Pixelship

Try it in your browser on itch.io

A free procedural spaceship generator that runs in your browser. It makes top-down pixel-art spaceship sprites for 2D games and exports them as PNG sprite sheets you can drop straight into your engine.

Every ship is generated, not drawn. A seed becomes a shaped noise field, a cellular automaton smooths it into a hull, and the generator works out where the thrusters, guns and lights belong from the shape itself. You get animated exhaust, throttle and banking frames for turns.

Live demo

Interactive sprites demonstration: stmn.itch.io/pixelship-sprites-demonstration

A small shooter where every ship, colour and animation came out of this generator. It also doubles as the documentation for the mount-point export: it fires bullets from the ships' actual gun barrels using exactly the data that export serialises, and the barrels move with the wings when a ship banks.

Seven ship families

Interceptors, dreadnoughts, mantas, organic hive craft, angular shards and radially symmetric alien designs - each one a different region of the same 33 controls. Hit randomize, lock the ships you like so re-rolls skip them, then tune silhouette, wings, lighting and colour.

What you get

• 33 live controls - silhouette, wings, the automaton itself, lighting, hardpoints and colour. Every one of them changes the output; there are no decorative sliders.
• Looping animation - engine exhaust, throttle, running lights and banking poses. Exported strips loop seamlessly by construction.
• Size independence - 16 to 96 px, and a seed keeps its design at every size. Prototype small, export large.
• Sprite sheet export - each row a bank pose, each column an animation frame, plus a fleet sheet for a whole squadron in one file.
• Mount points export - a small JSON with the gun, thruster and light coordinates for every bank pose, in frame-local pixels. Without it you would be measuring twenty numbers per ship by hand in an image editor.
• Draw your own hull - the first tile in the gallery opens a pixel editor. Sketch a silhouette and it gets everything a generated one gets: thrusters and guns detected from the shape itself, lighting, palette, banking poses and sprite-sheet export. Mirrored as you draw by default, or turn the mirror off for an asymmetric hull, with a live animated preview of the finished ship.
• A saved library - bookmark a ship and it comes back exactly, because what is stored is the recipe, not an image.

Nothing installs, nothing uploads. Your settings and saved ships stay in your browser.

Using the mount points

The sprite sheet says what a ship looks like; the mount file says where its parts are. Coordinates are pixels inside one frame, origin at the frame's top-left, and each entry carries the sheet row it belongs to:

var pose = data.poses[poseRow];              // row in the sheet you are drawing
pose.guns.forEach(function (g) {
  spawnBullet(ship.x + g.x, ship.y + g.y);   // ship.x/y = frame top-left
});

That is the whole trick. Engines work the same way for exhaust. If you flip a sprite vertically for a descending enemy, mirror the mounts too or the bullets come out of the wrong end. The file itself carries these notes, so you do not have to come back here for them.

Running it locally

Plain ES5, no build step, no dependencies, no network calls. Opening index.html straight off disk works, but serve the directory instead if you want localStorage to behave - browsers treat file:// origins inconsistently, and that is where the saved library lives.

python3 -m http.server 8080
# generator      -> http://localhost:8080/
# sprites demo   -> http://localhost:8080/game/

Project layout

Path	What lives there
index.html	The generator: markup, styling and the script tags that assemble it
lab/	The engine. Headless and DOM-free, so every stage is testable under node
app/	The browser UI: panel, gallery, hand-drawn hull editor, storage, intro
game/	The sprites demonstration - a small shooter that consumes the exports
press/	Promo renders and the itch.io page copy; lab/press.js regenerates the renders
build.js	Assembles dist/ and dist-game/ into the itch.io HTML5 bundles

The pipeline, in lab/: shape.js (noise field -> cellular automaton -> hull mask) -> mounts.js (thrusters, guns, cockpit and lights read off the shape) -> shading.js (directional lighting, ambient occlusion, rim and spec) -> palette.js (hull ramp and outline) -> compose.js (ties them together) -> bank.js (turn poses) -> sprite.js (frames, strips and sheet geometry).

Tests

Each stage has a node test that runs on its own, no framework:

for t in lab/*.test.js; do node "$t"; done

Some of them write comparison renders into lab/out/ so a change to the shading or palette can be inspected rather than only asserted.

Licence

The generator is MIT - see LICENSE.

The sprites you make with it are not. They are released into the public domain under CC0 1.0: use them however you like, including commercially, with no attribution required. No credit needed - but if you ship something with these sprites in it, a link to your game is always welcome.