Unity 2019.2 introduced new feature for adding secondary textures in Sprite editor. If you want to use it in your current project with lot of sprites, it can result into tedious manual work. In this tutorial I will show simple script, that can do all the hard work for you.
In previous tutorial we created local package for sharing common code between multiple Unity projects. Unfortunately, when this package is displayed in Visual Studio, it is missing original structure of folders. All files are put onto a big pile. In this tutorial we will fix it.