[x3d-public] X3D agenda 2 OCT 2020: shadows, audio concepts

[Michalis Kamburelis]

About

"""
For the new Shape component and X3D4 support of glTF, we think that
- all the node signatures and field definitions work,
- prose definitions need some polishing by Dick and Don,
- good progress achieved on validation and examples.

Question: do we now support shadows satisfactorily?  Are any more
fields needed for scoping (turning on/off) shadows in a scene?
"""

Just to make it clear, *nothing* in my work on PBR (and related
material upgrades in X3Dv4) relates to shadows. They are an
independent topic, and the current X3Dv4 neither hinders nor advances
this topic, compared to X3D 3.

Various browsers (and, more generally, rendering engines independent
of X3D) present different approaches to shadows.

1. We can think of adding basic support for shadows to the light
sources. We need to be careful though about adding something limited,
that actually covers a wide range of possible shadows implementations
(shadow maps and shadow volumes, with many possible variants),
otherwise browsers would have to ignore it / misinterpret to "fit"
into their wildly different shadows algorithms. I would start with
simple

    SFBool shadows FALSE # enable/disable shadows from this light

    SFFloat shadowsPriority 0 # in case browser supports only a
limited number of shadow-casting lights, it should prioritize the
light sources with largest priority

2. I am not sure whether adding stuff for shadows is a priority in
X3Dv4, to be honest. It's not critically problematic that shadows
stuff remains in browser-specific extensions. Their details would
remain in browser-specific extensions anyway, due to varying
possibilities in varying implementations.

    I mean, it would be nice to have something about shadows in X3Dv4.
But I think we already spent a long time making X3Dv4, and we still
have a long time to review it :)

Regards,
Michalis

pt., 2 paź 2020 o 16:06 Don Brutzman <brutzman at nps.edu> napisał(a):
>
> Review meeting today.
>
> [1] Web3D Teleconference Information
>       https://www.web3d.org/member/teleconference-information
>
> > Please use the following link for all Web3D Consortium Meetings.
> >
> > Join URL: https://us02web.zoom.us/j/81634670698?pwd=a1VPeU5tN01rc21Oa3hScUlHK0Rxdz09
>
> ---
>
> 1. Web3D Outreach and Web3D 2020 Conference
>
> a. X3D in a Box, Anita
>
> [1.0] ref
>
> b. Conference registration is FREE and open, schedule going online over next week
>
> [b] Web3D 2020 Conference registration
>      https://web3d.siggraph.org
>
> With free registration, and with all conference content going online, we may keep registration open... indefinitely.  Interesting opportunities to think about.
>
> ---
>
> 2. X3D Shadows
>
> For the new Shape component and X3D4 support of glTF, we think that
> - all the node signatures and field definitions work,
> - prose definitions need some polishing by Dick and Don,
> - good progress achieved on validation and examples.
>
> Question: do we now support shadows satisfactorily?  Are any more fields needed for scoping (turning on/off) shadows in a scene?
>
> ---
>
> 3. X3D4 Audio and Sound
>
> Excellent progress towards finalizing the Sound component.
>
> [3.1] [x3d-public] X3D4 Sound meeting 30 SEP 2020: Web3D 2020 preparations, Gain and ChannelSelector nodes,
>        avoiding channel indices via parent-child MFNode field relationships
>        https://www.web3d.org/mailman/private/x3d-public_web3d.org/2020-October/013721.html
>
> [3.2] [x3d-public] X3D4 Sound meeting 30 SEP 2020: (part 2)
>        https://www.web3d.org/mailman/private/x3d-public_web3d.org/2020-October/013722.html
>
> Definition for review:
>
> > We need an X3D definition for "audio graph" term.  Suggested draft:
> >
> > * An /audio graph/ is a collection of nodes structured to process audio inputs and outputs
> >    in a manner that is constrained to match the structure allowed by the Web Audio API.
> >
> > We have defined all of the new nodes (beyond Sound, Spatial Sound and AudioClip) to match the terms and capabilities of Web Audio API.
> >
> > This means a collection of the new nodes, that together can create and process sound, produce a result that needs to inputs for our Sound and SpatialSound nodes.  In combination, the output is similar to a computational version of a simple AudioClip node.  It is a source, computationally created, whereas the AudioClip is a prerecorded version.
>
> Audio and sound concept summary:
>
> > ========================================
> > Basic stages for flow of sound, from source to destination:
> >
> > a. Sources of sound (perhaps an audio file or MicrophoneSource, perhaps signal processing of channels in audio graph),
> >
> > b. X3D Sound or SpatialSound node (defining location direction and characteristics of expected sound production in virtual 3D space),
> >
> > c. Propagation (attenuation model, may be modified by AcousticProperties based on surrounding geometry),
> >
> > d. Reception point (avatar "ears" or recordable listening point at some location and direction, that "hears" result, with left-right pan and spatialization).
> > ========================================
>
> ---
>
> Be there or be square!  8)
>
> all the best, Don
> --
> Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
> Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
> X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman
>
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