hv_go.hpp

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#ifndef PCL_RECOGNITION_IMPL_HV_GO_HPP_
#define PCL_RECOGNITION_IMPL_HV_GO_HPP_
 
#include <pcl/recognition/hv/hv_go.h>
#include <pcl/common/common.h> // for getMinMax3D
#include <pcl/common/time.h>
#include <pcl/point_types.h>
 
#include <memory>
#include <numeric>
 
template<typename PointT, typename NormalT>
inline void extractEuclideanClustersSmooth(const typename pcl::PointCloud<PointT> &cloud, const typename pcl::PointCloud<NormalT> &normals, float tolerance,
    const typename pcl::search::Search<PointT>::Ptr &tree, std::vector<pcl::PointIndices> &clusters, double eps_angle, float curvature_threshold,
    unsigned int min_pts_per_cluster, unsigned int max_pts_per_cluster = (std::numeric_limits<int>::max) ())
{
 
  if (tree->getInputCloud ()->size () != cloud.size ())
  {
    PCL_ERROR("[pcl::extractEuclideanClusters] Tree built for a different point cloud dataset\n");
    return;
  }
  if (cloud.size () != normals.size ())
  {
    PCL_ERROR("[pcl::extractEuclideanClusters] Number of points in the input point cloud different than normals!\n");
    return;
  }
  // If tree gives sorted results, we can skip the first one because it is the query point itself
  const std::size_t nn_start_idx = tree->getSortedResults () ? 1 : 0;
 
  // Create a bool vector of processed point indices, and initialize it to false
  std::vector<bool> processed (cloud.size (), false);
 
  pcl::Indices nn_indices;
  std::vector<float> nn_distances;
  // Process all points in the indices vector
  int size = static_cast<int> (cloud.size ());
  for (int i = 0; i < size; ++i)
  {
    if (processed[i])
      continue;
 
    std::vector<unsigned int> seed_queue;
    int sq_idx = 0;
    seed_queue.push_back (i);
 
    processed[i] = true;
 
    while (sq_idx < static_cast<int> (seed_queue.size ()))
    {
 
      if (normals[seed_queue[sq_idx]].curvature > curvature_threshold)
      {
        sq_idx++;
        continue;
      }
 
      // Search for sq_idx
      if (!tree->radiusSearch (seed_queue[sq_idx], tolerance, nn_indices, nn_distances))
      {
        sq_idx++;
        continue;
      }
 
      for (std::size_t j = nn_start_idx; j < nn_indices.size (); ++j)
      {
        if (processed[nn_indices[j]]) // Has this point been processed before ?
          continue;
 
        if (normals[nn_indices[j]].curvature > curvature_threshold)
        {
          continue;
        }
 
        //processed[nn_indices[j]] = true;
        // [-1;1]
 
        double dot_p = normals[seed_queue[sq_idx]].normal[0] * normals[nn_indices[j]].normal[0]
            + normals[seed_queue[sq_idx]].normal[1] * normals[nn_indices[j]].normal[1]
            + normals[seed_queue[sq_idx]].normal[2] * normals[nn_indices[j]].normal[2];
 
        if (std::abs (std::acos (dot_p)) < eps_angle)
        {
          processed[nn_indices[j]] = true;
          seed_queue.push_back (nn_indices[j]);
        }
      }
 
      sq_idx++;
    }
 
    // If this queue is satisfactory, add to the clusters
    if (seed_queue.size () >= min_pts_per_cluster && seed_queue.size () <= max_pts_per_cluster)
    {
      pcl::PointIndices r;
      r.indices.resize (seed_queue.size ());
      for (std::size_t j = 0; j < seed_queue.size (); ++j)
        r.indices[j] = seed_queue[j];
 
      std::sort (r.indices.begin (), r.indices.end ());
      r.indices.erase (std::unique (r.indices.begin (), r.indices.end ()), r.indices.end ());
 
      r.header = cloud.header;
      clusters.push_back (r); // We could avoid a copy by working directly in the vector
    }
  }
}
 
template<typename ModelT, typename SceneT>
mets::gol_type pcl::GlobalHypothesesVerification<ModelT, SceneT>::evaluateSolution(const std::vector<bool> & active, int changed)
{
  float sign = 1.f;
  //update explained_by_RM
  if (active[changed])
  {
    //it has been activated
    updateExplainedVector (recognition_models_[changed]->explained_, recognition_models_[changed]->explained_distances_, explained_by_RM_,
        explained_by_RM_distance_weighted, 1.f);
    updateUnexplainedVector (recognition_models_[changed]->unexplained_in_neighborhood, recognition_models_[changed]->unexplained_in_neighborhood_weights,
        unexplained_by_RM_neighboorhods, recognition_models_[changed]->explained_, explained_by_RM_, 1.f);
    updateCMDuplicity(recognition_models_[changed]->complete_cloud_occupancy_indices_, complete_cloud_occupancy_by_RM_, 1.f);
  } else
  {
    //it has been deactivated
    updateExplainedVector (recognition_models_[changed]->explained_, recognition_models_[changed]->explained_distances_, explained_by_RM_,
        explained_by_RM_distance_weighted, -1.f);
    updateUnexplainedVector (recognition_models_[changed]->unexplained_in_neighborhood, recognition_models_[changed]->unexplained_in_neighborhood_weights,
        unexplained_by_RM_neighboorhods, recognition_models_[changed]->explained_, explained_by_RM_, -1.f);
    updateCMDuplicity(recognition_models_[changed]->complete_cloud_occupancy_indices_, complete_cloud_occupancy_by_RM_, -1.f);
    sign = -1.f;
  }
 
  int duplicity = getDuplicity ();
  float good_info = getExplainedValue ();
 
  float unexplained_info = getPreviousUnexplainedValue ();
  float bad_info = static_cast<float> (getPreviousBadInfo ())
      + (recognition_models_[changed]->outliers_weight_ * static_cast<float> (recognition_models_[changed]->bad_information_)) * sign;
 
  setPreviousBadInfo (bad_info);
 
  int n_active_hyp = 0;
  for(const bool i : active) {
    if(i)
      n_active_hyp++;
  }
 
  float duplicity_cm = static_cast<float> (getDuplicityCM ()) * w_occupied_multiple_cm_;
  return static_cast<mets::gol_type> ((good_info - bad_info - static_cast<float> (duplicity) - unexplained_info - duplicity_cm - static_cast<float> (n_active_hyp)) * -1.f); //return the dual to our max problem
}
 
///////////////////////////////////////////////////////////////////////////////////////////////////
template<typename ModelT, typename SceneT>
void pcl::GlobalHypothesesVerification<ModelT, SceneT>::initialize()
{
  //clear stuff
  recognition_models_.clear ();
  unexplained_by_RM_neighboorhods.clear ();
  explained_by_RM_distance_weighted.clear ();
  explained_by_RM_.clear ();
  mask_.clear ();
  indices_.clear (),
  complete_cloud_occupancy_by_RM_.clear ();
 
  // initialize mask to false
  mask_.resize (complete_models_.size ());
  for (std::size_t i = 0; i < complete_models_.size (); i++)
    mask_[i] = false;
 
  indices_.resize (complete_models_.size ());
 
  NormalEstimator_ n3d;
  scene_normals_.reset (new pcl::PointCloud<pcl::Normal> ());
 
  n3d.setRadiusSearch (radius_normals_);
  n3d.setInputCloud (scene_cloud_downsampled_);
  n3d.compute (*scene_normals_);
 
  //check nans...
  int j = 0;
  for (std::size_t i = 0; i < scene_normals_->size (); ++i)
  {
    if (!std::isfinite ((*scene_normals_)[i].normal_x) || !std::isfinite ((*scene_normals_)[i].normal_y)
        || !std::isfinite ((*scene_normals_)[i].normal_z))
      continue;
 
    (*scene_normals_)[j] = (*scene_normals_)[i];
    (*scene_cloud_downsampled_)[j] = (*scene_cloud_downsampled_)[i];
 
    j++;
  }
 
  scene_normals_->points.resize (j);
  scene_normals_->width = j;
  scene_normals_->height = 1;
 
  scene_cloud_downsampled_->points.resize (j);
  scene_cloud_downsampled_->width = j;
  scene_cloud_downsampled_->height = 1;
 
  explained_by_RM_.resize (scene_cloud_downsampled_->size (), 0);
  explained_by_RM_distance_weighted.resize (scene_cloud_downsampled_->size (), 0.f);
  unexplained_by_RM_neighboorhods.resize (scene_cloud_downsampled_->size (), 0.f);
 
  //compute segmentation of the scene if detect_clutter_
  if (detect_clutter_)
  {
    //initialize kdtree for search
    scene_downsampled_tree_.reset (new pcl::search::KdTree<SceneT>);
    scene_downsampled_tree_->setInputCloud (scene_cloud_downsampled_);
 
    std::vector<pcl::PointIndices> clusters;
    double eps_angle_threshold = 0.2;
    int min_points = 20;
    float curvature_threshold = 0.045f;
 
    extractEuclideanClustersSmooth<SceneT, pcl::Normal> (*scene_cloud_downsampled_, *scene_normals_, inliers_threshold_ * 2.f, scene_downsampled_tree_,
        clusters, eps_angle_threshold, curvature_threshold, min_points);
 
    clusters_cloud_.reset (new pcl::PointCloud<pcl::PointXYZI>);
    clusters_cloud_->points.resize (scene_cloud_downsampled_->size ());
    clusters_cloud_->width = scene_cloud_downsampled_->width;
    clusters_cloud_->height = 1;
 
    for (std::size_t i = 0; i < scene_cloud_downsampled_->size (); i++)
    {
      pcl::PointXYZI p;
      p.getVector3fMap () = (*scene_cloud_downsampled_)[i].getVector3fMap ();
      p.intensity = 0.f;
      (*clusters_cloud_)[i] = p;
    }
 
    float intens_incr = 100.f / static_cast<float> (clusters.size ());
    float intens = intens_incr;
    for (const auto &cluster : clusters)
    {
      for (const auto &vertex : cluster.indices)
      {
        (*clusters_cloud_)[vertex].intensity = intens;
      }
 
      intens += intens_incr;
    }
  }
 
  //compute cues
  {
    pcl::ScopeTime tcues ("Computing cues");
    recognition_models_.resize (complete_models_.size ());
    int valid = 0;
    for (int i = 0; i < static_cast<int> (complete_models_.size ()); i++)
    {
      //create recognition model
      recognition_models_[valid].reset (new RecognitionModel ());
      if(addModel (visible_models_[i], complete_models_[i], recognition_models_[valid])) {
        indices_[valid] = i;
        valid++;
      }
    }
 
    recognition_models_.resize(valid);
    indices_.resize(valid);
  }
 
  //compute the bounding boxes for the models
  ModelT min_pt_all, max_pt_all;
  min_pt_all.x = min_pt_all.y = min_pt_all.z = std::numeric_limits<float>::max ();
  max_pt_all.x = max_pt_all.y = max_pt_all.z = (std::numeric_limits<float>::max () - 0.001f) * -1;
 
  for (std::size_t i = 0; i < recognition_models_.size (); i++)
  {
    ModelT min_pt, max_pt;
    pcl::getMinMax3D (*complete_models_[indices_[i]], min_pt, max_pt);
    if (min_pt.x < min_pt_all.x)
      min_pt_all.x = min_pt.x;
 
    if (min_pt.y < min_pt_all.y)
      min_pt_all.y = min_pt.y;
 
    if (min_pt.z < min_pt_all.z)
      min_pt_all.z = min_pt.z;
 
    if (max_pt.x > max_pt_all.x)
      max_pt_all.x = max_pt.x;
 
    if (max_pt.y > max_pt_all.y)
      max_pt_all.y = max_pt.y;
 
    if (max_pt.z > max_pt_all.z)
      max_pt_all.z = max_pt.z;
  }
 
  int size_x, size_y, size_z;
  size_x = static_cast<int> (std::ceil (std::abs (max_pt_all.x - min_pt_all.x) / res_occupancy_grid_)) + 1;
  size_y = static_cast<int> (std::ceil (std::abs (max_pt_all.y - min_pt_all.y) / res_occupancy_grid_)) + 1;
  size_z = static_cast<int> (std::ceil (std::abs (max_pt_all.z - min_pt_all.z) / res_occupancy_grid_)) + 1;
 
  complete_cloud_occupancy_by_RM_.resize (size_x * size_y * size_z, 0);
 
  for (std::size_t i = 0; i < recognition_models_.size (); i++)
  {
 
    std::map<int, bool> banned;
    std::map<int, bool>::iterator banned_it;
 
    for (const auto& point: *complete_models_[indices_[i]])
    {
      const int pos_x = static_cast<int> (std::floor ((point.x - min_pt_all.x) / res_occupancy_grid_));
      const int pos_y = static_cast<int> (std::floor ((point.y - min_pt_all.y) / res_occupancy_grid_));
      const int pos_z = static_cast<int> (std::floor ((point.z - min_pt_all.z) / res_occupancy_grid_));
 
      const int idx = pos_z * size_x * size_y + pos_y * size_x + pos_x;
      banned_it = banned.find (idx);
      if (banned_it == banned.end ())
      {
        complete_cloud_occupancy_by_RM_[idx]++;
        recognition_models_[i]->complete_cloud_occupancy_indices_.push_back (idx);
        banned[idx] = true;
      }
    }
  }
 
  {
    pcl::ScopeTime tcues ("Computing clutter cues");
#pragma omp parallel for \
  default(none) \
  schedule(dynamic, 4) \
  num_threads(omp_get_num_procs())
    for (int j = 0; j < static_cast<int> (recognition_models_.size ()); j++)
      computeClutterCue (recognition_models_[j]);
  }
 
  cc_.clear ();
  n_cc_ = 1;
  cc_.resize (n_cc_);
  for (std::size_t i = 0; i < recognition_models_.size (); i++)
    cc_[0].push_back (static_cast<int> (i));
 
}
 
template<typename ModelT, typename SceneT>
void pcl::GlobalHypothesesVerification<ModelT, SceneT>::SAOptimize(std::vector<int> & cc_indices, std::vector<bool> & initial_solution)
{
 
  //temporal copy of recogniton_models_
  std::vector<RecognitionModelPtr> recognition_models_copy;
  recognition_models_copy = recognition_models_;
 
  recognition_models_.clear ();
 
  for (const int &cc_index : cc_indices)
  {
    recognition_models_.push_back (recognition_models_copy[cc_index]);
  }
 
  for (std::size_t j = 0; j < recognition_models_.size (); j++)
  {
    RecognitionModelPtr recog_model = recognition_models_[j];
    for (std::size_t i = 0; i < recog_model->explained_.size (); i++)
    {
      explained_by_RM_[recog_model->explained_[i]]++;
      explained_by_RM_distance_weighted[recog_model->explained_[i]] += recog_model->explained_distances_[i];
    }
 
    if (detect_clutter_)
    {
      for (std::size_t i = 0; i < recog_model->unexplained_in_neighborhood.size (); i++)
      {
        unexplained_by_RM_neighboorhods[recog_model->unexplained_in_neighborhood[i]] += recog_model->unexplained_in_neighborhood_weights[i];
      }
    }
  }
 
  int occupied_multiple = 0;
  for(const auto& i : complete_cloud_occupancy_by_RM_) {
    if(i > 1) {
      occupied_multiple+=i;
    }
  }
 
  setPreviousDuplicityCM(occupied_multiple);
  //do optimization
  //Define model SAModel, initial solution is all models activated
 
  int duplicity;
  float good_information_ = getTotalExplainedInformation (explained_by_RM_, explained_by_RM_distance_weighted, &duplicity);
  float bad_information_ = 0;
  float unexplained_in_neighboorhod = getUnexplainedInformationInNeighborhood (unexplained_by_RM_neighboorhods, explained_by_RM_);
 
  for (std::size_t i = 0; i < initial_solution.size (); i++)
  {
    if (initial_solution[i])
      bad_information_ += recognition_models_[i]->outliers_weight_ * static_cast<float> (recognition_models_[i]->bad_information_);
  }
 
  setPreviousExplainedValue (good_information_);
  setPreviousDuplicity (duplicity);
  setPreviousBadInfo (bad_information_);
  setPreviousUnexplainedValue (unexplained_in_neighboorhod);
 
  SAModel model;
  model.cost_ = static_cast<mets::gol_type> ((good_information_ - bad_information_
                                               - static_cast<float> (duplicity)
                                               - static_cast<float> (occupied_multiple) * w_occupied_multiple_cm_
                                               - static_cast<float> (recognition_models_.size ())
                                               - unexplained_in_neighboorhod) * -1.f);
 
  model.setSolution (initial_solution);
  model.setOptimizer (this);
  SAModel best (model);
 
  move_manager neigh (static_cast<int> (cc_indices.size ()));
 
  mets::best_ever_solution best_recorder (best);
  mets::noimprove_termination_criteria noimprove (max_iterations_);
  mets::linear_cooling linear_cooling;
  mets::simulated_annealing<move_manager> sa (model, best_recorder, neigh, noimprove, linear_cooling, initial_temp_, 1e-7, 2);
  sa.setApplyAndEvaluate(true);
 
  {
    pcl::ScopeTime t ("SA search...");
    sa.search ();
  }
 
  best_seen_ = static_cast<const SAModel&> (best_recorder.best_seen ());
  for (std::size_t i = 0; i < best_seen_.solution_.size (); i++)
  {
    initial_solution[i] = best_seen_.solution_[i];
  }
 
  recognition_models_ = recognition_models_copy;
 
}
 
///////////////////////////////////////////////////////////////////////////////////////////////////
template<typename ModelT, typename SceneT>
void pcl::GlobalHypothesesVerification<ModelT, SceneT>::verify()
{
  initialize ();
 
  //for each connected component, find the optimal solution
  for (int c = 0; c < n_cc_; c++)
  {
    //TODO: Check for trivial case...
    //TODO: Check also the number of hypotheses and use exhaustive enumeration if smaller than 10
    std::vector<bool> subsolution (cc_[c].size (), true);
    SAOptimize (cc_[c], subsolution);
    for (std::size_t i = 0; i < subsolution.size (); i++)
    {
      mask_[indices_[cc_[c][i]]] = (subsolution[i]);
    }
  }
}
 
template<typename ModelT, typename SceneT>
bool pcl::GlobalHypothesesVerification<ModelT, SceneT>::addModel(typename pcl::PointCloud<ModelT>::ConstPtr & model,
    typename pcl::PointCloud<ModelT>::ConstPtr & complete_model, RecognitionModelPtr & recog_model)
{
  //voxelize model cloud
  recog_model->cloud_.reset (new pcl::PointCloud<ModelT> ());
  recog_model->complete_cloud_.reset (new pcl::PointCloud<ModelT> ());
 
  float size_model = resolution_;
  pcl::VoxelGrid<ModelT> voxel_grid;
  voxel_grid.setInputCloud (model);
  voxel_grid.setLeafSize (size_model, size_model, size_model);
  voxel_grid.filter (*(recog_model->cloud_));
 
  pcl::VoxelGrid<ModelT> voxel_grid2;
  voxel_grid2.setInputCloud (complete_model);
  voxel_grid2.setLeafSize (size_model, size_model, size_model);
  voxel_grid2.filter (*(recog_model->complete_cloud_));
 
  {
    //check nans...
    int j = 0;
    for (auto& point: *(recog_model->cloud_))
    {
      if (!isXYZFinite (point))
        continue;
 
      (*recog_model->cloud_)[j] = point;
      j++;
    }
 
    recog_model->cloud_->points.resize (j);
    recog_model->cloud_->width = j;
    recog_model->cloud_->height = 1;
  }
 
  if (recog_model->cloud_->points.empty ())
  {
    PCL_WARN("The model cloud has no points..\n");
    return false;
  }
 
  //compute normals unless given (now do it always...)
  pcl::NormalEstimation<ModelT, pcl::Normal> n3d;
  recog_model->normals_.reset (new pcl::PointCloud<pcl::Normal> ());
  n3d.setRadiusSearch (radius_normals_);
  n3d.setInputCloud ((recog_model->cloud_));
  n3d.compute (*(recog_model->normals_));
 
  //check nans...
  int j = 0;
  for (std::size_t i = 0; i < recog_model->normals_->size (); ++i)
  {
    if (isNormalFinite((*recog_model->normals_)[i]))
      continue;
 
    (*recog_model->normals_)[j] = (*recog_model->normals_)[i];
    (*recog_model->cloud_)[j] = (*recog_model->cloud_)[i];
    j++;
  }
 
  recog_model->normals_->points.resize (j);
  recog_model->normals_->width = j;
  recog_model->normals_->height = 1;
 
  recog_model->cloud_->points.resize (j);
  recog_model->cloud_->width = j;
  recog_model->cloud_->height = 1;
 
  std::vector<int> explained_indices;
  std::vector<float> outliers_weight;
  std::vector<float> explained_indices_distances;
 
  pcl::Indices nn_indices;
  std::vector<float> nn_distances;
 
  std::map<int, std::shared_ptr<std::vector<std::pair<int, float>>>> model_explains_scene_points; //which point i from the scene is explained by a points j_k with dist d_k from the model
 
  outliers_weight.resize (recog_model->cloud_->size ());
  recog_model->outlier_indices_.resize (recog_model->cloud_->size ());
 
  std::size_t o = 0;
  for (std::size_t i = 0; i < recog_model->cloud_->size (); i++)
  {
    if (!scene_downsampled_tree_->radiusSearch ((*recog_model->cloud_)[i], inliers_threshold_, nn_indices, nn_distances, std::numeric_limits<int>::max ()))
    {
      //outlier
      outliers_weight[o] = regularizer_;
      recog_model->outlier_indices_[o] = static_cast<int> (i);
      o++;
    } else
    {
      for (std::size_t k = 0; k < nn_distances.size (); k++)
      {
        std::pair<int, float> pair = std::make_pair (i, nn_distances[k]); //i is a index to a model point and then distance
        auto it = model_explains_scene_points.find (nn_indices[k]);
        if (it == model_explains_scene_points.end ())
        {
          std::shared_ptr<std::vector<std::pair<int, float>>> vec (new std::vector<std::pair<int, float>> ());
          vec->push_back (pair);
          model_explains_scene_points[nn_indices[k]] = vec;
        } else
        {
          it->second->push_back (pair);
        }
      }
    }
  }
 
  outliers_weight.resize (o);
  recog_model->outlier_indices_.resize (o);
 
  recog_model->outliers_weight_ = (std::accumulate (outliers_weight.begin (), outliers_weight.end (), 0.f) / static_cast<float> (outliers_weight.size ()));
  if (outliers_weight.empty ())
    recog_model->outliers_weight_ = 1.f;
 
  pcl::IndicesPtr indices_scene (new pcl::Indices);
  //go through the map and keep the closest model point in case that several model points explain a scene point
 
  int p = 0;
 
  for (auto it = model_explains_scene_points.cbegin (); it != model_explains_scene_points.cend (); it++, p++)
  {
    std::size_t closest = 0;
    float min_d = std::numeric_limits<float>::min ();
    for (std::size_t i = 0; i < it->second->size (); i++)
    {
      if (it->second->at (i).second > min_d)
      {
        min_d = it->second->at (i).second;
        closest = i;
      }
    }
 
    float d = it->second->at (closest).second;
    float d_weight = -(d * d / (inliers_threshold_)) + 1;
 
    //it->first is index to scene point
    //using normals to weight inliers
    Eigen::Vector3f scene_p_normal = (*scene_normals_)[it->first].getNormalVector3fMap ();
    Eigen::Vector3f model_p_normal =
        (*recog_model->normals_)[it->second->at(closest).first].getNormalVector3fMap();
    float dotp = scene_p_normal.dot (model_p_normal) * 1.f; //[-1,1] from antiparallel through perpendicular to parallel
 
    if (dotp < 0.f)
      dotp = 0.f;
 
    explained_indices.push_back (it->first);
    explained_indices_distances.push_back (d_weight * dotp);
 
  }
 
  recog_model->bad_information_ = static_cast<int> (recog_model->outlier_indices_.size ());
  recog_model->explained_ = explained_indices;
  recog_model->explained_distances_ = explained_indices_distances;
 
  return true;
}
 
template<typename ModelT, typename SceneT>
void pcl::GlobalHypothesesVerification<ModelT, SceneT>::computeClutterCue(RecognitionModelPtr & recog_model)
{
  if (detect_clutter_)
  {
 
    float rn_sqr = radius_neighborhood_GO_ * radius_neighborhood_GO_;
    pcl::Indices nn_indices;
    std::vector<float> nn_distances;
 
    std::vector < std::pair<int, int> > neighborhood_indices; //first is indices to scene point and second is indices to explained_ scene points
    for (pcl::index_t i = 0; i < static_cast<pcl::index_t> (recog_model->explained_.size ()); i++)
    {
      if (scene_downsampled_tree_->radiusSearch ((*scene_cloud_downsampled_)[recog_model->explained_[i]], radius_neighborhood_GO_, nn_indices,
          nn_distances, std::numeric_limits<int>::max ()))
      {
        for (std::size_t k = 0; k < nn_distances.size (); k++)
        {
          if (nn_indices[k] != i)
            neighborhood_indices.emplace_back (nn_indices[k], i);
        }
      }
    }
 
    //sort neighborhood indices by id
    std::sort (neighborhood_indices.begin (), neighborhood_indices.end (),
        [] (const auto& p1, const auto& p2) { return p1.first < p2.first; });
 
    //erase duplicated unexplained points
    neighborhood_indices.erase (
        std::unique (neighborhood_indices.begin (), neighborhood_indices.end (),
            [] (const auto& p1, const auto& p2) { return p1.first == p2.first; }), neighborhood_indices.end ());
 
    //sort explained points
    std::vector<int> exp_idces (recog_model->explained_);
    std::sort (exp_idces.begin (), exp_idces.end ());
 
    recog_model->unexplained_in_neighborhood.resize (neighborhood_indices.size ());
    recog_model->unexplained_in_neighborhood_weights.resize (neighborhood_indices.size ());
 
    std::size_t p = 0;
    std::size_t j = 0;
    for (const auto &neighborhood_index : neighborhood_indices)
    {
      if ((j < exp_idces.size ()) && (neighborhood_index.first == exp_idces[j]))
      {
        //this index is explained by the hypothesis so ignore it, advance j
        j++;
      } else
      {
        //indices_in_nb[i] < exp_idces[j]
        //recog_model->unexplained_in_neighborhood.push_back(neighborhood_indices[i]);
        recog_model->unexplained_in_neighborhood[p] = neighborhood_index.first;
 
        if ((*clusters_cloud_)[recog_model->explained_[neighborhood_index.second]].intensity != 0.f
            && ((*clusters_cloud_)[recog_model->explained_[neighborhood_index.second]].intensity
                == (*clusters_cloud_)[neighborhood_index.first].intensity))
        {
 
          recog_model->unexplained_in_neighborhood_weights[p] = clutter_regularizer_;
 
        } else
        {
          //neighborhood_indices[i].first gives the index to the scene point and second to the explained scene point by the model causing this...
          //calculate weight of this clutter point based on the distance of the scene point and the model point causing it
          float d = static_cast<float> (pow (
              ((*scene_cloud_downsampled_)[recog_model->explained_[neighborhood_index.second]].getVector3fMap ()
                  - (*scene_cloud_downsampled_)[neighborhood_index.first].getVector3fMap ()).norm (), 2));
          float d_weight = -(d / rn_sqr) + 1; //points that are close have a strong weight*/
 
          //using normals to weight clutter points
          Eigen::Vector3f scene_p_normal = (*scene_normals_)[neighborhood_index.first].getNormalVector3fMap ();
          Eigen::Vector3f model_p_normal = (*scene_normals_)[recog_model->explained_[neighborhood_index.second]].getNormalVector3fMap ();
          float dotp = scene_p_normal.dot (model_p_normal); //[-1,1] from antiparallel through perpendicular to parallel
 
          if (dotp < 0)
            dotp = 0.f;
 
          recog_model->unexplained_in_neighborhood_weights[p] = d_weight * dotp;
        }
        p++;
      }
    }
 
    recog_model->unexplained_in_neighborhood_weights.resize (p);
    recog_model->unexplained_in_neighborhood.resize (p);
  }
}
 
#define PCL_INSTANTIATE_GoHV(T1,T2) template class PCL_EXPORTS pcl::GlobalHypothesesVerification<T1,T2>;
 
#endif /* PCL_RECOGNITION_IMPL_HV_GO_HPP_ */