Fixing Mesh Degeneracies

Example of fixing degenerated faces

• C++

  #include <MRMesh/MRMesh.h>
  #include <MRMesh/MRMeshLoad.h>
   
  #include <iostream>
  #include <MRMesh/MRBox.h>
  #include <MRMesh/MRMeshFixer.h>
   
  int main()
  {
      auto mesh = MR::MeshLoad::fromAnySupportedFormat( "mesh.stl" );
      if ( !mesh )
      {
          std::cerr << mesh.error() << std::endl;
          return 1;
      }
   
      // you can set various parameters for the resolving process; see the documentation for more info
      std::ignore = MR::fixMeshDegeneracies( *mesh, {
          .maxDeviation = 1e-5f * mesh->computeBoundingBox().diagonal(),
          .tinyEdgeLength = 1e-3f,
      } );
   
      return 0;
  }

• Python

  import sys
   
  import meshlib.mrmeshpy as mrmeshpy
   
  # Load mesh
  mesh = mrmeshpy.loadMesh("mesh.stl")
   
  # you can set various parameters for the resolving process; see the documentation for more info
  params = mrmeshpy.FixMeshDegeneraciesParams()
  params.maxDeviation = 1e-5 * mesh.computeBoundingBox().diagonal()
  params.tinyEdgeLength = 1e-3
   
  mrmeshpy.fixMeshDegeneracies(mesh, params)
   
  mrmeshpy.saveMesh(mesh, "fixed_mesh.stl")

• C

  #include <MRCMesh/MRMesh.h>
  #include <MRCMesh/MRMeshFixer.h>
  #include <MRCMesh/MRMeshLoad.h>
  #include <MRCMesh/MRMeshSave.h>
  #include <MRCMesh/MRString.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( int argc, char* argv[] )
  {
      int rc = EXIT_FAILURE;
      if ( argc != 2 && argc != 3 )
      {
          fprintf( stderr, "Usage: %s INPUT [OUTPUT]", argv[0] );
          return rc;
      }
   
      const char* input = argv[1];
      const char* output = ( argc == 2 ) ? argv[1] : argv[2];
   
      // Load mesh.
      MR_expected_MR_Mesh_std_string* meshEx = MR_MeshLoad_fromAnySupportedFormat_2( input, 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 ) ) );
          goto fail_mesh_loading;
      }
   
      // you can set various parameters for the resolving process; see the documentation for more info
      MR_FixMeshDegeneraciesParams* params = MR_FixMeshDegeneraciesParams_DefaultConstruct();
      // maximum permitted deviation
      const MR_Box3f bbox = MR_Mesh_computeBoundingBox_1( mesh, NULL );
      MR_FixMeshDegeneraciesParams_Set_maxDeviation( params, 1e-5f * MR_Box3f_diagonal( &bbox ) );
      // maximum length of edges to be collapsed
      MR_FixMeshDegeneraciesParams_Set_tinyEdgeLength( params, 1e-3f );
   
      MR_expected_void_std_string* degeneraciesEx = MR_fixMeshDegeneracies( mesh, params );
      MR_FixMeshDegeneraciesParams_Destroy( params );
   
      if ( MR_expected_void_std_string_GetError( degeneraciesEx ) )
      {
          fprintf( stderr, "Failed to fix mesh degeneracies: %s\n", MR_std_string_Data( MR_expected_void_std_string_GetError( degeneraciesEx ) ) );
          goto fail_fix_degen;
      }
   
      // Save result
      MR_expected_void_std_string* saveEx = MR_MeshSave_toAnySupportedFormat_3( mesh, output, 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_fix_degen:
      MR_expected_void_std_string_Destroy( degeneraciesEx );
  fail_mesh_loading:
      MR_expected_MR_Mesh_std_string_Destroy( meshEx );
      return rc;
  }

• C#

  using System.Reflection;
   
  public static class MeshFixDegeneraciesExample
  {
      public static void Run(string[] args)
      {
          try
          {
              if (args.Length != 2 && args.Length != 3)
              {
                  Console.WriteLine("Usage: {0} MeshFixDegeneraciesExample INPUT [OUTPUT]", Assembly.GetExecutingAssembly().GetName().Name);
                  return;
              }
   
              string inputFile = args[1];
              string outputFile = args.Length == 3 ? args[2] : inputFile;
   
              var mesh = MR.MeshLoad.FromAnySupportedFormat(inputFile);
   
              MR.FixMeshDegeneraciesParams parameters = new();
              parameters.MaxDeviation = mesh.ComputeBoundingBox().Diagonal() * 1e-5f;
              parameters.TinyEdgeLength = 1e-3f;
   
              MR.FixMeshDegeneracies(mesh, parameters);
              MR.MeshSave.ToAnySupportedFormat(mesh, outputFile);
          }
          catch (Exception e)
          {
              Console.WriteLine("Error: {0}", e.Message);
          }
      }
  }