Region Merge Small

Name	Type	Description
領域 regions	RegionMap Required	小領域を統合する RegionMap です

Name	Type	Description
領域 regions	RegionMap	小領域統合後の RegionMap です
プレビュー preview	Image	小領域統合後の色分け確認用画像です
ラベル labels	Map	Inspector に重ねるIDラベル位置です

Parameters

Name	Type	Default	Range	Description / Options
最小面積 min_area	Int	4	1–4294967295	この面積未満の領域を隣接領域へ統合します
最大反復 max_passes	Int	4	1–16	小領域統合を繰り返す最大回数です
統合先 target	Enum	LongestBorder	—	統合先の選び方です接触辺優先`LongestBorder` もっとも長く接している隣接領域へ統合します大きい隣接`LargestNeighbor` もっとも大きい隣接領域へ統合します
シード seed	Int	1	0–99999	プレビュー色に使うシードです
ID表示 show_ids	Bool	false	—	Inspector のプレビュー上に領域IDラベルを表示します

Overview

A cleanup node that absorbs fragment regions that are too small into their neighbors. Generated regions often contain a few-pixel fragments that make the image look noisy when filled directly. Insert this between the generator and region_fill to clean up the surfaces.

Category: Generate / Region / Edit
Use cases: reduce small fragment regions so fills, boundaries, and masks are easier to work with

Usage tips

Its standard position is immediately after generation: region_cells (or another generator) → region_merge_small → region_fill. It is nearly essential after region_noise, which readily produces fragments.
min_area is a pixel count. Start with the default, which removes areas smaller than 4, enable ID display, and raise it while inspecting the result.
Excessive merging also removes the character of the surfaces. The trick is to stop once the noise blends into its surroundings.

Related nodes

region_cells / region_noise / region_voronoi — generators that can produce fragments
region_fill — color the cleaned regions
region_split_islands — the reverse operation, separating islands
region_filter — select regions by conditions

Merge target

Value	Description
`LongestBorder`	If a neighboring stable region meets the minimum area, merges into the one sharing the longest boundary. If all neighbors are small, first merges small regions together.
`LargestNeighbor`	Merges into the largest adjacent region.

How to use

Connect nodes as in Region Cells.regions -> Region Merge Small.regions -> Region Fill.regions.

Raising min_area reduces the number of small fragment regions. Applying it too strongly also removes surface detail, so enable ID display and adjust while checking the merged result.

If the input RegionMap loops horizontally or vertically, the node also treats opposite edges as adjacent when selecting merge targets. A small region at a seam in tiled material can therefore merge naturally into the region on the opposite side.

min_area is a pixel area. Raising it increases the number of merge candidates, but the goal is not to turn everything into large masses; it is to blend overly small noise into its surroundings. Use LargestNeighbor for strong absorption into large surfaces, or the default LongestBorder to preserve a natural boundary flow.

Input Ports

Output Ports