I want to connect two meshes together without creating any holes at the connected part. Could you tell me how to do that?

[JihoKang24]

Hi devs,

When merging, I want to fill only the holes created at the connected part, without filling any other holes that are not at the connection
when we concate two mesh

mesh A

mesh B

when use merge and unitemesh I got this result

but check this img in your inspector I got a holes in connected area
How can I solve this problem?

always thank you for your helps

[Grantim]

Hello!

Neither merge nor union fill or stitch holes, so I suggest you need to Merge and Stich:

MeshLib/source/MRMesh/MRMeshFillHole.h

Lines 85 to 109 in 087f409

	/** \brief Stitches two holes in Mesh\n
	*
	* Build cylindrical patch to fill space between two holes represented by one of their edges each,\n
	* default metric: ComplexStitchMetric
	*
	* \image html fill/before_stitch.png "Before" width = 250cm
	* \image html fill/stitch.png "After" width = 250cm
	*
	* Next picture show, how newly generated faces can be smoothed
	* \ref MR::positionVertsSmoothly
	* \ref MR::subdivideMesh
	* \image html fill/stitch_smooth.png "Stitch with smooth" width = 250cm
	*
	* \param mesh mesh with hole
	* \param a EdgeId which represents 1st hole (should not have valid left FaceId)
	* \param b EdgeId which represents 2nd hole (should not have valid left FaceId)
	* \param params parameters of holes stitching
	*
	* \sa \ref fillHole
	* \sa \ref StitchHolesParams
	*/
	MRMESH_API void buildCylinderBetweenTwoHoles( Mesh & mesh, EdgeId a, EdgeId b, const StitchHolesParams& params = {} );
	/// this version finds holes in the mesh by itself and returns false if they are not found
	MRMESH_API bool buildCylinderBetweenTwoHoles( Mesh & mesh, const StitchHolesParams& params = {} );

https://meshlib.io/documentation/Cpp/group__FillHoleGroup.html#gaa096c69aa6c5cf97a783e92aa3a70157

If you know that these holes have exact matching by vertices you could also try uniteCloseVertices instead if buildCylinderBetweenTwoHoles:

MeshLib/source/MRMesh/MRMeshBuilder.h

Lines 91 to 97 in 087f409

	/// the function finds groups of mesh vertices located closer to each other than \param closeDist, and unites such vertices in one;
	/// then the mesh is rebuilt from the remaining triangles
	/// \param optionalVertOldToNew is the mapping of vertices: before -> after
	/// \param uniteOnlyBd if true then only boundary vertices can be united, all internal vertices (even close ones) will remain
	/// \return the number of vertices united, 0 means no change in the mesh
	MRMESH_API int uniteCloseVertices( Mesh & mesh, float closeDist, bool uniteOnlyBd = true,
	VertMap * optionalVertOldToNew = nullptr );

[JihoKang24]

thank you grant!