[x3d-public] X3D agenda 3 MAR 2022: announcements, Mantis issues, NurbsSweptSurface NurbsSwungSurface, planning

Fri Mar 4 03:59:05 PST 2022

1. As for SpotLight:

    I made images where I tested various values for beamWidth, with
the intuitive goal to make "beamWidth close, but not equal, to
cutOffAngle". To show penumbra, but make it a narrow penumbra.

    They are available on
https://github.com/michaliskambi/x3d-tests/tree/master/beam_width_test_images
. (You can download whole repo
https://github.com/michaliskambi/x3d-tests to easily get them on your
disk.)

    In all cases, cutOffAngle = pi/4 . As I proposed on last meeting,
I think cutOffAngle = pi/4 , as default, is good: it matches previous
X3D >= 3.2, it matches glTF. It it *wider* than probably most real
spot lights, but I feel this is just something authors should adjust.

    So I just tested 4 possible beamWidth values:

    - pi * 1/8 (0.125)
    - pi * 1/6 (~0.166)
    - pi * 3/16 (0.1875) (I think Vince proposed this already at one
past meeting?)
    - pi * 7/32 (0.21875)

    I tested them in various environments. I deliberately wanted to
see them in some "real", textured, non-trivial 3D level, not just in
artificial empty 3D scene -- to judge them.

    Action on the meeting: I propose we just choose one the above 4
beamWidth values. And then it's done. We fix X3D spec with cutOffAngle
= default pi/4, beamWidth = default we choose today,

2. On the meeting, I'd also like to briefly mention Khronos glTF certification:

    https://www.khronos.org/3dcommerce/certification/

    https://www.khronos.org/3dcommerce/certification/certified-viewers/

    https://github.com/KhronosGroup/3DC-Certification

    https://github.khronos.org/3DC-Sample-Viewer/

    The process is already open to participants. Although they also
plan to extend it, with more test-cases, with precise light
environment definitions in glTF.

    I want to test Castle Game Engine / view3dscene with it :) Aside
from a gain for Castle Game Engine / view3dscene, this will also be a
gain for X3Dv4: we should prove this way that X3Dv4 nodes can really
100% express what glTF specification describes.

    The certification covers features from glTF core spec + glTF
punctual lighting extension + (right now) there is a practical
requirement on browser to have a specific environment lighting
built-in. So I believe we're close to "just having it" in Castle Game
Engine / view3dscene. And it is connected with EnvironmentLight in
Castle Game Engine / view3dscene, which is something I want to finish
soon anyway.

3. We talked at one point about making particle system emitter an X3DChildNode.

    I looked at spec,
https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/components/particleSystems.html
, and this would be wrong. The current state of spec is good:
X3DParticleEmitterNode is supposed to be placed within
ParticleSystem.emitter field. And ParticleSystem is a X3DShapeNode
(which is already X3DChildNode).

    So, let's not change anything here. It wouldn't be valid to allow
X3DParticleEmitterNode directly inside some grouping nodes.

Regards,
Michalis

pt., 4 mar 2022 o 08:05 Brutzman, Donald (Don) (CIV)
<brutzman at nps.edu> napisał(a):
>
> 1.       Regular Friday meeting Friday 08-0900 pacific, call information follows.  All inputs and participation welcome.
>
>
>
> Videoconference Connectivity:
>
> https://us02web.zoom.us/j/81634670698?pwd=a1VPeU5tN01rc21Oa3hScUlHK0Rxdz09
> https://zoom.us/j/148206572  Password 483805
> https://www.web3d.org/member/teleconference-information
>
>
>
> 2.       A lot of great things are happening!  Announcements welcome.   8)
>
>
>
> https://www.web3d.org/x3d4
> https://www.web3d.org/x3dv4-highlights
>
>
>
> 3.       We have a few pending Mantis issues (e.g. Spotlight default values) that maybe can be resolved.
>
>
>
> https://www.web3d.org/member-only/mantis/view_all_bug_page.php
>
>
>
> X3D4 Architecture
> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/Architecture.html
>
>
>
> 4.       Problem:  I’m not sure that NurbsSweptSurface and NurbsSwungSurface are well defined.
>
>
>
>
>
> X3D4 Architecture, 27 Nurbs Component, 27.4.11 NurbsSweptSurface
> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/components/nurbs.html#NurbsSweptSurface
>
>
>
> X3D4 Architecture, 27 Nurbs Component, 27.4.11 NurbsSwungSurface
> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/components/nurbs.html#NurbsSwungSurface
>
>
>
> Got better figures?  No actual NURBS appear to be in the figures, just spines…
> Got examples?
> First-pass discussion: what needs to be done to improve these?
>
>
>
>
>
> 5.       Planning our next meetings
>
>
>
> 11 MAR 2022, achieving WebXR support for X3DOM
>
> https://www.x3dom.org
>
>
>
> 18 MAR 2022, do we have complete implementations of X3D Geospatial Component?
>
> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/components/geospatial.html
>
>
>
> 6.       and…   wait for it…   Have Fun With X3D!     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 https:// faculty.nps.edu/brutzman
>
>
>
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