# 📐  L2 Spec — Photometric Stereo Mismatch-Only Spec

**ID:** `L2-098-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-098`](/artifact/l1/L1-098)

> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.55 · **Delta tier:** 5
> **⛓ On-chain block:** 41547813

---

## 1. Domain Ω

**Type:** `range`

| Parameter | Unit | Range |
|---|---|---|
| H | px | 128 – 2048 |
| W | px | 128 – 2048 |
| K lights | — | 3 – 96 |
| Photon count | — | 50 – 10000 |
| Ambient residual | — | 0.0 – 0.3 |
| Inter reflections | — | 0.0 – 0.3 |
| Specular fraction | — | 0.0 – 0.5 |
| Cast shadow fraction | — | 0.0 – 0.4 |
| Light direction error | — | 0.0 – 0.05 |

## 2. Tolerance (ε)

**Type:** `fn`

```
3.0 + 25.0 * specular_fraction + 20.0 * cast_shadow_fraction - 0.8 * log2(K_lights / 3) + 10.0 * light_direction_error / 0.05
```

## 3. Difficulty

| Property | Value |
|---|---|
| Difficulty score | 0.55 |
| Delta tier | 5 |

## 4. Fingerprint

`5907a11c8ca115870261b956e30be7b7db7eae2f0f6545723bf03c5f66546885`

## 5. On-chain Registration

- **Chain hash:** `0x523031ed6c83d9e56ccab87dc60584e4a83bc7c196deb2e35c6e602cae48766e`
- **Chain tx hash:** `0xb9be4e9a27140412aef082ebbe07324142f79e0b26bd64ceed83eb45521e7414`
- **Chain block:** `41547813`

---

## File Mapping

This bundle consists of: `L2-098-001.md`, `L2-098-001.json`.

| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-098-001.md` | Source of truth — edit this | Human or LLM |
| `L2-098-001.json` | Structured metadata for the registry | LLM regenerates from the sections above |

**Prompt for your LLM after editing this Markdown:**

> Read the attached Markdown. Regenerate the sibling `.json` so every field matches.
> Preserve the schema documented in the rows above.
> Output each file in its own fenced code block tagged with the filename.
> Output only the JSON object.

_This Markdown was auto-synthesized from the catalog row for `L2-098-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._