img2threejs

The saved excerpt is a snapshot from when this skill was listed. The external source remains the complete and most current version.

---
name: img2threejs
description: Turn an object or character reference image into a quality-gated, animation-ready procedural Three.js model built in code. Use for image-to-3D reconstruction, detail-accurate object rebuilds, stylized/likeness-maximized human characters, sculpt specs, and staged code generation.
license: Apache-2.0
version: 2.0.0
---

# img2threejs — Image to procedural Three.js

Rebuild the object visible in a reference image as a **code-only** procedural Three.js model,
gated by a staged sculpting pipeline and an AI-vision self-correction loop. This is
reconstruction-by-code, **not** photogrammetry, mesh extraction, or downloaded art packs. That
promise governs how the model is *built* — it says nothing about which file formats it can
subsequently be *exported* to; an explicitly-selected emission target (`--target <kind>`) is a
terminal, whole-artifact transform of the already-built model, verified to its own stated limit,
never a second way to build one.

Agent-agnostic: works under Claude Code, Codex, or OpenCode. Wherever this doc says "agent
vision" or "agent browser tool", use whatever the host provides — native image reading, a
browser MCP (playwright/chrome-devtools), the project preview, or a user-supplied screenshot.

This file is the always-loaded router: it holds the order of operations and every hard rule as one
line. The full contract behind each rule lives in the `grimoire/` or `docs/` file that rule names —
read the named file at the moment you reach that stage, not before.

## Canonical shared checkout

Keep one checkout of this repository and let every host enter it through a symlink, so Claude and
Codex execute the same code instead of drifting apart:

```text
~/.claude/skills/img2threejs -> <your checkout>
~/.codex/skills/img2threejs  -> <your checkout>
```

## When To Use

The user attaches/points to an object image and wants a procedural Three.js model, a
reconstruction/animation/destruction plan, a sculpt spec, or code. Also for material studies,
action-ready props, game objects, botanical/mechanical parts, and stylized reconstructions.

## Core Promise

Sculpt from a photo, in order — never one-shot a mesh:
1. **Run `python3 forge/next.py --state .img2threejs/state.json [<spec>]` first**, at every start,
   resume, and before every correction iteration. It reports the ordered checklist, exact next
   command, evidence status, and bounded correction-loop status; it never replaces the spec/pass
   gates. Obey a hard stop; never continue from memory.
2. **Validate** the image is a suitable 3D target (`grimoire/intake/validation_rubric.md`).
3. **Assess** object class + complexity, then write a `qualityContract` before any code.
4. **Spec** it: component hierarchy, materials, lighting, pivots, sockets, action anchors.
5. **Build pass-by-pass** from blockout → structure → form → material → lighting → interaction → optimization.
6. **Verify** each pass with a screenshot compared against the reference; fail a pass if an
   identity-defining feature is wrong even when the global score looks fine.

State explicitly when output is approximate/stylized/low-poly. A single image cannot reveal
hidden sides or guarantee exact geometry — say so instead of faking confidence.

## Mandatory Local State Gate

Conversation context is disposable; `.img2threejs/state.json` is the local checklist authority.
Initialize once per reconstruction, then gate every step through it:

```bash
python3 forge/state.py init --state .img2threejs/state.json --reference <img> --profile <generic|character|installed-domain> --spec object-sculpt-spec.json
python3 forge/next.py --state .img2threejs/state.json [object-sculpt-spec.json]
python3 forge/state.py mark <step-id> --state .img2threejs/state.json --evidence <path>
```

- `next.py` prints the current step, pass, incomplete mandatory steps, exact next command, and
  `loop/max`. Exit code 3 or `status=stopped` is a hard stop: report the reason and request input.
  Never byp