This module is not polished and I do not plan on adding features or fixing bugs. It is here as the successor of Terpy which was an OOP oriented approach to this problem of changing many objects’ transparency at the same time. This one is more performant and easier to use. Hopefully you find it useful. Please change it for whatever use case you need.
Model link: https://create.roblox.com/store/asset/18967249808/ChangeTransparency