Stitching holes

Example of stitching holes (connect two holes with a cylinder)

• C++

  #include <MRMesh/MRMesh.h>
  #include <MRMesh/MRMeshFillHole.h>
  #include <MRMesh/MRMeshLoad.h>
  #include <MRMesh/MRMeshSave.h>
   
  int main()
  {
      // Load meshes
      auto meshARes = MR::MeshLoad::fromAnySupportedFormat( "meshAwithHole.stl" );
      auto meshBRes = MR::MeshLoad::fromAnySupportedFormat( "meshBwithHole.stl" );
   
      // Unite meshes
      MR::Mesh mesh = std::move( meshARes.value() );
      mesh.addMesh( meshBRes.value() );
   
      // Find holes (expect that there are exactly 2 holes)
      std::vector<MR::EdgeId> edges = mesh.topology.findHoleRepresentiveEdges();
      if ( edges.size() != 2 )
          return 1;
   
      // Connect two holes
      MR::StitchHolesParams params;
      params.metric = MR::getUniversalMetric( mesh );
      MR::buildCylinderBetweenTwoHoles( mesh, edges.front(), edges.back(), params );
   
      // Save result
      auto saveRes = MR::MeshSave::toAnySupportedFormat( mesh, "stitchedMesh.stl" );
   
      return 0;
  }

• Python

  import meshlib.mrmeshpy as mrmeshpy
   
  # Load meshes
  mesh_a = mrmeshpy.loadMesh("meshAwithHole.stl")
  mesh_b = mrmeshpy.loadMesh("meshBwithHole.stl")
   
  # Unite meshes
  mesh = mrmeshpy.mergeMeshes([mesh_a, mesh_b])
   
  # Find holes
  edges = mesh.topology.findHoleRepresentiveEdges()
   
  # Connect two holes
  params = mrmeshpy.StitchHolesParams()
  params.metric = mrmeshpy.getUniversalMetric(mesh)
  mrmeshpy.buildCylinderBetweenTwoHoles(mesh, edges[0], edges[1], params)
   
  # Save result
  mrmeshpy.saveMesh(mesh, "stitchedMesh.stl")

• C

  #include <MRCMesh/MRMesh.h>
  #include <MRCMesh/MRMeshFillHole.h>
  #include <MRCMesh/MRMeshLoad.h>
  #include <MRCMesh/MRMeshMetrics.h>
  #include <MRCMesh/MRMeshSave.h>
  #include <MRCMesh/MRMeshTopology.h>
  #include <MRCMisc/expected_MR_Mesh_std_string.h>
  #include <MRCMisc/expected_void_std_string.h>
  #include <MRCMisc/std_string.h>
  #include <MRCMisc/std_vector_MR_EdgeId.h>
   
  #include <stdio.h>
  #include <stdlib.h>
   
  int main( void )
  {
      int rc = EXIT_FAILURE;
   
      // Load meshes:
   
      // First mesh, which will be moved.
      MR_expected_MR_Mesh_std_string* meshEx = MR_MeshLoad_fromAnySupportedFormat_2( "meshA.stl", NULL, NULL );
      MR_Mesh* mesh = MR_expected_MR_Mesh_std_string_GetMutableValue( meshEx );
      if ( !mesh )
      {
          fprintf( stderr, "Failed to load mesh A: %s\n", MR_std_string_Data( MR_expected_MR_Mesh_std_string_GetError( meshEx ) ) );
          goto fail_mesh_loading_a;
      }
   
      // Second mesh, static.
      MR_expected_MR_Mesh_std_string* mesh2Ex = MR_MeshLoad_fromAnySupportedFormat_2( "meshB.stl", NULL, NULL );
      MR_Mesh* mesh2 = MR_expected_MR_Mesh_std_string_GetMutableValue( mesh2Ex );
      if ( !mesh2 )
      {
          fprintf( stderr, "Failed to load mesh B: %s\n", MR_std_string_Data( MR_expected_MR_Mesh_std_string_GetError( mesh2Ex ) ) );
          goto fail_mesh_loading_b;
      }
   
      // Unite meshes
      MR_Mesh_addMesh_3( mesh, mesh2, NULL, NULL );
   
      // Find holes (expect that there are exactly 2 holes)
      MR_std_vector_MR_EdgeId* edges = MR_MeshTopology_findHoleRepresentiveEdges( MR_Mesh_Get_topology( mesh ), NULL );
      if ( MR_std_vector_MR_EdgeId_Size( edges ) != 2 )
      {
          fprintf( stderr, "Expected exactly 2 holes to stitch, but found %zu\n", MR_std_vector_MR_EdgeId_Size( edges ) );
          goto fail_not_two_holes;
      }
   
      // Connect two holes
      MR_StitchHolesParams* params = MR_StitchHolesParams_DefaultConstruct();
   
      MR_FillHoleMetric* metric = MR_getUniversalMetric( mesh );
      MR_StitchHolesParams_Set_metric( params, MR_PassBy_Move, metric );
      MR_FillHoleMetric_Destroy( metric );
   
      // We also have a version of this function (`MR_buildCylinderBetweenTwoHoles_2()`) that finds the two holes automatically.
      // Here we've found them manually for demonstration purposes.
      MR_buildCylinderBetweenTwoHoles_4( mesh, *MR_std_vector_MR_EdgeId_At( edges, 0 ), *MR_std_vector_MR_EdgeId_At( edges, 1 ), params );
      MR_StitchHolesParams_Destroy( params );
   
      // Save result
      MR_expected_void_std_string* saveEx = MR_MeshSave_toAnySupportedFormat_3( mesh, "MeshStitched.stl", NULL, NULL);
      if ( MR_expected_void_std_string_GetError( saveEx ) )
      {
          fprintf( stderr, "Failed to save mesh: %s\n", MR_std_string_Data( MR_expected_void_std_string_GetError( saveEx ) ) );
          goto fail_save;
      }
   
      rc = EXIT_SUCCESS;
  fail_save:
      MR_expected_void_std_string_Destroy( saveEx );
  fail_not_two_holes:
      MR_std_vector_MR_EdgeId_Destroy( edges );
  fail_mesh_loading_b:
      MR_expected_MR_Mesh_std_string_Destroy( mesh2Ex );
  fail_mesh_loading_a:
      MR_expected_MR_Mesh_std_string_Destroy( meshEx );
      return rc;
  }