Sanitise node names

[ghost]

This glTF does not convert and trow this error:

Warning: in SdfPath at line 97 of /tmp/USD-19.11/pxr/usd/lib/sdf/path.cpp -- Ill-formed SdfPath </root/Hay_+undefined__101>: syntax error
Traceback (most recent call last):
  File "/usr/local/gltf2usd/Source/gltf2usd.py", line 923, in <module>
    convert_to_usd(os.path.expanduser(args.gltf_file), os.path.abspath(os.path.expanduser(args.usd_file)), args.fps, args.scale, args.arkit, args.verbose, args.use_euler_rotation, args.optimize_textures, args.generate_texture_transform_texture, args.scale_texture)
  File "/usr/local/gltf2usd/Source/gltf2usd.py", line 832, in convert_to_usd
    usd = GLTF2USD(gltf_file=gltf_file, usd_file=temp_usd_file, fps=fps, scale=scale, verbose=verbose, use_euler_rotation=use_euler_rotation, optimize_textures=optimize_textures, generate_texture_transform_texture=generate_texture_transform_texture, scale_texture=scale_texture)
  File "/usr/local/gltf2usd/Source/gltf2usd.py", line 75, in __init__
    self.convert()
  File "/usr/local/gltf2usd/Source/gltf2usd.py", line 801, in convert
    self.convert_nodes_to_xform()
  File "/usr/local/gltf2usd/Source/gltf2usd.py", line 91, in convert_nodes_to_xform
    self._convert_node_to_xform(node, parent_transform)
  File "/usr/local/gltf2usd/Source/gltf2usd.py", line 102, in _convert_node_to_xform
    xformPrim = UsdGeom.Xform.Define(self.stage, '{0}/{1}'.format(usd_xform.GetPath(), GLTF2USDUtils.convert_to_usd_friendly_node_name(node.name)))
pxr.Tf.ErrorException: 
    Error in 'pxrInternal_v0_19__pxrReserved__::UsdStage::_IsValidPathForCreatingPrim' at line 3019 in file /tmp/USD-19.11/pxr/usd/lib/usd/stage.cpp : 'Path must be an absolute path: <>'

It appears to be related to the node name "Hay-+undefined-". The + sign seems to break it and it shouldn't because it is valid for the glTF spec.

[ephb]

The same is true for the the exclamation mark ! and underscore _ sign as well as any umlauts like"äöü".

[ghost]

This is quote blocking for us, any chance you could look at it @kcoley :) ?

[ephb]

@sayduck-daniel can't you change your node names? This is the way I currently work around this.

[kcoley]

The issue here is that the USD API has more restrictions on supported characters than glTF. It may be better in this case to try to change your node names

[ghost]

We did it on our side. But I still think the gltf2usd should always work when we give him a valid glTF, specially when this glTF could come from a user and pass a glTF validator test.