Ok let's say your knob is called knbVelocity and you have a reference to it in onInit
const knbVelocity = Content.getComponent("knbVelocity");In the onNoteOn callback you can use the knob's value to set the Message's velocity.
Message.setVelocity(knbVelocity.getValue());Ideally this should be done using two MIDI processors. The Interface script should be deferred - which means you won't be able to use setVelocity there. A second MIDI processor should be used for setting the velocity, and the knob on the GUI should be connected the knob of the second MIDI processor.
