Mesh extrude

Example of extrude faces on mesh

• C++

  #include <MRMesh/MRBitSet.h>
  #include <MRMesh/MRBitSetParallelFor.h>
  #include <MRMesh/MRId.h>
  #include <MRMesh/MRMesh.h>
  #include <MRMesh/MRMeshExtrude.h>
  #include <MRMesh/MRMeshLoad.h>
  #include <MRMesh/MRMeshSave.h>
  #include <MRMesh/MRRegionBoundary.h>
   
  #include <iostream>
   
  int main()
  {
      // Load mesh
      auto loadRes = MR::MeshLoad::fromAnySupportedFormat( "mesh.stl" );
      if ( !loadRes.has_value() )
      {
          std::cerr << loadRes.error() << std::endl;
          return 1;
      }
      MR::Mesh& mesh = *loadRes;
   
      // Select faces to extrude
      MR::FaceBitSet facesToExtrude;
      facesToExtrude.autoResizeSet( MR::FaceId( 1 ) );
      facesToExtrude.autoResizeSet( MR::FaceId( 2 ) );
   
      // Create duplicated verts on region boundary
      MR::makeDegenerateBandAroundRegion( mesh, facesToExtrude );
   
      // Find vertices that will be moved
      auto vertsForMove = MR::getIncidentVerts( mesh.topology, facesToExtrude );
   
      MR::BitSetParallelFor( vertsForMove, [&] ( MR::VertId v )
      {
          // Move each vertex
          mesh.points[v] += MR::Vector3f::plusZ();
      } );
   
      // Invalidate internal caches after manual changing
      mesh.invalidateCaches();
   
      // Save mesh
      if ( auto saveRes = MR::MeshSave::toAnySupportedFormat( mesh, "extrudedMesh.stl" ); !saveRes )
      {
          std::cerr << saveRes.error() << std::endl;
          return 1;
      }
  }

• Python

  import meshlib.mrmeshpy as mrmeshpy
   
  # Load mesh
  mesh = mrmeshpy.loadMesh("mesh.stl")
   
  # Prepare region to extrude
  faces_to_extrude = mrmeshpy.FaceBitSet()
  faces_to_extrude.resize(3, False)
  faces_to_extrude.set(mrmeshpy.FaceId(1), True)
  faces_to_extrude.set(mrmeshpy.FaceId(2), True)
   
  # Create duplicated verts on region boundary
  mrmeshpy.makeDegenerateBandAroundRegion(mesh, faces_to_extrude)
   
  # Find vertices that will be moved
  verts_for_move = mrmeshpy.getIncidentVerts(mesh.topology, faces_to_extrude)
   
  # Move each vertex
  for v in range(verts_for_move.size()):
      if verts_for_move.test(mrmeshpy.VertId(v)):
          mesh.points.vec[v] += mrmeshpy.Vector3f(0.0, 0.0, 1.0)
   
  # Invalidate internal caches after manual changing
  mesh.invalidateCaches()
   
  # Save mesh
  mrmeshpy.saveMesh(mesh, "extrudedMesh.stl")

• C

  #include <MRCMesh/MRBitSet.h>
  #include <MRCMesh/MRMesh.h>
  #include <MRCMesh/MRMeshExtrude.h>
  #include <MRCMesh/MRMeshLoad.h>
  #include <MRCMesh/MRMeshSave.h>
  #include <MRCMesh/MRRegionBoundary.h>
  #include <MRCMesh/MRVector.h>
  #include <MRCMisc/expected_MR_Mesh_std_string.h>
  #include <MRCMisc/expected_void_std_string.h>
  #include <MRCMisc/std_string.h>
   
  #include <stdio.h>
  #include <stdlib.h>
   
  int main( void )
  {
      int rc = EXIT_FAILURE;
   
      // Load mesh.
      MR_expected_MR_Mesh_std_string* meshEx = MR_MeshLoad_fromAnySupportedFormat_2( "mesh.stl", NULL, NULL );
      MR_Mesh* mesh = MR_expected_MR_Mesh_std_string_GetMutableValue( meshEx );
   
      // Handle failure to load mesh.
      if ( !mesh )
      {
          fprintf( stderr, "Failed to load mesh: %s\n", MR_std_string_Data( MR_expected_MR_Mesh_std_string_GetError( meshEx ) ) );
          MR_expected_MR_Mesh_std_string_Destroy( meshEx );
          return 1;
      }
   
      // Select faces to extrude
      MR_FaceBitSet* facesToExtrude = MR_FaceBitSet_DefaultConstruct();
      MR_BitSet_autoResizeSet_2( MR_FaceBitSet_MutableUpcastTo_MR_BitSet( facesToExtrude ), 1, NULL );
      MR_BitSet_autoResizeSet_2( MR_FaceBitSet_MutableUpcastTo_MR_BitSet( facesToExtrude ), 2, NULL );
   
      // Create duplicated verts on region boundary
      MR_makeDegenerateBandAroundRegion( mesh, facesToExtrude, NULL );
   
      // Find vertices that will be moved
      MR_VertBitSet* vertsToMove = MR_getIncidentVerts_2_MR_FaceBitSet( MR_Mesh_Get_topology( mesh ), facesToExtrude );
      MR_Vector3f* points = MR_VertCoords_data( MR_Mesh_GetMutable_points( mesh ) );
      MR_Vector3f shift = MR_Vector3f_plusZ();
      size_t numPoints = MR_VertCoords_size( MR_Mesh_GetMutable_points( mesh ) );
      for ( size_t i = 0; i < numPoints; ++i )
          if ( MR_VertBitSet_test( vertsToMove, (MR_VertId){ i } ) )
              points[i] = MR_add_MR_Vector3f( &points[i], &shift );
   
      // Invalidate internal caches after manual changing
      MR_Mesh_invalidateCaches( mesh, NULL );
   
      // Save result
      MR_expected_void_std_string* saveEx = MR_MeshSave_toAnySupportedFormat_3( mesh, "extruded_mesh.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 ) ) );
      else
          rc = EXIT_SUCCESS;
   
      MR_VertBitSet_Destroy( vertsToMove );
      MR_FaceBitSet_Destroy( facesToExtrude );
      MR_expected_MR_Mesh_std_string_Destroy( meshEx );
      return rc;
  }