How to Test World Rules with the Live Seed Preview

Opening the Seed Preview

Before generating a full world, you can test your rule configurations using the built-in preview tool:

1. Start a new world setup, switch the world type to Custom, and click Edit rules.

2. Tweak your chosen generation values in categories such as Terrain, Caves, or Biomes.

3. Click the Generate Preview button inside the editor.

Evaluating Test Landscapes

The editor opens a live seed preview window showing a spinning 3D model of a landscape generated from a random seed using your active settings.

• Examine Terrain and Elevation: Check whether mountain heights, surface slopes, and plains conform to your custom terrain rules.
• Check Surface Features: Observe how foliage distribution, surface decoration, and biome placements appear on the preview terrain.
• Review Underground Openings: See how modified cave parameters shape exposed cavern mouths and landscape cuts.

If the result requires further adjustment, close the preview window, fine-tune the parameter sliders, and select Generate Preview again until the terrain matches your goals.