I did initially add MPE to the Soundplane client, but after that, Randy added it to the official client.
MPE is now supported by lots of controllers Rise, Linnstrument, Eigenharps, Soundplane and Continuum… and I’m sure the new ones planned will support.
these are kind of marketing terms by Roli, as they existed already on all other controllers…
Strike = (note on) Velocity
Glide = X axis implemented as Pitchbend
Slide = Y axis implemented as CC 74
Press = Z axis implemented as (channel) Pressure
Lift = release Velocity (most commonly left out attribute, but nice when exists)
(I really wish Roli would avoid trying to ‘take over’ MPE… or pretend its there invention, its not its basically a variant as Haken have used from the beginning, and was Roger Linns idea to extend into a standard)
spec is here, but honestly the spec makes it sound more complicated than it really is… and currently most controllers/synths only use it in the ‘basic’ form…
(I think most developer are ‘dipping there toes in the water’ at this stage)
MPE in its basic form, each touch is put on a separate midi channel , 2-16 (assuming no splits, which is the most supported version) , midi channel 1 is reserved for global messages e.g. say a mod wheel (cc1) or breath controller (cc2)
It has a couple of NRPNs, which which a client can use to ‘enter MPE mode’, and also set the pitchbend range (the default should be 48 semitones) , but whilst these are sent by all the controllers, many clients (synths) don’t bother/ignore with them, finding it easier just to have a mode switch and independent PB range control.
(actually the NRPN approach is flawed… since it assumes the controller will be switched to MPE mode after then synth has started, but of course, a musical might already have the controller in MPE then start the synth… so the synth wouldn’t get the NRPNs)
I implemented MPE on Axoloti (and Reaktor/Max), and have used on various synth patches I’ve created… the mapping is pretty trivial assuming the parameters you want to map are controllable per voice.