Region Split Islands

Name	Type	Description
領域 regions	RegionMap Required	離れた島を分離する RegionMap です

Name	Type	Description
領域 regions	RegionMap	離れた島を別IDにした RegionMap です
プレビュー preview	Image	島分離後の領域を色分けした確認用画像です
ラベル labels	Map	Inspector に重ねるIDラベル位置です
概要 summary	Map	元ID数と分離後の島数です

Parameters

Name	Type	Default	Range	Description / Options
接続判定 connection_mode	Enum	Visible	—	ループ端の接続を同じ島として扱うかです表示上`Visible` 画面上で離れて見える島を分離しますループ考慮`Wrapped` 左右/上下ループで接続している島は同じIDとして扱います
ID順 id_order	Enum	SourceThenTopLeft	—	分離した島へIDを割り当てる順番です元ID優先`SourceThenTopLeft` 元IDごとに、左上に近い島からIDを割り当てます左上から`TopLeft` 左上に近い島から小さいIDを割り当てます右下から`BottomRight` 右下に近い島から小さいIDを割り当てます面積昇順`AreaAsc` 面積が小さい島から小さいIDを割り当てます面積降順`AreaDesc` 面積が大きい島から小さいIDを割り当てますランダム`Random` 安定したランダム順でIDを割り当てます
シード seed	Int	1	0–99999	ランダム順とプレビュー色に使うシードです
ID表示 show_ids	Bool	false	—	Inspector のプレビュー上に島IDラベルを表示します

Overview

Separates disconnected islands that share one ID, assigning each island its own ID. It turns outputs such as region_noise, where the same level appears at multiple locations, into one-ID-per-island data that can be processed individually.

Category: Generate / Region / Edit
Uses: masking disconnected islands individually after wrapping or merging, assigning IDs to visible islands, and aligning ID labels with extraction results

Usage tips

Remember it by the symptom: if selecting an ID with region_mask also selects distant areas, insert this node beforehand.
It is almost always paired with region_noise, because level IDs naturally form multiple islands.
For tile assets, set connection testing to Wrapped so islands connected across an edge remain one island.

Related nodes

region_noise — a common source of disconnected islands
region_mask — extracts individual islands
region_remap — arranges ID order before or after splitting
region_merge_small — cleans up small islands after splitting

Connectivity

Value	Description
`Visible`	Separate islands that look disconnected on the canvas, even when they connect across a wrapped edge
`Wrapped`	Account for `wrap_x` / `wrap_y` on the input RegionMap and keep islands connected across left/right or top/bottom edges under one ID

ID order

Value	Description
`SourceThenTopLeft`	Group by source ID, then assign IDs from the island nearest the top-left
`TopLeft`	Assign lower IDs to islands nearest the top-left
`BottomRight`	Assign lower IDs to islands nearest the bottom-right
`AreaAsc`	Assign lower IDs to smaller islands
`AreaDesc`	Assign lower IDs to larger islands
`Random`	Assign IDs in a stable random order based on the seed

How to use

Connect it after Region Merge Small or Region Remap to process islands that remain disconnected under the same ID individually.

Use Wrapped connectivity when preserving wrapped connections for a tile. Use the default Visible connectivity when each visually separate island should be extracted as its own mask.

This node works well with generators such as Region Noise and Image To Regions, where the same ID can appear in several disconnected locations. If Region Mask selects several locations at once, split them into per-island IDs here.

summary is a review Map. Use regions for downstream region processing, or preview to inspect the result as an image.

Input Ports

Output Ports