W3C home > Mailing lists > Public > public-audio@w3.org > July to September 2013

Re: [web-audio-api] (AudioPannerNodeUnits): AudioPannerNode units are underspecified (#135)

From: Olivier Thereaux <notifications@github.com>
Date: Wed, 11 Sep 2013 07:29:51 -0700
To: WebAudio/web-audio-api <web-audio-api@noreply.github.com>
Message-ID: <WebAudio/web-audio-api/issues/135/24244436@github.com>
> [Original comment](https://www.w3.org/Bugs/Public/show_bug.cgi?id=17411#4) by Chris Rogers on W3C Bugzilla. Tue, 04 Dec 2012 18:34:46 GMT

(In reply to [comment #4](#issuecomment-24244429))
> (In reply to [comment #3](#issuecomment-24244425))
> > Sorry Marcus, I wasn't clear about that part.  The doppler effect uses the
> > .speedOfSound attribute in conjunction with the velocity vectors for both
> > the AudioPannerNode and the AudioListener.  These velocity vectors are in
> > meters/second and are independent of the units used for position and
> > orientation.  This is taken directly from the OpenAL specification.
> 
> I still don't understand why we need to have a unit at all (I see nothing in
> the algorithm that depends on actual units). Could it not be unit-less, and
> work just as it is? It would be confusing (IMO) to force the usage of m/s
> for some vectors, and then let people use whatever they want (e.g. inches or
> miles) for other vectors.
> 
> I'd personally prefer an all-or-nothing solution: either all vectors are in
> m and m/s, or they are all in [custom] and [custom]/s, or possibly even
> [custom_length] and [custom_length]/[custom_time] (like miles/h).

I'm just taking this interpretation from the OpenAL specification.  But you're right, we could just say that .speedOfSound is the speed in arbitrary units which are also used by the velocity vectors.  These units are independent of the units used for position and orientation vectors.

How does that sound?

---
Reply to this email directly or view it on GitHub:
https://github.com/WebAudio/web-audio-api/issues/135#issuecomment-24244436
Received on Wednesday, 11 September 2013 14:35:33 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:50:11 UTC