TranslationFactor.h

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/* ----------------------------------------------------------------------------
 
 * GTSAM Copyright 2010-2020, Georgia Tech Research Corporation,
 * Atlanta, Georgia 30332-0415
 * All Rights Reserved
 * Authors: Frank Dellaert, et al. (see THANKS for the full author list)
 
 * See LICENSE for the license information
 
 * -------------------------------------------------------------------------- */
 
#pragma once

 
#include <gtsam/base/Vector.h>
#include <gtsam/geometry/Point3.h>
#include <gtsam/geometry/Unit3.h>
#include <gtsam/linear/NoiseModel.h>
#include <gtsam/nonlinear/NonlinearFactor.h>
#include <gtsam/nonlinear/NoiseModelFactorN.h>
 
namespace gtsam {

class TranslationFactor : public NoiseModelFactorT<Vector3, Point3, Point3> {
 private:
  typedef NoiseModelFactorT<Vector3, Point3, Point3> Base;
  Point3 measured_w_aZb_;
 
 public:
  // Provide access to the Matrix& version of evaluateError:
  using Base::evaluateError;

  TranslationFactor() {}
 
  TranslationFactor(Key a, Key b, const Unit3& w_aZb,
                    const SharedNoiseModel& noiseModel)
      : Base(noiseModel, a, b), measured_w_aZb_(w_aZb.point3()) {}

  Vector3 evaluateError(const Point3& Ta, const Point3& Tb,
                        OptionalMatrixType H1,
                        OptionalMatrixType H2) const override {
    const Point3 dir = Tb - Ta;
    Matrix33 H_predicted_dir;
    const Point3 predicted =
        normalize(dir, H1 || H2 ? &H_predicted_dir : nullptr);
    if (H1) *H1 = -H_predicted_dir;
    if (H2) *H2 = H_predicted_dir;
    return predicted - measured_w_aZb_;
  }
 
 private:
#if GTSAM_ENABLE_BOOST_SERIALIZATION
  friend class boost::serialization::access;
  template <class ARCHIVE>
  void serialize(ARCHIVE& ar, const unsigned int /*version*/) {
    ar& boost::serialization::make_nvp(
        "Base", boost::serialization::base_object<Base>(*this));
  }
#endif
};  // \ TranslationFactor

class BilinearAngleTranslationFactor
    : public NoiseModelFactorT<Vector3, Point3, Point3, Vector1> {
 private:
  typedef NoiseModelFactorT<Vector3, Point3, Point3, Vector1> Base;
  Point3 measured_w_aZb_;
 
 public:
  BilinearAngleTranslationFactor() {}
 
  BilinearAngleTranslationFactor(Key a, Key b, Key scale_key,
                                 const Unit3& w_aZb,
                                 const SharedNoiseModel& noiseModel)
      : Base(noiseModel, a, b, scale_key), measured_w_aZb_(w_aZb.point3()) {}
 
  // Provide access to the Matrix& version of evaluateError:
  using Base::evaluateError;

  Vector3 evaluateError(const Point3& Ta, const Point3& Tb,
                        const Vector1& scale, OptionalMatrixType H1,
                        OptionalMatrixType H2,
                        OptionalMatrixType H3) const override {
    // Ideally we should use a positive real valued scalar datatype for scale.
    const double abs_scale = std::abs(scale[0]);
    const Point3 predicted = (Tb - Ta) * abs_scale;
    if (H1) {
      *H1 = -Matrix3::Identity() * abs_scale;
    }
    if (H2) {
      *H2 = Matrix3::Identity() * abs_scale;
    }
    if (H3) {
      *H3 = scale[0] >= 0 ? (Tb - Ta) : (Ta - Tb);
    }
    return predicted - measured_w_aZb_;
  }
 
 private:
#if GTSAM_ENABLE_BOOST_SERIALIZATION
  friend class boost::serialization::access;
  template <class ARCHIVE>
  void serialize(ARCHIVE& ar, const unsigned int /*version*/) {
    ar& boost::serialization::make_nvp(
        "Base", boost::serialization::base_object<Base>(*this));
  }
#endif
};  // \ BilinearAngleTranslationFactor
}  // namespace gtsam