What a blob autotile is
A terrain like grass on dirt needs a different tile for every way its neighbors can sit around it: an edge on the left, a corner at the top right, a thin strip, a lonely island. Counting all eight neighbors, there are 47 different shapes. With all 47 drawn, an engine can pick the right one automatically while you paint. That set is called a blob tileset, and drawing it by hand is a day of careful pixel work.
Two ways to build it
From two textures. Choose a terrain and a background from the built-in pixel materials or drop your own seamless textures. Shape the edge with the sliders. Edge inset sets how far the background shows into a tile at an edge. Ragged edge breaks straight lines into a natural shoreline that still lines up from tile to tile. Outline and shadow give the terrain depth. From an RPG Maker A2 tile. RPG Maker draws autotiles as a small 2 × 3 block and builds every shape from quarter tiles. Drop one and the tool expands it into the full 47 tiles any engine can use.
Using it in Godot 4
Put the PNG and the .tres file in the same folder of your project and open the TileSet on a TileMapLayer. The terrain is already set to Match Corners and Sides with every peering bit filled in. Pick the terrain in the Terrains tab and paint.
Using it in Tiled and RPG Maker
In Tiled, open the .tsx file. It has a mixed Wang set, so the Terrain Brush paints with the right tiles. For RPG Maker MV and MZ, use the A2 block exported at 48 px tile size and paste it into your A2 sheet.
Test before you export
The map at the top uses the tiles as you change them. Paint, erase, roll a new island and look for seams or shapes that read wrong. Everything runs in your browser. Your textures are not uploaded.