[Cleanup] Remove unused Polygon3 dependency (#1528)

[SHAI-Akshay-Tripathi]

Summary

Closes #1528.

Polygon3 was listed in two requirements files but is not imported or used
anywhere in the codebase. As noted in #1528, the package bundles the GPC
component which carries proprietary licensing terms (Other/Proprietary License on PyPI), which can create friction for commercial users.

Changes

• Removed Polygon3 from requirements.txt
• Removed Polygon3 from vlmeval/dataset/utils/Ocrbench_v2/requirements.txt

Verification

Searched the full codebase for any usage of Polygon3 / GPC:

[TianhaoLiang2000]

Thanks for the cleanup.

Could you please double-check this dependency before removing it? Polygon3 appears to be used by OCRBench v2: spotting_eval/script.py dynamically imports Polygon and uses plg.Polygon(...) for text spotting evaluation. This path is reached from OCRBench v2’s text spotting en metric, so removing the requirement may break that benchmark.

[SHAI-Akshay-Tripathi]

You're right, thanks for catching this — my verification was flawed. I grepped for Polygon3, but the package imports as Polygon, and in spotting_eval/script.py it's loaded dynamically via importlib.import_module('Polygon') (from the evaluation_imports() dict), so there's no literal import line to find. It's then used in plg.Polygon(...) at lines 100 and 115, with no try/except fallback.
I confirmed the path is live: OCRBench_v2 → ocrbrnch_v2_eval.py → the "text spotting en" branch (line 344) → spotting_evaluation(...) → spotting_metric.py → script.py. So removing the dependency would break OCRBench v2 text spotting, exactly as you noted.
Closing this since the "unused" premise doesn't hold. Sorry for the noise!