This is a Java program I made to make it easier to Godot users and anybody who wants to generate a tileset from 3 basic tiles without having to draw every single one of them.

You can just download the released jar file, launch it, select your png file with the 3 basic tiles in this order:

Here are the samples and the results generated from those samples

Tiles:

Results:

Tutorial:

First: You open the file choosing dialog box

Second: You navigate to the nanotiles you created

Finally: You press generate and I hope it suits your needs

⚠️ Generated image file is saved into the directory that the jar file is! Keep making awesome games!: