I have a point cloud (.pcd) file, from which I have generated normals. Now I want to display the input point cloud along with the generated normals in the same viewer window (not in multiple viewports). The code I have developed is
#include <iostream>
#include <pcl/io/pcd_io.h>
#include <pcl/point_types.h>
#include <pcl/features/normal_3d.h>
#include <pcl/visualization/cloud_viewer.h>
#include <pcl/visualization/pcl_visualizer.h>
#include <pcl/features/integral_image_normal.h>
int main ()
{
// load point cloud
pcl::PointCloud<pcl::PointXYZ>::Ptr cloud (new pcl::PointCloud<pcl::PointXYZ>);
if (pcl::io::loadPCDFile<pcl::PointXYZ> ("table_scene_mug_stereo_textured.pcd", *cloud) == -1)
{
PCL_ERROR ("Couldn't read file table_scene_mug_stereo_textured.pcd \n");
return (-1);
}
std::cout << "Loaded "
<< cloud->width * cloud->height
<< " data points from test_pcd.pcd with the following fields: "
<< std::endl;
std::cout << "Input cloud Point Size "
<< cloud->points.size ()
<< std::endl;
// organized or unorganized normal estimation
pcl::PointCloud<pcl::Normal>::Ptr cloud_normals (new pcl::PointCloud<pcl::Normal>);
if (cloud->isOrganized ())
{
std::cout << "Computing normals Inside organized block " << std::endl;
pcl::IntegralImageNormalEstimation<pcl::PointXYZ, pcl::Normal> ne;
ne.setInputCloud (cloud);
ne.setNormalEstimationMethod (ne.AVERAGE_3D_GRADIENT);
ne.setNormalSmoothingSize (float (0.03));
ne.setDepthDependentSmoothing (true);
ne.compute (*cloud_normals);
}
else
{
std::cout << "Computing normals Inside non-organized block " << std::endl;
pcl::NormalEstimation<pcl::PointXYZ, pcl::Normal> ne;
ne.setInputCloud (cloud);
pcl::search::KdTree<pcl::PointXYZ>::Ptr tree (new pcl::search::KdTree<pcl::PointXYZ> ());
ne.setSearchMethod (tree);
ne.setRadiusSearch (0.03);
ne.compute (*cloud_normals);
}
std::cout << "cloud_normals Point Size "<< cloud_normals->points.size () << std::endl;
//write the normals to a PCD file
pcl::PCDWriter writer;
writer.write("computed_normals.pcd", *cloud_normals, false);
// visualize normals
pcl::visualization::PCLVisualizer viewer("PCL Viewer");
viewer.setBackgroundColor (0.0, 0.0, 0.0);
viewer.addPointCloud< pcl::PointXYZRGB >( cloud, "cloud", 0);
viewer.addPointCloudNormals<pcl::PointXYZ,pcl::Normal>(cloud, cloud_normals);
while (!viewer.wasStopped ())
{
viewer.spinOnce ();
}
return 0;
}
When I try to debug the code, I am getting an error
no instance of overloaded function "pcl::visualization::PCLVisualizer::addPointCloud" matches the
argument list
in the line
viewer.addPointCloud< pcl::PointXYZRGB >( cloud, "cloud", 0);
I have referred the documentation and spent quite some time in the web to solve this problem without success.
Am I adding point cloud to the viewer correctly? If not please let me know the correct way of adding the point cloud to the viewer along with the generated normals.
You have tried to add the wrong type of point cloud. Change the line to:
viewer.addPointCloud< pcl::PointXYZ >( cloud, "cloud", 0);
This question was also answered here:
http://www.pcl-users.org/Point-Cloud-Library-Error-while-adding-point-cloud-to-PCL-Visualizer-viewer-td4046232.html
For more information about types of point clouds, reference the PCL library here:
http://pointclouds.org/documentation/tutorials/adding_custom_ptype.php#what-pointt-types-are-available-in-pcl
Related
I‘ve been trying to understand smart pointers, and as I understood, smart pointer will destroy themselves once they are not reachable through the code.
For this reason I was trying to implement a demonstration for this behavior:
#include<iostream>
#include<memory>
using namespace std;
void shared(){
cout<<"Shared Pointer:"<<endl;
shared_ptr<int> number = make_shared<int>(50);
cout<<*number<<endl;
cout<<number<<endl;
}
int main(){
int address;
shared();
cout<<"please enter the targeted address:"<<endl;
cin>>address;
int *pointer = (int *) address;
cout<<"we found this number: "<<*pointer<<endl;
}
output:
Shared Pointer:
50
0xf28c30
please enter the targeted address:
15895600 // I just converted the hexdecimal above to decimal number.
we found this number: 50
So I‘m able to retrieve the value 50 from outside the function shared(), by manually entering its address in the console.
Isn‘t supposed to be null or random number? If this is normal then how smartpointers are made to avoid memory leaks!?
P.S: doing the same test using a normal pointer will produce the same results unless we add delete pointer; (which is the expected behavior)
I appreciate any idea about this specific behavior.
To make sure that the memory was deleted it is better to test the smart pointers with a class
class Greeting {
public:
Greeting()
{
std::cout << "Hello" << std::endl;
}
~Greeting()
{
std::cout << "Bye" << std::endl;
}
};
void shared() {
shared_ptr<Greeting> var = make_shared<Greeting>();
}
int main() {
std::cout << "Start" << std::endl;
shared();
std::cout << "End" << std::endl;
}
You will get the following output:
Start //Start of the main
Hello // When creating the object (the resource)
Bye // **When destructing the object (the resource)**
End //End the main
I'm not very good at character devices, so I need your help. A have a char device(let's call it /dev/my_light) which is a light sensor. I have to read the data from this file and transform it to the brightness value and then pass it to the brightness manager that changes the brightness of my screen. The problem is that when I read the value for some period of time I get old values from the file.I assume there is a buffer(again not sure how character devices exactly work). Whereas when I use cat /dev/my_light I see new data! Is it possible to get rid off the buffer and read new values that were written to the file just right now. Here is my code in Qt:
void MySensor::updateMySensor()
{
Packet packet;
packet.startByte = 0;
packet.mantissa = 0;
packet.exp = 0;
d->device = ::open(d->path.toStdString().c_str(), O_RDONLY);
if (d->device == -1)
{
qDebug() << Q_FUNC_INFO << "can't open the sensor";
return;
}
ssize_t size = ::read(d->device, &packet, sizeof(packet));
close(d->device);
if (size == -1)
{
qDebug() << errno;
return;
}
packet.exp &= 0x0F;
float illumination = pow(2, packet.exp) * packet.mantissa * 0.045;
if(d->singleShot) emit lightSensorIsRunning(true);
emit illuminationRead(illumination);
}
The mySensor function is called every second. I tried to call it each 200 msec but it didn't help. The value of illumination stays old for about 7 seconds(!) whereas the value that I get from cat is new just immediately.
Thank you in advance!
I can't test with your specific device, however, I'm using the keyboard as a read only device.
The program attempts to connect to keyboard and read all keys pressed inside and outside the window. It's a broad solution you'll have to adapt to meet your demands.
Note that I'm opening the file with O_RDONLY | O_NONBLOCK which means open in read only mode and no wait for the event be triggered(some notifier needed to know when data is ready!) respectively.
You'll need super user privilege to run this example!
#include <QtCore>
#include <fcntl.h>
#include <linux/input.h>
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
const char *device_name = "/dev/input/by-path/platform-i8042-serio-0-event-kbd";
int descriptor = open(device_name, O_RDONLY | O_NONBLOCK);
if (descriptor < 0)
{
qDebug() << "Error" << strerror(errno);
return a.exec();
}
QFile device;
if (!device.open(descriptor, QFile::ReadOnly))
{
qDebug() << "Error" << qPrintable(device.errorString());
return a.exec();
}
QSocketNotifier notifier(device.handle(), QSocketNotifier::Read);
QObject::connect(¬ifier, &QSocketNotifier::activated, ¬ifier, [&](int socket){
Q_UNUSED(socket)
struct input_event ev;
QByteArray data = device.readAll();
qDebug() << "Event caught:"
<< "\n\nDATA SIZE" << data.size()
<< "\nSTRUCT COUNT" << data.size() / int(sizeof(input_event))
<< "\nSTRUCT SIZE" << sizeof(input_event);
qDebug() << ""; //New line
while (data.size() >= int(sizeof(input_event)))
{
memcpy(&ev, data.data(), sizeof(input_event));
data.remove(0, int(sizeof(input_event)));
qDebug() << "TYPE" << ev.type << "CODE" << ev.code << "VALUE" << ev.value << "TIME" << ev.time.tv_sec;
}
qDebug() << ""; //New line
});
return a.exec();
}
I want to use QSettings to save my window's dimensions so I came up with these two functions to save & load the settings:
void MainWindow::loadSettings()
{
settings = new QSettings("Nothing","KTerminal");
int MainWidth = settings->value("MainWidth").toInt();
int MainHeight = settings->value("MainHeight").toInt();
std::cout << "loadSettings " << MainWidth << "x" << MainHeight << std::endl;
std::cout << "file: " << settings->fileName().toLatin1().data() << std::endl;
if (MainWidth && MainHeight)
this->resize(MainWidth,MainHeight);
else
this->resize(1300, 840);
}
void MainWindow::saveSettings()
{
int MainHeight = this->size().height();
int MainWidth = this->size().width();
std::cout << "file: " << settings->fileName().toLatin1().data() << std::endl;
std::cout << "saveSettings " << MainWidth << "x" << MainHeight << std::endl;
settings->setValue("MainHeight",MainHeight);
settings->setValue("MainWidth",MainWidth);
}
Now, I can see the demensions being extracted in saveSettings as expected but no file gets created and hence loadSettings will always load 0 only. Why is this?
QSettings isn't normally instantiated on the heap. To achieve the desired effect that you are looking for, follow the Application Example and how it is shown in the QSettings documentation.
void MainWindow::readSettings()
{
QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName());
const QByteArray geometry = settings.value("geometry", QByteArray()).toByteArray();
if (geometry.isEmpty()) {
const QRect availableGeometry = QApplication::desktop()->availableGeometry(this);
resize(availableGeometry.width() / 3, availableGeometry.height() / 2);
move((availableGeometry.width() - width()) / 2,
(availableGeometry.height() - height()) / 2);
} else {
restoreGeometry(geometry);
}
}
void MainWindow::writeSettings()
{
QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName());
settings.setValue("geometry", saveGeometry());
}
Also note the use of saveGeometry() and restoreGeometry(). Other similarly useful functions for QWidget based GUIs are saveState() and restoreState() (not shown in the above example).
I strongly recommend the zero parameter constructor of QSettings, and to setup the defaults in your main.cpp, like so:
QSettings::setDefaultFormat(QSettings::IniFormat); // personal preference
qApp->setOrganizationName("Moose Soft");
qApp->setApplicationName("Facturo-Pro");
Then when you want to use QSettings in any part of your application, you simply do:
QSettings settings;
settings.setValue("Category/name", value);
// or
QString name_str = settings.value("Category/name", default_value).toString();
QSettings in general is highly optimized, and works really well.
Hope that helps.
Some other places where I've talked up usage of QSettings:
Using QSettings in a global static class
https://stackoverflow.com/a/14365937/999943
I found a very strange problem with this pointer in c++11's lambda.
#include <string>
#include <iostream>
using namespace std;
#include <boost/signals2.hpp>
boost::signals2::signal<void()> sig;
struct out {
void print_something() {
cout << "something" << endl;
}
out() {
auto start = [&] {
cout << "this in start: " << this << endl;
this->print_something();
};
cout << "this in constructor: " << this << endl;
// sig.connect(start);
sig.connect([&] {
cout << "this in signal: " << this << endl;
start();
});
this->print_something();
}
};
int main() {
out o;
sig();
}
The code prints three this(s) pointer at different location. I was expecting that all the three this pointer should be the same value, but they are not. Here's the output:
this in constructor: 00F3FABB
something
this in signal: 00F3FABB
this in start: 00F3FB00
something
Question 1: Why is this in start has different value? How to correct it?
Question 2: Since the this in start is a different pointer, it shouldn't be able to call print_something(). I would expect a crash on this but it works fine. Why?
You capture start by reference, but the variable start and the contained lambda function get destroyed at the end of out().
Later the signal handler tries to call start(), but the lambda function doesn't exist anymore. Maybe the memory where its this was stored was overwritten in the mean time, causing unexpected output.
The call to print_something() doesn't crash despite of the invalid this because the function doesn't actually try to use this. The printing in the function is independent of this and the lookup of print_somethings address can happen at compile time so that calling the function doesn't access this at runtime.
I am a novice C++ coder and obviously not very good at it. I am having an immense amount of trouble with this program.
I am getting syntax errors on my opening and closing parenthesis on my functions, syntax errors on my "<" in my header cpp file, and errors that I'm missing parenthesis.
My first stack is not recognized (main driver file) and in my StackType.cpp file - original is an "undeclared identifier".
Lastly, the left of Push must have class/struct/union - in my for loop when filling the first stack with the rings.
I apologize for all of these issues in advance. Any help you could give me would be greatly appreciated!
Thank you.
======================Stack Header================================
// File: StackType.h
// Stack template class definition.
// Dynamic array implementation
#ifndef StackType
#define StackType
template <class ItemType>
class StackType
{
private:
int ItemType;
ItemType *myStack; // pointer to dynamic array
int _top, _maxSize; // using underscores to remind that it's private
public:
StackType(int numRings = 50); // Constructor
StackType (const StackType<ItemType>&); // Copy Constructor
// Member Functions
void Push(ItemType); // Push
void Pop(ItemType &); // Pop
void stackTop(ItemType &) const; // retrieve top
bool stackIsEmpty() const; // Test for Empty stack
bool stackIsFull() const; // Test for Full stack
~StackType(); // Destructor
};
#endif
=====================Stack cpp file==================================
#include "StackType.h"
#include "stdafx.h"
#include <iostream>
#include <stdio.h>
// Constructor with argument, size is numRings, limit is 50 (set in .h header)
template <class ItemType>
StackType<ItemType>::StackType()
{
_maxSize = numRings;
_top = -1;
}
// Copy Constructor
template <class ItemType>
StackType<ItemType>::StackType(const StackType<ItemType>& original :
_maxSize(original._maxSize), top(original._top)
{
myStack = new ItemType[_maxSize];
for (int i = 0; i <= top; i++) myStack[i] = original.myStack[i];
}
// Destructor
template <class ItemType>
StackType<ItemType>::~StackType()
{
delete [] myStack;
}
// Push
template <class ItemType>
void StackType<ItemType>::Push(StackType<ItemType> ringVal)
{
if(stackIsFull()) cout << "\t There is not enough available memory = the stack is
full!" << endl;
else myStack[++_top] = ringVal;
}
// Pop
template <class ItemType>
void StackType<ItemType>::Pop(StackType<ItemType> &ringVal)
{
if(stackIsEmpty()) cout << "\t The stack is empty!" << endl;
else ringVal = myStack[_top--];
}
// Retrieve stack top without removing it
template <class ItemType>
void StackType<ItemType>::stackTop(StackType<ItemType> &ringVal) const
{
if(stackIsEmpty()) cout << "The stack is empty!";
else ringVal = myStack[_top];
}
// Test for Empty stack
template <class ItemType>
bool StackType<ItemType>::stackIsEmpty() const
{
return (_top < 0);
}
// Test for Full stack
template <class ItemType>
bool StackType<class ItemType>::stackIsFull() const
{
return (_top >= (_maxSize - 1));
}
// end StackType.cpp
=========================Main Driver file=======================================
#include "StackType.h"
#ifdef _DEBUG
#include "StackType.cpp"
#endif // _DEBUG
#include <stack>
#include "StdAfx.h"
#include <iostream>
using namespace std;
// Global Variable - Counter to display the number of moves.
int count = 0;
class StackType;
// Functions Prototypes
void MoveRings(StackType<ItemType>&, StackType<ItemType>&);
// Function to move the rings
void Pegs(int D,StackType<ItemType>& b,StackType<ItemType>& e, StackType<ItemType>& h);
// This is a recursive function.
void Display (int, StackType <ItemType>& , StackType<ItemType>&, StackType<ItemType>&);
// Function to display the pegs
// Main - Driver File
int main()
{
// create 3 empty stacks
StackType<ItemType> FirstPeg; // Receiving an error that this is not identified
StackType<ItemType> EndPeg;
StackType<ItemType> HelperPeg;
// Number of rings.
int numRings;
cout << "\n\t *********** Rings to Pegs (Towers of Hanoi) ***********\n" << endl;
cout << "\t Please Enter the number of rings you want to play with: ";
// Input number of rings
cin >> numRings;
cout << endl;
while(numRings < 0 || isalpha(numRings)) // To make sure that the user did not
// enter an invalid number
{
cout << " Your entry is invalid. Please use only integers. Please re-
enter: ";
cin >> numRings;
cout << endl;
}
for(int i = 1; i <= numRings; i++)
// Fill the first peg with the number of rings.
{
FirstPeg.Push(i);
}
Pegs(int, StackType<ItemType>&, StackType<ItemType>&, StackType<ItemType>&);
// To call the recursive function that will move the rings
Display (int, StackType<ItemType>&, StackType<ItemType>&, StackType<ItemType>&);
// To call the display function
cin.clear();
cin.ignore('\n');
cin.get();
return 0;
}
// This function will move an ring from first peg to the second peg
void MoveRings(StackType<ItemType>& beg, StackType<ItemType>& theEnd) //End
{
int r; // disk will be removed from one stack and added to the other
beg.Pop(r);//pop from source
theEnd.Push(r);//and move to target
}
// This function displays the moves
void Display(int R, StackType<ItemType>& toBegin , StackType<ItemType>& toEnd,
StackType<ItemType>& toHelp)
{
StackType<int> B;// create temporarily first stack
StackType<int> E;// create temporarily End(End) stack
StackType<int> H;// create temporarily helper stack
for(int i = 1; i <= R; i++)
{
toBegin.Pop(i);//moves the ring from source
B.Push(i);//to the temporarily stack to display it
cout << "Beginning Peg:" << &B << endl;
toEnd.Pop(i);//moves the ring from source
E.Push(i);//to the temporarily stack to display it
cout << " End(Final) Peg: " << &E << endl;
toHelp.Pop(i);//moves the ring from source
H.Push(i);//to the temporarily stack to display it
cout << " Helper Peg:" << &H << endl;
}
}
//-------------------------------------------------------------------
void Pegs(int D,StackType<ItemType>& b,StackType<ItemType>& e,StackType<ItemType>& h)
// This is a recursive function.
{
if (D == 0) // The base
{
return 1;
}
else if(D == 1) // If there is only one ring, move this ring from the
// first peg to the end(final) peg
{
MoveRings(b, e); // moves the ring from the first to the end(final) peg
cout<<" Really? You have entered one ring..." << endl;
cout<<" It moves directly from the first peg to the End peg." << endl;
count++; // increment the number of moves
cout << "There has been " << count << " move. "<< endl;// display the
// number of moves
Display (D, b, e, h);
}
else if (D > 1) // a recursive function in order to move the rings
{
Pegs(D - 1, b, e, h); // to move N-1 rings from the first peg to the
// end(final) peg by using the helper peg
MoveRings(b, e);// to move the last ring to the end(final) peg
count++; // increment the number of steps before displaying
cout << "There has been " << count << " moves. "<< endl;
Pegs(D - 1, b, e, h);
// to move N-1 rings from the helper peg to the end(final) peg with the help of
// first peg
//Display ( D(rings), First Peg, End(Final) Peg, Helper Peg );
}
}
One problem that I can see immediately is that your header file defines StackType to prevent double inclusion, which is also used as a class name. After #define StackType, it ends up being a macro that expands to nothing, so your code looks like class { ... }.
You should use a symbol to prevent double inclusion that isn't used for anything else. The typical thing to use is STACKTYPE_H for a file called StackType.h.
Once you've fixed this, some other problems you're experiencing might go away. Please come back with an update if you're having more problems, and post the exact compiler errors if you do.