[X3D-Public] improved validation tests for sound nodes; add ability avoiding audio attenuation altogether

[Michalis Kamburelis]

Don Brutzman wrote:
> I've often thought we might benefit by having a way to just make a
> sound audible without having to worry about all this non-visible
> geometry (see attached slideset excerpt for some sense of how
> involved it can be).
>
> Why don't we add an initializeOnly field that allows an author to
> disable all attenuation?  This would seem to be essential for
> user-interface responses.  Putting some set of 4 extremely large
> values in for min/max front/back is error prone and not very
> intuitive.  How about the following backwards-compatible addition to
> Sound node:
>
> SFBool  []  attenuate TRUE
>
> If author sets attenuate="false" then all of the computational sound
> features are disabled and the clip simply plays as recorded.

I agree, such field would be useful.

As for view3dscene, we actually treat "spatialize" field just like you 
described above. So "spatialize FALSE" disables all 3D effects and the 
sound will play as-is.

Which is not exactly correct per the specification (that says that 
ellipsoid dimensions should still have an effect even spatialize=FALSE). 
But it's useful, just you describe --- a simple way to disable 3D sounds 
is often needed, e.g. for UI sounds. And it was natural to implement it 
that way too :)

Also, stereo sound files are never attenuated. They always behave like 
spatialize=FALSE for view3dscene. Because that's how OpenAL behaves, and 
it just makes sense (it's not obvious how you would attenuate 
multi-channel sound).

Michalis