Fix PhysX scene data for joint-labeled bodies (#6041)

## Summary
- skip USD joint prims when building the global PhysX scene-data
rigid-body view
- resolve Newton visualization body labels that point at USD joints
through their rigid-body targets
- add focused regression coverage for the ShadowHand-style joint/body
leaf-name collision

## Validation
- python3 -m py_compile
source/isaaclab_newton/isaaclab_newton/physics/newton_manager.py
source/isaaclab_physx/isaaclab_physx/physics/physx_manager.py
source/isaaclab/test/sim/test_newton_manager_visualization_state.py
source/isaaclab_physx/test/sim/test_physx_scene_data_backend.py
- git diff --check
- focused pytest attempted locally, but this worktree uses
/usr/bin/python3.12 without Isaac Lab runtime deps (`lazy_loader`) and
USD bindings (`pxr`) installed

Author: ooctipus

source/isaaclab/changelog.d/zhengyuz-physx-scene-data-shadowhand.skip

@@ -161,3 +161,24 @@ def test_update_visualization_state_noop_when_backend_is_newton(monkeypatch):
     NewtonManager.update_visualization_state()
     assert NewtonManager._model == "live-model"
     assert NewtonManager._state_0 == "live-state"
+
+
+def test_resolve_scene_data_body_paths_uses_joint_body_targets():
+    """PhysX visualization sync maps Newton joint labels to the actual body prim path."""
+    import pytest
+
+    pytest.importorskip("pxr")
+    from isaaclab_newton.physics import NewtonManager
+
+    from pxr import Usd, UsdGeom, UsdPhysics
+
+    stage = Usd.Stage.CreateInMemory()
+    body_prim = UsdGeom.Xform.Define(stage, "/World/envs/env_0/Robot/robot0_forearm").GetPrim()
+    UsdPhysics.RigidBodyAPI.Apply(body_prim)
+    joint = UsdPhysics.FixedJoint.Define(stage, "/World/envs/env_0/Robot/joints/robot0_forearm")
+    joint.GetBody1Rel().SetTargets([body_prim.GetPath()])
+
+    body_paths = ["/World/envs/env_0/Robot/joints/robot0_forearm"]
+    resolved_paths = NewtonManager._resolve_scene_data_body_paths(body_paths, stage)
+
+    assert resolved_paths == ["/World/envs/env_0/Robot/robot0_forearm"]

source/isaaclab/test/sim/test_newton_manager_visualization_state.py

@@ -0,0 +1,5 @@
+Fixed
+^^^^^
+
+* Fixed Newton visualizers on PhysX simulations when a Newton body label points
+  at a USD joint prim by resolving the label through the joint's rigid-body target.

source/isaaclab_newton/changelog.d/zhengyuz-physx-scene-data-shadowhand.rst

@@ -1861,12 +1861,38 @@ def update_visualization_state(cls, scene_data_provider: SceneDataProvider | Non
         if cls._scene_data is None:
             cls._scene_data = SceneDataFormat.Transform()
         if cls._scene_data_mapping is None:
-            body_paths = list(getattr(cls._model, "body_label", None) or [])
+            body_paths = cls._resolve_scene_data_body_paths(list(cls._model.body_label), scene_data_provider.usd_stage)
             cls._scene_data_mapping = scene_data_provider.create_mapping(body_paths)
 
         cls._scene_data.transforms = cls._state_0.body_q
         scene_data_provider.get_transforms(cls._scene_data, mapping=cls._scene_data_mapping)
 
+    @staticmethod
+    def _resolve_scene_data_body_paths(body_paths: list[str | None], stage) -> list[str | None]:
+        """Map Newton joint labels to their target rigid-body prim paths."""
+        if stage is None:
+            return body_paths
+
+        from pxr import UsdPhysics
+
+        def _joint_body_path(prim):
+            joint = UsdPhysics.Joint(prim)
+            for rel in (joint.GetBody1Rel(), joint.GetBody0Rel()):
+                for target_path in rel.GetTargets():
+                    target_prim = stage.GetPrimAtPath(target_path)
+                    if target_prim.IsValid() and target_prim.HasAPI(UsdPhysics.RigidBodyAPI):
+                        return target_path.pathString
+            return None
+
+        resolved_paths = body_paths.copy()
+        for index, body_path in enumerate(body_paths):
+            if body_path is None:
+                continue
+            prim = stage.GetPrimAtPath(body_path)
+            if prim.IsValid() and prim.IsA(UsdPhysics.Joint):
+                resolved_paths[index] = _joint_body_path(prim) or body_path
+        return resolved_paths
+
     @classmethod
     def get_state_1(cls) -> State:
         """Get the next state."""

source/isaaclab_newton/isaaclab_newton/physics/newton_manager.py

@@ -0,0 +1,5 @@
+Fixed
+^^^^^
+
+* Fixed PhysX scene-data rigid-body view discovery to ignore USD joint prims
+  even when an asset authors ``RigidBodyAPI`` on them.

source/isaaclab_physx/changelog.d/zhengyuz-physx-scene-data-shadowhand.rst

@@ -191,6 +191,8 @@ def get_rigid_body_view(self) -> omni.physics.tensors.RigidBodyView | None:
         rigid_body_paths: list[str] = []
         non_rigid_body_names: set[str] = set()
         for prim in stage.Traverse():
+            if prim.IsA(UsdPhysics.Joint):
+                continue
             prim_path = prim.GetPath().pathString
             if prim.HasAPI(UsdPhysics.RigidBodyAPI):
                 rigid_body_paths.append(prim_path)

source/isaaclab_physx/isaaclab_physx/physics/physx_manager.py

@@ -0,0 +1,44 @@
+# Copyright (c) 2022-2026, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+from types import SimpleNamespace
+
+import pytest
+
+pytest.importorskip("pxr")
+pytest.importorskip("omni.physics.tensors")
+
+
+def test_scene_data_rigid_body_view_skips_joint_prims_with_rigid_body_api(monkeypatch):
+    """Joint prims must not be passed to PhysX tensor rigid-body views."""
+    from isaaclab_physx.physics import physx_manager
+    from isaaclab_physx.physics.physx_manager import PhysxSceneDataBackend
+
+    from pxr import Usd, UsdGeom, UsdPhysics
+
+    stage = Usd.Stage.CreateInMemory()
+    body_prim = UsdGeom.Xform.Define(stage, "/World/envs/env_0/Robot/robot0_forearm").GetPrim()
+    UsdPhysics.RigidBodyAPI.Apply(body_prim)
+    joint_prim = UsdPhysics.FixedJoint.Define(stage, "/World/envs/env_0/Robot/joints/robot0_forearm").GetPrim()
+    UsdPhysics.RigidBodyAPI.Apply(joint_prim)
+
+    captured_paths = []
+
+    class _SimulationView:
+        def create_rigid_body_view(self, body_paths):
+            captured_paths.extend(body_paths)
+            return SimpleNamespace(prim_paths=body_paths)
+
+    monkeypatch.setattr(
+        physx_manager.omni.usd,
+        "get_context",
+        lambda: SimpleNamespace(get_stage=lambda: stage),
+    )
+
+    backend = PhysxSceneDataBackend()
+    backend.simulation_view = _SimulationView()
+    backend.get_rigid_body_view()
+
+    assert captured_paths == ["/World/envs/env_*/Robot/robot0_forearm"]