Visual Servoing Platform  version 3.6.1 under development (2024-05-21)

Visual servoing experiment on 4 points with a visualization from the camera and from an external view using vpSimulator.

* ViSP, open source Visual Servoing Platform software.
* Copyright (C) 2005 - 2023 by Inria. All rights reserved.
* This software is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* See the file LICENSE.txt at the root directory of this source
* distribution for additional information about the GNU GPL.
* For using ViSP with software that can not be combined with the GNU
* GPL, please contact Inria about acquiring a ViSP Professional
* Edition License.
* See for more information.
* This software was developed at:
* Inria Rennes - Bretagne Atlantique
* Campus Universitaire de Beaulieu
* 35042 Rennes Cedex
* France
* If you have questions regarding the use of this file, please contact
* Inria at
* This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
* Description:
* Simulation of a visual servoing with visualization.
#include <visp3/core/vpConfig.h>
#include <visp3/core/vpDebug.h>
#include <visp3/ar/vpSimulator.h>
#include <visp3/core/vpCameraParameters.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/core/vpImage.h>
#include <visp3/core/vpIoTools.h>
#include <visp3/core/vpMath.h>
#include <visp3/core/vpTime.h>
#include <visp3/io/vpParseArgv.h>
#include <visp3/robot/vpSimulatorCamera.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/visual_features/vpFeaturePoint.h>
#include <visp3/vs/vpServo.h>
#define GETOPTARGS "di:h"
#define SAVE 0
void usage(const char *name, const char *badparam, std::string ipath)
fprintf(stdout, "\n\
Simulation Servo 4points.\n\
%s [-i <input image path>] [-d] [-h]\n",
fprintf(stdout, "\n\
OPTIONS: Default\n\
-i <input image path> %s\n\
Set image input path.\n\
From this path read \"iv/4points.iv\"\n\
cad model.\n\
Setting the VISP_INPUT_IMAGE_PATH environment\n\
variable produces the same behaviour than using\n\
this option.\n\
-d \n\
Disable the image display. This can be useful \n\
for automatic tests using crontab under Unix or \n\
using the task manager under Windows.\n\
Print the help.\n\n",
if (badparam)
fprintf(stdout, "\nERROR: Bad parameter [%s]\n", badparam);
bool getOptions(int argc, const char **argv, std::string &ipath, bool &display)
const char *optarg;
int c;
while ((c = vpParseArgv::parse(argc, argv, GETOPTARGS, &optarg)) > 1) {
switch (c) {
case 'i':
ipath = optarg;
case 'd':
display = false;
case 'h':
usage(argv[0], nullptr, ipath);
return false;
usage(argv[0], optarg, ipath);
return false;
if ((c == 1) || (c == -1)) {
// standalone param or error
usage(argv[0], nullptr, ipath);
std::cerr << "ERROR: " << std::endl;
std::cerr << " Bad argument " << optarg << std::endl << std::endl;
return false;
return true;
static void *mainLoop(void *_simu)
vpSimulator *simu = static_cast<vpSimulator *>(_simu);
vpServo task;
float sampling_time = 0.040f; // Sampling period in second
std::cout << std::endl;
std::cout << "-------------------------------------------------------" << std::endl;
std::cout << " Test program for vpServo " << std::endl;
std::cout << " Eye-in-hand task control, articular velocities are computed" << std::endl;
std::cout << " Simulation " << std::endl;
std::cout << " task : servo 4 points " << std::endl;
std::cout << "-------------------------------------------------------" << std::endl;
std::cout << std::endl;
// Sets the initial camera location
vcMo[0] = 0.3;
vcMo[1] = 0.2;
vcMo[2] = 3;
vcMo[3] = 0;
vcMo[4] = vpMath::rad(0);
vcMo[5] = vpMath::rad(40);
vpHomogeneousMatrix wMo; // Set to identity
vpHomogeneousMatrix wMc; // Camera location in world frame
wMc = wMo * cMo.inverse();
wMc = wMo * cMo.inverse();
// Sets the point coordinates in the world frame
vpPoint point[4];
point[0].setWorldCoordinates(-0.1, -0.1, 0);
point[1].setWorldCoordinates(0.1, -0.1, 0);
point[2].setWorldCoordinates(0.1, 0.1, 0);
point[3].setWorldCoordinates(-0.1, 0.1, 0);
// Project : computes the point coordinates in the camera frame and its 2D
// coordinates
for (int i = 0; i < 4; i++)
// Sets the desired position of the point
for (int i = 0; i < 4; i++)
vpFeatureBuilder::create(p[i], point[i]); // retrieve x,y and Z of the vpPoint structure
// Sets the desired position of the point
pd[0].buildFrom(-0.1, -0.1, 1);
pd[1].buildFrom(0.1, -0.1, 1);
pd[2].buildFrom(0.1, 0.1, 1);
pd[3].buildFrom(-0.1, 0.1, 1);
// Define the task
// We want an eye-in-hand control law
// Articular velocity are computed
// Set the position of the end-effector frame in the camera frame as identity
// Set the Jacobian (expressed in the end-effector frame)
vpMatrix eJe;
// We want to see a point on a point
for (int i = 0; i < 4; i++)
task.addFeature(p[i], pd[i]);
// Set the gain
std::cout << "Display task information" << std::endl;
vpTime::wait(1000); // Sleep 1s to ensure that all the thread are initialized
unsigned int iter = 0;
// visual servo loop
while (iter++ < 100) {
double t = vpTime::measureTimeMs();
wMc = robot.getPosition();
cMo = wMc.inverse() * wMo;
for (int i = 0; i < 4; i++) {
vpFeatureBuilder::create(p[i], point[i]);
v = task.computeControlLaw();
if (SAVE == 1) {
char name[FILENAME_MAX];
snprintf(name, FILENAME_MAX, "/tmp/image.%04u.external.png", iter);
std::cout << name << std::endl;
snprintf(name, FILENAME_MAX, "/tmp/image.%04u.internal.png", iter);
vpTime::wait(t, sampling_time * 1000); // Wait 40 ms
std::cout << "\nDisplay task information" << std::endl;
void *a = nullptr;
return a;
int main(int argc, const char **argv)
try {
std::string env_ipath;
std::string opt_ipath;
std::string ipath;
std::string filename;
bool opt_display = true;
// Get the visp-images-data package path or VISP_INPUT_IMAGE_PATH
// environment variable value
// Set the default input path
if (!env_ipath.empty())
ipath = env_ipath;
// Read the command line options
if (getOptions(argc, argv, opt_ipath, opt_display) == false) {
// Get the option values
if (!opt_ipath.empty())
ipath = opt_ipath;
// Compare ipath and env_ipath. If they differ, we take into account
// the input path coming from the command line option
if (!opt_ipath.empty() && !env_ipath.empty()) {
if (ipath != env_ipath) {
std::cout << std::endl << "WARNING: " << std::endl;
std::cout << " Since -i <visp image path=" << ipath << "> "
<< " is different from VISP_IMAGE_PATH=" << env_ipath << std::endl
<< " we skip the environment variable." << std::endl;
// Test if an input path is set
if (opt_ipath.empty() && env_ipath.empty()) {
usage(argv[0], nullptr, ipath);
std::cerr << std::endl << "ERROR:" << std::endl;
std::cerr << " Use -i <visp image path> option or set VISP_INPUT_IMAGE_PATH " << std::endl
<< " environment variable to specify the location of the " << std::endl
<< " image path where test images are located." << std::endl
<< std::endl;
fMo[2][3] = 0;
if (opt_display) {
simu.initInternalViewer(300, 300);
simu.initExternalViewer(300, 300);
// Load the cad model
filename = vpIoTools::createFilePath(ipath, "iv/4points.iv");
catch (const vpException &e) {
std::cout << "Catch an exception: " << e << std::endl;
int main()
std::cout << "You do not have Coin3D and SoQT or SoWin or SoXt functionalities enabled..." << std::endl;
std::cout << "Tip:" << std::endl;
<< "- Install Coin3D and SoQT or SoWin or SoXt, configure ViSP again using cmake and build again this example"
<< std::endl;
Generic class defining intrinsic camera parameters.
Implementation of column vector and the associated operations.
Definition: vpColVector.h:163
error that can be emitted by ViSP classes.
Definition: vpException.h:59
static void create(vpFeaturePoint &s, const vpCameraParameters &cam, const vpDot &d)
Class that defines a 2D point visual feature which is composed by two parameters that are the cartes...
void buildFrom(double x, double y, double Z)
void track(const vpHomogeneousMatrix &cMo)
Implementation of an homogeneous matrix and operations on such kind of matrices.
vpHomogeneousMatrix inverse() const
static std::string getViSPImagesDataPath()
Definition: vpIoTools.cpp:1834
static std::string createFilePath(const std::string &parent, const std::string &child)
Definition: vpIoTools.cpp:2197
static double rad(double deg)
Definition: vpMath.h:127
Implementation of a matrix and operations on matrices.
Definition: vpMatrix.h:146
static bool parse(int *argcPtr, const char **argv, vpArgvInfo *argTable, int flags)
Definition: vpParseArgv.cpp:69
Class that defines a 3D point in the object frame and allows forward projection of a 3D point in the ...
Definition: vpPoint.h:77
void setWorldCoordinates(double oX, double oY, double oZ)
Definition: vpPoint.cpp:110
Implementation of a pose vector and operations on poses.
Definition: vpPoseVector.h:189
void get_eJe(vpMatrix &eJe) vp_override
void setVelocity(const vpRobot::vpControlFrameType frame, const vpColVector &vel) vp_override
Definition: vpRobot.h:82
void setMaxTranslationVelocity(double maxVt)
Definition: vpRobot.cpp:236
void setInteractionMatrixType(const vpServoIteractionMatrixType &interactionMatrixType, const vpServoInversionType &interactionMatrixInversion=PSEUDO_INVERSE)
Definition: vpServo.cpp:378
Definition: vpServo.h:162
void addFeature(vpBasicFeature &s_cur, vpBasicFeature &s_star, unsigned int select=vpBasicFeature::FEATURE_ALL)
Definition: vpServo.cpp:329
void set_cVe(const vpVelocityTwistMatrix &cVe_)
Definition: vpServo.h:1028
void print(const vpServo::vpServoPrintType display_level=ALL, std::ostream &os=std::cout)
Definition: vpServo.cpp:169
void setLambda(double c)
Definition: vpServo.h:976
void set_eJe(const vpMatrix &eJe_)
Definition: vpServo.h:1091
void setServo(const vpServoType &servo_type)
Definition: vpServo.cpp:132
vpColVector computeControlLaw()
Definition: vpServo.cpp:703
Definition: vpServo.h:196
Class that defines the simplest robot: a free flying camera.
Implementation of a simulator based on Coin3d (
Definition: vpSimulator.h:99
void load(const char *file_name)
load an iv file
void setInternalCameraParameters(vpCameraParameters &cam)
set internal camera parameters
virtual void mainLoop()
activate the mainloop
void setExternalCameraParameters(vpCameraParameters &cam)
set external camera parameters
void initMainApplication()
perform some initialization in the main program thread
void initApplication(void *(*start_routine)(void *))
begin the main program
void getCameraPosition(vpHomogeneousMatrix &_cMf)
get the camera position (from an homogeneous matrix)
Definition: vpSimulator.h:248
void setZoomFactor(float zoom)
set the size of the camera/frame
void setCameraPosition(vpHomogeneousMatrix &cMf)
set the camera position (from an homogeneous matrix)
void initExternalViewer(unsigned int nlig, unsigned int ncol)
initialize the external view
void write(const char *fileName)
virtual void initInternalViewer(unsigned int nlig, unsigned int ncol)
initialize the camera view
void closeMainApplication()
void display(vpImage< unsigned char > &I, const std::string &title)
Display a gray-scale image.
VISP_EXPORT int wait(double t0, double t)
VISP_EXPORT double measureTimeMs()