Function uniform_sampling

tools/mesh_sampling.cpp:134–180

}

void
uniform_sampling (vtkSmartPointer<vtkPolyData> polydata, std::size_t n_samples, bool calc_normal, bool calc_color, pcl::PointCloud<pcl::PointXYZRGBNormal> & cloud_out)
{
  polydata->BuildCells ();
  vtkSmartPointer<vtkCellArray> cells = polydata->GetPolys ();

  double p1[3], p2[3], p3[3], totalArea = 0;
  std::vector<double> cumulativeAreas (cells->GetNumberOfCells (), 0);
  vtkIdType npts = 0;
  vtkCellPtsPtr ptIds = nullptr;
  std::size_t cellId = 0;
  for (cells->InitTraversal (); cells->GetNextCell (npts, ptIds); cellId++)
  {
    polydata->GetPoint (ptIds[0], p1);
    polydata->GetPoint (ptIds[1], p2);
    polydata->GetPoint (ptIds[2], p3);
    totalArea += vtkTriangle::TriangleArea (p1, p2, p3);
    cumulativeAreas[cellId] = totalArea;
  }

  cloud_out.resize (n_samples);
  cloud_out.width = static_cast<std::uint32_t> (n_samples);
  cloud_out.height = 1;

  for (std::size_t i = 0; i < n_samples; i++)
  {
    Eigen::Vector3f p;
    Eigen::Vector3f n (0, 0, 0);
    Eigen::Vector3f c (0, 0, 0);
    randPSurface (polydata, &cumulativeAreas, totalArea, p, calc_normal, n, calc_color, c);
    cloud_out[i].x = p[0];
    cloud_out[i].y = p[1];
    cloud_out[i].z = p[2];
    if (calc_normal)
    {
      cloud_out[i].normal_x = n[0];
      cloud_out[i].normal_y = n[1];
      cloud_out[i].normal_z = n[2];
    }
    if (calc_color)
    {
      cloud_out[i].r = static_cast<std::uint8_t>(c[0]);
      cloud_out[i].g = static_cast<std::uint8_t>(c[1]);
      cloud_out[i].b = static_cast<std::uint8_t>(c[2]);
    }
  }
}

using namespace pcl;
using namespace pcl::io;