Mesh Weighted Offset

Example of mesh weighted offset

• C++

  #include "MRMesh/MRTorus.h"
  #include "MRMesh/MRMesh.h"
  #include "MRMesh/MRParallelFor.h"
  #include "MRVoxels/MRWeightedPointsShell.h"
  #include "MRVoxels/MROffset.h"
  #include "MRMesh/MRMeshSave.h"
  #include <iostream>
   
  int main()
  {
      // Create some mesh
      auto mesh = MR::makeTorus();
   
      // Create VertScalars obj with weights for every vertex
      auto vertSize = mesh.topology.vertSize();
      MR::VertScalars scalars( vertSize );
      MR::ParallelFor( scalars, [&] ( MR::VertId v )
      {
          scalars[v] = std::abs( mesh.points[v].x / 5.0f ); // Individual extra offset sizes for points
      } );
   
      auto params = MR::WeightedShell::ParametersMetric();
      // Algorithm is voxel based, voxel size affects performance and form of result mesh
      params.voxelSize = MR::suggestVoxelSize( mesh, 1000 );
      // common basic offset applied for all point
      // Vertex-specific weighted offsets applied after the basic one
      params.offset = 0.2f;
      params.dist.maxWeight = *std::max_element( MR::begin( scalars ), MR::end( scalars ) ); // should always have maximum between weights provided
   
      auto res = MR::WeightedShell::meshShell( mesh, scalars, params );
      if ( !res.has_value() )
      {
          std::cerr << res.error();
          return 1;
      }
   
      auto saveRes = MR::MeshSave::toAnySupportedFormat( *res, "offset_weighted.ctm" );
      if ( !saveRes.has_value() )
      {
          std::cerr << saveRes.error();
          return 1;
      }
      return 0;
  }

• Python

  from meshlib import mrmeshpy
   
  # Create some mesh
  mesh = mrmeshpy.makeTorus(primaryRadius=1.0,
                            secondaryRadius=0.1,
                            primaryResolution=16,
                            secondaryResolution=16)
  verts_num = mesh.points.size()
   
  # Create VertScalars obj with weights for every vertex
  scalars = mrmeshpy.VertScalars(verts_num)
  for i in range(verts_num):
      weight = abs(mesh.points.vec[i].x / 5) # Individual extra offset sizes for points
      scalars.vec[i] = weight
   
  # ===params
   
  params = mrmeshpy.WeightedShell.ParametersMetric()
  # Algorithm is voxel based, voxel size affects performance and form of result mesh
  params.voxelSize = mrmeshpy.suggestVoxelSize(mesh, 10000)
  # common basic offset applied for all point
  # Vertex-specific weighted offsets applied after the basic one
  params.offset = 0.2
  params.dist.maxWeight = max(scalars.vec) # should always have maximum between weights provided
   
  # ===offset
  res = mrmeshpy.WeightedShell.meshShell(mesh, scalars, params)
   
  mrmeshpy.saveMesh(res, "offset_weighted.ctm")

• C

  #include <MRCMesh/MRTorus.h>
  #include <MRCMesh/MRMesh.h>
  #include <MRCMesh/MRMeshTopology.h>
  #include <MRCMesh/MRMeshPart.h>
  #include <MRCMesh/MRVector.h>
  #include <MRCVoxels/MRWeightedPointsShell.h>
  #include <MRCMesh/MRClosestWeightedPoint.h>
  #include <MRCVoxels/MROffset.h>
  #include <MRCMesh/MRMeshSave.h>
  #include <MRCMisc/std_string.h>
  #include <MRCMisc/std_vector_MR_Vector3f.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>
  #include <string.h>
   
  #define abs(a) a >= 0 ? a : -a;
   
  int main( void )
  {
      int rc = EXIT_FAILURE;
      // Create some mesh
      MR_Mesh* mesh = MR_makeTorus( NULL, NULL, NULL, NULL, NULL );
   
      // Create VertScalars obj with weights for every vertex
      MR_uint64_t vertSize = MR_MeshTopology_vertSize( MR_Mesh_Get_topology( mesh ) );
      MR_VertScalars* scalars = MR_VertScalars_Construct_1_uint64_t( vertSize );
      float maxWeight = 0.0f;
      for ( MR_uint64_t i = 0; i < vertSize; ++i )
      {
          const MR_std_vector_MR_Vector3f* points = MR_VertCoords_Get_vec_( MR_Mesh_Get_points( mesh ) );
          float weight = abs( MR_std_vector_MR_Vector3f_At( points, i )->x / 5.0f );
          MR_VertScalars_data( scalars )[i] = weight;
          if ( weight > maxWeight )
          {
              maxWeight = weight;
          }
      }
   
      MR_WeightedShell_ParametersMetric* params = MR_WeightedShell_ParametersMetric_DefaultConstruct();
      // Algorithm is voxel based, voxel size affects performance and form of result mesh
      MR_WeightedShell_ParametersBase* base = MR_WeightedShell_ParametersMetric_MutableUpcastTo_MR_WeightedShell_ParametersBase( params );
      MR_MeshPart* mp = MR_MeshPart_Construct( mesh, NULL );
      MR_WeightedShell_ParametersBase_Set_voxelSize( base, MR_suggestVoxelSize( mp, 1000.0f ) );
      // common basic offset applied for all point
      // Vertex-specific weighted offsets applied after the basic one
      MR_WeightedShell_ParametersBase_Set_offset( base, 0.2f );
      MR_DistanceFromWeightedPointsParams* dist = MR_WeightedShell_ParametersMetric_GetMutable_dist( params );
      MR_DistanceFromWeightedPointsParams_Set_maxWeight( dist, maxWeight );
   
      MR_expected_MR_Mesh_std_string* res = MR_WeightedShell_meshShell_3_MR_VertScalars( mesh, scalars, params );
      MR_Mesh* resMesh = MR_expected_MR_Mesh_std_string_GetMutableValue( res );
      if ( !resMesh )
      {
          fprintf( stderr, "Failed to create shell: %s\n", MR_std_string_Data( MR_expected_MR_Mesh_std_string_GetError( res ) ) );
          goto fail_shell;
      }
   
      MR_expected_void_std_string* saveEx = MR_MeshSave_toAnySupportedFormat_3( resMesh, "offset_weighted.ctm", 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; // error while saving file
      }
   
      rc = EXIT_SUCCESS;
  fail_save:
      MR_expected_void_std_string_Destroy( saveEx );
   
  fail_shell:
      MR_expected_MR_Mesh_std_string_Destroy( res );
   
      MR_MeshPart_Destroy( mp );
      MR_WeightedShell_ParametersMetric_Destroy( params );
      MR_VertScalars_Destroy( scalars );
      MR_Mesh_Destroy( mesh );
      return rc;
  }