UsdGlTFFileFormat::Read fails to files with non-filesystem resolvedPaths.

[expenses]

Hi! I tried to get guc working with the custom resolver I've been working on but unfortunately it fails upon trying to load the file:
Failed to open "iroh://doc/pajzuzssv2l7wg7iruxixkbc7nfcm42gqfqbmzz5hux4im4v2yea/m5wfirrpirqw2ylhmvseqzlmnvsxilthnr2gmaa.gltf" - unable to parse glTF file: file not found

The problem is that this code assumes that resolvedPath is on the local filesystem:

guc/src/libguc/src/fileFormat.cpp

Lines 97 to 106 in 0fb7f76

	bool UsdGlTFFileFormat::Read(SdfLayer* layer,
	const std::string& resolvedPath,
	bool metadataOnly) const
	{
	cgltf_data* gltf_data = nullptr;
	if (!load_gltf(resolvedPath.c_str(), &gltf_data))
	{
	TF_RUNTIME_ERROR("unable to load glTF file %s", resolvedPath.c_str());
	return false;
	}

Ideally you'd call something like ArGetResolver().OpenAsset(resolvedPath) to get an ArAsset and then use the bytes from ArAsset::GetBuffer to load the glTF data. This is a bit of a hastle not gonna lie, but it would mean that assets using custom URI schemas (iroh:// for me, but also http://) would load perfectly.

[pablode]

Thank you very much for this report! This is an oversight, and your proposed solution makes sense. Will implement it soon-ish!

[expenses]

Additionally, I think you want to return relative paths for existing on-disk assets. At the moment you get absolute paths like @/home/ashley/projects/glTF-Sample-Models/2.0/DamagedHelmet/glTF/Default_normal.jpg@ which a HTTP resolver isn't going to be able to resolve if the anchor path looks like http://localhost:8000/DamagedHelmet.gltf. I haven't done a deep dive into how the internals work yet, so I'm not sure how the the images embedded in a binary file like http://localhost:8000/DamagedHelmet.glb should be resolved. Presumably just extracted to a temporary directory?

[pablode]

Hi, I just implemented the feature in this branch. I have yet to test it with an actual custom resolver.

EDIT: it's now in dev and will be released soon.

[pablode]

This is now implemented in v0.4, thanks for the patience!