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<div class="moz-cite-prefix"><font color="blue"><font color="black">Below
is my response reviewed by 3D Formats WG. Don's questions were
pulled out and included here in <font color="green">green</font>.</font><br>
</font></div>
<div class="moz-cite-prefix"><font color="blue"><br>
</font></div>
<div class="moz-cite-prefix"><font color="blue"><br>
</font></div>
<div class="moz-cite-prefix"><font color="green">> Question about
Draco: thought it was usable as a preprocessor for glTF files
that could produce .glb files, but is that incorrect? </font></div>
<br>
<div class="moz-cite-prefix">Draco is compatible with glTF. There is
an extension (Announcement:
<a class="moz-txt-link-freetext"
href="https://www.khronos.org/news/press/khronos-announces-gltf-geometry-compression-extension-google-draco"
moz-do-not-send="true">https://www.khronos.org/news/press/khronos-announces-gltf-geometry-compression-extension-google-draco</a>;
Specification:
<a class="moz-txt-link-freetext"
href="https://github.com/KhronosGroup/glTF/blob/master/extensions/2.0/Khronos/KHR_draco_mesh_compression/README.md"
moz-do-not-send="true">https://github.com/KhronosGroup/glTF/blob/master/extensions/2.0/Khronos/KHR_draco_mesh_compression/README.md</a>)
that is required for this (Draco) to work.</div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix"> <font color="green">> If Draco is
compatible with glTF do we need to mention it (as an optional
perhaps) in X3D4? <br>
</font></div>
<font color="green"> </font>
<div class="moz-cite-prefix"><font color="green">> If
Draco-compressed files are not compatible with glTF files, what
is the relationship? What are their intentions? </font><br>
</div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">Depends on what level of glTF support
Web3D wishes to impose on X3D. Draco support is an extension to
the core glTF V2.0 specification. Draco is fundamentally a
memory-based operation. The GitHub package from Google includes
encoders and decoders. The glTF extension handles the Draco
Bitstream (<a class="moz-txt-link-freetext"
href="https://google.github.io/draco/spec/"
moz-do-not-send="true">https://google.github.io/draco/spec/</a>)<br>
</div>
<div class="moz-cite-prefix"><br>
</div>
<br>
<div class="moz-cite-prefix"><font color="blue"><font color="green">>
Near-term impact: do we need to add any comments in X3D4
submission to ISO ballot (deadline 5 May)? </font><br>
</font></div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">That is a Web3D issue.</div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix"><font color="green">> Long-term
impact: can we encourage use of Draco-processed loading of glTF
models, or will we need to wait until revisiting X3D Compressed
Binary Encoding?</font> </div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">The Asset Creation Guidelines
(<a class="moz-txt-link-freetext"
href="https://github.com/KhronosGroup/3DC-Asset-Creation/blob/main/asset-creation-guidelines/RealtimeAssetCreationGuidelines.md"
moz-do-not-send="true">https://github.com/KhronosGroup/3DC-Asset-Creation/blob/main/asset-creation-guidelines/RealtimeAssetCreationGuidelines.md</a><b>)
</b>from the 3D Commerce WG of Khronos recommends using Draco
compression for geometry and use of KTX images (<a
class="moz-txt-link-freetext"
href="https://www.khronos.org/ktx/" moz-do-not-send="true">https://www.khronos.org/ktx/</a>)
for image transmission/GPU use. It is up to Web3D Consortium to
determine how X3D wishes to use them.</div>
<div class="moz-cite-prefix"><br>
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<div class="moz-cite-prefix"><br>
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<div class="moz-cite-prefix">Leonard Daly<br>
</div>
<div class="moz-cite-prefix"><br>
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<div class="moz-cite-prefix"><br>
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<div class="moz-cite-prefix"><br>
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<div class="moz-cite-prefix">On 4/22/2021 8:23 AM, Don Brutzman
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:a52a22b1-d685-b7e3-e5a3-d563c4627ce9@nps.edu">Hello
Web3D-Khronos Liaison Experts! Here are some public questions for
you, originating in our CAD Design Printing Scanning and X3D
Working Groups. <br>
<br>
Question about Draco: thought it was usable as a preprocessor for
glTF files that could produce .glb files, but is that incorrect? <br>
<br>
* <a class="moz-txt-link-freetext"
href="https://google.github.io/draco" moz-do-not-send="true">https://google.github.io/draco</a>
<br>
<br>
"Draco is an open-source library for compressing and decompressing
3D geometric meshes and point clouds. It is intended to improve
the storage and transmission of 3D graphics." <br>
<br>
If Draco is compatible with glTF do we need to mention it (as an
optional perhaps) in X3D4? <br>
<br>
If Draco-compressed files are not compatible with glTF files, what
is the relationship? What are their intentions? <br>
<br>
Near-term impact: do we need to add any comments in X3D4
submission to ISO ballot (deadline 5 May)? <br>
<br>
Long-term impact: can we encourage use of Draco-processed loading
of glTF models, or will we need to wait until revisiting X3D
Compressed Binary Encoding? <br>
<br>
Thanks in advance for all inquiry and insight. <br>
<br>
all the best, Don <br>
</blockquote>
<p><br>
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<div class="moz-signature">-- <br>
<font class="tahoma,arial,helvetica san serif" color="#333366"> <font
size="+1"><b>Leonard Daly</b></font><br>
3D Systems & Cloud Consultant<br>
LA ACM SIGGRAPH Past Chair<br>
President, Daly Realism - <i>Creating the Future</i> </font></div>
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