Add use_normal_length_as_confidence parameter to Poisson surface reconstruction

[shlok-ramlab]

Type

• Bug fix (non-breaking change which fixes an issue): Fixes #
• New feature (non-breaking change which adds functionality). Resolves #
• Breaking change (fix or feature that would cause existing functionality to not work as expected) Resolves #

Motivation and Context

Poisson surface reconstruction uses a confidence value to weight the influence of each point during reconstruction. By default, all points are weighted equally (confidence = 0). This change exposes a use_normal_length_as_confidence flag that passes the normal vector lengths as per-point confidence to the Poisson solver.

Checklist:

• I have run python util/check_style.py --apply to apply Open3D code style
  to my code.
• This PR changes Open3D behavior or adds new functionality.
  • Both C++ (Doxygen) and Python (Sphinx / Google style) documentation is
    updated accordingly.
  • I have added or updated C++ and / or Python unit tests OR included test
    results (e.g. screenshots or numbers) here.
• I will follow up and update the code if CI fails.
• For fork PRs, I have selected Allow edits from maintainers.

Description

Adds a use_normal_length_as_confidence boolean parameter (default false) to TriangleMesh.create_from_point_cloud_poisson(). When set to True, the Poisson solver uses confidence=1, which causes it to use the magnitude of each point's normal vector as a per-point confidence weight. This is a non-breaking change.

No unit test was added as the change is a single boolean flag affecting a well tested solver, let me know if that's needed.

[update-docs]

Thanks for submitting this pull request! The maintainers of this repository would appreciate if you could update the CHANGELOG.md based on your changes.

[Copilot]

Pull request overview

This PR exposes a new use_normal_length_as_confidence boolean flag on Poisson surface reconstruction (TriangleMesh::CreateFromPointCloudPoisson / TriangleMesh.create_from_point_cloud_poisson) to optionally weight samples using the magnitude of their input normals.

Changes:

• Add use_normal_length_as_confidence parameter to the C++ TriangleMesh::CreateFromPointCloudPoisson API (default false).
• Thread the new flag into the Poisson reconstruction implementation to enable “confidence” handling.
• Expose the flag in the Python binding and add parameter documentation.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

File	Description
cpp/pybind/geometry/trianglemesh.cpp	Adds the new Python-exposed argument and corresponding docstring entry.
cpp/open3d/geometry/TriangleMesh.h	Extends the public C++ API with the new optional parameter and Doxygen docs.
cpp/open3d/geometry/SurfaceReconstructionPoisson.cpp	Wires the new flag into the Poisson execution path by enabling confidence handling.

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[shlok-ramlab]

@benjaminum Reminding for the review! Let me know if anything is missing.