[PD] Modular Switching/Matrix
derek at x-i.net
Tue Oct 24 14:59:45 CEST 2006
I can't seem to find the original post for this, hope I'm not missing
any important points!
> On Mon, 23 Oct 2006, Greg Surges wrote:
>> I'm a music composition/technology major at the University of
>> Wisconsin-Milwaukee, currently taking a course in PD, and also
>> studying it in private lessons.
That's really interesting! Sara Kolster and I just lectured at UW
earlier this year, and did a PD workshop at the Hotcakes Gallery. Who is
teaching PD there now?
>> I am wondering if anyone has any
>> experience with matrix-type switching, i.e. a modular system in which
>> any module can connect to any other module in any order.
Like Frank Barknecht mentioned, the IEM matrix objects are one way to
go. Otherwise, you could dynamically generate [send~] + [receive~] pairs
via named abstractions.
>> I also need the ability for the system to allow recursive patching.
Recursive patching can really cause problems in PD, since it relies
quite heavily on a specific order of operations to keep from getting
into DSP loops. Using [send~] and [receive~] pairs is one way around
this, since they automatically include a delay of one DSP block. But you
still have problems of a depth-first order of operations, so that if you
use oscillatorA to amplitude modulate oscillatorB (for example), and
oscillatorB goes on to modify some parameter of osciallatorA again, you
have to be very careful about where all these patches are depth-wise in
relation to each other. If one is "less deep" (i.e. fewer
subpatches/abstractions down) than the other, your feedback system will
not work. The first amplitude modulation will not occur because the
second modulation which starts the whole chain hasn't happened yet,
resulting in a no signal situation which would not occur in the analog
synthesis world AFAIK. I have not seen this issue addressed or
documented very well (aside from the warnings about depth first message
passing in Miller's examples), and I just recently ran into it myself
which trying to make a supercomplex self-modulating synthesizer. Let me
know if this does/doesn't make sense or apply to your work, and I'll try
derek holzer ::: http://www.umatic.nl
---Oblique Strategy # 160:
"Towards the insignificant"
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