Hello Julian, I have done a wind chime there is 2-3 years ago with PD/GEM/PMPD. I used PHP to get on the web the value of direction and force of wind in differents cities in Europe. Here a link for a video without sound (i remove it from the export) : http://djrayban2.free.fr/Movie/windChime.mov ++
Jack Le 8 août 08 à 12:16, cyrille henry a écrit : > hello, > > > Mark Sexton a écrit : >> Hi Julian >> Building a physical model of a wind chime might be easier than you >> think, if >> you use modal or banded waveguide approaches to physical modelling >> rather >> than the brute force approach of pmpd. > > pmpd aim to model the movement, not the sound. > the hamer and the tube of a simple wind chime could be modeled with > about 10 masses. > To create a physical model of the sound is very different. > but you need both to model the wind chime. > > Cyrille > > > > > > > >> >> If you think of the wind chimes should as stiff bars, banded >> waveguides >> would be ideal and are much more computationally efficient to >> implement than >> brute force approaches: a resonant filter and delay per mode you >> want to >> synthesis. I'd recommend perhaps starting with a simple modal >> implementation using filters and build up from there. This paper >> gives a >> good introduction: >> http://www.cs.ubc.ca/~kvdoel/publications/modalpaper.pdf >> >> >> If you're not familiar with modal synthesis and banded waveguides >> there's >> plenty of information online and Perry Cook's book gives a good >> overview of >> a range of approaches to modelling. >> http://www.cs.princeton.edu/~prc/AKPetersBook.htm >> >> Some starting hints if you want to go down this route: >> >> 1. Create an impulse: a buffer of noise or single sample impulse >> 2. Feed this into perhaps 5 band pass IIR filters with a very >> narrow Q, >> these will provide your resonant modes for each chime. >> 3. The frequencies of these filters will probably be non-integer >> multiples >> of the fundamental, eventually you can get these by analysing an >> actual wind >> chime, but if you wanted to build a proof of concept now then >> these are >> typical modes of an aluminium bar (you can find further modal >> frequency >> ratios in the Csound manual): >> [1, 2.756, 5.423, 8.988, 13.448, 18.680] >> 4. Scale the outputs of each of the resonant filters as >> appropriate, this >> should be straight forward once you've done an audio analysis of >> your wind >> chime. >> >> At this point you have a simple resonating model of a wind chime. >> >> 5. Perhaps replace the impulse: you can remove the resonant >> components of >> your wind chime recording and this will leave you with the >> original noise >> impulse. Using this to trigger your model should help improve >> realism. >> 6. Create a banded waveguide version, by adding feedback delays >> for each >> mode. (have a read of this paper and a look at Fig. 4): >> http://soundlab.cs.princeton.edu/publications/1999_icmc_bar.pdf >> >> There's a few further tweaks and improvements that can be done, but >> something along these lines should give a good result, be fairly >> easy to >> implement and run more efficiently than brute force. >> >> Happy to chat more on or off list on the physical model side or >> algorithmic >> composition side, but you may find it easier than you thought once >> you get >> going. >> >> >> All the best >> >> Mark Sexton >> Senior Lecturer >> MSc Computational Sound >> University of Portsmouth >> >>> Message: 2 >>> Date: Thu, 7 Aug 2008 12:30:51 +0100 >>> From: "Julian Brooks" <[EMAIL PROTECTED]> >>> Subject: [PD] physical modelling/general pd - mentor/tuition sought >>> (money offered) >>> To: <[email protected]> >>> Message-ID: <[EMAIL PROTECTED]@virgin.net> >>> Content-Type: text/plain; charset="us-ascii" >>> >>> Hi all, >>> >>> >>> >>> I have a 12 month project as part of a masters degree, where I >>> wish to build >>> a physical model of a wind chime. I then want to use the >>> interface to play >>> some of my indeterminate compositions. I was going to attempt it >>> for my >>> undergraduate degree but realised that it was far too complex for >>> the >>> available time that I had then. >>> >>> >>> >>> I have been using pd for a few years now, list lurking, working >>> through >>> basic examples, building simple tools, using other peoples >>> patches etc. But >>> this is too complex for me to do on my own. At my uni there >>> isn't anyone >>> with better skills than me and I don't know of any local fellow >>> patchers. >>> >>> >>> >>> Now as a musician, when I need to up my skills, I will look to >>> find some >>> lessons when I have got as far as I can on my own. >>> >>> >>> >>> So here goes... >>> >>> >>> >>> Is there anyone with an hour a week to spare who can offer some >>> mentoring/tuition for what we can deem to be the 'going rate'. I >>> am more >>> than happy to do this remotely/online, I'm sure there is a way we >>> can work >>> it out. There would be full credit given of course. >>> >>> >>> >>> Pmpd seems like the way to go with this. I have worked through the >>> examples, and, although I have my eye on what examples I would >>> presume to be >>> the best starting points, I'm struggling to get started. The >>> physical >>> modelling is where I first need to start but there's loads of pd >>> stuff I >>> would like to be able to work through with someone, so this could >>> be a (me >>> love you)longtime regular small money earner, if anyone's >>> interested. >>> >>> >>> >>> I am in Hebden Bridge, West Yorkshire, UK, by the way. Any >>> pd'ers local, >>> give us a shout. >>> >>> >>> >>> Best wishes to all, >>> >>> >>> >>> Jb >>> >> >> >> >> _______________________________________________ >> [email protected] mailing list >> UNSUBSCRIBE and account-management -> http://lists.puredata.info/ >> listinfo/pd-list >> >> > > _______________________________________________ > [email protected] mailing list > UNSUBSCRIBE and account-management -> http://lists.puredata.info/ > listinfo/pd-list _______________________________________________ [email protected] mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
