Hi Ricky, Although out tools do amplitude scaling and provide different options for fall-off curves and the omni-towards-zero-trick, I would strongly urge you to add air-absorption, doppler and some sort of early late reflections to the signals. Rumsey (2001) has a nice description of the elements needed to build convincing depth perception.
My general experience is that the natural factors for everything (dB drop-off, air-absorption filter-coeffs and doppler speeds) need to exaggerated in order to sound natural, unless you simulate the entire acoustic environment, like the IRCAM Spat does for example. As for realistically simulating sources within the unit circle, that is an whole topic by itself, which has mathematically correct solutions (NFC, bound to specific decoder layout) and empirically working practical solutions. hth Jan - - Zurich University of the Arts Department of Music Institute for Computer Music and Sound Technology - - Jan Schacher Associate Researcher - Principal Investigator Swiss National Science Foundation - - Pfingstweidstrasse 96, P.O. Box, CH-8031 Zurich, Switzerland - - www.zhdk.ch www.icst.net On 12. Apr. 2015, at 11:09 PM, Dave Malham <[email protected]> wrote: > Thanks, Trond, I really, really should have remember the ICST stuff myself! > > Dave > > On 12 April 2015 at 20:44, Trond Lossius <[email protected]> wrote: > >> Hi, >> >> boids and flocking algorithms have been used in quite a few works >> developed at ICST in Zurich. I have the impression that often this has been >> done by implementing boids/flocking in OpenFramework, and sending OSC >> messages to Max, where ambisonic processing is done using the ICST >> ambisonic externals. You’ll find several publications on the topic here: >> >> https://www.zhdk.ch/index.php?id=icst_publications_main >> >> The ICST externals for Max using gain adjustments to emulate distance. >> When sources are located within the unit circle, the order of the encoding >> will be modified so that a source located at the very center will be omni >> only. >> >> Although not ambisonic, I would also look towards the work on >> spatialisation by John Chowning, and how he modifies gain, reverb and >> dry/wet balance to emulate distance. This is discussed in details e.g. in >> the book on computer music by Dodge and Jerse. A recent piece by John >> Chowning was presented in an outdoor setting during ICMS / SMC 2014 in >> Athens, and I have to say that I was deeply impressed with how he managed >> to create illusions of sound objects moving in space using only four >> speakers. >> >> Ircam Spat is a third option to check out. Spat can work with ambisonic as >> well as other spatialisation algorithms, and also emulates air filtering >> and reverb. >> >> >> Best, >> Trond >> >> >> >> >>> On 12 Apr 2015, at 18:35, Ricky Graham <[email protected]> wrote: >>> >>> Hi Dave, >>> >>> I guess I’d like to hear how others have mapped the output from boids to >> whatever ambisonic panner they’re using. I will have a look for the ICMC >> paper. >>> >>> While I have your attention, I can use ambilib~ as an example. Would you >> simply map the cartesian to polar output to the azimuth (phase) and >> distance (amplitude) parameters of your externals? >>> >>> I hope you enjoyed the croissants. >>> >>> Ricky >>> >>>> On Apr 12, 2015, at 12:00 PM, [email protected] wrote: >>>> >>>> Message: 4 >>>> Date: Sun, 12 Apr 2015 09:12:32 +0100 >>>> From: Dave Malham <[email protected] <mailto: >> [email protected]>> >>>> To: Surround Sound discussion group <[email protected] <mailto: >> [email protected]>> >>>> Subject: Re: [Sursound] Boids for Ambisonic Panning >>>> Message-ID: >>>> <CAPw+1zTGodgrsoYtKWhNe=DZVwMy8t1tV= >> [email protected] <mailto:CAPw+1zTGodgrsoYtKWhNe >> [email protected]>> >>>> Content-Type: text/plain; charset="utf-8" >>>> >>>> Hi Ricky, >>>> Boids has been around for a long time and I'm certain it's been >>>> used quite a few times in electroacoustic compositions - in fact, I >> seem to >>>> remember one of our students on the Music Technology course here at York >>>> doing so. Trouble is, I'm darned if I can remember his or her name >> (which >>>> will be no surprise to anyone who's been on that course - my apologies >> to >>>> the person concerned if they are reading this :-). Your best bet would >> be >>>> to look through the Proceedings of the ICMC from around '87 and maybe >> the >>>> Computer Music Journal. >>>> >>>> I'm not sure what you mean by "...difficult to scale in terms of >>>> distance". Are you referring to the mapping of the notional distances >> in >>>> the boid simulation to the things which we use perceptually to deduce >> the >>>> distance of a sound source? That's opening up an interesting can of >> worms! >>>> Do a search in the archives for "giant geese" to see the fun we had >> talking >>>> (arguing) about it last time. A lot will depend on wether the sound >> sources >>>> are "familiar" or not - we can easily tell that a thunder storm (or a >> jet) is >>>> distant or nearby because we are familiar with them as "perceptual >> objects" >>>> and can construe them within the acoustic space we are listening in but >>>> with constructed sounds that we are not familiar with we are stuck with >>>> "immediate" (and to some extent, unreliable) cues like direct to >>>> reverberant ratios, the pattern of early reflections, HF rolloff and >> maybe >>>> distortion (loud sounds have distortion which increases with distance). >> If >>>> he's currently on the list, I suspect Peter Lennox will jump in here and >>>> tell me I've got it all wrong :-). >>>> >>>> Anyway, I'm sure much/all of this is old news for you but I had to >> have >>>> something to occupy a Sunday morning whilst waiting for the croissants >> to >>>> warm up .... >>>> >>>> All the best.... >>>> >>>> Dave >>> >>> -------------- next part -------------- >>> An HTML attachment was scrubbed... >>> URL: < >> https://mail.music.vt.edu/mailman/private/sursound/attachments/20150412/08ac65b7/attachment.html >>> >>> _______________________________________________ >>> Sursound mailing list >>> [email protected] >>> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, >> edit account or options, view archives and so on. >> >> _______________________________________________ >> Sursound mailing list >> [email protected] >> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, >> edit account or options, view archives and so on. >> > > > > -- > > As of 1st October 2012, I have retired from the University. > > These are my own views and may or may not be shared by the University > > Dave Malham > Honorary Fellow, Department of Music > The University of York > York YO10 5DD > UK > > 'Ambisonics - Component Imaging for Audio' > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <https://mail.music.vt.edu/mailman/private/sursound/attachments/20150412/c17674f8/attachment.html> > _______________________________________________ > Sursound mailing list > [email protected] > https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit > account or options, view archives and so on. _______________________________________________ Sursound mailing list [email protected] https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on.
