[x3d-public] My proposal of changes to X3D to enable PBR and other material improvements

[Michalis Kamburelis]

Hi,

First of all, sorry for an absence in the last ~2 months. I had a lot
of work around Castle Game Engine and our games (all using X3D :) ),
and it ate my time. I'm slowly back to being active here.

I recently mentioned at X3D teleconference my initial version of
proposed spec changes, to add to X3D PBR, and in general improve our
materials (to also add normalmaps, to pull some useful ideas from
CommonSurfaceShader etc.). Today I reread and improved this page a
bit. I would encourage any comments about it, especially from people
who may want to implement it :) We want to make it part of X3D
specification, so this is a chance to resolve any issues :)

1. The proposed specification changes are on
https://github.com/michaliskambi/x3d-tests/wiki/Specification-changes,-to-include-PBR-and-related-features
.

There are two "companion" pages about PBR on my wiki:

2. https://github.com/michaliskambi/x3d-tests/wiki/How-to-add-PBR-to-X3D%3F
- This describes the rationale behind various decisions. Many thanks
to all with whom I talked on x3d-public, in particular to Andreas
Plesch for many excellent ideas.

3. https://github.com/michaliskambi/x3d-tests/wiki/What-is-PBR-and-why-do-we-want-it-in-X3D%3F
- This is a collection of information about PBR, why do we want it,
and how others handle PBR (e.g. glTF, Unity use PBR).

The top-most page with all 3 links is on
https://github.com/michaliskambi/x3d-tests/wiki/Include-PBR-(PhysicalMaterial-and-related-concepts)-in-the-official-X3D-specification
.

Best regards,
Michalis