legacy path: FBX output, ONE animation per task).
# Non-biped rigs may batch up to 5 presets per task via --animations.
# NEVER pass --animate-in-place: it corrupts the bake (mirrored limbs / exploded
# skinning). Strip root motion in the engine instead.
python3 <this-skill-dir>/scripts/threejs_3d_asset.py postprocess \
  --type animate_retarget --original-task-id RIG_TASK_ID --rig-type quadruped \
  --animations preset:idle,preset:walk,preset:run \
  --wait --download --out-dir assets/models/animated

python3 <this-skill-dir>/scripts/threejs_3d_asset.py postprocess \
  --type conversion --original-task-id TASK_ID --format GLTF \
  --face-limit 20000 --wait --download --out-dir assets/models/gltf

python3 <this-skill-dir>/scripts/threejs_3d_asset.py postprocess \
  --type stylize_model --original-task-id TASK_ID --style voxel \
  --wait --download --out-dir assets/models/voxel

Animated character pipeline (generation -> prerigcheck -> validated rig with retries -> retargets -> downloads). The pipeline routes itself by body plan: biped characters automatically use the v1.0-20240301 anatomical rig with one FBX per animation (plain preset names are mapped onto the preset:biped:* library); creatures use the v2.5-20260210 rig with GLB clips:

python3 <this-skill-dir>/scripts/threejs_3d_asset.py character-pipeline \
  --prompt "stylized cyber runner character, T-pose, full body, game-ready outfit, readable silhouette" \
  --animations preset:idle,preset:walk,preset:run,preset:jump \
  --out-dir assets/models/cyber-runner

# Creature example: stance language matters — generate in the pose the preset expects.
python3 <this-skill-dir>/scripts/threejs_3d_asset.py character-pipeline \
  --prompt "stylized wolf, quadrupedal stance, all four legs planted and separated, full body" \
  --rig-type quadruped --animations preset:quadruped:walk \
  --out-dir assets/models/wolf

Three.js Image Generator Pairing

Use threejs-image-generator before 3D generation when the asset benefits from a strong 2D reference:

• Character concept, full-body T-pose/A-pose, front/side/back variants.
• Building, prop, vehicle, weapon, pickup, enemy, obstacle, or terrain tile reference.
• Style sheet for a whole asset family.
• Texture references: terrain, rock, metal, fabric, decals, skyboxes, backgrounds, UI materials.
• Logos, faction marks, pickup icons, hazard signs, cockpit decals, HUD symbols, and GUI panels.

Load references/image-generator-workflows.md for prompt patterns before generating or editing 2D inputs.

Three.js Integration

Load references/threejs-integration.md before importing Tripo outputs into a browser game. In short:

• Prefer GLB/PBR outputs for Three.js.
• Use GLTFLoader for loading.
• Use AnimationMixer for rigged/animated GLBs.
• Keep generated model files out of client-side API flows; generation is a tooling step.
• Inspect triangle count, texture count, material count, file size, scale, pivot, bounds, and animation clips.
• Use generated 3D assets as hero/high-fidelity content, then build surrounding prop kits procedurally or with additional threejs-3d-generator / threejs-image-generator passes.

Rigging and Animation Reliability

Load references/api-notes.md for the full parameter tables, retarget mechanics, and the animation prohibitions (the canonical source for all three). The rules that prevent most failures:

• Generate characters as one fused mesh: keep --quad and --generate-parts off (generate_parts disables texturing; quad forces FBX output).
• Require full-body T-pose or A-pose, arms away from body, symmetric, no props fused to the silhouette. Verify the rendered preview is actually in T/A-pose before rigging; regenerate if not.
• Run animate_prerigcheck first (it takes no model version) and use the detected rig_type for animate_rig and preset selection. riggable=false means regenerate with a clearer pose, not force-rig.
• riggable=true does not guarantee a usable rig. After rigging, validate the skeleton before retargeting: threejs_3d_asset.py validate-rig rig-model.glb --rig-type biped (the character-pipeline does this automatically). Check both presence AND chain depth: a rig with a 1-bone leg or 2-bone arm warps every clip.
• Auto-rigging is nondeterministic. On validation failure, retry the rig task (~25 credits) before regenerating the model — character-pipeline --rig-retries N (default 2) automates this, and --model-task-id TASK_ID resumes from an existing generation. Armored/hard-surface characters need the most retries; organic meshes usually rig first try.
• Creatures get exactly one preset (walk/march). For multi-mode creatures (crawl + fly dragons), rig the same model twice — ground rig type for the locomotion preset, avian for wing chains — and drive wings procedurally in Three.js or via external clips on a mixamo-spec rig.
• Rig version is the main quality lever, and it differs by body plan (measured June 2026). The character-pipeline routes this automatically; only override --rig-model-version deliberately:
  • HUMANOIDS: v1.0-20240301 (anatomical Mixamo-like skeleton with twist bones + the large preset:biped:* clip library: idle, walk, run, slash, jump, dances, ...). The v2.x limb-chain rigger went 0/16 on humanoid meshes — armored or not, T-pose or A-pose — always producing asymmetric chains.
  • CREATURES: v2.5-20260210 (v2.x handles quadruped/avian well: symmetric 5-6 bone chains).
• For v1.0 rigs, retarget with --model-version default (omit the version): the retarget enum rejects explicit v1.0-20240301 (HTTP 400 code 2017) but the server default handles v1.0 rigs.
• v1.0 retargets must use --out-format fbx (the script enforces this): Tripo's GLB bake on this path exports twist-bone transforms in the wrong space and limbs collapse into the torso — the FBX of the same task is correct. Load with three.js FBXLoader or convert offline. v2.5 creature retargets are fine as GLB.
• Use --spec tripo (default) when Tripo presets will be retargeted; --spec mixamo rigs cannot be used with Tripo retarget and are only for external animation pipelines.
• animate_retarget takes the RIG task ID (not the generation task ID). Batch up to 5 presets per task with --animations; batched clips return named NlaTrack, NlaTrack.001, … in request order — map by index and rename after import. See references/api-notes.md for the v1.0-vs-v2.5 batching and out-format rules.
• Only 16 presets exist for v2.5 rigs (no preset:attack; use preset:slash/preset:shoot). Non-biped rig types have a single locomotion preset each; plan extra creature motion procedurally or via external retargeting.
• A creature's MESH STANCE drives how presets read: a quadruped walk on an upright-standing dragon looks like a human walking. Generate creatures in the stance the animation expects (horizontal body, all fours planted) — the pipeline only auto-appends T-pose language for biped rigs.
• After download, run threejs_3d_asset.py validate-animation clip.glb (keyframe QA: flags scale tracks, limb-stretching translation tracks, extreme rotations, and reports per-clip duration/channel coverage), then verify motion visually in the engine.
• Never use --animate-in-place (verified to corrupt clips: mirrored/crossed limbs on v1.0 rigs, exploded skinning on v2.5 — full detail in references/api-notes.md). Keep root motion baked and convert to in-place at import instead; exact engine snippet in references/threejs-integration.md.
• After download, inspect gltf.animations clip names and counts before wiring the AnimationMixer.

Quality Rules

• Improve the user's prompt with material, silhouette, camera/readability, scale, and game-use constraints.
• For riggable characters, include full-body T-pose or A-pose in the prompt or create a T-pose reference image first.
• For Three.js games, request GLB/PBR, reasonable face limits, and texture quality matched to the performance budget.
• For mobile/browser games, favor smart_low_poly, face_limit, later conversion, or low-poly postprocess when the asset is too expensive.
• Always download output URLs immediately after success.
• Report the credential probe output, reference ledger, task IDs, output paths, model version, texture/geometry settings, animations, conversion settings, Three.js import notes, and any missing/failed steps.