How it works:
On the right you'll see an x-y plot, there are 128 discrete x-y pairs; each x has a bar you raise or lower by drawing on the plot, the height of the bar is the output of the MMap object (and can be negative).
On the left you can select where 'x' comes from. Which 'x' is being used is indicated by a yellow bar. The top tab selects different a few different modes of reading input, while the bottom tab assigns a modulation source for the modes that require one.
Two modes don't use the modulation source:
'Key' sets x as a function of what key you're pressing, i.e. C2 is 12 steps from C3, MIDI Note numbers 0 and 127 are the lower and upper bounds.
'Alternate' starts at 0 and moves to the next value each time a new note arrives.
In the case of polyphony, only one note is represented graphically (the lower or first played note) but the two notes will be calculated independently. For example if you have:
- *a maximum height bar followed by a negative maximum height bar
*MMap mapped to modulate the pan control of an oscillator
*and you play a 2-note chord in 'alternate mode'
Two modes work off modulation sources: Map smooth and map quantize. They are pretty similar*, and they require you to select a modulation source.
LFOs are centered, a sine wave will move right of center, left of center over the course of a single cycle.
Envelopes translate whatever amplitude would be generated at a specific point in time to 'x'. E.g. an envelope with a moderate attack and full sustain would move from 0 to 127 and hold there.
The rest of the options behave pretty much as you would expect. Gate is really boring
* They just deal with the fractional x values modulation sources can create a little differently. Smooth interpolates the two y values given from the closest x values while quantize just rounds off the x and returns that y.
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Seems like there is a lot of voodoo you can pull with this object. Being able to draw directly on the graph makes it really accessible to quick experiment. So even if you're doing something that could be done differently through some other modulation scheme, using MMap can be much quicker and more natural to think about. So it's a cool, quite 'Zebra'-esque tool.
[edit] Another cool thing about the graphical display of this, is you can get visual feedback on what a modulation source is doing. For example, you could set it to modulate some parameter with a magnitude of zero, and use it just to display where an LFO is jumping.
