Re: [Algorithms] Spherical harmonics for room acoustic modelling

[Deano <de...@ra...>]

Search for wave tracing in the literature. For acoustics, wave behavior is
vital unlike most lighting equations, as such you need to model waves
transfer and also for most audio surfaces unlike visual surfaces they are
not 100% reflective and so subsurface scattering is way more important.

 

There is some interesting work out there, including at least one GPGPU
real-time system.

 

Deano

 

From: Oscar Forth [mailto:os...@tr...] 
Sent: 17 July 2010 20:10
To: Game Development Algorithms
Subject: [Algorithms] Spherical harmonics for room acoustic modelling

 

I will admit first off I don't have a great knowledge of things like
Pre-computed Radiance Transfer but I was having a chat with a colleague
recently on how audio research lags behind video research in gaming.

 

One idea that we were talking about is using spherical harmonics in a
similar way to PRT to do some sort of Pre-computed Acoustic Transfer.

 

Basically you'd add a new material type to a room that would give you the
sound reflectivity of a given surface.   You could then use the same
techniques (obviously calculated with something like OpenCL) to give you a
good model of how sound moves round a room.  Has anyone done anything like
this?

 

It kinda struck me that you'd be able to model things like acoustic
reflections off a hard surface, acoustic dispersion from soft surfaces as
well as getting things like occluders thrown in as a bonus.  Add to that you
could use the same techniques as are used for translucent surfaces to model
sound transfer through a surface and the slight bending of audio round
corners.

 

Are there any papers on the subject at all?  It struck me as something worth
finding more out about as it would give the ability to create truly rich
sound scapes with very little actual fiddling needed to get it right.  You'd
just pass the model through your PAT calculation engine then play sounds and
get them playing right.

 

Any thoughts?

 

Cheers!

 

Oscar