gtsam/geometry/Pose3.cpp

252 lines
7.7 KiB
C++

/* ----------------------------------------------------------------------------
* GTSAM Copyright 2010, 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
* -------------------------------------------------------------------------- */
/**
* @file Pose3.cpp
* @brief 3D Pose
*/
#include <iostream>
#include <gtsam/geometry/Pose3.h>
#include <gtsam/base/Lie-inl.h>
using namespace std;
using namespace boost::numeric::ublas;
namespace gtsam {
/** Explicit instantiation of base class to export members */
INSTANTIATE_LIE(Pose3);
static const Matrix I3 = eye(3), _I3=-I3, I6 = eye(6), Z3 = zeros(3, 3);
/* ************************************************************************* */
// Calculate Adjoint map
// Ad_pose is 6*6 matrix that when applied to twist xi, returns Ad_pose(xi)
// Experimental - unit tests of derivatives based on it do not check out yet
Matrix Pose3::AdjointMap() const {
const Matrix R = R_.matrix();
const Vector t = t_.vector();
Matrix A = skewSymmetric(t)*R;
Matrix DR = collect(2, &R, &Z3);
Matrix Dt = collect(2, &A, &R);
return gtsam::stack(2, &DR, &Dt);
}
/* ************************************************************************* */
void Pose3::print(const string& s) const {
R_.print(s + ".R");
t_.print(s + ".t");
}
/* ************************************************************************* */
bool Pose3::equals(const Pose3& pose, double tol) const {
return R_.equals(pose.R_,tol) && t_.equals(pose.t_,tol);
}
/* ************************************************************************* */
#ifdef CORRECT_POSE3_EXMAP
/** Modified from Murray94book version (which assumes w and v normalized?) */
template<> Pose3 expmap(const Vector& xi) {
// get angular velocity omega and translational velocity v from twist xi
Point3 w(xi(0),xi(1),xi(2)), v(xi(3),xi(4),xi(5));
double theta = w.norm();
if (theta < 1e-5) {
static const Rot3 I;
return Pose3(I, v);
}
else {
Point3 n(w/theta); // axis unit vector
Rot3 R = Rot3::rodriguez(n.vector(),theta);
double vn = n.dot(v); // translation parallel to n
Point3 n_cross_v = n.cross(v); // points towards axis
Point3 t = (n_cross_v - R*n_cross_v)/theta + vn*n;
return Pose3(R, t);
}
}
Vector logmap(const Pose3& p) {
Vector w = logmap(p.rotation()), T = p.translation().vector();
double t = norm_2(w);
if (t < 1e-5)
return concatVectors(2, &w, &T);
else {
Matrix W = skewSymmetric(w/t);
Matrix Ainv = I3 - (0.5*t)*W + ((2*sin(t)-t*(1+cos(t)))/(2*sin(t))) * (W * W);
Vector u = Ainv*T;
return concatVectors(2, &w, &u);
}
}
Pose3 expmap(const Pose3& T, const Vector& d) {
return compose(T,Pose3::Expmap(d));
}
Vector logmap(const Pose3& T1, const Pose3& T2) {
return Pose3::logmap(between(T1,T2));
}
#else
/* ************************************************************************* */
/* incorrect versions for which we know how to compute derivatives */
Pose3 Pose3::Expmap(const Vector& d) {
Vector w = sub(d, 0,3);
Vector u = sub(d, 3,6);
return Pose3(Rot3::Expmap(w), Point3::Expmap(u));
}
/* ************************************************************************* */
// Log map at identity - return the translation and canonical rotation
// coordinates of a pose.
Vector Pose3::Logmap(const Pose3& p) {
const Vector w = Rot3::Logmap(p.rotation()), u = Point3::Logmap(p.translation());
return concatVectors(2, &w, &u);
}
/** These are the "old-style" expmap and logmap about the specified
* pose. Increments the offset and rotation independently given a translation and
* canonical rotation coordinates. Created to match ML derivatives, but
* superseded by the correct exponential map story in .cpp */
Pose3 Pose3::expmap(const Vector& d) const {
return Pose3(R_.expmap(sub(d, 0, 3)),
t_.expmap(sub(d, 3, 6)));
}
/** Independently computes the logmap of the translation and rotation. */
Vector Pose3::logmap(const Pose3& pp) const {
const Vector r(R_.logmap(pp.rotation())),
t(t_.logmap(pp.translation()));
return concatVectors(2, &r, &t);
}
#endif
/* ************************************************************************* */
Matrix Pose3::matrix() const {
const Matrix R = R_.matrix(), T = Matrix_(3,1, t_.vector());
const Matrix A34 = collect(2, &R, &T);
const Matrix A14 = Matrix_(1,4, 0.0, 0.0, 0.0, 1.0);
return gtsam::stack(2, &A34, &A14);
}
/* ************************************************************************* */
Pose3 Pose3::transform_to(const Pose3& pose) const {
Rot3 cRv = R_ * Rot3(pose.R_.inverse());
Point3 t = pose.transform_to(t_);
return Pose3(cRv, t);
}
/* ************************************************************************* */
Point3 Pose3::transform_from(const Point3& p,
boost::optional<Matrix&> H1, boost::optional<Matrix&> H2) const {
if (H1) {
#ifdef CORRECT_POSE3_EXMAP
const Matrix R = R_.matrix();
Matrix DR = R*skewSymmetric(-p.x(), -p.y(), -p.z());
*H1 = collect(2,&DR,&R);
#else
Matrix DR;
R_.rotate(p, DR, boost::none);
*H1 = collect(2,&DR,&I3);
#endif
}
if (H2) *H2 = R_.matrix();
return R_ * p + t_;
}
/* ************************************************************************* */
Point3 Pose3::transform_to(const Point3& p,
boost::optional<Matrix&> H1, boost::optional<Matrix&> H2) const {
const Point3 result = R_.unrotate(p - t_);
if (H1) { // *H1 = Dtransform_to1(pose, p);
const Point3& q = result;
Matrix DR = skewSymmetric(q.x(), q.y(), q.z());
#ifdef CORRECT_POSE3_EXMAP
*H1 = collect(2, &DR, &_I3);
#else
Matrix DT = - R_.transpose(); // negative because of sub
*H1 = collect(2,&DR,&DT);
#endif
}
if (H2) *H2 = R_.transpose();
return result;
}
/* ************************************************************************* */
Pose3 Pose3::compose(const Pose3& p2,
boost::optional<Matrix&> H1, boost::optional<Matrix&> H2) const {
if (H1) {
#ifdef CORRECT_POSE3_EXMAP
*H1 = AdjointMap(inverse(p2));
#else
const Rot3& R2 = p2.rotation();
const Point3& t2 = p2.translation();
Matrix DR_R1 = R2.transpose(), DR_t1 = Z3;
Matrix DR = collect(2, &DR_R1, &DR_t1);
Matrix Dt;
transform_from(t2, Dt, boost::none);
*H1 = gtsam::stack(2, &DR, &Dt);
#endif
}
if (H2) {
#ifdef CORRECT_POSE3_EXMAP
*H2 = I6;
#else
Matrix R1 = rotation().matrix();
Matrix DR = collect(2, &I3, &Z3);
Matrix Dt = collect(2, &Z3, &R1);
*H2 = gtsam::stack(2, &DR, &Dt);
#endif
}
return (*this) * p2;
}
/* ************************************************************************* */
Pose3 Pose3::inverse(boost::optional<Matrix&> H1) const {
if (H1)
#ifdef CORRECT_POSE3_EXMAP
{ *H1 = - AdjointMap(p); }
#else
{
Matrix Rt = R_.transpose();
Matrix DR_R1 = -R_.matrix(), DR_t1 = Z3;
Matrix Dt_R1 = -skewSymmetric(R_.unrotate(t_).vector()), Dt_t1 = -Rt;
Matrix DR = collect(2, &DR_R1, &DR_t1);
Matrix Dt = collect(2, &Dt_R1, &Dt_t1);
*H1 = gtsam::stack(2, &DR, &Dt);
}
#endif
Rot3 Rt = R_.inverse();
return Pose3(Rt, Rt*(-t_));
}
/* ************************************************************************* */
// between = compose(p2,inverse(p1));
Pose3 Pose3::between(const Pose3& p2, boost::optional<Matrix&> H1,
boost::optional<Matrix&> H2) const {
Matrix invH;
Pose3 invp1 = inverse(invH);
Matrix composeH1;
Pose3 result = invp1.compose(p2, composeH1, H2);
if (H1) *H1 = composeH1 * invH;
return result;
}
/* ************************************************************************* */
} // namespace gtsam