[3.0.0-beta2] Fix PhysX scene data for joint-labeled bodies

[ooctipus]

Summary

• Cherry-picks Fix PhysX scene data for joint-labeled bodies #6041 onto release/3.0.0-beta2.
• Skips USD joint prims when building the global PhysX scene-data rigid-body view.
• Resolves Newton visualization body labels that point at USD joints through their rigid-body targets.
• Adds regression coverage for joint/body leaf-name collisions.

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 upstream/release/3.0.0-beta2...HEAD
• python3 tools/changelog/cli.py check release/3.0.0-beta2
• pre-commit run --files source/isaaclab/changelog.d/zhengyuz-physx-scene-data-shadowhand.skip source/isaaclab/test/sim/test_newton_manager_visualization_state.py source/isaaclab_newton/changelog.d/zhengyuz-physx-scene-data-shadowhand.rst source/isaaclab_newton/isaaclab_newton/physics/newton_manager.py source/isaaclab_physx/changelog.d/zhengyuz-physx-scene-data-shadowhand.rst source/isaaclab_physx/isaaclab_physx/physics/physx_manager.py source/isaaclab_physx/test/sim/test_physx_scene_data_backend.py
• Focused pytest attempted with python3 and ./isaaclab.sh -p; this local checkout did not have the needed runtime package setup, so the tests stopped at missing isaaclab_newton/toml imports before exercising the change.

[greptile-apps]

Greptile Summary

This PR cherry-picks a fix from release/3.0.0-beta2 that addresses two related issues with PhysX scene data and Newton visualization when USD joint prims share leaf names with rigid bodies (the ShadowHand use case). A joint-skip guard is added to PhysxSceneDataBackend.get_rigid_body_view, and a new _resolve_scene_data_body_paths helper resolves Newton body labels that point at USD joints to their real rigid-body targets.

• physx_manager.py: Joint prims (prim.IsA(UsdPhysics.Joint)) are now skipped before the RigidBodyAPI check during stage traversal, preventing ghost joint entries from polluting the PhysX tensor rigid-body view.
• newton_manager.py: update_visualization_state now calls _resolve_scene_data_body_paths to remap any Newton body label that points at a joint prim to the joint's Body1Rel (falling back to Body0Rel) rigid-body target before building the scene-data mapping.
• New regression tests cover both the physx-side joint skip and the Newton-side joint-to-body-path resolution.

Confidence Score: 4/5

The PhysX-side joint skip is safe and well-tested; the Newton-side resolver logic is correct, but the removal of the defensive body_label guard can crash update_visualization_state for any model where body_label is None.

The newton_manager.py change introduced a regression: the old call used getattr(cls._model, 'body_label', None) or [] to handle a missing or None attribute, and the new list(cls._model.body_label) strips that safety. Any model variant where body_label is None will raise TypeError at runtime inside update_visualization_state, breaking Newton visualization sync for those models.

source/isaaclab_newton/isaaclab_newton/physics/newton_manager.py — specifically line 1838 where the body_label guard was weakened.

Important Files Changed

Filename	Overview
source/isaaclab_newton/isaaclab_newton/physics/newton_manager.py	Adds _resolve_scene_data_body_paths; replaces defensive getattr/or-[] guard with direct body_label access, introducing a potential crash if body_label is None.
source/isaaclab_physx/isaaclab_physx/physics/physx_manager.py	Adds joint-prim skip guard before RigidBodyAPI check; change is minimal, correct, and well-tested.
source/isaaclab_physx/test/sim/test_physx_scene_data_backend.py	New test file validating that joint prims with RigidBodyAPI are excluded from the rigid-body view; follows module-level importorskip pattern correctly.
source/isaaclab/test/sim/test_newton_manager_visualization_state.py	Adds a test for the new joint-to-body-path resolution; uses pytest.importorskip inside the function body (unusual pattern, but functionally correct).
source/isaaclab_newton/changelog.d/zhengyuz-physx-scene-data-shadowhand.rst	Changelog entry for Newton side of the fix; clear and accurate description.
source/isaaclab_physx/changelog.d/zhengyuz-physx-scene-data-shadowhand.rst	Changelog entry for PhysX side of the fix; clear and accurate description.
source/isaaclab/changelog.d/zhengyuz-physx-scene-data-shadowhand.skip	Empty skip marker for the isaaclab package changelog; intentional.

Sequence Diagram

sequenceDiagram
    participant Consumer
    participant NewtonManager
    participant SceneDataProvider
    participant PhysxSceneDataBackend
    participant UsdStage

    Consumer->>NewtonManager: update_visualization_state()
    NewtonManager->>NewtonManager: _ensure_visualization_model()
    alt _scene_data_mapping is None
        NewtonManager->>NewtonManager: _resolve_scene_data_body_paths(body_label, stage)
        loop For each body path that is a USD joint
            NewtonManager->>UsdStage: GetPrimAtPath(body_path)
            UsdStage-->>NewtonManager: joint prim
            NewtonManager->>NewtonManager: _joint_body_path(prim)
            NewtonManager->>UsdStage: GetBody1Rel / GetBody0Rel targets
            UsdStage-->>NewtonManager: rigid-body target path
        end
        NewtonManager->>SceneDataProvider: create_mapping(resolved_body_paths)
        SceneDataProvider-->>NewtonManager: _scene_data_mapping
    end
    NewtonManager->>SceneDataProvider: get_transforms(_scene_data, mapping)
    SceneDataProvider->>PhysxSceneDataBackend: get_rigid_body_view()
    alt _rigid_body_view is None
        PhysxSceneDataBackend->>UsdStage: Traverse()
        loop For each prim
            PhysxSceneDataBackend->>PhysxSceneDataBackend: skip if prim.IsA(UsdPhysics.Joint)
            PhysxSceneDataBackend->>PhysxSceneDataBackend: append if HasAPI(RigidBodyAPI)
        end
        PhysxSceneDataBackend->>PhysxSceneDataBackend: compact env paths to wildcards
        PhysxSceneDataBackend->>PhysxSceneDataBackend: create_rigid_body_view(body_paths)
    end
    PhysxSceneDataBackend-->>SceneDataProvider: rigid body transforms
    SceneDataProvider-->>NewtonManager: transforms written to _state_0.body_q

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_{Reviews (1): Last reviewed commit: "Fix PhysX scene data for joint-labeled b..." | Re-trigger Greptile}

[greptile-apps]

The original call used getattr(cls._model, "body_label", None) or [] which safely handled both a missing attribute and a None value. The new code calls list(cls._model.body_label) directly — if body_label is None (which the original guard explicitly anticipated), this raises TypeError: 'NoneType' is not iterable. If the attribute is absent on some model variant, it raises AttributeError. Both crash update_visualization_state at runtime after the surrounding guard already verified only that cls._model is not None.

Suggested change

	body_paths = cls._resolve_scene_data_body_paths(list(cls._model.body_label), scene_data_provider.usd_stage)
	raw_labels = getattr(cls._model, "body_label", None) or []
	body_paths = cls._resolve_scene_data_body_paths(list(raw_labels), scene_data_provider.usd_stage)

[greptile-apps]

pytest.importorskip placed inside the test body rather than at module level is inconsistent with how test_physx_scene_data_backend.py handles the same dependency. Function-level placement works — pytest will skip the test correctly — but moving it to module level would align with the project pattern established in the companion test file.

Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!