[x3d-public] Fwd: thinking about X3DJSONLD/X3DOM/glTF interoperability

[Don Brutzman]

On 7/5/2017 11:21 PM, John Carlson wrote:
> Now that I think about it, it makes sense to use glTF as model for composability. Hmm.

On 7/7/2017 9:24 PM, Andreas Plesch wrote:
> 
>     One could probably include a textured big box or sphere as background in glTF file. Fog may be possible with a custom shader. After all, glTF by itself requires definition of shaders. Only the glTF extensions provide predefined shaders for standard (KHR,PBR) materials. 
> 
> It turns out that this is now reversed with gltf2. Core gltf2 has standard materials, and custom shaders were relegated to an extension.

Johannes Behr reported at Web3D 2017 Conference last month that efforts to integrate SRC capabilities in glTF are complete.  This coincided with the release announcement of glTF 2 and physically based rendering capabilities.

Not included in this SRC integration is progressive-mesh streaming.  Johannes further indicated that their algorithms in that domain continue to change frequently, so stabilization on standardized approaches to mesh streaming might not be advisable at this time.

Here is the glTF 2.0 announcement from Web3D 2017:
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Khronos Releases glTF 2.0 Specification
Runtime 3D Asset Delivery Format Enhanced with Platform Independent Physically Based Rendering
June 5, 2017 – 6:00 AM Pacific Time -- Brisbane, Australia
https://www.khronos.org/news/press/khronos-releases-gltf-2.0-specification

"The Khronos™ Group, an open consortium of leading hardware and software companies, announces from the Web3D 2017 Conference the immediate availability of the finalized glTF 2.0 specification incorporating industry feedback received from developers through the provisional specification that was made available for review on GitHub.

The release of glTF 2.0 delivers a significant upgrade to glTF 1.0, an extensible, runtime neutral, open standard format for real-time delivery of 3D assets, which describes full scenes with compact transmission and fast load time. In response to major functionality requests from the developer community using glTF 1.0, the release of glTF 2.0 adds Physically Based Rendering (PBR) for portable, consistent description of materials. In glTF 1.0, a material was defined with a GLSL shader, which suited WebGL, but was problematic when importing a glTF model into a Direct3D or Metal application. Through using PBR, visually arresting glTF 2.0 models are now consistently portable to any rendering API. A PBR material is defined by a few concise parameters that can be used to generate shaders for any rendering API. glTF 2.0 defines a simple to implement, but powerful, PBR model that provides high-quality materials, and yet, is scalable to suit the capabilities of different classes of platform and device." [...]
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We plan to devote an X3D Working Group meeting to examine how all this great progress modifies our standardization advancement efforts, both for compression and for rendering.

	X3D Compressed Binary Encoding Activity
	http://www.web3d.org/working-groups/x3d/compressed-binary-encoding-activity

Including advanced physically based rendering (PBR) materials has been on our X3Dv4 feature list since last summer when Timo Sturm showed such dramatic demos at Web3D and SIGGRAPH conferences.

	X3D Version 4.0 Development: Candidate Capabilities
	http://www.web3d.org/wiki/index.php/X3D_version_4.0_Development#Candidate_Capabilities

	Materials: advanced parameters
	HDR: Improvements in both materials and rendering for high definition rendering technological advances.

Another intriguing development: should X3D Inline node (url field) accept glTF models, in addition to X3D and VRML?

Related consideration: is there impact/influence on X3D Shader improvements that Michalis Kamburelis has proposed and demonstrated?

Lots to consider.  SIGGRAPH sessions will no doubt reveal even more about how we can align these mature capabilities effectively in X3Dv4.

Onward we go.  Continuing insights and progress are welcome!

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