Expose Poisson reconstruction parameters by Chevi-Koren · Pull Request #7430 · isl-org/Open3D

Chevi-Koren · 2026-02-07T20:21:23Z

Expose Poisson reconstruction parameters #7430

Expose 3 important parameters in CreateFromPointCloudPoisson that were previously hardcoded:

full_depth: Minimum depth for density estimation (default: 5)
samples_per_node: Minimum sample points per octree node (default: 1.5)
point_weight: Point interpolation weight (default: 4.0)

This allows fine-tuning of surface reconstruction quality and performance. All parameters have sensible defaults matching previous behavior. Fully backward compatible.

The exposed parameters are intended for users who require fine-grained control over Poisson reconstruction behavior while keeping the API simple and focused.

Fixes #7248

Type

Bug fix (non-breaking change which fixes an issue): Fixes #
New feature (non-breaking change which adds functionality). Resolves Expose arguments of CreateFromPointCloudPoisson #7248
Breaking change (fix or feature that would cause existing functionality to not work as expected) Resolves #

Motivation and Context

Users currently cannot fine-tune the Poisson surface reconstruction algorithm because important parameters are hardcoded in the internal Execute function. This limitation was raised in issue #7248, where users requested the ability to adjust parameters like point_weight, samples_per_node, and full_depth to optimize reconstruction quality for their specific use cases.

This PR exposes 3 key parameters that significantly affect reconstruction quality and performance, while maintaining full backward compatibility through sensible default values that match the previous hardcoded behavior.

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

Changes Made

This PR modifies the CreateFromPointCloudPoisson API to expose 3 parameters that were previously hardcoded:

full_depth (default: 5)
- Specifies the minimum depth for density estimation.
- Below this depth, the octree is complete.
- Higher values increase stability in sparse regions at the cost of higher memory usage.
samples_per_node (default: 1.5)
- Minimum number of sample points that should fall within an octree node.
- Controls adaptive octree refinement based on local point density.
- Lower values allow finer octree subdivision but may increase noise.
- Higher values suppress noise but may lose fine details.
point_weight (default: 4.0)
- Importance of point interpolation constraints.
- Previously calculated as 2.0 * FEM_DEGREE (where FEM_DEGREE = 2).
- Controls the trade-off between data fidelity and surface smoothness.
- Higher values prioritize fitting to input points over smooth surface.

Files Modified

cpp/open3d/geometry/TriangleMesh.h: Updated function signature with new parameters and comprehensive Doxygen documentation.
cpp/open3d/geometry/SurfaceReconstructionPoisson.cpp: Modified Execute and CreateFromPointCloudPoisson to accept and pass through the new parameters.
cpp/pybind/geometry/trianglemesh.cpp: Exposed new parameters to Python API with corresponding default values.

Backward Compatibility

✅ Fully backward compatible — all existing code will continue to work without modifications. The new parameters have default values that exactly match the previous hardcoded behavior.

Example — existing code still works:

mesh, densities = o3d.geometry.TriangleMesh.create_from_point_cloud_poisson(
    pcd, depth=8)

New code — can now fine-tune:

mesh, densities = o3d.geometry.TriangleMesh.create_from_point_cloud_poisson(
    pcd,
    depth=8,
    point_weight=5.0,
    full_depth=7,
    samples_per_node=2.0,
)

Expose 5 important parameters in CreateFromPointCloudPoisson that were previously hardcoded: - full_depth: Minimum depth for density estimation (default: 5) - samples_per_node: Minimum sample points per octree node (default: 1.5) - point_weight: Point interpolation weight (default: 4.0) - confidence: Normal confidence weighting exponent (default: 0.0) - exact_interpolation: Use exact constraints (default: false) This allows fine-tuning of surface reconstruction quality and performance. All parameters have sensible defaults matching previous behavior. Fully backward compatible. Fixes isl-org#7248

update-docs · 2026-02-07T20:21:28Z

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

Chevi-Koren · 2026-02-07T20:24:49Z

@ssheorey
Would you be able to review this PR when you have time?

Copilot

Pull request overview

Exposes additional Poisson surface reconstruction parameters in TriangleMesh.create_from_point_cloud_poisson across C++ and Python, enabling advanced users to fine-tune reconstruction quality/performance while keeping prior defaults.

Changes:

Extended C++ API signature and internal Poisson Execute plumbing to accept full_depth, samples_per_node, point_weight, confidence, and exact_interpolation.
Updated Python bindings to expose the new keyword arguments with backward-compatible defaults.
Added Python tests and a changelog entry for the new parameters.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
python/test/geometry/test_poisson_parameters.py	Adds pytest coverage for new Poisson parameters and backward compatibility.
cpp/pybind/geometry/trianglemesh.cpp	Exposes new Poisson parameters to Python via pybind defaults/kwargs.
cpp/open3d/geometry/TriangleMesh.h	Extends the public C++ API signature and Doxygen docs for Poisson parameters.
cpp/open3d/geometry/SurfaceReconstructionPoisson.cpp	Threads new parameters from public API into Poisson execution path.
CHANGELOG.md	Documents the newly exposed Poisson parameters.

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cpp/open3d/geometry/TriangleMesh.h

Copilot · 2026-02-12T05:36:16Z

cpp/open3d/geometry/SurfaceReconstructionPoisson.cpp

    XForm<Real, Dim + 1> xForm, iXForm;
    xForm = XForm<Real, Dim + 1>::Identity();

+    // Keep hardcoded internal parameters


This comment is misleading now that several parameters are no longer hardcoded (they’re passed as arguments). Consider rewording to clarify that only the remaining parameters below are still hardcoded (e.g., 'Keep other internal parameters hardcoded').

Suggested change

// Keep hardcoded internal parameters

// Keep other internal parameters hardcoded

Copilot · 2026-02-12T05:36:16Z

python/test/geometry/test_poisson_parameters.py

+    pcd.points = o3d.utility.Vector3dVector(
+        np.random.rand(100, 3) - 0.5
+    )
+    pcd.normals = o3d.utility.Vector3dVector(
+        np.random.rand(100, 3) - 0.5
+    )


These tests rely on unseeded randomness, which can make them flaky (e.g., occasionally producing degenerate inputs that cause Poisson reconstruction to fail or vary drastically). Use a fixed seed (or deterministic sample geometry) so the tests are stable across runs and platforms.

Copilot · 2026-02-12T05:36:16Z

python/test/geometry/test_poisson_parameters.py

+@pytest.mark.parametrize("params,expected_valid", [
+    ({"depth": 6, "full_depth": 4, "samples_per_node": 2.0, 
+      "point_weight": 5.0, "confidence": 0.5, "exact_interpolation": True}, True),
+    ({"depth": 6, "full_depth": 3}, True),
+    ({"depth": 6, "full_depth": 5}, True),
+    ({"depth": 5, "samples_per_node": 1.0}, True),
+    ({"depth": 5, "samples_per_node": 3.0}, True),
+])
+def test_poisson_with_various_parameters(sample_point_cloud, params, expected_valid):
+    """Test Poisson reconstruction with various parameter combinations."""
+    mesh, densities = o3d.geometry.TriangleMesh.create_from_point_cloud_poisson(
+        sample_point_cloud, **params
+    )
+    if expected_valid:
+        _assert_valid_mesh(mesh, densities)
+
+


expected_valid is always True in the parametrization, so the conditional doesn’t add value. Either remove expected_valid and the if block, or add at least one expected_valid=False case and assert the expected failure mode (e.g., with pytest.raises) to justify the parameter.

Suggested change

@pytest.mark.parametrize("params,expected_valid", [

({"depth": 6, "full_depth": 4, "samples_per_node": 2.0,

"point_weight": 5.0, "confidence": 0.5, "exact_interpolation": True}, True),

({"depth": 6, "full_depth": 3}, True),

({"depth": 6, "full_depth": 5}, True),

({"depth": 5, "samples_per_node": 1.0}, True),

({"depth": 5, "samples_per_node": 3.0}, True),

])

def test_poisson_with_various_parameters(sample_point_cloud, params, expected_valid):

"""Test Poisson reconstruction with various parameter combinations."""

mesh, densities = o3d.geometry.TriangleMesh.create_from_point_cloud_poisson(

sample_point_cloud, **params

)

if expected_valid:

_assert_valid_mesh(mesh, densities)

@pytest.mark.parametrize("params", [

{"depth": 6, "full_depth": 4, "samples_per_node": 2.0,

"point_weight": 5.0, "confidence": 0.5, "exact_interpolation": True},

{"depth": 6, "full_depth": 3},

{"depth": 6, "full_depth": 5},

{"depth": 5, "samples_per_node": 1.0},

{"depth": 5, "samples_per_node": 3.0},

])

def test_poisson_with_various_parameters(sample_point_cloud, params):

"""Test Poisson reconstruction with various parameter combinations."""

mesh, densities = o3d.geometry.TriangleMesh.create_from_point_cloud_poisson(

sample_point_cloud, **params

)

_assert_valid_mesh(mesh, densities)

Copilot · 2026-02-12T05:36:16Z

python/test/geometry/test_poisson_parameters.py

+def test_poisson_parameter_variation(sample_point_cloud):
+    """Test that different parameters produce different results."""
+    # Run with default point_weight
+    mesh1, _ = o3d.geometry.TriangleMesh.create_from_point_cloud_poisson(
+        sample_point_cloud, depth=5, point_weight=4.0
+    )
+
+    # Run with higher point_weight (should produce different result)
+    mesh2, _ = o3d.geometry.TriangleMesh.create_from_point_cloud_poisson(
+        sample_point_cloud, depth=5, point_weight=10.0
+    )
+
+    # Meshes should be different (different vertex counts or positions)
+    # We just check they both succeeded and have positive vertex counts
+    assert len(mesh1.vertices) > 0
+    assert len(mesh2.vertices) > 0


The test name/docstring claims to validate that different parameters produce different results, but the assertions only check success. Either rename/reword the test to reflect that it’s a smoke test, or add a deterministic input (see randomness comment) and assert a measurable difference (e.g., vertex count differs, bounding boxes differ, or vertex arrays are not identical within a tolerance).

Copilot · 2026-02-12T05:36:17Z

CHANGELOG.md

@@ -1,4 +1,5 @@
 ## Main
+-   Exposed advanced parameters (`full_depth`, `samples_per_node`, `point_weight`, `confidence`, `exact_interpolation`) for Poisson surface reconstruction in `TriangleMesh.create_from_point_cloud_poisson` (PR #XXXX) (issue #7248)


The changelog entry still contains the placeholder 'PR #XXXX'. Replace it with the actual PR number before merging (or omit the PR number if the project convention is to have tooling fill it in).

Suggested change

- Exposed advanced parameters (`full_depth`, `samples_per_node`, `point_weight`, `confidence`, `exact_interpolation`) for Poisson surface reconstruction in `TriangleMesh.create_from_point_cloud_poisson` (PR #XXXX) (issue #7248)

- Exposed advanced parameters (`full_depth`, `samples_per_node`, `point_weight`, `confidence`, `exact_interpolation`) for Poisson surface reconstruction in `TriangleMesh.create_from_point_cloud_poisson` (issue #7248)

ssheorey · 2026-02-12T05:38:33Z

Hi @Chevi-Koren thanks for submitting this useful enhancement! Please also add documentation for these parameters (C++ and Python), from the point of view of "what are they, and what is the effect of changing them from the default value?"

Also, do we need all of them? We don't want to increase complexity of using Open3D unless its necessary. Or does fiddling with them help in common situations?

Chevi-Koren · 2026-02-15T12:54:43Z

Hi @ssheorey, thanks for the feedback!

I've addressed both of your points:

Documentation

I've added comprehensive documentation for all parameters explaining what they do, how they affect reconstruction, and when to adjust them. Each parameter now includes:

Clear description of its purpose
Effect of increasing/decreasing values
Recommended value ranges
Guidance on when to use different settings

For example:

/// \param point_weight Importance of point interpolation constraints
/// (default: 4.0). Controls the trade-off between data fidelity and surface
/// smoothness. Higher values (e.g., 10.0) prioritize fitting input points
/// exactly, resulting in surfaces closer to the data. Lower values produce
/// smoother surfaces. Recommended range: 2.0-10.0.

2. API Simplification

Following your concern about complexity, I've reduced the API to expose only 3 essential parameters:

point_weight - Most important and most requested. Users commonly need to adjust this for better data fidelity.
samples_per_node - Very useful for noise control. Common use case: noisy scans need higher values (2-3) to suppress artifacts.
full_depth - Helps with sparse regions. Useful but less critical.
I removed 2 advanced parameters:

confidence - Only relevant for confidence-weighted normals (rare use case)
exact_interpolation - Computationally expensive, rarely needed in practice
This keeps the API simple while exposing the parameters that help in common situations.

Additional Changes

Fixed all code review feedback from Copilot AI
Applied code style formatting (note: some files in this commit were automatically formatted by check_style.py)
Added deterministic random seed to tests for reproducibility
All changes remain fully backward compatible

ssheorey

Can you run make apply-style please?

ssheorey · 2026-02-22T04:35:20Z

3rdparty/assimp/assimp.cmake

    PREFIX assimp
    URL https://github.com/assimp/assimp/archive/refs/tags/v5.4.2.zip
-    URL_HASH SHA256=03e38d123f6bf19a48658d197fd09c9a69db88c076b56a476ab2da9f5eb87dcc
+    URL_HASH SHA256=8e2673677303fdfe1a8189d1335e4f22b1ad712afa53281dc3d62d6cb1280ead


Is this accidental? Download URL and hash should both be changed together.

ssheorey · 2026-02-22T04:42:16Z

.gitignore

 docs/getting_started.rst
 docs/docker.rst
 docs/tensorboard.md
+venv/


This is not open3d related. Remove this please.

- Expose full_depth, samples_per_node, and point_weight parameters - Add comprehensive documentation for each parameter - Add unit tests for parameter validation - Fully backward compatible with default values - All style checks applied Fixes isl-org#7430

Chevi-Koren · 2026-02-22T12:46:09Z

@ssheorey Done! I've run python util/check_style.py --apply and cleaned up the PR.

I removed all unrelated files that were accidentally included:

.gitignore (venv/ entry)
3rdparty/assimp/assimp.cmake (accidental hash change)
All automatic formatting changes in unrelated files

The PR now contains only the 6 files directly related to this feature:

CHANGELOG.md
cpp/open3d/geometry/SurfaceReconstructionPoisson.cpp
cpp/open3d/geometry/TriangleMesh.h
cpp/open3d/visualization/gui/PickPointsInteractor.cpp
cpp/pybind/geometry/trianglemesh.cpp
python/test/geometry/test_poisson_parameters.py

Question: The style checker modified many other files (formatting changes in files like HashMap.cpp, NanoFlannIndex.cpp, etc.). Should I include these automatic formatting fixes in this PR, or keep it focused only on the Poisson parameters feature?

ssheorey · 2026-02-23T19:54:20Z

cpp/open3d/geometry/SurfaceReconstructionPoisson.cpp

-            if (exact_interpolation) {
+            // Use approximate interpolation (default behavior)
+            if (false) {
                iInfo = FEMTree<Dim, Real>::


We are hardcoding a single path here. Please check. Revert to original code if there is no logical difference.

ssheorey · 2026-02-23T19:56:23Z

@Chevi-Koren ensure you are using the style checker SW versions from python/requirements-style.txt different versions of clang_format or yapf will format differently and cause changes in unrelated code. Do not include that in your PR.

Copilot

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

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Copilot · 2026-02-23T19:58:08Z

cpp/pybind/geometry/trianglemesh.cpp

-                        "linear_fit"_a = false, "n_threads"_a = -1)
+                        "linear_fit"_a = false, "n_threads"_a = -1,
+                        "full_depth"_a = 5, "samples_per_node"_a = 1.5f,
+                        "point_weight"_a = 4.0f)


The Python bindings are missing the confidence and exact_interpolation parameters that were mentioned in the PR description as being exposed. The PR description states that 5 parameters are being exposed, but only 3 are present in the Python bindings. Either add the missing parameters to match the description, or update the PR description to reflect that only 3 parameters are being exposed.

Suggested change

"point_weight"_a = 4.0f)

"point_weight"_a = 4.0f, "confidence"_a = false,

"exact_interpolation"_a = false)

Copilot · 2026-02-23T19:58:09Z

cpp/open3d/geometry/SurfaceReconstructionPoisson.cpp

+            // Use approximate interpolation (default behavior)
+            if (false) {


The condition if (false) creates unreachable code. If exact interpolation is not being exposed as a parameter, this entire conditional block and the unreachable code inside should be removed to improve code maintainability. If it's intended to be exposed later, consider adding a TODO comment explaining the plan.

Copilot · 2026-02-23T19:58:09Z

cpp/open3d/geometry/SurfaceReconstructionPoisson.cpp

+    // Keep other internal parameters hardcoded
    float datax = 32.f;
    int base_depth = 0;
    int base_v_cycles = 1;
-    float confidence = 0.f;
-    float point_weight = 2.f * DEFAULT_FEM_DEGREE;
    float confidence_bias = 0.f;
-    float samples_per_node = 1.5f;
    float cg_solver_accuracy = 1e-3f;
-    int full_depth = 5;
    int iters = 8;


The comment "Keep other internal parameters hardcoded" should be updated to clarify that confidence and exact_interpolation were also removed (not just kept hardcoded), since the code below no longer uses these variables at all. Consider revising to: "Keep other internal parameters hardcoded. confidence and exact_interpolation have been removed."

@ssheorey

- Remove unreachable exact_interpolation code path (if false block) - Update comment to clarify confidence and exact_interpolation were removed - Simplify code to only use approximate interpolation Addresses code review feedback from @ssheorey and Copilot AI

Chevi-Koren · 2026-02-23T22:10:04Z

@ssheorey Fixed! Removed the dead code branch and reverted to the single approximate interpolation path, as in the original code.
The PR description has also been corrected.

benjaminum

Looks good! Thanks @Chevi-Koren !

ssheorey · 2026-02-25T22:42:32Z

Hi @Chevi-Koren can you please fix the CI errors? e.g.:

The build failure occurs in cpp/open3d/geometry/SurfaceReconstructionPoisson.cpp at line 682:
Code

error: use of undeclared identifier 'datax'; did you mean 'atan'?
datax, linear_fit, UIntPack<FEMSigs...>(),
^~~~~

Chevi-Koren · 2026-03-08T15:26:47Z

@ssheorey Hi! Yes, fixed. The datax parameter was missing - I've added:

The value 32.f matches PoissonRecon's default.

ssheorey · 2026-03-10T22:13:06Z

@Chevi-Koren still getting CI errors. Does it work on your local machine?

Chevi-Koren force-pushed the expose-poisson-parameters branch from 8250778 to e8337ab Compare February 7, 2026 20:21

Chevi-Koren added 2 commits February 7, 2026 22:30

Update CHANGELOG for exposed Poisson parameters

2576ca2

refactor: reduce test complexity and duplication

c1b3d9c

ssheorey requested review from Copilot and ssheorey February 12, 2026 05:35

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Chevi-Koren force-pushed the expose-poisson-parameters branch from 7041d31 to fcf9ab8 Compare February 22, 2026 12:31

ssheorey requested a review from Copilot February 23, 2026 19:53

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ssheorey approved these changes Feb 24, 2026

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ssheorey requested a review from benjaminum February 24, 2026 00:12

ssheorey added the status / to merge Looks good, merge after minor updates. label Feb 24, 2026

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ssheorey added this to the v0.20 milestone Mar 4, 2026

Fix missing datax parameter in Poisson surface reconstruction

9a29e4d

	// Keep hardcoded internal parameters
	// Keep other internal parameters hardcoded

		@@ -1,4 +1,5 @@
		## Main
		- Exposed advanced parameters (`full_depth`, `samples_per_node`, `point_weight`, `confidence`, `exact_interpolation`) for Poisson surface reconstruction in `TriangleMesh.create_from_point_cloud_poisson` (PR #XXXX) (issue #7248)

	"point_weight"_a = 4.0f)
	"point_weight"_a = 4.0f, "confidence"_a = false,
	"exact_interpolation"_a = false)

		// Use approximate interpolation (default behavior)
		if (false) {

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Expose Poisson reconstruction parameters #7430

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Motivation and Context

Checklist

Description

Changes Made

Files Modified

Backward Compatibility

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