integrated_vgicp_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/types/gaussian_voxelmap_cpu.hpp>
#include <gtsam_points/factors/integrated_matching_cost_factor.hpp>
#include <gtsam_points/factors/integrated_gicp_factor.hpp>
 
namespace gtsam_points {
 
struct GaussianVoxel;
 
template <typename SourceFrame = gtsam_points::PointCloud>
class IntegratedVGICPFactor_ : public gtsam_points::IntegratedMatchingCostFactor {
public:
  EIGEN_MAKE_ALIGNED_OPERATOR_NEW
  using shared_ptr = gtsam_points::shared_ptr<IntegratedVGICPFactor_>;
 
  IntegratedVGICPFactor_(
    gtsam::Key target_key,
    gtsam::Key source_key,
    const GaussianVoxelMap::ConstPtr& target_voxels,
    const std::shared_ptr<const SourceFrame>& source);
 
  IntegratedVGICPFactor_(
    const gtsam::Pose3& fixed_target_pose,
    gtsam::Key source_key,
    const GaussianVoxelMap::ConstPtr& target_voxels,
    const std::shared_ptr<const SourceFrame>& source);
 
  virtual ~IntegratedVGICPFactor_() 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_fused_cov_cache_mode(FusedCovCacheMode mode) { mahalanobis_cache_mode = mode; }
 
  int num_inliers() const {
    const int outliers = std::count(correspondences.begin(), correspondences.end(), nullptr);
    return correspondences.size() - outliers;
  }
 
  double inlier_fraction() const { return num_inliers() / static_cast<double>(correspondences.size()); }
 
  const std::shared_ptr<const GaussianVoxelMapCPU>& get_target() const { return target_voxels; }
 
  gtsam::NonlinearFactor::shared_ptr clone() const override { return gtsam::NonlinearFactor::shared_ptr(new IntegratedVGICPFactor_(*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;
  FusedCovCacheMode mahalanobis_cache_mode;
 
  // I'm unhappy to have mutable members...
  mutable Eigen::Isometry3d linearization_point;
  mutable std::vector<const GaussianVoxel*> correspondences;
  mutable std::vector<Eigen::Matrix4d> mahalanobis_full;
  mutable std::vector<Eigen::Matrix<float, 6, 1>> mahalanobis_compact;
 
  std::shared_ptr<const GaussianVoxelMapCPU> target_voxels;
  std::shared_ptr<const SourceFrame> source;
};
 
using IntegratedVGICPFactor = IntegratedVGICPFactor_<>;
 
}  // namespace gtsam_points