Crash inference bug fix

[mnabian]

PhysicsNeMo Pull Request

Description

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.
• The CHANGELOG.md is up to date with these changes.
• An issue is linked to this pull request.
• If I am implementing a new model or modifying any existing model, I have followed the Models Implementation Coding Standards.

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[greptile-apps]

Greptile Summary

This PR fixes a crash in the inference script by removing the tempfile.TemporaryDirectory + symlink approach (which was the source of the crash) and instead passing each run's directory path directly as data_dir to the dataset. It also adds multi-GPU inference documentation to the README and corrects a copyright year in d3plot_reader.py.

Key changes and issues found:

• Core fix (inference.py): Replaces the fragile tempfile + os.symlink pattern with a direct data_dir=run_path pass. This is simpler and avoids the symlink-related crash. The README is updated to document the new required directory layout (run_<ID>/ subfolders containing the run files).
• VTP output directory naming mismatch (inference.py:186): vtp_frames_dir is built from the run folder name (e.g., output_run_0), but vtp_reader.py creates its frame output directory from the VTP file stem (e.g., output_Run0 for Run0.vtp). Per the README's documented layout, these names differ — causing the os.path.isdir check to always fail and silently skip all VTP export despite inference completing normally.
• Stale comment (inference.py:158): The inline comment still references "tmpdir" even though the temporary directory mechanism was removed.
• Copyright year fix (d3plot_reader.py): Copyright year corrected from 2026 to 2025 — no functional impact.

Important Files Changed

Filename	Overview
examples/structural_mechanics/crash/inference.py	Removes tempfile+symlink approach and passes run_path directly as data_dir; introduces a naming mismatch between vtp_frames_dir (based on run folder name) and the output dirs created by vtp_reader.py (based on VTP filename stem), which will cause VTP export to always be skipped when filenames differ from run folder names.
examples/structural_mechanics/crash/d3plot_reader.py	Only changes copyright year from 2026 to 2025 — no functional changes.
examples/structural_mechanics/crash/README.md	Adds inference directory structure documentation and multi-GPU inference instructions; the documented run_<ID>/Run<N>.vtp layout highlights the naming discrepancy that could cause VTP export failure.

_{Last reviewed commit: d9c121d}

[greptile-apps]

_{3 files reviewed, 2 comments}

_{Edit Code Review Agent Settings | Greptile}

[mnabian]

/blossom-ci

[ktangsali]

LGTM