SEA3D + Google Draco

[sunag]

SEA3D I.O. Tools
http://sunag.github.io/sea3d/IO/index.html

• new SEA3DDraco.js extension
• update webgl_loader_sea3d.html example
• new file mascot.draco.tjs.sea ( Google Draco )
• new file mascot.o3dgc.tjs.sea to comparation ( Open3DGC )
• Draco libs update ( webgl_loader_draco.html work done )

[donmccurdy]

Awesome, great work! 🎉

I assume you saw that Draco is working on support for animation and morph targets as well? Would be curious to hear what compression ratios and decode times you're getting, and any feedback. 🙂

[donmccurdy]

Both Draco and LZMA on the same asset?

[sunag]

LZMA is used for content ( Animations, Mesh ( Not geometry ), Sprite, Lines, Skeleton, Custom Data ... ) Draco only for geometry.

[donmccurdy]

The Draco decoder has an isVersionSupported method that can be used to verify the model was encoded by a version of the library that the current decoder is compatible with — it may be worth storing the Draco version in the asset and checking it here. The Draco library does not guarantee that future versions will be backward compatible (although clearly that is prioritized). The glTF Draco extension is currently locked to a particular version of the Draco library bitstream, to ensure long-term compatibility.

[sunag]

Thank you for tip! Really without update the draco libs this not work.

[sunag]

@donmccurdy I believe that if update the draco_decoder any version of draco is compatible until then?

[donmccurdy]

I believe that if update the draco_decoder any version of draco is compatible until then?

Do you mean, an up-to-date draco_decoder is compatible with files created by any previous version of draco_encoder? I believe that is true today. But it is possible that some future version of draco_decoder may not support older files, so recording the encoder version — or just requiring models be created with a particular encoder version — might be safest.

See google/draco#79.

[donmccurdy]

(it's totally fine that you're updating the draco libs here though — we have a gltf/ subfolder for the encoder/decoder version required by glTF)

[sunag]

I test isVersionSupported but this method is out-of-date (I did not understand the reason for this method to be in JS and not in c++ core). The Draco file version is 2.2 this method returns false, 1.1 for example returns true. I belive that this method work with glTF because fixed version of Draco is bellow of 2. I will consider your tip using try/catch, decoder.DecodeBufferToMesh( buffer, mesh ) thanks!

https://github.com/google/draco/blob/master/src/draco/javascript/emscripten/version.js

I think that for a reformulate versions of Draco I think of creating a new class, SEA3DDraco2.js or other class inside this script.

[sunag]

I will consider your tip using try/catch

Or decoder.DecodeBufferToMesh( buffer, mesh ), this method too checks compatibility with versions.

[donmccurdy]

Ok, the warning looks good!

[sunag]

@donmccurdy Thank you!

I assume you saw that Draco is working on support for animation and morph targets as well?

It would be great! Draco support many vectors of various types. I think it will not be hard I think that only for quantization indices is not really necessary.
https://github.com/sunag/sea3d/blob/9eabaecc56871fa6da9bc35328e89a0092daaa68/IO/IO.js#L174

Would be curious to hear what compression ratios and decode times you're getting, and any feedback.

I still have the comparations yet. I will share as soon as possible.

[mrdoob]

Thanks!