Build characters from parts.

A composite sprite is a grid of smaller tiles arranged into a larger character. The base is typically a 2×2 grid of 16×16 tiles, giving you a 32×32 result. Each slot in the grid — top-left, top-right, bottom-left, bottom-right — can hold any compatible tile.

Draw a bare-headed body, then create separate head tiles: helmet, crown, hood, wizard hat. Each one drops into the same slot. Combine them with armor variants (leather, chain, plate) and weapon variants (sword, staff, bow) and you get dozens of unique characters from a handful of parts.

# warrior.pax — composite with equipment variants
[[composite]]
name = "warrior"
grid = [2, 2]

[composite.slots]
head    = ["bare", "helmet", "crown"]
body    = ["tunic", "chain_mail", "plate"]
weapon  = ["sword", "axe", "spear"]

When tiles sit next to each other, the seam has to be invisible. PIXL checks that touching edges share the same colors at matching pixel positions. If a helmet’s bottom row doesn’t line up with the body’s top row, you get a warning with the exact pixel coordinates that need fixing.

Many character parts are symmetrical. Draw the left-facing version and PIXL generates the right-facing mirror automatically. For walking animations, compose each frame from the same parts with different leg tiles.

Describe a new equipment piece in the chat — “a horned Viking helmet with a nose guard” — and PIXL generates a 16×16 tile that matches your existing body’s edge colors and style. It inherits the project palette and respects the seam constraints automatically.

Expand all combinations into a single atlas PNG or export each variant as a separate file. PIXL generates the sprite sheet layout and optional metadata for Godot, Unity, or any engine that reads TexturePacker JSON.