Filenames and output roles

The default output is <outDir>/<category>/<assetId>.png when category is set, otherwise <outDir>/<assetId>.png; file overrides it. Structural sets expand one asset into outputs[] with stable roles such as tile-00 and filenames such as terrain-tile-00.png. Consumers should use roles rather than assuming array position. See tiles.

{
  "styles": { "base": { "generator": "map", "outDir": "art/base" } },
  "assets": {
    "anvil": { "prompt": "an anvil" },                              // art/base/anvil.png
    "hammer": { "prompt": "a hammer", "category": "tools" },        // art/base/tools/hammer.png
    "sign": { "prompt": "a shop sign", "file": "ui/shop-sign.png" }  // art/base/ui/shop-sign.png
  }
}

A set keeps the same stem and adds the role: a character base bot in a style with outDir: "art/cast" lands as art/cast/bot-south.png, bot-west.png, and so on; a loop as bot.walk-frame-00.png onwards.