GLTF exported by Three.js cannot import into Facebook 3D post

[Ben-Mack]

Facebook recently annouced 3D post, with ability to view GLTF file on new feed.

I tried this GLTF binary sample, it working fine ( https://github.com/KhronosGroup/glTF-Sample-Models/tree/master/2.0/CesiumMilkTruck/glTF-Binary )

But GLB file exported from this Three.js example ( https://threejs.org/examples/?q=gltf#misc_exporter_gltf ) is not working, Facebook return this error:

GLB File Invalid: 3D Model Not Posted | Your 3D model could not be posted as it contains features we don't support, is of a file type we don't support, or contains errors

_

GLTF model validation by Facebook: https://developers.facebook.com/tools/3d/validation

Tutorial on how to upload GLTF file to Facebook: https://developers.facebook.com/docs/sharing/3d-posts#creating-3d-posts

[donmccurdy]

Testing Editor exports with their validator, I'm seeing this:

screenshot

Running the same model through the official validator, I see:

GLB_CHUNK_LENGTH_UNALIGNED | Length of 0x4e4f534a chunk is not aligned to 4-byte boundaries.

... which was partially fixed with #13220, I guess there was another warning for GLB. I'm a little surprised that's an issue though, as three.js can render it anyway, but let's try fixing that and see if it solves the problem.

[donmccurdy]

Another validation warning when there is a camera, which our demo includes (but Facebook has stated in the FAQ they don't support cameras in the GLB, anyway) —

[mrdoob]

Closing in favour of #13397