Files with external `http://` uri refererences can't be procesed with gltf-pipeline

[hybridherbst]

I'm trying to convert some old glTF 1.1 files to glTF 2.0.

While that works in general, it seems that external references throw up gltf-pipeline:

Here's an example:

https://storage.googleapis.com/assets.icosa.gallery/63208108939333337/63210051195686758/GLTF/sketch.gltf
https://storage.googleapis.com/assets.icosa.gallery/63208108939333337/63210051195686758/GLTF/sketch.bin

To reproduce:

• download the two files above
• run gltf-pipeline -i sketch.gltf -o sketch.glb
• note the exception being thrown

Expected
External references are kept as external references

Additional Context
While the issue here is happening during glTF 1.1 -> glTF 2.0 conversion, I believe this also affects general use with glTF 2.0.

[andybak]

To add some detail - this is (as far as I know) specifically a Tilt Brush thing. But there's a fair number of Tilt Brush GLTF v1 files out in the wild.

Is there any reason gltf-pipeline shouldn't treat file references as opaque unless requested to handle them?

[hybridherbst]

Here's a glTF file without the tiltbrush extension(s) that has the same issue:
needle_godot_plush_ref.gltf.zip

This one is even simpler (just a grey sphere):
NeedleSphereReference.gltf.zip

Quick test:

Tool	Can load these files
model-viewer	✓
needle-engine	✓
Gestaltor	✖
glTF Validator	✖
glTFast	✖
UnityGLTF	✖