Delegates close stage logic in SimulationContext to Stage utility

[ooctipus]

Description

This PR refactors the code further

Removes remaining refactorable omni.usd usage

Refactores SimulationContext.clear_instance to delegate stage teardown to
isaaclab.sim.utils.close_stage instead of manually clearing the stage cache,
thread-local context, and Kit USD context inline.

Updates isaaclab.sim.utils.close_stage to also close the Kit USD context stage
(omni.usd.get_context().close_stage()) when Kit is running, making it a complete
stage teardown function.

Fixes # (issue)

Type of change

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

Screenshots

Please attach before and after screenshots of the change if applicable.

Checklist

• I have read and understood the contribution guidelines
• I have run the pre-commit checks 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

[greptile-apps]

Greptile Summary

This PR successfully refactors stage teardown logic by consolidating stage cleanup into the close_stage() utility function. The main changes delegate SimulationContext.clear_instance() stage teardown to stage_utils.close_stage(), which now handles stage cache clearing, thread-local context cleanup, and Kit USD context stage closure in one place. Additionally, the PR removes remaining direct dependencies on omni.usd across scripts by replacing calls with IsaacLab's unified sim_utils API (get_current_stage() and close_stage()).

Key changes:

• Enhanced close_stage() to close Kit USD context stage when Kit is running, making it symmetric with stage initialization
• Removed manual stage cache and context management from SimulationContext.clear_instance() in favor of centralized close_stage() call
• Replaced 5 script files' direct omni.usd usage with sim_utils wrappers for better abstraction
• Cleaned up unused omni.usd import from prims.py

Confidence Score: 5/5

• This PR is safe to merge with minimal risk - it's a clean refactoring that consolidates existing logic
• The refactoring consolidates duplicate stage teardown code into a single utility function without changing behavior. All replacements are semantically equivalent (e.g., omni.usd.get_context().get_stage() → sim_utils.get_current_stage()), and the enhanced close_stage() now properly handles all cleanup that was previously done inline. The changes improve maintainability by reducing code duplication and removing direct omni.usd dependencies.
• No files require special attention

Important Files Changed

Filename	Overview
source/isaaclab/isaaclab/sim/utils/stage.py	Enhanced close_stage() to also close Kit USD context stage when Kit is running, making it a complete stage teardown utility
source/isaaclab/isaaclab/sim/simulation_context.py	Refactored clear_instance() to delegate stage teardown to stage_utils.close_stage() instead of manually managing stage cache and contexts
scripts/environments/teleoperation/teleop_se3_agent.py	Replaced omni.usd.get_context().close_stage() with sim_utils.close_stage() to use centralized stage closing utility
scripts/tools/record_demos.py	Replaced omni.usd.get_context().close_stage() with sim_utils.close_stage() to use centralized stage closing utility

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[SimulationContext.clear_instance] --> B{Stage Teardown}
    B --> C[stage_utils.close_stage]
    C --> D[Clear UsdUtils.StageCache]
    C --> E[Set _context.stage = None]
    C --> F{Kit Running?}
    F -->|Yes| G[omni.usd.get_context.close_stage]
    F -->|No| H[Skip Kit Context Cleanup]
    
    I[Script Files] --> J{Stage Access}
    J -->|Get Stage| K[sim_utils.get_current_stage]
    J -->|Close Stage| L[sim_utils.close_stage]
    
    K -.->|abstracts| M[omni.usd.get_context.get_stage]
    L -.->|abstracts| G
    
    style C fill:#90EE90
    style A fill:#87CEEB
    style I fill:#FFD700

Loading

_{Last reviewed commit: d873772}

[greptile-apps]

_{10 files reviewed, no comments}

_{Edit Code Review Agent Settings | Greptile}