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Merge branch 'ign-math6' into LolaSegura/python_interface
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scpeters authored Sep 8, 2021
2 parents 9a40ad9 + b3804bf commit 9e6df0f
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161 changes: 161 additions & 0 deletions eigen3/include/ignition/math/eigen3/Util.hh
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/*
* Copyright (C) 2021 Open Source Robotics Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/

#ifndef IGNITION_MATH_EIGEN3_UTIL_HH_
#define IGNITION_MATH_EIGEN3_UTIL_HH_

#include <vector>

#include <Eigen/Geometry>
#include <Eigen/Eigenvalues>

#include <ignition/math/AxisAlignedBox.hh>
#include <ignition/math/Matrix3.hh>
#include <ignition/math/OrientedBox.hh>
#include <ignition/math/Pose3.hh>
#include <ignition/math/Quaternion.hh>
#include <ignition/math/Vector3.hh>
#include <ignition/math/eigen3/Conversions.hh>

namespace ignition
{
namespace math
{
namespace eigen3
{
/// \brief Get covariance matrix from a set of 3d vertices
/// https://github.com/isl-org/Open3D/blob/76c2baf9debd460900f056a9b51e9a80de9c0e64/cpp/open3d/utility/Eigen.cpp#L305
/// \param[in] _vertices a vector of 3d vertices
/// \return Covariance matrix
inline Eigen::Matrix3d covarianceMatrix(
const std::vector<math::Vector3d> &_vertices)
{
if (_vertices.empty())
return Eigen::Matrix3d::Identity();

Eigen::Matrix<double, 9, 1> cumulants;
cumulants.setZero();
for (const auto &vertex : _vertices)
{
const Eigen::Vector3d &point = math::eigen3::convert(vertex);
cumulants(0) += point(0);
cumulants(1) += point(1);
cumulants(2) += point(2);
cumulants(3) += point(0) * point(0);
cumulants(4) += point(0) * point(1);
cumulants(5) += point(0) * point(2);
cumulants(6) += point(1) * point(1);
cumulants(7) += point(1) * point(2);
cumulants(8) += point(2) * point(2);
}

Eigen::Matrix3d covariance;

cumulants /= static_cast<double>(_vertices.size());

covariance(0, 0) = cumulants(3) - cumulants(0) * cumulants(0);
covariance(1, 1) = cumulants(6) - cumulants(1) * cumulants(1);
covariance(2, 2) = cumulants(8) - cumulants(2) * cumulants(2);
covariance(0, 1) = cumulants(4) - cumulants(0) * cumulants(1);
covariance(1, 0) = covariance(0, 1);
covariance(0, 2) = cumulants(5) - cumulants(0) * cumulants(2);
covariance(2, 0) = covariance(0, 2);
covariance(1, 2) = cumulants(7) - cumulants(1) * cumulants(2);
covariance(2, 1) = covariance(1, 2);
return covariance;
}

/// \brief Get the oriented 3d bounding box of a set of 3d
/// vertices using PCA
/// http://codextechnicanum.blogspot.com/2015/04/find-minimum-oriented-bounding-box-of.html
/// \param[in] _vertices a vector of 3d vertices
/// \return Oriented 3D box
inline ignition::math::OrientedBoxd verticesToOrientedBox(
const std::vector<math::Vector3d> &_vertices)
{
math::OrientedBoxd box;

// Return an empty box if there are no vertices
if (_vertices.empty())
return box;

math::Vector3d mean;
for (const auto &point : _vertices)
mean += point;
mean /= static_cast<double>(_vertices.size());

Eigen::Vector3d centroid = math::eigen3::convert(mean);
Eigen::Matrix3d covariance = covarianceMatrix(_vertices);

// Eigen Vectors
Eigen::SelfAdjointEigenSolver<Eigen::Matrix3d>
eigenSolver(covariance, Eigen::ComputeEigenvectors);
Eigen::Matrix3d eigenVectorsPCA = eigenSolver.eigenvectors();

// This line is necessary for proper orientation in some cases.
// The numbers come out the same without it, but the signs are
// different and the box doesn't get correctly oriented in some cases.
eigenVectorsPCA.col(2) =
eigenVectorsPCA.col(0).cross(eigenVectorsPCA.col(1));

// Transform the original cloud to the origin where the principal
// components correspond to the axes.
Eigen::Matrix4d projectionTransform(Eigen::Matrix4d::Identity());
projectionTransform.block<3, 3>(0, 0) = eigenVectorsPCA.transpose();
projectionTransform.block<3, 1>(0, 3) =
-1.0f * (projectionTransform.block<3, 3>(0, 0) * centroid);

Eigen::Vector3d minPoint(INF_I32, INF_I32, INF_I32);
Eigen::Vector3d maxPoint(-INF_I32, -INF_I32, -INF_I32);

// Get the minimum and maximum points of the transformed cloud.
for (const auto &point : _vertices)
{
Eigen::Vector4d pt(0, 0, 0, 1);
pt.head<3>() = math::eigen3::convert(point);
Eigen::Vector4d tfPoint = projectionTransform * pt;
minPoint = minPoint.cwiseMin(tfPoint.head<3>());
maxPoint = maxPoint.cwiseMax(tfPoint.head<3>());
}

const Eigen::Vector3d meanDiagonal = 0.5f * (maxPoint + minPoint);

// quaternion is calculated using the eigenvectors (which determines
// how the final box gets rotated), and the transform to put the box
// in correct location is calculated
const Eigen::Quaterniond bboxQuaternion(eigenVectorsPCA);
const Eigen::Vector3d bboxTransform =
eigenVectorsPCA * meanDiagonal + centroid;

math::Vector3d size(
maxPoint.x() - minPoint.x(),
maxPoint.y() - minPoint.y(),
maxPoint.z() - minPoint.z()
);
math::Pose3d pose;
pose.Rot() = math::eigen3::convert(bboxQuaternion);
pose.Pos() = math::eigen3::convert(bboxTransform);

box.Size(size);
box.Pose(pose);
return box;
}
}
}
}

#endif
172 changes: 172 additions & 0 deletions eigen3/src/Util_TEST.cc
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/*
* Copyright (C) 2021 Open Source Robotics Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/

#include <gtest/gtest.h>

#include <ignition/math/eigen3/Util.hh>

using namespace ignition;

/////////////////////////////////////////////////
/// \brief Test the oriented box converted from a set of vertices
TEST(EigenUtil, verticesToOrientedBox)
{
std::vector<math::Vector3d> vertices;

vertices.push_back(math::Vector3d(1, 0, 0.5));
vertices.push_back(math::Vector3d(2, 0.1, 0.4));
vertices.push_back(math::Vector3d(2, 1, 3));
vertices.push_back(math::Vector3d(1.6, 0.3, 0.1));
vertices.push_back(math::Vector3d(1.5, 0.5, 1));
vertices.push_back(math::Vector3d(1.4, 1, 3));
vertices.push_back(math::Vector3d(1, 0.4, 0.7));
vertices.push_back(math::Vector3d(0.9, 1.3, 0));
vertices.push_back(math::Vector3d(0.6, 4, 2));
vertices.push_back(math::Vector3d(0, 3, 3));
vertices.push_back(math::Vector3d(-1, -2, 4));
vertices.push_back(math::Vector3d(-2, -2, 0.6));

math::OrientedBoxd box = math::eigen3::verticesToOrientedBox(
vertices);

auto position = box.Pose().Pos();
auto rotation = box.Pose().Rot();
auto size = box.Size();

double error = 0.1;

EXPECT_NEAR(size.X(), 3.09, error);
EXPECT_NEAR(size.Y(), 4.39, error);
EXPECT_NEAR(size.Z(), 6.63, error);

EXPECT_NEAR(position.X(), 0.38, error);
EXPECT_NEAR(position.Y(), 0.47, error);
EXPECT_NEAR(position.Z(), 1.96, error);

EXPECT_NEAR(rotation.Roll(), -1.66, error);
EXPECT_NEAR(rotation.Pitch(), 0.4, error);
EXPECT_NEAR(rotation.Yaw(), 2.7, error);
}

/////////////////////////////////////////////////
TEST(EigenUtil, emptyVertices)
{
std::vector<math::Vector3d> emptyVertices;

math::OrientedBoxd box = math::eigen3::verticesToOrientedBox(
emptyVertices);

auto position = box.Pose().Pos();
auto rotation = box.Pose().Rot();
auto size = box.Size();

EXPECT_DOUBLE_EQ(size.X(), 0);
EXPECT_DOUBLE_EQ(size.Y(), 0);
EXPECT_DOUBLE_EQ(size.Z(), 0);

EXPECT_DOUBLE_EQ(position.X(), 0);
EXPECT_DOUBLE_EQ(position.Y(), 0);
EXPECT_DOUBLE_EQ(position.Z(), 0);

EXPECT_DOUBLE_EQ(rotation.Roll(), 0);
EXPECT_DOUBLE_EQ(rotation.Pitch(), 0);
EXPECT_DOUBLE_EQ(rotation.Yaw(), 0);
}

/////////////////////////////////////////////////
TEST(EigenUtil, simpleBox)
{
std::vector<math::Vector3d> vertices;

vertices.push_back(math::Vector3d(-1, -1, -1));
vertices.push_back(math::Vector3d(-1, 1, -1));
vertices.push_back(math::Vector3d(1, -1, -1));
vertices.push_back(math::Vector3d(1, 1, -1));
vertices.push_back(math::Vector3d(-1, -1, 1));
vertices.push_back(math::Vector3d(-1, 1, 1));
vertices.push_back(math::Vector3d(1, -1, 1));
vertices.push_back(math::Vector3d(1, 1, 1));

math::OrientedBoxd box = math::eigen3::verticesToOrientedBox(
vertices);

auto position = box.Pose().Pos();
auto rotation = box.Pose().Rot();
auto size = box.Size();

double error = 0.1;

EXPECT_NEAR(size.X(), 2, error);
EXPECT_NEAR(size.Y(), 2, error);
EXPECT_NEAR(size.Z(), 2, error);

EXPECT_NEAR(position.X(), 0, error);
EXPECT_NEAR(position.Y(), 0, error);
EXPECT_NEAR(position.Z(), 0, error);

EXPECT_NEAR(rotation.Roll(), 0, error);
EXPECT_NEAR(rotation.Pitch(), 0, error);
EXPECT_NEAR(rotation.Yaw(), 0, error);
}

/////////////////////////////////////////////////
TEST(EigenUtil, covarianceTest)
{
std::vector<math::Vector3d> vertices;

vertices.push_back(math::Vector3d(1, 0, 0.5));
vertices.push_back(math::Vector3d(2, 0.1, 0.4));
vertices.push_back(math::Vector3d(2, 1, 3));
vertices.push_back(math::Vector3d(1.6, 0.3, 0.1));
vertices.push_back(math::Vector3d(1.5, 0.5, 1));
vertices.push_back(math::Vector3d(1.4, 1, 3));
vertices.push_back(math::Vector3d(1, 0.4, 0.7));

Eigen::Matrix3d covariance = math::eigen3::covarianceMatrix(
vertices);

double error = 0.1;

EXPECT_NEAR(covariance(0), 0.145714, error);
EXPECT_NEAR(covariance(1), 0.04, error);
EXPECT_NEAR(covariance(2), 0.115714, error);
EXPECT_NEAR(covariance(3), 0.04, error);
EXPECT_NEAR(covariance(4), 0.136327, error);
EXPECT_NEAR(covariance(5), 0.392653, error);
EXPECT_NEAR(covariance(6), 0.115714, error);
EXPECT_NEAR(covariance(7), 0.392653, error);
EXPECT_NEAR(covariance(8), 1.29959, error);
}

/////////////////////////////////////////////////
TEST(EigenUtil, covarianceEmptyTest)
{
std::vector<math::Vector3d> vertices;

Eigen::Matrix3d covariance = math::eigen3::covarianceMatrix(
vertices);

EXPECT_DOUBLE_EQ(covariance(0), 1);
EXPECT_DOUBLE_EQ(covariance(1), 0);
EXPECT_DOUBLE_EQ(covariance(2), 0);
EXPECT_DOUBLE_EQ(covariance(3), 0);
EXPECT_DOUBLE_EQ(covariance(4), 1);
EXPECT_DOUBLE_EQ(covariance(5), 0);
EXPECT_DOUBLE_EQ(covariance(6), 0);
EXPECT_DOUBLE_EQ(covariance(7), 0);
EXPECT_DOUBLE_EQ(covariance(8), 1);
}
2 changes: 2 additions & 0 deletions src/python/CMakeLists.txt
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Expand Up @@ -63,6 +63,7 @@ if (PYTHONLIBS_FOUND)
Angle_TEST
Color_TEST
GaussMarkovProcess_TEST
Kmeans_TEST
Line2_TEST
Line3_TEST
PID_TEST
Expand All @@ -76,6 +77,7 @@ if (PYTHONLIBS_FOUND)
Triangle_TEST
Vector2_TEST
Vector3_TEST
Vector3Stats_TEST
Vector4_TEST
)

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