Visual Servoing Platform  version 3.5.1 under development (2022-07-05)

Servo a sphere:

* ViSP, open source Visual Servoing Platform software.
* Copyright (C) 2005 - 2019 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 2D visual servoing on a sphere.
* Authors:
* Eric Marchand
* Fabien Spindler
#include <stdio.h>
#include <stdlib.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/core/vpMath.h>
#include <visp3/core/vpSphere.h>
#include <visp3/gui/vpDisplayGDI.h>
#include <visp3/gui/vpDisplayGTK.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/io/vpParseArgv.h>
#include <visp3/robot/vpSimulatorCamera.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/visual_features/vpFeatureEllipse.h>
#include <visp3/vs/vpServo.h>
#include <visp3/vs/vpServoDisplay.h>
// List of allowed command line options
#define GETOPTARGS "cdh"
void usage(const char *name, const char *badparam);
bool getOptions(int argc, const char **argv, bool &click_allowed, bool &display);
void usage(const char *name, const char *badparam)
fprintf(stdout, "\n\
Simulation of a 2D visual servoing on a sphere:\n\
- eye-in-hand control law,\n\
- velocity computed in the camera frame,\n\
- display the camera view.\n\
%s [-c] [-d] [-h]\n",
fprintf(stdout, "\n\
OPTIONS: Default\n\
Disable the mouse click. Useful to automaze the \n\
execution of this program without humain intervention.\n\
-d \n\
Turn off the display.\n\
Print the help.\n");
if (badparam)
fprintf(stdout, "\nERROR: Bad parameter [%s]\n", badparam);
bool getOptions(int argc, const char **argv, bool &click_allowed, bool &display)
const char *optarg_;
int c;
while ((c = vpParseArgv::parse(argc, argv, GETOPTARGS, &optarg_)) > 1) {
switch (c) {
case 'c':
click_allowed = false;
case 'd':
display = false;
case 'h':
usage(argv[0], NULL);
return false;
usage(argv[0], optarg_);
return false;
if ((c == 1) || (c == -1)) {
// standalone param or error
usage(argv[0], NULL);
std::cerr << "ERROR: " << std::endl;
std::cerr << " Bad argument " << optarg_ << std::endl << std::endl;
return false;
return true;
int main(int argc, const char **argv)
#if (defined(VISP_HAVE_LAPACK) || defined(VISP_HAVE_EIGEN3) || defined(VISP_HAVE_OPENCV))
try {
bool opt_display = true;
bool opt_click_allowed = true;
// Read the command line options
if (getOptions(argc, argv, opt_click_allowed, opt_display) == false) {
return (EXIT_FAILURE);
vpImage<unsigned char> I(512, 512, 0);
// We open a window using either X11, GTK or GDI.
#if defined VISP_HAVE_X11
vpDisplayX display;
#elif defined VISP_HAVE_GTK
vpDisplayGTK display;
#elif defined VISP_HAVE_GDI
vpDisplayGDI display;
#elif defined VISP_HAVE_OPENCV
vpDisplayOpenCV display;
if (opt_display) {
#if defined(VISP_HAVE_X11) || defined(VISP_HAVE_GTK) || defined(VISP_HAVE_GDI) || defined(VISP_HAVE_OPENCV)
// Display size is automatically defined by the image (I) size
display.init(I, 100, 100, "Camera view...");
// Display the image
// The image class has a member that specify a pointer toward
// the display that has been initialized in the display declaration
// therefore is is no longuer necessary to make a reference to the
// display variable.
double px = 600, py = 600;
double u0 = I.getWidth() / 2., v0 = I.getHeight() / 2.;
vpCameraParameters cam(px, py, u0, v0);
vpServo task;
// sets the initial camera location
cMo[0][3] = 0.1;
cMo[1][3] = 0.2;
cMo[2][3] = 2;
// Compute the position of the object in the world frame
wMo = wMc * cMo;
cMod[0][3] = 0;
cMod[1][3] = 0;
cMod[2][3] = 1;
// sets the sphere coordinates in the world frame
vpSphere sphere;
sphere.setWorldCoordinates(0, 0, 0, 0.1);
// sets the desired position of the visual feature
// computes the sphere coordinates in the camera frame and its 2D
// coordinates sets the current position of the visual feature
// define the task
// - we want an eye-in-hand control law
// - robot is controlled in the camera frame
// we want to see a sphere on a sphere
task.addFeature(p, pd);
// set the gain
// Display task information
unsigned int iter = 0;
// loop
while (iter++ < 200) {
std::cout << "---------------------------------------------" << iter << std::endl;
// get the robot position
// Compute the position of the object frame in the camera frame
cMo = wMc.inverse() * wMo;
// new sphere position: retrieve x,y and Z of the vpSphere structure
if (opt_display) {
vpServoDisplay::display(task, cam, I);
// compute the control law
v = task.computeControlLaw();
std::cout << "Task rank: " << task.getTaskRank() << std::endl;
// send the camera velocity to the controller
std::cout << "|| s - s* || = " << (task.getError()).sumSquare() << std::endl;
if (opt_display && opt_click_allowed) {
vpDisplay::displayText(I, 20, 20, "Click to quit...", vpColor::white);
// Display task information
} catch (const vpException &e) {
std::cout << "Catch a ViSP exception: " << e << std::endl;
std::cout << "Cannot run this example: install Lapack, Eigen3 or OpenCV" << std::endl;
Generic class defining intrinsic camera parameters.
Implementation of column vector and the associated operations.
Definition: vpColVector.h:131
static const vpColor white
Definition: vpColor.h:212
Display for windows using GDI (available on any windows 32 platform).
Definition: vpDisplayGDI.h:129
The vpDisplayGTK allows to display image using the GTK 3rd party library. Thus to enable this class G...
Definition: vpDisplayGTK.h:135
The vpDisplayOpenCV allows to display image using the OpenCV library. Thus to enable this class OpenC...
Use the X11 console to display images on unix-like OS. Thus to enable this class X11 should be instal...
Definition: vpDisplayX.h:135
static bool getClick(const vpImage< unsigned char > &I, bool blocking=true)
static void display(const vpImage< unsigned char > &I)
static void flush(const vpImage< unsigned char > &I)
static void displayText(const vpImage< unsigned char > &I, const vpImagePoint &ip, const std::string &s, const vpColor &color)
error that can be emited by ViSP classes.
Definition: vpException.h:72
static void create(vpFeaturePoint &s, const vpCameraParameters &cam, const vpDot &d)
Class that defines 2D ellipse visual feature.
void track(const vpHomogeneousMatrix &cMo)
Implementation of an homogeneous matrix and operations on such kind of matrices.
vpHomogeneousMatrix inverse() const
unsigned int getWidth() const
Definition: vpImage.h:246
unsigned int getHeight() const
Definition: vpImage.h:188
static bool parse(int *argcPtr, const char **argv, vpArgvInfo *argTable, int flags)
Definition: vpParseArgv.cpp:69
void setVelocity(const vpRobot::vpControlFrameType frame, const vpColVector &vel)
Definition: vpRobot.h:83
static void display(const vpServo &s, const vpCameraParameters &cam, const vpImage< unsigned char > &I, vpColor currentColor=vpColor::green, vpColor desiredColor=vpColor::red, unsigned int thickness=1)
Definition: vpServo.h:155
unsigned int getTaskRank() const
Definition: vpServo.cpp:1783
void print(const vpServo::vpServoPrintType display_level=ALL, std::ostream &os=std::cout)
Definition: vpServo.cpp:303
void setLambda(double c)
Definition: vpServo.h:404
void setServo(const vpServoType &servo_type)
Definition: vpServo.cpp:215
vpColVector getError() const
Definition: vpServo.h:278
vpColVector computeControlLaw()
Definition: vpServo.cpp:926
void addFeature(vpBasicFeature &s, vpBasicFeature &s_star, unsigned int select=vpBasicFeature::FEATURE_ALL)
Definition: vpServo.cpp:487
Class that defines the simplest robot: a free flying camera.
Class that defines a 3D sphere in the object frame and allows forward projection of a 3D sphere in th...
Definition: vpSphere.h:83
void setWorldCoordinates(const vpColVector &oP)
Definition: vpSphere.cpp:62