Mesh Decimation

Example of mesh decimation

• C++

  #include <MRMesh/MRMeshFwd.h>
  #include <MRMesh/MRMeshLoad.h>
  #include <MRMesh/MRMeshSave.h>
  #include <MRMesh/MRMesh.h>
  #include <MRMesh/MRMeshDecimate.h>
  #include <MRMesh/MRBuffer.h>
   
  #include <iostream>
   
  int main()
  {
      // Load mesh
      auto meshRes = MR::MeshLoad::fromAnySupportedFormat( "mesh.stl" );
      if ( !meshRes.has_value() )
      {
          std::cerr << meshRes.error() << std::endl;
          return 1;
      }
   
      MR::Mesh& mesh = *meshRes;
      
      // Repack mesh optimally.
      // It's not necessary but highly recommended to achieve the best performance in parallel processing
      mesh.packOptimally();
   
      // Setup decimate parameters
      MR::DecimateSettings settings;
   
      // Decimation stop thresholds, you may specify one or both
      settings.maxDeletedFaces = 1000; // Number of faces to be deleted
      settings.maxError = 0.05f; // Maximum error when decimation stops
   
      // Number of parts to simultaneous processing, greatly improves performance by cost of minor quality loss.
      // Recommended to set to the number of available CPU cores or more for the best performance
      settings.subdivideParts = 64;
   
      // Decimate mesh
      MR::decimateMesh( mesh, settings );
   
      // Save result
      if ( auto saveRes = MR::MeshSave::toAnySupportedFormat( mesh, "decimated_mesh.stl" ); !saveRes )
      {
          std::cerr << saveRes.error() << std::endl;
          return 1;
      }
   
      return 0;
  }

  Source mesh
  
  After decimate
  
• Python

  import meshlib.mrmeshpy as mrmeshpy
   
  # Load mesh
  mesh = mrmeshpy.loadMesh("mesh.stl")
   
  # Repack mesh optimally.
  # It's not necessary but highly recommended to achieve the best performance in parallel processing
  mesh.packOptimally()
   
  # Setup decimate parameters
  settings = mrmeshpy.DecimateSettings()
   
  # Decimation stop thresholds, you may specify one or both
  settings.maxDeletedFaces = 1000 # Number of faces to be deleted
  settings.maxError = 0.05 # Maximum error when decimation stops
   
  # Number of parts to simultaneous processing, greatly improves performance by cost of minor quality loss.
  # Recommended to set to number of CPU cores or more available for the best performance
  settings.subdivideParts = 64
   
  # Decimate mesh
  mrmeshpy.decimateMesh(mesh, settings)
   
  # Save result
  mrmeshpy.saveMesh(mesh, "decimatedMesh.stl")

  Source mesh
  
  After decimate
  
• C

  #include <MRCMesh/MRMesh.h>
  #include <MRCMesh/MRMeshDecimate.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( 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_value_mut( 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_error( meshEx ) ) );
          goto fail;
      }
   
      // Setup decimate parameters
      MR_DecimateSettings* params = MR_DecimateSettings_DefaultConstruct();
   
      // Decimation stop thresholds, you may specify one or both
      MR_DecimateSettings_Set_maxDeletedFaces( params, 1000 ); // Number of faces to be deleted
      MR_DecimateSettings_Set_maxError( params, 0.05f ); // Maximum error when decimation stops
   
      // Number of parts to simultaneous processing, greatly improves performance by cost of minor quality loss.
      // Recommended to set to the number of available CPU cores or more for the best performance
      MR_DecimateSettings_Set_subdivideParts( params, 64 );
   
      // Decimate mesh
      MR_DecimateResult* result = MR_decimateMesh( mesh, params );
      MR_DecimateSettings_Destroy( params );
   
      printf( "Removed %d vertices, %d faces\n", *MR_DecimateResult_Get_vertsDeleted( result ), *MR_DecimateResult_Get_facesDeleted( result ) );
      MR_DecimateResult_Destroy( result );
   
      // Save result
      MR_expected_void_std_string* saveEx = MR_MeshSave_toAnySupportedFormat_3( mesh, "decimated_mesh.stl", NULL, NULL);
      if ( MR_expected_void_std_string_error( saveEx ) )
      {
          fprintf( stderr, "Failed to save mesh: %s\n", MR_std_string_data( MR_expected_void_std_string_error( saveEx ) ) );
          goto fail;
      }
   
      rc = EXIT_SUCCESS;
  fail:
      MR_expected_MR_Mesh_std_string_Destroy( meshEx );
      return rc;
  }

  Source mesh
  
  After decimate
  
• C#

  public class MeshDecimateExample
  {
      public static void Run(string[] args)
      {
          try
          {
              // Load mesh
              var mesh = MR.MeshLoad.fromAnySupportedFormat("mesh.stl");
   
              // Setup decimate parameters
              MR.DecimateSettings ds = new();
              ds.strategy = MR.DecimateStrategy.MinimizeError;
              ds.maxError = 1e-5f * mesh.computeBoundingBox().diagonal();
              ds.tinyEdgeLength = 1e-3f;
              ds.packMesh = true;
   
              // Decimate mesh
              MR.DecimateResult result = MR.decimateMesh(mesh, ds);
   
              // Save result
              MR.MeshSave.toAnySupportedFormat(mesh, "decimated_mesh.stl");
          }
          catch (Exception e)
          {
              Console.WriteLine("Error: {0}", e.Message);
          }
      }
  }

  Source mesh
  
  After decimate