gtsam/tests/testTranslationRecovery.cpp

88 lines
3.1 KiB
C++

/* ----------------------------------------------------------------------------
* 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
* -------------------------------------------------------------------------- */
/**
* @file testTranslationRecovery.cpp
* @author Frank Dellaert
* @date March 2020
* @brief test recovering translations when rotations are given.
*/
#include <gtsam/sfm/TranslationRecovery.h>
#include <CppUnitLite/TestHarness.h>
#include <gtsam/slam/dataset.h>
using namespace std;
using namespace gtsam;
/* ************************************************************************* */
// We read the BAL file, which has 3 cameras in it, with poses. We then assume
// the rotations are correct, but translations have to be estimated from
// translation directions only. Since we have 3 cameras, A, B, and C, we can at
// most create three relative measurements, let's call them w_aZb, w_aZc, and
// bZc. These will be of type Unit3. We then call `recoverTranslations` which
// sets up an optimization problem for the three unknown translations.
TEST(TranslationRecovery, BAL) {
const string filename = findExampleDataFile("dubrovnik-3-7-pre");
SfmData db;
bool success = readBAL(filename, db);
if (!success) throw runtime_error("Could not access file!");
// Get camera poses, as Values
size_t j = 0;
Values poses;
for (auto camera : db.cameras) {
poses.insert(j++, camera.pose());
}
// Simulate measurements
const auto relativeTranslations = TranslationRecovery::SimulateMeasurements(
poses, {{0, 1}, {0, 2}, {1, 2}});
// Check
const Pose3 wTa = poses.at<Pose3>(0), wTb = poses.at<Pose3>(1),
wTc = poses.at<Pose3>(2);
const Point3 Ta = wTa.translation(), Tb = wTb.translation(),
Tc = wTc.translation();
const Rot3 aRw = wTa.rotation().inverse();
const Unit3 w_aZb = relativeTranslations.at({0, 1});
EXPECT(assert_equal(Unit3(Tb - Ta), w_aZb));
const Unit3 w_aZc = relativeTranslations.at({0, 2});
EXPECT(assert_equal(Unit3(Tc - Ta), w_aZc));
TranslationRecovery algorithm(relativeTranslations);
const auto graph = algorithm.buildGraph();
EXPECT_LONGS_EQUAL(3, graph.size());
// Translation recovery, version 1
const double scale = 2.0;
const auto result = algorithm.run(scale);
// Check result for first two translations, determined by prior
EXPECT(assert_equal(Point3(0, 0, 0), result.at<Point3>(0)));
EXPECT(assert_equal(Point3(2 * w_aZb.point3()), result.at<Point3>(1)));
// Check that the third translations is correct
Point3 expected = (Tc - Ta) * (scale / (Tb - Ta).norm());
EXPECT(assert_equal(expected, result.at<Point3>(2), 1e-4));
// TODO(frank): how to get stats back?
// EXPECT_DOUBLES_EQUAL(0.0199833, actualError, 1e-5);
}
/* ************************************************************************* */
int main() {
TestResult tr;
return TestRegistry::runAllTests(tr);
}
/* ************************************************************************* */