Being able to create and optimise textures is a very useful skill when developing for Minetest. There are many techniques relevant to working on pixel art textures, and understanding these techniques will greatly improve the quality of the textures you create.
Detailed approaches to creating good pixel art are outside the scope of this book, and instead only the most relevant basic techniques will be covered. There are many good online tutorials available, which cover pixel art in much more detail.
Using the Pencil
The pencil tool is available in most editors. When set to its lowest size, it allows you to edit one pixel at a time without changing any other parts of the image. By manipulating the pixels one at a time, you create clear and sharp textures without unintended blurring. It also gives you a high level of precision and control.
Textures used for nodes should generally be designed to tile. This means when you place multiple nodes with the same texture together, the edges line up correctly.
If you fail to match the edges correctly, the result is far less pleasing to look at.
Transparency is important when creating textures for nearly all craftitems and some nodes, such as glass. Not all editors support transparency, so make sure you choose an editor which is suitable for the textures you wish to create.
Using a consistent color palette is an easy way to make your art look a lot better. It’s a good idea to use one with a limited number of colors, perhaps 32 at most. Premade palettes can be found at lospec.com.
MS Paint is a simple editor which can be useful for basic texture design; however, it does not support transparency. This usually won’t matter when making textures for the sides of nodes, but if you need transparency in your textures you should choose a different editor.
Aseprite / LibreSprite
Aseprite is a proprietary pixel art editor. It contains a lot of useful features by default such as color palettes and animation tools.
LibreSprite is an open-source fork of Aseprite from before it went proprietary.
GIMP is commonly used in the Minetest community. It has quite a high learning curve because many of its features are not immediately obvious.
When using GIMP, make sure to use the Pencil tool with the Pixel brush and a size of 1. It’s also advisable to select the “Hard edge” checkbox for the Eraser tool.