export Similarity3 specalized BetweenFactor to python

Author: niwhsa9

gtsam/geometry/Similarity3.h

@@ -202,6 +202,18 @@ class GTSAM_EXPORT Similarity3 : public LieGroup<Similarity3, 7> {
   /// @{
 
  private:
+
+  #ifdef GTSAM_ENABLE_BOOST_SERIALIZATION
+    /** Serialization function */
+    friend class boost::serialization::access;
+    template<class Archive>
+    void serialize(Archive & ar, const unsigned int /*version*/) {
+      ar & BOOST_SERIALIZATION_NVP(R_);
+      ar & BOOST_SERIALIZATION_NVP(t_);
+      ar & BOOST_SERIALIZATION_NVP(s_);
+    }
+  #endif
+
   /// Calculate expmap and logmap coefficients.
   static Matrix3 GetV(Vector3 w, double lambda);
 

gtsam/slam/slam.i

@@ -7,12 +7,13 @@ namespace gtsam {
 #include <gtsam/geometry/Cal3DS2.h>
 #include <gtsam/geometry/SO4.h>
 #include <gtsam/navigation/ImuBias.h>
+#include <gtsam/geometry/Similarity3.h>
 
 // ######
 
 #include <gtsam/slam/BetweenFactor.h>
 template <T = {double, Vector, gtsam::Point2, gtsam::Point3, gtsam::Rot2, gtsam::SO3,
-               gtsam::SO4, gtsam::Rot3, gtsam::Pose2, gtsam::Pose3,
+               gtsam::SO4, gtsam::Rot3, gtsam::Pose2, gtsam::Pose3, gtsam::Similarity3,
                gtsam::imuBias::ConstantBias}>
 virtual class BetweenFactor : gtsam::NoiseModelFactor {
   BetweenFactor(size_t key1, size_t key2, const T& relativePose,