integrated_gicp_factor.hpp

// SPDX-License-Identifier: MIT
// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
 
#pragma once
 
#include <gtsam/nonlinear/NonlinearFactor.h>
 
#include <memory>
#include <gtsam_points/util/gtsam_migration.hpp>
#include <gtsam_points/types/point_cloud.hpp>
#include <gtsam_points/factors/integrated_matching_cost_factor.hpp>
 
namespace gtsam_points {
 
struct NearestNeighborSearch;
 
enum class FusedCovCacheMode {
  FULL,     // Full matrix (4x4 double : 128 bit per point, fast)
  COMPACT,  // Compact matrix (upper-trianguler of 3x3 float, 24 bit per point, intermediate)
  NONE      // No cache (0 bit per point, slow)
};
 
template <typename TargetFrame = gtsam_points::PointCloud, typename SourceFrame = gtsam_points::PointCloud>
class IntegratedGICPFactor_ : public gtsam_points::IntegratedMatchingCostFactor {
public:
  EIGEN_MAKE_ALIGNED_OPERATOR_NEW
  using shared_ptr = gtsam_points::shared_ptr<IntegratedGICPFactor_>;
 
  IntegratedGICPFactor_(
    gtsam::Key target_key,
    gtsam::Key source_key,
    const std::shared_ptr<const TargetFrame>& target,
    const std::shared_ptr<const SourceFrame>& source,
    const std::shared_ptr<const NearestNeighborSearch>& target_tree);
 
  IntegratedGICPFactor_(
    gtsam::Key target_key,
    gtsam::Key source_key,
    const std::shared_ptr<const TargetFrame>& target,
    const std::shared_ptr<const SourceFrame>& source);
 
  IntegratedGICPFactor_(
    const gtsam::Pose3& fixed_target_pose,
    gtsam::Key source_key,
    const std::shared_ptr<const TargetFrame>& target,
    const std::shared_ptr<const SourceFrame>& source,
    const std::shared_ptr<const NearestNeighborSearch>& target_tree);
 
  IntegratedGICPFactor_(
    const gtsam::Pose3& fixed_target_pose,
    gtsam::Key source_key,
    const std::shared_ptr<const TargetFrame>& target,
    const std::shared_ptr<const SourceFrame>& source);
 
  virtual ~IntegratedGICPFactor_() override;
 
  virtual void print(const std::string& s = "", const gtsam::KeyFormatter& keyFormatter = gtsam::DefaultKeyFormatter) const override;
 
  virtual size_t memory_usage() const override;
 
  void set_num_threads(int n) { num_threads = n; }
 
  void set_max_correspondence_distance(double dist) { max_correspondence_distance_sq = dist * dist; }
 
  void set_correspondence_update_tolerance(double angle, double trans) {
    correspondence_update_tolerance_rot = angle;
    correspondence_update_tolerance_trans = trans;
  }
 
  void set_fused_cov_cache_mode(FusedCovCacheMode mode) { mahalanobis_cache_mode = mode; }
 
  double inlier_fraction() const {
    const int outliers = std::count(correspondences.begin(), correspondences.end(), -1);
    const int inliers = correspondences.size() - outliers;
    return static_cast<double>(inliers) / correspondences.size();
  }
 
  gtsam::NonlinearFactor::shared_ptr clone() const override { return gtsam::NonlinearFactor::shared_ptr(new IntegratedGICPFactor_(*this)); }
 
private:
  virtual void update_correspondences(const Eigen::Isometry3d& delta) const override;
 
  virtual double evaluate(
    const Eigen::Isometry3d& delta,
    Eigen::Matrix<double, 6, 6>* H_target = nullptr,
    Eigen::Matrix<double, 6, 6>* H_source = nullptr,
    Eigen::Matrix<double, 6, 6>* H_target_source = nullptr,
    Eigen::Matrix<double, 6, 1>* b_target = nullptr,
    Eigen::Matrix<double, 6, 1>* b_source = nullptr) const override;
 
private:
  int num_threads;
  double max_correspondence_distance_sq;
  FusedCovCacheMode mahalanobis_cache_mode;
 
  std::shared_ptr<const NearestNeighborSearch> target_tree;
 
  // I'm unhappy to have mutable members...
  double correspondence_update_tolerance_rot;
  double correspondence_update_tolerance_trans;
  mutable Eigen::Isometry3d linearization_point;
  mutable Eigen::Isometry3d last_correspondence_point;
  mutable std::vector<long> correspondences;
  mutable std::vector<Eigen::Matrix4d> mahalanobis_full;
  mutable std::vector<Eigen::Matrix<float, 6, 1>> mahalanobis_compact;
 
  std::shared_ptr<const TargetFrame> target;
  std::shared_ptr<const SourceFrame> source;
};
 
using IntegratedGICPFactor = IntegratedGICPFactor_<>;
 
}  // namespace gtsam_points