SpriteKiln

English | Português (BR) | 한국어 | 日本語 | 简体中文

Animated pixel-art sprites from procedural 3D models, made to be driven by coding AIs.

A character is a small YAML file: a skeleton, 3D shapes, materials and animations. SpriteKiln renders it into pixel art in 8 directions (top-down 3/4) or in profile (side view), with exact frame timing, gameplay events, attachment points, a normal map for dynamic light and an emissive layer, ready for Godot, Unity, MonoGame or any engine that reads Aseprite sheets.

You do not have to write the YAML. Your coding assistant (Claude Code, Codex, Gemini, Copilot, Cursor) does, from a description or a splash art: it edits the spec, renders, looks at the images and fixes what it sees. You direct.

Why

• Consistent by construction. One camera, one light and one palette for every asset, in every direction and frame. No drift between the north-east walk and the south-west attack.
• Cheap to change. "Make the hat bigger" or "slow down the windup" is a one-line edit, not a redraw of 300 frames.
• Game-ready. Per-frame durations, events (hit, step_l, windup) on the right frame, sockets (muzzles, hands, impact points), the pivot on the ground for y-sorting, normal and emissive maps.
• Made for AIs. One set of instructions for every assistant, an MCP server whose tools return images, a JSON Schema for the spec, errors with file:line:column, and an art-direction review in numbers for assistants that cannot see.
• Pure Python, any OS. numpy, Pillow and PyYAML; no GPU, no Blender. Tested on Windows, macOS and Linux.

Install

Python 3.10 or newer. Install the spritekiln command with pipx, which keeps it isolated and on your PATH:

Windows (PowerShell; no Python yet? winget install Python.Python.3.13, then open a new terminal)

py -m pip install --user pipx
py -m pipx ensurepath
py -m pipx install "spritekiln[mcp]"

macOS (Terminal, with Homebrew)

brew install pipx
pipx ensurepath
pipx install "spritekiln[mcp]"

Linux (Debian/Ubuntu shown; Fedora: sudo dnf install pipx, Arch: sudo pacman -S python-pipx)

sudo apt install pipx
pipx ensurepath
pipx install "spritekiln[mcp]"

Then open a new terminal and check with spritekiln --version. [mcp] adds the tools for AI assistants; pipx install spritekiln is enough for the command line alone. For renders about 6× faster, install "spritekiln[mcp,fast]" instead (a compiled renderer; Intel Macs keep the plain one). uv, a virtual environment, upgrading and troubleshooting: Install SpriteKiln.

Upgrade

In a virtual environment on Windows, run python -m spritekiln update. Assets rendered again with a new version can look different (0.3 changed the shading): the changelog says what changed.

Quick start

The commands are the same on every system.

1. Set up your folder (once)

Open a terminal in your game's folder, or in an empty folder if you only want sprites, and tell SpriteKiln which engine the sprites are for and which AI assistant will make them:

spritekiln init --engine godot --ai claude

Name several assistants with commas: --ai claude,cursor. init writes spritekiln.toml (specs go to art/specs/, exports to the folder above), the instructions your assistant reads before it starts, and the config of the MCP server through which it calls SpriteKiln. Details: Use SpriteKiln with your AI.

2. Ask your assistant for a sprite

Open the folder in your assistant and describe the character:

Make a hooded goblin scout with a short sword. Start from the template, check all 8 directions, then render idle, walk and attack and export them.

The first time, before it makes anything, the assistant interviews you about the art style: top-down or side view, how many pixels tall a character is on screen, directions, colours, outline and shading, proportions, how much face a character shows, the feel of the animation and your references. The answers go to spritekiln.toml (spritekiln style shows them); every later sprite follows them, and they change only when you ask ("from now on, no outlines").

Then it writes the spec, renders, looks at the images and fixes what it sees. You review the GIFs in art/specs/characters/<name>/out/<name>/preview/ and ask for changes ("bigger hat", "faster swing"). Have a splash art? Hand it over: From your splash art, with an AI.

3. Or do it by hand

The same commands your assistant runs:

spritekiln style set --height 48 --outline selective                 # the art style, once (all answers: -h)
spritekiln new knight                                                # art/specs/characters/knight/knight.yaml
spritekiln pose art/specs/characters/knight/knight.yaml --dirs all   # one pose in 8 directions, ~1 s each
spritekiln render art/specs/characters/knight/knight.yaml --export   # all animations, exported to the engine

Edit the YAML between pose runs: Your first character in 10 minutes walks through it.

Showcase

RIN-7 · side view, 48 px	The Ranger · top-down, 64 px	Thor · top-down, 100 px
7 clips (idle, run, jump, rise, fall, land, attack), 84 frames	4 clips in 8 directions (idle, run, dash, attack), 288 frames	13 clips in 8 directions, 696 frames in a 128 px frame
splash → sprite	splash → sprite	splash → sprite

Made by Claude Code following the recipe (modeler, art director, animator). RIN-7 and the Ranger come from test projects of 0.3, Thor from one of 0.1; the Templar and the Huntress were made for the game Hunt Tower. All of them, with more animations: showcase/.

What's new

0.3 (2026-10-30)

• Sharper forms: extruded and revolved profiles, tubes, shells and cuts give blades, plates, brims and capes crisp edges instead of inflated blobs.
• Materials that read: finishes (metal, soft, matte, glossy) with highlights, creases and edge lights, and surface paint for bands, rivets and emblems.
• Your style, applied: the renderer applies the project's outline, shading (soft, flat, toon), inner lines, dither and light to every asset; spritekiln style preview shows the choices side by side.
• Bases and kits: extends: humanoid and 20 built-in kits (weapons, shields, headwear, capes, belts, heads and hair), so a character states only what is its own.
• Better first characters: head and hair kits, a question about faces in the style interview, and pose --focus head close-ups.
• Faster: frames 1.5–3× faster with tighter bounds, about 6× more with [fast], and --draft previews.

0.2 (2026-10-25)

• Before the first asset, the assistant interviews you about the art style and records it in spritekiln.toml; every later asset follows it.
• spritekiln update upgrades SpriteKiln and refreshes the AI instructions of your game folders.

Everything else: CHANGELOG.

How it works

spec.yaml ──► skeleton + IK ──► SDF shapes ──► raymarched render ──► pixelize ──► atlas + JSON
 (bones,      (expressions per   (ellipsoids,   (colour, normals,     (palette ramps,   + normal map
  shapes,      frame: cycles,     extrudes,      depth, paint;         outline