godot-demo-projects/plugins/addons/simple_import_plugin

Material Import Plugin Demo

This plugin demo shows how a custom import system can be added to the editor. In this case, it imports a material. For more information, see this documentation article: https://docs.godotengine.org/en/latest/tutorials/plugins/editor/import_plugins.html

In the editor, try opening test.mtxt. Godot will recognize it and import it as a material because of this plugin.