Terrain Triangulation Example

Example of generating a triangulation from a terrain scan (specific pointcloud).

• C++

  #include <MRMesh/MRPointsLoad.h>
  #include <MRMesh/MRPointCloud.h>
  #include <MRMesh/MRTerrainTriangulation.h>
  #include <MRMesh/MRMeshSave.h>
  #include <MRMesh/MRColor.h>
  #include <iostream>
   
  int main()
  {
      // load points
      MR::VertColors colors;
      MR::PointsLoadSettings pls;
      pls.colors = &colors;
      auto loadRes = MR::PointsLoad::fromAnySupportedFormat( "TerrainPoints.ply", pls );
      if ( !loadRes.has_value() )
      {
          std::cerr << loadRes.error() << "\n";
          return 1; // error while loading file
      }
      auto triangulationRes = MR::terrainTriangulation( loadRes->points.vec_ );
      if ( !triangulationRes.has_value() )
      {
          std::cerr << triangulationRes.error() << "\n";
          return 1; // error while triangulating
      }
   
      MR::SaveSettings ss;
      if ( loadRes->points.vec_.size() == colors.size() )
      ss.colors = &colors;
      auto saveRes = MR::MeshSave::toAnySupportedFormat( *triangulationRes, "TerrainMesh.ctm", ss );
      if ( !saveRes.has_value() )
      {
          std::cerr << saveRes.error() << "\n";
          return 1; // error while saving file
      }
      return 0;
  }

• Python

  from meshlib import mrmeshpy as mm
  from pathlib import Path
   
  colors = mm.VertColors()
  lps = mm.PointsLoadSettings()
  lps.colors = colors
  pc = mm.loadPoints("TerrainPoints.ply",lps)
   
  terrain_mesh = mm.terrainTriangulation(pc.points.vec)
   
  mss = mm.SaveSettings()
  if (pc.points.vec.size() == colors.size()):
      mss.colors = colors
  mm.saveMesh(terrain_mesh, "TerrainMesh.ctm",mss)

• C

  #include <MRCMesh/MRPointsLoad.h>
  #include <MRCMesh/MRPointsLoadSettings.h>
  #include <MRCMesh/MRVector.h>
  #include <MRCMesh/MRPointCloud.h>
  #include <MRCMesh/MRTerrainTriangulation.h>
  #include <MRCMesh/MRMeshSave.h>
  #include <MRCMesh/MRSaveSettings.h>
  #include <MRCMesh/MRColor.h>
  #include <MRCMisc/expected_MR_Mesh_std_string.h>
  #include <MRCMisc/expected_MR_PointCloud_std_string.h>
  #include <MRCMisc/expected_void_std_string.h>
  #include <MRCMisc/std_vector_MR_Color.h>
  #include <MRCMisc/std_vector_MR_Vector3f.h>
  #include <MRCMisc/std_string.h>
   
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
   
  int main( void )
  {
      int rc = EXIT_FAILURE;
      // load points
      MR_VertColors* colors = MR_VertColors_DefaultConstruct();
      MR_PointsLoadSettings* pls = MR_PointsLoadSettings_DefaultConstruct();
      MR_PointsLoadSettings_Set_colors( pls, colors );
      MR_expected_MR_PointCloud_std_string* loadRes = MR_PointsLoad_fromAnySupportedFormat_2( "TerrainPoints.ply", NULL, pls );
      MR_PointCloud* pc = MR_expected_MR_PointCloud_std_string_GetMutableValue( loadRes );
      if ( !pc )
      {
          fprintf( stderr, "Failed to load points: %s\n", MR_std_string_Data( MR_expected_MR_PointCloud_std_string_GetError( loadRes ) ) );
          goto fail_load; // error while loading file
      }
   
      MR_expected_MR_Mesh_std_string* triangulationRes = MR_terrainTriangulation(
          MR_PassBy_Copy,
          MR_VertCoords_GetMutable_vec_( MR_PointCloud_GetMutable_points( pc ) ),
          MR_PassBy_DefaultArgument, NULL );
      MR_Mesh* mesh = MR_expected_MR_Mesh_std_string_GetMutableValue( triangulationRes );
      if ( !mesh )
      {
          fprintf( stderr, "Failed to triangulate points: %s\n", MR_std_string_Data( MR_expected_MR_Mesh_std_string_GetError( triangulationRes ) ) );
          goto fail_triangulation; // error while triangulating
      }
   
      MR_SaveSettings* ss = MR_SaveSettings_DefaultConstruct();
      if ( MR_std_vector_MR_Color_Size( MR_VertColors_Get_vec_( colors ) ) ==
           MR_std_vector_MR_Vector3f_Size( MR_VertCoords_Get_vec_( MR_PointCloud_Get_points( pc ) ) )
           )
      {
          MR_SaveSettings_Set_colors( ss, colors );
      }
   
      MR_expected_void_std_string* saveEx = MR_MeshSave_toAnySupportedFormat_3( mesh, "TerrainMesh.ctm", NULL, ss );
      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 );
   
      MR_SaveSettings_Destroy( ss );
  fail_triangulation:
      MR_expected_MR_Mesh_std_string_Destroy( triangulationRes );
  fail_load:
      MR_expected_MR_PointCloud_std_string_Destroy( loadRes );
   
      MR_PointsLoadSettings_Destroy( pls );
      MR_VertColors_Destroy( colors );
      return rc;
  }