<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Thu, Jul 6, 2017 at 12:33 PM, Leonard Daly <span dir="ltr"><<a href="mailto:Leonard.Daly@realism.com" target="_blank">Leonard.Daly@realism.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<div class="m_-5049345809419836349m_-277172184226130333moz-cite-prefix">John,<br>
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<div dir="auto">XSeen is taking the approach of treating glTF as a
model. What are others doing? Is anyone considering the whole
scenegraph? Why or why not? Is glTF as a model done because
Three.js treats glTF as a mesh (I don't know if three.js does
this or not)?</div>
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XSeen and A-Frame both use the glTF loader for THREE. The loader
imports the entire model and texture (a mesh in THREE terminology).
Both also include all of the animations and any scene graph
structure. However, that structure (including animations) is sort-of
encapsulated from the rest of the scene graph. There are no events
that are fired during animation sequences. <br></div></blockquote><div> <br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div text="#000000" bgcolor="#FFFFFF">
X3DOM treats the glTF file as what can be represented in a single
Shape node - geometry + appearance. Transforms and animation are not
included.<br><br></div></blockquote><div><br></div><div>X3DOM should be able to apply the gltf transforms in the latest dev. versions. Animations would need serious work to support, I believe.</div><div>A concern is that X3DOM only supports glTF1 while glTF2 will take over pretty quickly now that it is out. </div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div text="#000000" bgcolor="#FFFFFF"><blockquote type="cite">
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<div dir="auto">What do people think of the low level nature of
glTF as opposed to X3D? </div>
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glTF ranges from low-level (geometry + basic appearance) to full
scene graph. I am not sure how to interpret your question.<br>
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glTF is becoming the standard exchange format. It includes (more or
less) everything in FBX, but it is open. It has more options than
OBJ, and is smaller in size. I think it is necessary to be able to
process glTF and include it in a scene graph, much like the glTF
importer for THREE. Yes, it does overlap with X3D. <br>
<br></div></blockquote><div><br></div><div>I think this is a nice characterization. glTF = gl Transport Format.</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div text="#000000" bgcolor="#FFFFFF">
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<div dir="auto">While it makes it less understandable, I can see
how keeping glTF low level would improve performance at the
expense of file size. Has anyone compared and contrasted the
two standards?</div>
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Which two standards - X3D & glTF? glTF has better animation, it
has been adopted by more users and content creators (people &
software). It comes in a binary and text forms. It has the potential
for being the entire scene graph. It includes shaders and advanced
appearance (bump maps, ambient occlusion, etc.).<br>
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On the downside, I don't think it has audio, movie textures,
environmental effects (fog, background, etc.), or sensors. I may be
wrong about some of these items because I haven't studied glTF in
its entirety -- I just haven't come across those capabilities yet.<br>
<br></div></blockquote><div><br></div><div>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. Apart from audio, the biggest difference may be that glTF content is not supposed to interact with the outside including the viewer, as far as I can tell. glTF does not support internal scripting. It has internal reuse (DEF/USE) of resources.<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div text="#000000" bgcolor="#FFFFFF">
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<div dir="auto">Are there glTF importer/exporters for blender
yet? If not, why not?</div>
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There will be a BOF at SIGGRAPH about Blender exporters including a
glTF exporter. I am not sure about an importer. Since there is a
THREE loader, I suspect it would not be that difficult to build an
importer.</div></blockquote><div><br></div><div>Meshes, lights, animations, standard materials should be able to be digested.It could be difficult to have a lossless import -edit - export cycle.</div><div><br></div><div>-Andreas</div></div><br clear="all"><div><br></div>-- <br><div class="m_-5049345809419836349gmail_signature" data-smartmail="gmail_signature">Andreas Plesch<br>39 Barbara Rd.<br>Waltham, MA 02453</div>
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