WorldGen Editor Preview

WorldGen Editor Preview is a developer companion tool for the Minecraft mod waterflane/WorldGen-Editor.

It is a static preview tool for continents.json, made to help modpack and worldgen developers tune island layouts before generating test worlds in Minecraft.

Open index.html in a browser and load JSON with Open JSON, or edit the text directly in the left panel and press Apply JSON.

What It Shows

• island shapes using the same mask algorithm as the mod;
• island, ocean, and archipelago entries from continents.json;
• deep ocean, ocean, shore, land, and core zones;
• island centers, coordinate grid, zoom, and pan;
• quality modes for fast editing, balanced inspection, or exact final coastline checks;
• worker-based rendering so exact previews do not block the browser UI;
• quick island focus from the list;
• loading and downloading continents.json.

Important

This is an island mask preview, not a full Minecraft worldgen simulation. It does not simulate vanilla terrain, surface rules, structures, caves, or biome features. Its job is to quickly check size, position, rotation, roughness, and shape seed without creating new worlds over and over.

Fast and Balanced modes use an approximate 32-bit noise hash for quick editing. Full exact mode uses the same 64-bit island mask math as the mod and runs in a Web Worker when the browser allows it. GPU rendering is intentionally not used for exact mode because Java-style 64-bit integer noise does not map cleanly to WebGL/WebGPU floats; this keeps the exact view deterministic on machines with or without a discrete GPU.

License

WorldGen Editor Preview is licensed under the MIT License. See LICENSE.txt.