[x3d-public] X3D working group minutes 21 JAN 2022: Mantis issue resolutions for gllTF

[Brutzman, Donald (Don) (CIV)]

Thanks 1M Michalis. When you are satisfied, absent any further comment, I expect we will be resolving most or all remaining glTF2 issues for X3D4 architecture.

[p.s. link obfuscation removed from this reply]

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

-----Original Message-----
From: Michalis Kamburelis <michalis.kambi at gmail.com> 
Sent: Tuesday, January 25, 2022 8:17 PM
To: Brutzman, Donald (Don) (CIV) <brutzman at nps.edu>
Cc: X3D Public Mailing List (x3d-public at web3d.org) <x3d-public at web3d.org>
Subject: Re: [x3d-public] X3D working group minutes 21 JAN 2022: Mantis issue resolutions for gllTF
Don,

I rechecked now the glTF specification (both the latest online version on [...] and the PDF send to ISO review (they should be equivalent)). I confirm there are no lights in glTF specification.

glTF adds lights only in extensions:

1. punctual (point, spot, directional):
[...]

2. EXT_lights_image_based (older approach, something similar to our
EnvironmentLight):
[...]

3. KHR_lights_environment (newer approach to something similar to our EnvironmentLight, in progress):
[...]

So for X3D EnvironmentLight, we don't have something to "directly copy" from glTF at this point. I observe both EXT_lights_image_based and KHR_lights_environment development,  and will try to align our EnvironmentLight with them as best as reasonably possible. Looks like KHR_lights_environment is more advanced, but also it is for now only a PR in-progress.

Regards,
Michalis

wt., 25 sty 2022 o 23:52 Brutzman, Donald (Don) (CIV) <brutzman at nps.edu> napisał(a):
>
> Thanks Michalis, sounds great.  How is this:
>
> Let's confirm no lights are defined in the recent Khronos ISO PAS submission for glTF.
>
> If indeed there is no definition in glTF for EnvironmentLight, then we can issue a "last call" for functional review by X3D implementers and authors, then finalize the X3D4 node definition.
>
> Group review and timeline to follow on Friday.  We can schedule a glTF review meeting after responses to that node are is sorted out.
>
> 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
>
> -----Original Message-----
> From: Michalis Kamburelis <michalis.kambi at gmail.com>
> Sent: Friday, January 21, 2022 11:48 AM
> To: Brutzman, Donald (Don) (CIV) <brutzman at nps.edu>
> Cc: X3D Public Mailing List (x3d-public at web3d.org) 
> <x3d-public at web3d.org>
> Subject: Re: [x3d-public] X3D working group minutes 21 JAN 2022: 
> Mantis issue resolutions for Text layout and glTF, IMPORT/EXPORT, 
> Projects Wish List, Blender
>
> Hi,
> Answers inline:)
>
> pt., 21 sty 2022 o 18:31 Brutzman, Donald (Don) (CIV) <brutzman at nps.edu> napisał(a):
>
> > Request review of major omnibus issue by Michalis:
> >
> > Mantis 1269 glTF physically based rendering PBR, advanced material 
> > textures and lighting
> > https://www.web3d.org/member-only/mantis/view.php?id=1269
> >
> > Our assessment is this is nearly complete, EnvironmentLight needs to be confirmed stable, we can reduce this from major (no blockers) and confirm we are on endgame.  Since Khronos has formally submitted glTF as Publicly Available Specification (PAS) to ISO, we should be able to confirm that we are fully aligned.  Michalis please meet with Dick and Don to sort out Mantis status.
>
> My status of EnvironmentLight thoughts is in
> [...]> . Initial CGE implementation is done, but it needs finishing and testing in more real-life cases. So, it's not finished, but advanced.
>
> The EnvironmentLight question should really be separated from the "glTF and PBR" stuff :) glTF spec doesn't even have lights at all, and EnvironmentLight (aka "image-based lighting") makes sense for both PBR and non-PBR materials.
>
> Please propose a meeting time next week (and put it in the calendar invite, to avoid any timezone confusion :) ). I'll happily meet and talk.
> [...]
>
> Regards,
> Michalis