how to remove this area?

[JihoKang24]

hello devs

when I subtract two mesh i got this result

I want to remove this thin area contains open mesh
what function can I use? for remove

I used MRMeshThickness but hard too specific area.

thank you for your helps

[Grantim]

Hello!

There are different ways to detect and remove this area:

1. Find too sharp edges and near area
2. Find overlaps area
3. Avoid them by offsetting "sub" mesh before boolean

Find too sharp edges and near area

Find sharp edges:

MeshLib/source/MRMesh/MRMesh.h

Lines 295 to 296 in 2505496

	/// finds all mesh edges where dihedral angle is distinct from planar PI angle on at least given value
	[[nodiscard]] MRMESH_API UndirectedEdgeBitSet findCreaseEdges( float angleFromPlanar ) const;

Convert to incident faces:

MeshLib/source/MRMesh/MRRegionBoundary.h

Lines 87 to 88 in 2505496

	/// composes the set of all faces incident to given edges
	[[nodiscard]] MRMESH_API FaceBitSet getIncidentFaces( const MeshTopology & topology, const UndirectedEdgeBitSet & edges );

Expand if needed:

MeshLib/source/MRMesh/MRExpandShrink.h

Lines 8 to 9 in 2505496

	/// adds to the region all faces within given number of hops (stars) from the initial region boundary
	MRMESH_API void expand( const MeshTopology & topology, FaceBitSet & region, int hops = 1 );

mesh.deleteFaces( ... ) than.

Find overlaps area

MeshLib/source/MRMesh/MROverlappingTris.h

Lines 9 to 22 in 2505496

	struct FindOverlappingSettings
	{
	/// maximal distance between closest points of one triangle and another overlapping triangle
	float maxDistSq = 1e-10f; // suggestion: multiply it on mesh.getBoundingBox().size().lengthSq();
	/// maximal dot product of one triangle and another overlapping triangle normals
	float maxNormalDot = -0.99f;
	/// consider triangle as overlapping only if the area of the oppositely oriented triangle is at least given fraction of the triangle's area
	float minAreaFraction = 1e-5f;
	/// for reporting current progress and allowing the user to cancel the algorithm
	ProgressCallback cb;
	};
	/// finds all triangles that have oppositely oriented close triangle in the mesh
	[[nodiscard]] MRMESH_API Expected<FaceBitSet> findOverlappingTris( const MeshPart & mp, const FindOverlappingSettings & settings );

mesh.deleteFaces( ... ) than.

Avoid them by offsetting "sub" mesh before boolean

Offset mesh B a little bit before boolean

MeshLib/source/MRVoxels/MROffset.h

Lines 101 to 108 in 2505496

	struct GeneralOffsetParameters : SharpOffsetParameters
	{
	using Mode = MR::OffsetMode;
	Mode mode = Mode::Standard;
	};
	/// Offsets mesh by converting it to voxels and back using one of three modes specified in the parameters
	[[nodiscard]] MRVOXELS_API Expected<Mesh> generalOffsetMesh( const MeshPart& mp, float offset, const GeneralOffsetParameters& params );

Perform booelan(...) than.