Custom UI 101 - FunkinModdingPlus/ModdingPlus GitHub Wiki
Introduction
Making custom notes aren't working right now but you can add death notes (or existing custom notes) and other types of notes with a program called "Funkin vortex" The program's readme sums everything up nicely
Funkin Vortex
"Usage: Keys 1-8 Place notes, and if you hold control while pressing a button and a note is there, it selects it. Moving the strumline with Up Arrow and Down Arrow while selecting a note sets its sustain. You hit escape to stop selecting. On the right there is also a menu which includes all the data shit, which works basically the same as base game one. You have to select it to edit notes (duh)
You can also hit the right/left arrow keys to edit the snap. This determines where you can move your strumline. The Q key cycles the note types. Current Supported notes are: Normal, Lift, Mine, Death. Drain is planned to be added, and is already added to modding plus code.
Hit Space to play (which probably crashes if no audio is loaded)
One difference is that it includes all notes at the same time. This lags a bit but i think it helps visualize sustains better and shit."