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/*
* Software License Agreement (BSD License)
*
* Copyright (c) 2018. Toyota Research Institute
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* * Neither the name of CNRS-LAAS and AIST nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/** @author Hongkai Dai <hongkai.dai@tri.global> */
#include <memory>
#include <utility>
#include <vector>
#include <gtest/gtest.h>
#include <Eigen/Dense>
#include "eigen_matrix_compare.h"
#include "fcl/narrowphase/collision_object.h"
#include "fcl/narrowphase/distance.h"
#include "fcl/narrowphase/distance_request.h"
#include "fcl/narrowphase/distance_result.h"
// For two spheres 1, 2, sphere 1 has radius1, and is centered at point A, with
// coordinate p_FA in some frame F; sphere 2 has radius2, and is centered at
// point B, with coordinate p_FB in the same frame F. Compute the (optionally
// signed) distance between the two spheres.
template <typename S>
S ComputeSphereSphereDistance(S radius1, S radius2, const fcl::Vector3<S>& p_FA,
const fcl::Vector3<S>& p_FB,
fcl::GJKSolverType solver_type,
bool enable_nearest_points,
bool enable_signed_distance,
fcl::DistanceResult<S>* result) {
// Pose of the sphere expressed in the frame F. X_FA is the pose of sphere 1
// in frame F, while X_FB is the pose of sphere 2 in frame F.
// We use monogram notation as in Drake, explained in
// http://drake.mit.edu/doxygen_cxx/group__multibody__spatial__pose.html
fcl::Transform3<S> X_FA, X_FB;
X_FA.setIdentity();
X_FB.setIdentity();
X_FA.translation() = p_FA;
X_FB.translation() = p_FB;
fcl::DistanceRequest<S> request;
request.enable_nearest_points = enable_nearest_points;
request.enable_signed_distance = enable_signed_distance;
request.gjk_solver_type = solver_type;
using CollisionGeometryPtr_t = std::shared_ptr<fcl::CollisionGeometry<S>>;
CollisionGeometryPtr_t sphere_geometry_1(new fcl::Sphere<S>(radius1));
CollisionGeometryPtr_t sphere_geometry_2(new fcl::Sphere<S>(radius2));
fcl::CollisionObject<S> sphere_1(sphere_geometry_1, X_FA);
fcl::CollisionObject<S> sphere_2(sphere_geometry_2, X_FB);
const S min_distance = fcl::distance(&sphere_1, &sphere_2, request, *result);
return min_distance;
}
template <typename S>
struct SphereSpecification {
// @param p_FC_ the center of the sphere C measured and expressed in a frame F
SphereSpecification(S m_radius, const fcl::Vector3<S>& p_FC_)
: radius(m_radius), p_FC(p_FC_) {}
S radius;
fcl::Vector3<S> p_FC;
};
template <typename S>
void CheckSphereToSphereDistance(const SphereSpecification<S>& sphere1,
const SphereSpecification<S>& sphere2,
fcl::GJKSolverType solver_type,
bool enable_nearest_points,
bool enable_signed_distance,
S min_distance_expected,
const fcl::Vector3<S>& p1_expected,
const fcl::Vector3<S>& p2_expected, S tol) {
fcl::DistanceResult<S> result;
const S min_distance = ComputeSphereSphereDistance<S>(
sphere1.radius, sphere2.radius, sphere1.p_FC, sphere2.p_FC, solver_type,
enable_nearest_points, enable_signed_distance, &result);
EXPECT_NEAR(min_distance, min_distance_expected, tol);
EXPECT_NEAR(result.min_distance, min_distance_expected, tol);
EXPECT_TRUE(fcl::CompareMatrices(result.nearest_points[0], p1_expected, tol));
EXPECT_TRUE(fcl::CompareMatrices(result.nearest_points[1], p2_expected, tol));
}
template <typename S>
struct SphereSphereDistance {
SphereSphereDistance(const SphereSpecification<S>& m_sphere1,
const SphereSpecification<S>& m_sphere2)
: sphere1(m_sphere1), sphere2(m_sphere2) {
min_distance =
(sphere1.p_FC - sphere2.p_FC).norm() - sphere1.radius - sphere2.radius;
const fcl::Vector3<S> AB = (sphere1.p_FC - sphere2.p_FC).normalized();
p_WP1 = sphere1.p_FC + AB * -sphere1.radius;
p_WP2 = sphere2.p_FC + AB * sphere2.radius;
}
SphereSpecification<S> sphere1;
SphereSpecification<S> sphere2;
S min_distance;
// The closest point P1 on sphere 1 is expressed in the world frame W.
fcl::Vector3<S> p_WP1;
// The closest point P2 on sphere 2 is expressed in the world frame W.
fcl::Vector3<S> p_WP2;
};
template <typename S>
void TestSeparatingSpheres(S tol, fcl::GJKSolverType solver_type) {
std::vector<SphereSpecification<S>> spheres;
spheres.emplace_back(0.5, fcl::Vector3<S>(0, 0, -1)); // sphere 1
spheres.emplace_back(0.6, fcl::Vector3<S>(1.2, 0, 0)); // sphere 2
spheres.emplace_back(0.4, fcl::Vector3<S>(-0.3, 0, 0)); // sphere 3
spheres.emplace_back(0.3, fcl::Vector3<S>(0, 0, 1)); // sphere 4
for (int i = 0; i < static_cast<int>(spheres.size()); ++i) {
for (int j = i + 1; j < static_cast<int>(spheres.size()); ++j) {
SphereSphereDistance<S> sphere_sphere_distance(spheres[i], spheres[j]);
bool enable_signed_distance = true;
CheckSphereToSphereDistance<S>(
spheres[i], spheres[j], solver_type, true, enable_signed_distance,
sphere_sphere_distance.min_distance, sphere_sphere_distance.p_WP1,
sphere_sphere_distance.p_WP2, tol);
// Now switch the order of sphere 1 with sphere 2 in calling
// fcl::distance function, and test again.
CheckSphereToSphereDistance<S>(
spheres[j], spheres[i], solver_type, true, enable_signed_distance,
sphere_sphere_distance.min_distance, sphere_sphere_distance.p_WP2,
sphere_sphere_distance.p_WP1, tol);
enable_signed_distance = false;
CheckSphereToSphereDistance<S>(
spheres[i], spheres[j], solver_type, true, enable_signed_distance,
sphere_sphere_distance.min_distance, sphere_sphere_distance.p_WP1,
sphere_sphere_distance.p_WP2, tol);
// Now switch the order of sphere 1 with sphere 2 in calling
// fcl::distance function, and test again.
CheckSphereToSphereDistance<S>(
spheres[j], spheres[i], solver_type, true, enable_signed_distance,
sphere_sphere_distance.min_distance, sphere_sphere_distance.p_WP2,
sphere_sphere_distance.p_WP1, tol);
// TODO (hongkai.dai@tri.global): Test enable_nearest_points=false.
}
}
}
GTEST_TEST(FCL_SPHERE_SPHERE, Separating_Spheres_INDEP) {
TestSeparatingSpheres<double>(1E-14, fcl::GJKSolverType::GST_INDEP);
}
GTEST_TEST(FCL_SPHERE_SPHERE, Separating_Spheres_LIBCCD) {
// TODO(hongkai.dai@tri.global): The accuracy of the closest point is only up
// to 1E-3, although gjkSolver::distance_tolerance is 1E-6. We should
// investigate the accuracy issue.
// Specifically, when setting `enable_signed_distance = true`, then except for
// the the pair of spheres (2, 3), the closest point between all other pairs
// fail to achieve tolerance 1E-6. When `enable_signed_distance = false`, then
// all pairs achieve tolerance 1E-6.
TestSeparatingSpheres<double>(1E-3, fcl::GJKSolverType::GST_LIBCCD);
}
//==============================================================================
int main(int argc, char* argv[]) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
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