Fix Pink IK USD-to-URDF conversion on aarch64 (#6177) (#6181)

# Description

- Remove the Pink IK runtime dependency on `nvidia.srl` and use Isaac
Sim's built-in `isaacsim.asset.exporter.urdf` converter.
- Normalize generated URDF joint limits so Pinocchio accepts Isaac Sim
exporter output (`effort`/`velocity` defaults and `inf` cleanup).
- Align affected GR1T2 and G1-Inspire Pink IK frame names with the
link/frame names produced by the Isaac Sim exporter.
- Remove the `nvidia-srl-usd-to-urdf` dependency from `isaaclab_mimic`.

- `python -m py_compile docs/conf.py
source/isaaclab/isaaclab/controllers/utils.py
source/isaaclab/test/controllers/test_controller_utils.py
source/isaaclab_tasks/isaaclab_tasks/contrib/pick_place/nutpour_gr1t2_pink_ik_env_cfg.py
source/isaaclab_tasks/isaaclab_tasks/contrib/pick_place/exhaustpipe_gr1t2_pink_ik_env_cfg.py
source/isaaclab_tasks/isaaclab_tasks/contrib/pick_place/pickplace_gr1t2_env_cfg.py
source/isaaclab_tasks/isaaclab_tasks/contrib/pick_place/pickplace_unitree_g1_inspire_hand_env_cfg.py`
- `git diff --check`
- Direct mocked smoke test of `convert_usd_to_urdf()` using Isaac Sim
exporter modules.
- Generated GR1T2 and G1-Inspire URDFs with
`isaacsim.asset.exporter.urdf`, sanitized them with the new utility, and
verified Pinocchio can load them and contains the adjusted target
frames:
  - `GR1T2_fourier_hand_6dof.urdf nq 54 nv 54 missing frames []`
  - `g1_29dof_inspire_hand.urdf nq 53 nv 53 missing frames []`
- Attempted focused pytest through `./isaaclab.sh -p -m pytest
source/isaaclab/test/controllers/test_controller_utils.py -k
convert_usd_to_urdf_uses_isaacsim_exporter -q`, but this worktree uses
system Python and is missing `lazy_loader`.
- Attempted Ruff on touched files, but no local Python environment had
Ruff installed.

## Type of change

<!-- As you go through the list, delete the ones that are not
applicable. -->

- Bug fix (non-breaking change which fixes an issue)
- New feature (non-breaking change which adds functionality)
- Breaking change (existing functionality will not work without user
modification)
- Documentation update

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## Checklist

- [ ] I have read and understood the [contribution
guidelines](https://isaac-sim.github.io/IsaacLab/main/source/refs/contributing.html)
- [ ] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] 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
- [ ] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

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Co-authored-by: ooctipus <zhengyuz@nvidia.com>

Author: kellyguo11

docs/conf.py

@@ -233,7 +233,6 @@
     "pink",
     "pinocchio",
     "qpsolvers",
-    "nvidia.srl",
     "flatdict",
     "filelock",
     "IPython",

source/isaaclab/changelog.d/fix-pink-ik-urdf-exporter.rst

@@ -0,0 +1,4 @@
+Fixed
+^^^^^
+
+* Fixed Pink IK USD-to-URDF conversion to use Isaac Sim's URDF exporter instead of the unavailable ``nvidia.srl`` package.

source/isaaclab/isaaclab/controllers/utils.py

@@ -14,6 +14,7 @@
 import os
 import re
 import sys
+import xml.etree.ElementTree as ET
 
 # import logger
 logger = logging.getLogger(__name__)
@@ -42,48 +43,41 @@ def convert_usd_to_urdf(usd_path: str, output_path: str, force_conversion: bool
 
     enable_extension("isaacsim.asset.exporter.urdf")
 
-    from nvidia.srl.from_usd.to_urdf import UsdToUrdf
-
-    usd_to_urdf_kwargs = {
-        "node_names_to_remove": None,
-        "edge_names_to_remove": None,
-        "root": None,
-        "parent_link_is_body_1": None,
-        "log_level": logging.ERROR,
-    }
-
     urdf_output_dir = os.path.join(output_path, "urdf")
-    urdf_file_name = os.path.basename(usd_path).split(".")[0] + ".urdf"
-    urdf_output_path = urdf_output_dir + "/" + urdf_file_name
+    urdf_file_name = os.path.splitext(os.path.basename(usd_path))[0] + ".urdf"
+    urdf_output_path = os.path.join(urdf_output_dir, urdf_file_name)
     urdf_meshes_output_dir = os.path.join(output_path, "meshes")
 
     if not os.path.exists(urdf_output_path) or not os.path.exists(urdf_meshes_output_dir) or force_conversion:
-        usd_to_urdf = UsdToUrdf.init_from_file(usd_path, **usd_to_urdf_kwargs)
         os.makedirs(urdf_output_dir, exist_ok=True)
         os.makedirs(urdf_meshes_output_dir, exist_ok=True)
 
-        output_path = usd_to_urdf.save_to_file(
-            urdf_output_path=urdf_output_path,
+        from isaacsim.asset.exporter.urdf import UsdToUrdfConverter
+
+        usd_to_urdf = UsdToUrdfConverter(
+            stage=usd_path,
+            root_prim_path=None,
+            mesh_dir_name="../meshes",
+            mesh_path_prefix="../meshes/",
             visualize_collision_meshes=False,
-            mesh_dir=urdf_meshes_output_dir,
-            mesh_path_prefix="",
         )
+        usd_to_urdf.convert(urdf_output_path)
 
-        # The current version of the usd to urdf converter creates "inf" effort,
-        # This has to be replaced with a max value for the urdf to be valid
-        # Open the file for reading and writing
-        with open(urdf_output_path) as file:
-            # Read the content of the file
-            content = file.read()
+        _sanitize_urdf_for_pinocchio(urdf_output_path)
+    return urdf_output_path, urdf_meshes_output_dir
 
-        # Replace all occurrences of 'inf' with '0'
-        content = content.replace("inf", "0.")
 
-        # Open the file again to write the modified content
-        with open(urdf_output_path, "w") as file:
-            # Write the modified content back to the file
-            file.write(content)
-    return urdf_output_path, urdf_meshes_output_dir
+def _sanitize_urdf_for_pinocchio(urdf_path: str) -> None:
+    """Fill Pinocchio-required non-kinematic joint-limit fields in exported URDFs."""
+    tree = ET.parse(urdf_path)
+    changed = False
+    for limit in tree.iter("limit"):
+        for attr in ("effort", "velocity"):
+            if limit.get(attr) in {None, "inf", "+inf", "-inf"}:
+                limit.set(attr, "0.")
+                changed = True
+    if changed:
+        tree.write(urdf_path, encoding="unicode")
 
 
 def change_revolute_to_fixed(urdf_path: str, fixed_joints: list[str], verbose: bool = False):

source/isaaclab/setup.py

@@ -73,7 +73,7 @@
 ]
 # Adds OpenUSD dependencies based on architecture for Kit less mode.
 INSTALL_REQUIRES += [
-    f"usd-core==25.11.0 ; ({SUPPORTED_ARCHS})",
+    f"usd-core>=25.11,<26.0 ; ({SUPPORTED_ARCHS})",
     f"usd-exchange>=2.2 ; ({SUPPORTED_ARCHS_ARM})",
 ]
 

source/isaaclab/test/controllers/test_controller_utils.py

@@ -13,14 +13,19 @@
 simulation_app = AppLauncher(headless=True).app
 
 import os
-
-# Import the function to test
+import sys
 import tempfile
+import xml.etree.ElementTree as ET
+from types import ModuleType
 
 import pytest
 import torch
 
-from isaaclab.controllers.utils import change_revolute_to_fixed, change_revolute_to_fixed_regex
+from isaaclab.controllers.utils import (
+    change_revolute_to_fixed,
+    change_revolute_to_fixed_regex,
+    convert_usd_to_urdf,
+)
 from isaaclab.utils.assets import ISAACLAB_NUCLEUS_DIR, retrieve_file_path
 from isaaclab.utils.io.torchscript import load_torchscript_model
 
@@ -121,6 +126,66 @@ def test_urdf_file(mock_urdf_content):
     shutil.rmtree(test_dir)
 
 
+def _mock_module(monkeypatch, name: str) -> ModuleType:
+    module = ModuleType(name)
+    monkeypatch.setitem(sys.modules, name, module)
+    return module
+
+
+def _mock_isaacsim_app(monkeypatch):
+    for module_name in (
+        "isaacsim",
+        "isaacsim.core",
+        "isaacsim.core.experimental",
+        "isaacsim.core.experimental.utils",
+    ):
+        _mock_module(monkeypatch, module_name).__path__ = []
+    enabled_extensions = []
+    app_module = _mock_module(monkeypatch, "isaacsim.core.experimental.utils.app")
+    app_module.enable_extension = enabled_extensions.append
+    return enabled_extensions
+
+
+def test_convert_usd_to_urdf_uses_isaacsim_exporter(monkeypatch, tmp_path):
+    """Test that USD-to-URDF conversion uses Isaac Sim's URDF exporter."""
+    enabled_extensions = _mock_isaacsim_app(monkeypatch)
+    for module_name in ("isaacsim.asset", "isaacsim.asset.exporter"):
+        _mock_module(monkeypatch, module_name).__path__ = []
+
+    converter_args = {}
+
+    class MockUsdToUrdfConverter:
+        def __init__(self, **kwargs):
+            converter_args.update(kwargs)
+
+        def convert(self, output_path):
+            with open(output_path, "w") as file:
+                file.write(
+                    '<robot><joint name="j" type="revolute">'
+                    '<limit lower="-inf" upper="inf" velocity="inf"/></joint></robot>'
+                )
+
+    urdf_module = _mock_module(monkeypatch, "isaacsim.asset.exporter.urdf")
+    urdf_module.UsdToUrdfConverter = MockUsdToUrdfConverter
+
+    urdf_path, mesh_path = convert_usd_to_urdf("/assets/gr1.usd", str(tmp_path))
+
+    assert enabled_extensions == ["isaacsim.asset.exporter.urdf"]
+    assert converter_args == {
+        "stage": "/assets/gr1.usd",
+        "root_prim_path": None,
+        "mesh_dir_name": "../meshes",
+        "mesh_path_prefix": "../meshes/",
+        "visualize_collision_meshes": False,
+    }
+    assert (urdf_path, mesh_path) == (str(tmp_path / "urdf" / "gr1.urdf"), str(tmp_path / "meshes"))
+    limit = ET.parse(urdf_path).find("joint/limit")
+    assert limit.attrib["lower"] == "-inf"
+    assert limit.attrib["upper"] == "inf"
+    assert limit.attrib["effort"] == "0."
+    assert limit.attrib["velocity"] == "0."
+
+
 # =============================================================================
 # Test cases for change_revolute_to_fixed function
 # =============================================================================

source/isaaclab_mimic/changelog.d/fix-pink-ik-urdf-exporter.rst

@@ -0,0 +1,4 @@
+Removed
+^^^^^^^
+
+* Removed the ``nvidia-srl-usd-to-urdf`` dependency now that Pink IK conversion uses Isaac Sim's URDF exporter.

source/isaaclab_mimic/setup.py

@@ -25,10 +25,6 @@
     "h5py==3.15.1",
 ]
 
-# nvidia-srl-usd-to-urdf depends on usd-core which has no aarch64 wheels
-if platform.machine() != "aarch64":
-    INSTALL_REQUIRES.append("nvidia-srl-usd-to-urdf")
-
 # robomimic has no Windows/macOS wheels; only add it on Linux
 if platform.system() == "Linux":
     INSTALL_REQUIRES.append("robomimic @ git+https://github.com/ARISE-Initiative/robomimic.git@v0.4.0")

source/isaaclab_tasks/changelog.d/fix-pink-ik-urdf-exporter.rst

@@ -0,0 +1,4 @@
+Fixed
+^^^^^
+
+* Updated GR1T2 and G1-Inspire Pink IK task frame names to match URDFs generated by Isaac Sim's exporter.

source/isaaclab_tasks/isaaclab_tasks/manager_based/manipulation/pick_place/exhaustpipe_gr1t2_pink_ik_env_cfg.py

@@ -82,14 +82,14 @@ def __post_init__(self):
                 fail_on_joint_limit_violation=False,
                 variable_input_tasks=[
                     FrameTaskCfg(
-                        frame="GR1T2_fourier_hand_6dof_left_hand_pitch_link",
+                        frame="left_hand_pitch_link",
                         position_cost=8.0,  # [cost] / [m]
                         orientation_cost=1.0,  # [cost] / [rad]
                         lm_damping=10,  # dampening for solver for step jumps
                         gain=0.5,
                     ),
                     FrameTaskCfg(
-                        frame="GR1T2_fourier_hand_6dof_right_hand_pitch_link",
+                        frame="right_hand_pitch_link",
                         position_cost=8.0,  # [cost] / [m]
                         orientation_cost=1.0,  # [cost] / [rad]
                         lm_damping=10,  # dampening for solver for step jumps
@@ -102,8 +102,8 @@ def __post_init__(self):
                         cost=0.2,
                         lm_damping=1,
                         controlled_frames=[
-                            "GR1T2_fourier_hand_6dof_left_hand_pitch_link",
-                            "GR1T2_fourier_hand_6dof_right_hand_pitch_link",
+                            "left_hand_pitch_link",
+                            "right_hand_pitch_link",
                         ],
                         controlled_joints=[
                             "left_shoulder_pitch_joint",

source/isaaclab_tasks/isaaclab_tasks/manager_based/manipulation/pick_place/nutpour_gr1t2_pink_ik_env_cfg.py

@@ -80,14 +80,14 @@ def __post_init__(self):
                 fail_on_joint_limit_violation=False,
                 variable_input_tasks=[
                     FrameTaskCfg(
-                        frame="GR1T2_fourier_hand_6dof_left_hand_pitch_link",
+                        frame="left_hand_pitch_link",
                         position_cost=8.0,  # [cost] / [m]
                         orientation_cost=1.0,  # [cost] / [rad]
                         lm_damping=10,  # dampening for solver for step jumps
                         gain=0.5,
                     ),
                     FrameTaskCfg(
-                        frame="GR1T2_fourier_hand_6dof_right_hand_pitch_link",
+                        frame="right_hand_pitch_link",
                         position_cost=8.0,  # [cost] / [m]
                         orientation_cost=1.0,  # [cost] / [rad]
                         lm_damping=10,  # dampening for solver for step jumps
@@ -100,8 +100,8 @@ def __post_init__(self):
                         cost=0.2,
                         lm_damping=1,
                         controlled_frames=[
-                            "GR1T2_fourier_hand_6dof_left_hand_pitch_link",
-                            "GR1T2_fourier_hand_6dof_right_hand_pitch_link",
+                            "left_hand_pitch_link",
+                            "right_hand_pitch_link",
                         ],
                         controlled_joints=[
                             "left_shoulder_pitch_joint",