Monday, September 26, 2011

Otomata + Monome * Supercollider

Last week I got a Monome and I've been playing with some Otomata stuff using a Supercollider implementation by Corey Kereliuk.
The first composition I put together was a simple, cheerful minimalist piece and one of the first things I've done using equal temperament (midi notes) in about 5 years.

20110918 Otomata by Backtrace

I started tweaking the code so that I could add more instruments (the above example has a percussive instrument and a sustained pulse-wave instrument) and having the cellular automata trigger a callback function when they hit a wall, instead of just triggering a synth. I could then load that callback function with whatever synths I wanted. I also started polling the instantiated Otomata object itself for global data (like the x,y positions of all the automata at a given moment) so I could use that for musical data. You can hear chord changes in this piece - I had the program I was using count the # of ticks that the sequencer routine was running and store these in a global variable, which I then used to cycle through a set of different scales.

After 4 days straight of playing with this stuff, I think you can sense the burnout setting in a little with this piece (at least that's how I felt about it - not that feel burned out creatively on Otomata, but that this is where my brain goes around 3 AM after playing with sounds all day):

20110922 Otomata by Backtrace

There are multiple instruments being triggered, some effect parameters (filter sweeps) being tweaked by the global state of the Otomata board. After recording this piece I decided it was time to clean up the code for it and try to get some useful, standalone application out of it.

I modifed the original class to a Proto (so I could tweak it at runtime, without having to recompile SC). I'm working on a Proto version of the Automaton class as well.

Musical information (scale, synths, starting pitch) was decoupled from the sequencer logic - scale and synth are now controlled via the synthFunc callback function and can be switched dynamically as the Otomata is running. See how synthFunc variable is added to the Automaton class in, and examples of its use in otomata.scd.

Methods to add and remove automata from a running otomata - ~removeOldest, ~removeNewest, and ~removeNth.

Global metadata about the otomata to give additional musical parameters across all of the automata - see the ~dSum, ~xySum, ~xSum, ~ySum. ~age attribute can be accessed to change values over time. I'd like to add similar attributes to each automaton, like age, # of collisions, # of wall hits, "dizziness" (# of right angle turns over time).

In the example code in otomata.scd I show how to use supercollider's function composition operator <> to attach multiple sound callbacks to 1 automaton. if you have 2 functions f(x) and g(x) then h = f<>g creates the function h = f(g(x)) - so whatever g returns is passed on to x. if you're chaining synth callbacks, the function should return the same "note" value that it takes.

Thanks to Corey for posting his code, and to Batuhan Bozkurt for designing the Otomata.

The code posted here is really meant as an example of how to use callback functions in SC and a couple of other techniques - but feel free to use it if you'd like. In the near future I'll post something that's a little more conceptually coherent.

No comments:

Post a Comment