# Rengi Forge: Sprite Normal Map Generator

> Rengi Forge: Sprite Normal Map Generator is a paid API for AI agents from rengi.dev, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-22).

Generates a normal map from a sprite or sprite sheet PNG, using bevel and surface detail for 2D lighting in Unity URP 2D and Godot

## Facts

- Endpoint: POST https://rengi.dev/v1/sprite-tools/normal-map?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-22
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/rengi-forge-sprite-normal-map-generator-bb9f8e98
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_z-yttIvaJGCtp8PbU_O0I

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability rengi-forge-sprite-normal-map-generator-bb9f8e98 -d '<json body>'
```

Example prompt: Generate a normal map for this sprite PNG — use a 12-pixel bevel, surface detail of 0.8, and OpenGL convention so it works with Unity URP 2D lighting.

## When to prefer this

Choose this endpoint when you need programmatically generated normal maps for 2D sprites or sprite sheets destined for Unity URP 2D or Godot lighting pipelines. It is purpose-built for game development workflows where preserving alpha transparency and choosing between OpenGL and DirectX conventions matters. Prefer it over generic image processing APIs because it combines silhouette-based bevel rounding with color-derived surface detail in a single call, and returns both a height map and a lit preview.

## Known failure modes

- Invalid or malformed base64 PNG input returns an error
- Image missing alpha/transparency channel may produce incorrect silhouette bevel
- Bevel value exceeding 256 or below 1 is rejected by schema validation
- Both image and imageUrl omitted causes a validation error
- Very large sprite sheets may time out or exceed payload limits
- Unsupported image format (non-PNG) may be rejected

## How this service works

Sprite tools: Normal map for a sprite or sprite sheet, for 2D lights in Unity URP 2D and Godot: a rounded bevel from the silhouette plus surface detail, alpha kept, OpenGL or DirectX; a height map and a preview lit by a moving light. Full schema: https://rengi.dev/v1/sprite-tools/schema

## Output

Returns a normal map image (PNG) generated from the sprite's silhouette bevel and color-derived surface detail, with the original alpha channel preserved, in either OpenGL (green-up) or DirectX convention. Also includes a height map and a preview image lit by a moving light to evaluate the result.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "bevel": {
   "type": "number",
   "maximum": 256,
   "minimum": 1,
   "description": "Rim width in pixels; from the sprite size when omitted."
  },
  "image": {
   "type": "string",
   "description": "Base64 PNG sprite or sheet with transparency."
  },
  "detail": {
   "type": "number",
   "default": 0.5,
   "maximum": 2,
   "minimum": 0,
   "description": "How much surface detail from the colors goes into the bumps."
  },
  "imageUrl": {
   "type": "string",
   "format": "uri"
  },
  "strength": {
   "type": "number",
   "default": 1,
   "maximum": 8,
   "minimum": 0.1
  },
  "convention": {
   "enum": [
    "opengl",
    "directx"
   ],
   "type": "string",
   "default": "opengl",
   "description": "opengl (green up) for Unity and Godot."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/rengi-forge-sprite-normal-map-generator-bb9f8e98/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from rengi.dev](https://www.zero.xyz/host/rengi.dev/llms.txt)