Migrate OVPhysX contact-sensor pose binding onto OvPhysxView (view series, part 5)

[AntoineRichard]

🔗 Stacked on top of #6224 (Part 1 — OvPhysxView)

Branched off #6224 as a sibling of the other migrations. Targets develop; until #6224 merges the diff includes the Part 1 OvPhysxView commits. Please review #6224 first.

Description

Part 5 of the OVPhysX view-migration series — the contact sensor. This is the partial one: only the RIGID_BODY_POSE pose binding (the track_pose path) is a TensorBinding the view can manage, so only it is migrated. The ContactBinding (net forces via read_net_forces, force matrix via read_force_matrix) is a separate ovphysx wheel API that OvPhysxView does not wrap — it is left exactly as-is.

• _initialize_impl builds an OvPhysxView for the pose binding (when track_pose) and obtains it via binding_for(TT.RIGID_BODY_POSE); the count-mismatch check and the pose_binding accessor are unchanged.
• The per-step pose read goes through read_into(TT.RIGID_BODY_POSE, ...) (cached reinterpret).
• The ContactBinding create/read/destroy paths are untouched.
• Internal refactor; no public API change.

Type of change

• Internal refactor (non-breaking)

Checklist

• I have run the pre-commit checks with ./isaaclab.sh --format
• My changes generate no new warnings
• Changelog fragment (.skip — internal refactor, no bump)

Testing

test_contact_sensor.py — cpu: 9 passed, 4 skipped; cuda: 9 passed, 4 skipped (exercises both the ContactBinding force path and the migrated pose-tracking path).

[greptile-apps]

Greptile Summary

Part 5 of the OVPhysX view-migration series. It introduces OvPhysxView — a lazy, string-keyed manager over OVPhysX TensorBinding handles — and migrates the ContactSensor's RIGID_BODY_POSE binding onto it; the ContactBinding (net forces / force matrix) is intentionally left on the direct wheel API.

• OvPhysxView (ovphysx_view.py): New 700-line class with lazy/eager binding creation, per-binding device policy (raises on CPU↔GPU mismatch), float32-reinterpret read-cache warming for structured Warp dtypes (wp.transformf, wp.spatial_vectorf), and a full nested error hierarchy.
• ContactSensor migration: _initialize_impl now builds an OvPhysxView and retrieves the binding via binding_for(); the per-step read switches from _pose_binding.read(buf) to _root_view.read_into(TT.RIGID_BODY_POSE, buf). The new _root_view field is not cleared in _invalidate_initialize_callback, leaving the view alive with a destroyed cached binding after simulation stop.

Confidence Score: 4/5

Safe to merge with one small fix: _root_view should be nulled in _invalidate_initialize_callback alongside _pose_binding.

The OvPhysxView core and its tests are solid. The one gap is in _invalidate_initialize_callback: _pose_binding.destroy() is called and _pose_binding is set to None, but _root_view — which caches that same binding in _root_view._bindings — is not cleared. Any access to _root_view between simulation stop and the next _initialize_impl would return a destroyed native handle. The fix is a single self._root_view = None line.

contact_sensor.py — specifically the _invalidate_initialize_callback teardown path.

Important Files Changed

Filename	Overview
source/isaaclab_ovphysx/isaaclab_ovphysx/sensors/contact_sensor/contact_sensor.py	Migrates the RIGID_BODY_POSE binding onto OvPhysxView; _root_view is not cleared in _invalidate_initialize_callback, leaving a zombie view holding a destroyed binding after simulation stop.
source/isaaclab_ovphysx/isaaclab_ovphysx/sim/views/ovphysx_view.py	New string-keyed TensorBinding manager; well-structured with lazy/eager modes, read-cache warming, device policy enforcement, and thorough error hierarchy.
source/isaaclab_ovphysx/test/sim/test_ovphysx_view.py	Comprehensive unit tests for OvPhysxView API mechanics against mock bindings; covers device policy, dtype safety, alias resolution, read-cache warming, and adversarial construction.
source/isaaclab_ovphysx/isaaclab_ovphysx/sim/views/init.pyi	Adds OvPhysxView to the public type-stub exports; straightforward and correct.
docs/source/api/lab_ovphysx/isaaclab_ovphysx.sim.views.rst	New RST page wiring the sim.views module into the API docs via automodule.
docs/source/api/index.rst	Adds sim.views entry to the isaaclab_ovphysx extension index.

Sequence Diagram

%%{init: {'theme': 'neutral'}}%%
sequenceDiagram
    participant CS as ContactSensor
    participant OPV as OvPhysxView
    participant PB as TensorBinding(RIGID_BODY_POSE)
    participant CB as ContactBinding

    CS->>OPV: OvPhysxView(physx, pattern, device)
    CS->>OPV: binding_for(TT.RIGID_BODY_POSE)
    OPV->>PB: physx.create_tensor_binding(RIGID_BODY_POSE)
    OPV-->>CS: _pose_binding (cached in _root_view._bindings)

    loop "Per step (track_pose=True)"
        CS->>OPV: read_into(TT.RIGID_BODY_POSE, _poses_flat_buf)
        OPV->>PB: binding.read(_read_view(dst))
    end

    Note over CS,CB: ContactBinding path unchanged
    CS->>CB: read_net_forces / read_force_matrix

    CS->>PB: _pose_binding.destroy()
    CS->>CS: "_pose_binding = None"
    Note over OPV: _root_view._bindings still holds destroyed PB

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sequenceDiagram
    participant CS as ContactSensor
    participant OPV as OvPhysxView
    participant PB as TensorBinding(RIGID_BODY_POSE)
    participant CB as ContactBinding

    CS->>OPV: OvPhysxView(physx, pattern, device)
    CS->>OPV: binding_for(TT.RIGID_BODY_POSE)
    OPV->>PB: physx.create_tensor_binding(RIGID_BODY_POSE)
    OPV-->>CS: _pose_binding (cached in _root_view._bindings)

    loop "Per step (track_pose=True)"
        CS->>OPV: read_into(TT.RIGID_BODY_POSE, _poses_flat_buf)
        OPV->>PB: binding.read(_read_view(dst))
    end

    Note over CS,CB: ContactBinding path unchanged
    CS->>CB: read_net_forces / read_force_matrix

    CS->>PB: _pose_binding.destroy()
    CS->>CS: "_pose_binding = None"
    Note over OPV: _root_view._bindings still holds destroyed PB

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Comments Outside Diff (1)

1. source/isaaclab_ovphysx/isaaclab_ovphysx/sensors/contact_sensor/contact_sensor.py, line 510-523 (link)

   _root_view not cleared on simulation stop

   _pose_binding.destroy() is called and _pose_binding is set to None, but _root_view is left alive with the destroyed binding still cached in _root_view._bindings[TT.RIGID_BODY_POSE]. _root_view._read_views also retains the float32 reinterpret of _poses_flat_buf. If anything calls _root_view.binding_for(TT.RIGID_BODY_POSE) between simulation stop and the next _initialize_impl, it gets a destroyed native handle back. The pattern is inconsistent: every other backend handle (_contact_binding, _pose_binding, _physx_instance) is explicitly nulled out, but the view that wraps _pose_binding is not. Add self._root_view = None after self._pose_binding = None to complete the teardown.

_{Reviews (1): Last reviewed commit: "Merge branch 'develop' into antoiner/fea..." | Re-trigger Greptile}

[AntoineRichard]

Fixed — _invalidate_initialize_callback now clears self._root_view alongside _pose_binding (commit b8453bd), so the destroyed pose binding the view caches is no longer reachable after a sim stop; _initialize_impl rebuilds a fresh view on the next play. The separate read-cache concern doesn't apply here: _poses_flat_buf is flat float32, so it's passed straight through to the binding and never cached.