[PD] trying to test 'pdp library and 'pdp_scan~'

[cyrille henry]

Le 16/01/2024 à 17:12, Alexandre Torres Porres a écrit :
> 
> Em ter., 16 de jan. de 2024 às 05:08, cyrille henry <ch at chnry.net <mailto:ch at chnry.net>> escreveu:
> 
>     Hello,
>     If you want to try scann synthesis, I suggest to try pmpd. specially example 47.
> 
> 
> Running this in Extended now, it looks amazing. Do we really need Gem though?

You need Gem to run this pmpd example, but you can easily adapt the patch to run it without Gem.

  I figure it is just for displaying the array which is also a model of a string, right?
yes, but since this string use 2d physical model (X and Y movement), you need 2 array to display masses displacement and it's not very friendly.

Perhaps one could use a Data Structure array instead?
yes, sure! This example was made before data-structure was a thing, but you can adapt it easily!

Or just nothing at all to just focus on the sound.
from my experience, for complex movement and shape of the string, having a visualisation help a lot. But it really depend on the way you play with it.


By the way, how do we set the frequency in your example? It seems fixed.

This is Pd, of course you can change the frequency! just adapt the patch to do whatever you want!!!
The patch is very simple : everything is obviously in [pd corde] (sorry for my french). [pd sound] is where the masses position are put on a table. [pd table_read] is where the tableread4~ object are located. You just have to change the phasor frequency...

> 
> As for pdp, it seems it tries to use the webcam or video sources and I don't understand why.
> 
> In fact I know nothing about scanned synthesis and I just ran into it by accident when reading about vector synthesis in wikipedia, and I even read the original paper but I couldn't figure it out much yet.
> 
> It sounds at first some kinda of wavetable synthesis but it is clearly physical modeling, right?

well. the article describe it as :
"The essence of scanned synthesis is to use a slowly
vibrating object whose resonant frequencies are low
enough so the performer can directly manipulate the
object's vibrations by motions of his body and to scan
(measure) the shape of the object along a periodic path by
a periodic scanning function whose period is the
fundamental frequency of the sound we wish to create."

So, yes, a wavetable synthesis with "slowly" updated table by an algorithm that you can interact with.


According to this definition, pdp_scan~ is not really a scann synthesis. But it's not very far, since it scann an array at sub-audio frequency.

The only example in the article is about a string, but one can imagine lot's of different topology of the physical model, lot's of different way to interact with the model, and lot's of different way to "play" the shape of the model...


> 
> Would love to dig more in it and provide an external myself but it looks quite complex...
all you need to explore scann synth is the pmpd lib and tabwrite / tabread~
A scan synth external will be more limited that what pmpd + pd can already offer.


Cheers
c

> 
> thanks
> 
> 
>     cheers
>     c
> 
> 
>     Le 15/01/2024 à 22:45, Alexandre Torres Porres a écrit :
>      > When reading about 'Scanned synthesis' in https://en.wikipedia.org/wiki/Scanned_synthesis <https://en.wikipedia.org/wiki/Scanned_synthesis> <https://en.wikipedia.org/wiki/Scanned_synthesis <https://en.wikipedia.org/wiki/Scanned_synthesis>> I see about the [pdp_scan~] external from 'pdp', but I can't use it... I can still try extended in my machine and it didn't really work back then, I get
>      >
>      > Applications/Pd-extended.app/Contents/Resources/extra/pdp/pdp.pd_darwin, 10): Library not loaded: /usr/X11R6/lib/libX11.6.dylib
>      >    Referenced from: /Applications/Pd-extended.app/Contents/Resources/extra/pdp/pdp.pd_darwin
>      >    Reason: image not found
>      > pdp: can't load library
>      >
>      > Purr Data can't load it either.
>      >
>      > The 'pdp' version in deken (0-0extended) doesn't work either and all print the same error.
>      >
>      > I wanted to check this object out, does anybody know where the source lives and if we can try and compile it?
>      >
>      > cheers
>      >
>      >
>      >
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