Generating preview images for stages

Overview

Custom stages can have preview images associated with them, that then show up in the game’s menus. This can be done by placing a 512x512 image named preview512.png, right next to the stage’s config.json file.

The game can also automatically generate preview images for you for all stages in an arcade-mode course. For starters, if you don’t have a course contianing your stages yet, we need to create one.

Creating a course containing your stages

If you look inside the game files, under RolledOut/Content/Courses is where all the arcade-mode courses live. They’re simple JSON files with a bit of metadata and a list of stages. Somewhere in here, create a course.json file and populate it with the following text.

{
  "config_version": "0.1.0",
  "metadata": {
    "uuid": "95951123-3989-4998-ba83-cc9b12df30c1",
    "name": { "fallback": "Alice's custom levels" },
    "tags": [],
    "creator_uuid": "00000000-0000-0000-0000-000000000000",
    "description": { "fallback": "Collection of my own custom levels" },
    "difficulty": 10
  },
  "stages": [
    "64dfa65a-f7a0-495a-b752-9b4b6906a356",
    "3aca1f67-51da-4119-bacd-b1dcab8ab530",
    "df6a81af-0613-4d2e-8c4e-d3c70f9e1423",
    "dd279aba-7e40-47ac-9f9c-7f6b8795439f"
  ]
}

Make sure to replace the course uuid with a randomly generated one - you can grab one from https://www.uuidgenerator.net/version4.

Inside the stages array is where a list of your stage UUIDs should go - replace the placeholder stage UUIDs in the template with your own ones. You can find the UUID for each stage from their stage config files (similarly to how courses have UUIDs in their metadata, stages do too).

Once you’re done, save the file, launch the game, and make sure your course shows up in the arcade menu. If it doesn’t, try hitting F4 in the game once or twice to see if there’s any information about what went wrong there.

Screenshotting stages in a course

Now that you have a course full of stages, it’s time to screenshot them. Before doing so however, you may want to increase your graphical settings tempoarily for nicer images.

To take the screenshots, head over to arcade mode, select your course, and hold Ctrl-Shift and click the start button. The game should begin screenshotting all the stages in the course, and saving preview512.png files next to each stage’s config for you.