QT+PCL 点云学习

Posted 2021-10-05 Leslie X徐

PCL 点云学习

概念

Point Cloud Libraries 点云库 和opencv处理图像一样，不过是3D图像的处理

支持文件格式

pcd格式文件

PCD不是第一个支持3D点云数据的文件类型，尤其是计算机图形学和计算几何学领域，已经创建了很多格式来描述任意多边形和激光扫描仪获取的点云。包括下面几种格式：

l PLY是一种多边形文件格式，由Stanford大学的Turk等人设计开发；

l STL是3D Systems公司创建的模型文件格式，主要应用于CAD、CAM领域；

l OBJ是从几何学上定义的文件格式，首先由Wavefront Technologies开发；

l X3D是符合ISO标准的基于XML的文件格式，表示3D计算机图形数据；

环境配置

Vtk，（visualization toolkit）是一个开源的免费软件系统，主要用于三维计算机图形学、图像处理和可视化

代码

1.实现读取文件

void main(){
    PointCloud<PointXYZ>::Ptr cloud(new PointCloud<PointXYZ>);

    if(io::loadPCDFile<PointXYZ>("FILEPATH",*cloud)==-1){
        qDebug("read file error");
        return;
    }

    viewer = new visualization::PCLVisualizer("rabbit viewer");

    viewer->addPointCloud(cloud);
    viewer->spin();
}

2.生成随机点云

void MainWindow::on_pushButton_clicked()
{
    PointCloud<PointXYZ>::Ptr cloud(new PointCloud<PointXYZ>);

    //设置点云数量
    cloud->points.resize(1000);

    //填充点云数据
    for(auto& i : cloud->points){//注意使用 auto& 要进行更改
        i.x = 1024*rand()/(RAND_MAX+1.0f);
        i.y = 1024*rand()/(RAND_MAX+1.0f);
        i.z = 1024*rand()/(RAND_MAX+1.0f);
    }


    if(viewer)viewer->close();
    //声明视窗
    viewer = new visualization::PCLVisualizer("3D viewer");
    //将视窗嵌入到qt的QVTKWidget中
    ui->widget->SetRenderWindow(viewer->getRenderWindow());

    //设置背景色
    viewer->setBackgroundColor(1.0f,0.5f,1.0f);
    //预处理点云颜色
    visualization::PointCloudColorHandlerCustom<PointXYZ> magenta(cloud,255,255,255);
    //把点云加载到视窗
    viewer->addPointCloud(cloud,magenta,"cloud");
    //设置点云大小
    viewer->setPointCloudRenderingProperties(visualization::PCL_VISUALIZER_POINT_SIZE,2,"cloud");

    //显示点云
    viewer->spinOnce();
    cloud->clear();

}

3.使用QVTKWidget显示

首先继承一个QVTKWidget类

//RoVTKWidget.hpp
#ifndef ROVTKWIDGET_H
#define ROVTKWIDGET_H

#include "QVTKWidget.h"

class RoVTKWidget : public QVTKWidget
{
public:
    RoVTKWidget(QWidget* parent);
};

#endif // ROVTKWIDGET_H

//RoVTKWidget.cpp
#include "RoVTKWidget.h"

RoVTKWidget::RoVTKWidget(QWidget* parent)
    :QVTKWidget(parent)
{
}

然后在窗口中将widget部件升级到RoVTKWidget

嵌入viewer的代码：

viewer.reset(new visualization::PCLVisualizer("3D viewer",false));
    ui->widget->SetRenderWindow(viewer->getRenderWindow());
    viewer->setupInteractor(ui->widget->GetInteractor(),ui->widget->GetRenderWindow());
    ui->widget->update();
//注意：不要再用viewer.spin()显示图像，而使用ui->widget->update()来显示图像
//需要关闭时，无需其他关闭操作，直接默认关闭窗口就可以，很方便

4.qt代码

头文件

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

#include "vtkRenderWindow.h"
#include "RoVTKWidget.h"

#include "vtkJPEGReader.h"
#include "vtkImageActor.h"
#include "vtkImageViewer2.h"

#include "pcl/io/pcd_io.h"
#include "pcl/point_types.h"
#include "pcl/visualization/pcl_visualizer.h"
using namespace pcl;

#include<QDebug>


QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private slots:

    void on_pushButton_clicked();

    void on_pushButton_2_clicked();

    void on_pushButton_3_clicked();

private:
    Ui::MainWindow *ui;
    visualization::PCLVisualizer::Ptr viewer {Q_NULLPTR};
    QMap<QString,PointCloud<PointXYZ>::Ptr> cloudMap;

    // QWidget interface
protected:
    virtual void closeEvent(QCloseEvent *event) override;
};
#endif // MAINWINDOW_H

源文件

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QFileDialog>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    viewer.reset(new visualization::PCLVisualizer("3D viewer",false));
    ui->widget->SetRenderWindow(viewer->getRenderWindow());
    viewer->setupInteractor(ui->widget->GetInteractor(),ui->widget->GetRenderWindow());
    ui->widget->update();
}

MainWindow::~MainWindow()
{
    delete ui;
}


void MainWindow::on_pushButton_clicked()
{
    if(!cloudMap.contains("cloud")){


    PointCloud<PointXYZ>::Ptr cloud(new PointCloud<PointXYZ>);
    cloudMap["cloud"]=cloud;

        //设置点云数量
        cloud->points.resize(1000);

        //填充点云数据
        for(auto& i : cloud->points){//注意使用 auto& 要进行更改
            i.x = 1024*rand()/(RAND_MAX+1.0f);
            i.y = 1024*rand()/(RAND_MAX+1.0f);
            i.z = 1024*rand()/(RAND_MAX+1.0f);
        }
        viewer->addPointCloud(cloud);
        }

        viewer->updatePointCloud(cloudMap["cloud"]);
        viewer->resetCamera();
        //显示点云
        ui->widget->update();
}


void MainWindow::on_pushButton_2_clicked()
{
    if(!cloudMap.contains("rabbit")){


    PointCloud<PointXYZ>::Ptr rabbit(new PointCloud<PointXYZ>);
    cloudMap["rabbit"]=rabbit;

    QString selectFilePath = QFileDialog::getOpenFileName(this, QString("选择图像文件"), QString(""), QString("图像(*.pcd)"));
    if(selectFilePath.isEmpty())
    {
        return ;
    }
        if(io::loadPCDFile<PointXYZ>(selectFilePath.toStdString(),*rabbit)==-1){
            qDebug("read file error");
            return;
        }

        viewer->addPointCloud(rabbit,"rabbit");
        viewer->addText("this is a rabbit",100,100);
         }
        viewer->updatePointCloud(cloudMap["rabbit"]);
        viewer->resetCamera();
        ui->widget->update();

}


void MainWindow::closeEvent(QCloseEvent *event)
{
//    ui->widget->close();
}


void MainWindow::on_pushButton_3_clicked()
{

    vtkSmartPointer<vtkRenderer> pRenderer = vtkSmartPointer<vtkRenderer>::New();
    vtkSmartPointer<vtkImageViewer2> pImageViewer = vtkSmartPointer<vtkImageViewer2>::New();
    vtkSmartPointer<vtkJPEGReader> jpegReader =  vtkSmartPointer<vtkJPEGReader>::New();


    QString selectFilePath = QFileDialog::getOpenFileName(this, QString("选择图像文件"), QString(""), QString("图像(*.jpeg)"));
    if(selectFilePath.isEmpty())
    {
        return ;
    }

    jpegReader->SetFileName(selectFilePath.toStdString().c_str());
    jpegReader->Update();

    pImageViewer->SetInputData(jpegReader->GetOutput());
    pImageViewer->SetRenderWindow(ui->widget->GetRenderWindow());
    pImageViewer->SetRenderer(pRenderer);
    pRenderer->ResetCamera();
    ui->widget->GetRenderWindow()->Render();

}

5.同一窗口不同视图显示多张点云

#include <iostream>
#include <pcl/io/pcd_io.h>
#include <pcl/point_types.h>
#include <pcl/filters/filter_indices.h>
#include <pcl/point_cloud.h>
#include <pcl/visualization/pcl_visualizer.h>
using namespace std;
 
int main()
{
 
	//***************************read PCD file*****************************************
	//在一个视图下同时显示两张点云图像
 
	pcl::PointCloud<pcl::PointXYZ>::Ptr source(new pcl::PointCloud<pcl::PointXYZ>());
	pcl::PointCloud<pcl::PointXYZ>::Ptr source2(new pcl::PointCloud<pcl::PointXYZ>());
	//输入点云路径
	string  filename1 = "jiancelou.pcd";
	string filename2 = "jiancelou(4).pcd";
	pcl::io::loadPCDFile(filename1, *source);
	pcl::io::loadPCDFile(filename2, *source2);
	cout << "点云加载成功！" << endl;
	boost::shared_ptr< pcl::visualization::PCLVisualizer > viewer(new pcl::visualization::PCLVisualizer("3D Viewer"));
	viewer->initCameraParameters();
	
	
	//在一个视图里显示两张点云图
	int v1(0);
	viewer->createViewPort(0.0, 0.0, 1.0 / 2.0, 1.0, v1);
	viewer->setBackgroundColor(28, 28, 28, v1);
	viewer->addText("Radius:0.01", 10, 10, "v1 text", v1);
	pcl::visualization::PointCloudColorHandlerCustom<pcl::PointXYZ> source_color(source, 0, 0, 0);
	viewer->addPointCloud<pcl::PointXYZ>(source, source_color, "sample cloud1", v1);
 
	int v2(0);
	viewer->createViewPort(1.0 / 2.0, 0.0, 1.0, 1.0, v2);
	viewer->setBackgroundColor(28, 28, 28, v2);
	viewer->addText("Radius:0.1", 10, 10, "v2 text", v2);
	pcl::visualization::PointCloudColorHandlerCustom<pcl::PointXYZ> source_color2(source2, 0, 0, 0);
	viewer->addPointCloud<pcl::PointXYZ>(source2, source_color2, "sample cloud2", v2);
 
	viewer->setPointCloudRenderingProperties(pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 3, "sample cloud1");
	viewer->setPointCloudRenderingProperties(pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 3, "sample cloud2");
 
	viewer->addCoordinateSystem(1.0);
	viewer->spin();
	return 0;
 
}

并排并列显示

void MainWindow::on_pushButton_4_clicked()
{
    
    QVector<PointCloud<PointXYZ>::Ptr> data;

    QStringList selectFilePath = QFileDialog::getOpenFileNames(this, QString("选择图像文件"), QString(""), QString("图像(*.pcd)"));
    if(selectFilePath.isEmpty()) {return ;}

    viewer->removeAllPointClouds();
    
    for(auto p : selectFilePath){
        PointCloud<PointXYZ>::Ptr newcloud(new PointCloud<PointXYZ>);
        io::loadPCDFile<PointXYZ>(p.toStdString(),*newcloud);
        data.append(newcloud);
    }

    //并列显示
    int cnt = data.size();
    QVector<int> v(cnt);
    for(int i=0;i<cnt;++i){
        viewer->createViewPort(double(i)/cnt,0.0,double(i+1)/cnt,1.0,v[i]);
        viewer->setBackgroundColor(0, 0, 10, v[i]);
        viewer->addPointCloud(data[i],QString("asd%1").arg(i).toStdString(),v[i]);
    }

    viewer->resetCamera();
    viewer->addCoordinateSystem(1.0);
    ui->widget->update();

}

//并排并列显示 代替并列显示
//计算列数和行数
    int col=0,row=0;
    qreal s = qSqrt(cnt);
    qreal sf = qFloor(s);
    qreal d = s-sf;
    if(d>=0.5){
        col=row=sf+1;
    }else if(d<0.5&&d>0){
        row = sf;
        col = row+1;
    }else if(d==0){
        col=row=sf;
    }
    qDebug()<<col<<" "<<row;
    QVector<int> v(col*row);
    int c=0;

//优先扫描列
    for(int j=0;j<row && c<cnt;++j)
    for(int i=0;i<col && c<cnt;++i)
    {
        viewer->createViewPort(double(i)/col,double(j)/row,double(i+1)/col,double(j+1)/row,v[c]);
        viewer->setBackgroundColor(double(j)/cnt, double(i)/cnt, 0, v[c]);
        viewer->addPointCloud(data[c],QString("asd%1%2").arg(j).arg(i).toStdString(),v[c]);
        c++;
    }