This is a C++ plugin/standalone program that makes rain sound in real time. It is tested as Unity Plugin (albeit some parameter interface does not work properly) and a standalone program. It should theorectically work as an VST3, if you compile it that way.
If you want to compile it, follow the instruction of another plugin I made JUCE VST3 Mixer and install juce. Use Projucer to load the .jucer file.
It was tested in VS2022.
This can also be compiled to be used as a Unity Native Plugin. This functionality is provided by JUCE. You probably need to write your own wrappers for the APIs if you wish to use this plugin in gameplay.
Mostly I composed the noises following the components from this Blog. The raindrop part is an improved version of Shaokang Li's raindrop generator. Overall, I like it. I listen to it when I sleep.
A demo showcasing the plugin with Unity Integration. See www.youtube.com/watch?v=s63pR9gFAVI If the above link does not work.