Ensures mesh name is compatible with USD convention in mesh converter (#1302)

# Description

Fixes #1287

**Issue details**: When using the convert_mesh.py script to convert .obj
to .usd, if the obj file in this scene starts with a
number(0c334eaabb844eaaad049cbbb2e0a4f2.obj), while the USD API
prohibits names that start with a number
[Link](https://openusd.org/release/api/group__group__tf___string.html#gaa129b294af3f68d01477d430b70d40c8).
This issue is described in more detail here:
[Link](https://forums.developer.nvidia.com/t/cant-create-prims-if-name-starts-with-number/249617).

Also deleted useless debugging output code.

## Type of change

- Bug fix (non-breaking change which fixes an issue)

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [ ] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

source/extensions/omni.isaac.lab/omni/isaac/lab/sim/converters/mesh_converter.py

@@ -10,7 +10,7 @@ import omni
 import omni.kit.commands
 import omni.usd
 from omni.isaac.core.utils.extensions import enable_extension
-from pxr import Usd, UsdGeom, UsdPhysics, UsdUtils
+from pxr import Tf, Usd, UsdGeom, UsdPhysics, UsdUtils
 
 from omni.isaac.lab.sim.converters.asset_converter_base import AssetConverterBase
 from omni.isaac.lab.sim.converters.mesh_converter_cfg import MeshConverterCfg
@@ -81,6 +81,16 @@ class MeshConverter(AssetConverterBase):
         mesh_file_basename, mesh_file_format = os.path.basename(cfg.asset_path).split(".")
         mesh_file_format = mesh_file_format.lower()
 
+        # Check if mesh_file_basename is a valid USD identifier
+        if not Tf.IsValidIdentifier(mesh_file_basename):
+            # Correct the name to a valid identifier and update the basename
+            mesh_file_basename_original = mesh_file_basename
+            mesh_file_basename = Tf.MakeValidIdentifier(mesh_file_basename)
+            omni.log.warn(
+                f"Input file name '{mesh_file_basename_original}' is an invalid identifier for the mesh prim path."
+                f" Renaming it to '{mesh_file_basename}' for the conversion."
+            )
+
         # Convert USD
         asyncio.get_event_loop().run_until_complete(
             self._convert_mesh_to_usd(

source/standalone/tools/convert_mesh.py

@@ -106,10 +106,6 @@ def main():
     if not os.path.isabs(dest_path):
         dest_path = os.path.abspath(dest_path)
 
-    print(dest_path)
-    print(os.path.dirname(dest_path))
-    print(os.path.basename(dest_path))
-
     # Mass properties
     if args_cli.mass is not None:
         mass_props = schemas_cfg.MassPropertiesCfg(mass=args_cli.mass)