PCL点云库学习笔记（可视化1）

可视化

一、CloudViewer

1.1 用几行代码可视化应用程序中的某些内容

#include <pcl/visualization/cloud_viewer.h>
 //
 void foo ()
 {
   pcl::PointCloud<pcl::PointXYZRGB>::Ptr cloud;
   //..........填充点云
   //创建一个CloudViewer类的可视化的对象，进行简单的显示
   pcl::visualization::CloudViewer viewer ("Simple Cloud Viewer");
   viewer.showCloud (cloud);
   
   while (!viewer.wasStopped ())
   {
   }
 }

1.2 完整的可视化例子
例子中PCLVisualizer``是``CloudViewer的后端，但它在自己的线程中运行。要访问它，必须使用回调函数.

#include <pcl/visualization/cloud_viewer.h>
#include <iostream>
#include <pcl/io/io.h>
#include <pcl/io/pcd_io.h>
   
int user_data;
 
//下面的函数是回调函数，只执行一次，参数是PCLVisualizer可视化对象
//设置可视化背景的颜色，和添加一个圆球几何体
void viewerOneOff (pcl::visualization::PCLVisualizer& viewer)
{
   viewer.setBackgroundColor (1.0, 0.5, 1.0);//设置背景颜色
   pcl::PointXYZ o;//创建点云中的一个点
   o.x = 1.0;
   o.y = 0;
   o.z = 0;
   viewer.addSphere (o, 0.25, "sphere", 0);//以这个点为圆心创建一个球
   std::cout << "i only run once" << std::endl;
   
}
 
 //在可视化对象中，添加一个刷新显示字符串  
void viewerPsycho (pcl::visualization::PCLVisualizer& viewer)
{
   static unsigned count = 0;
   std::stringstream ss;
   ss << "Once per viewer loop: " << count++;
   viewer.removeShape ("text", 0);//从屏幕中删除添加的形状
   viewer.addText (ss.str(), 200, 300, "text", 0);//在屏幕上加一行文本
   
   //FIXME: possible race condition here:
   user_data++;
}
   
int main ()
{
   //创建点云，然后读取PCD文件
   pcl::PointCloud<pcl::PointXYZRGBA>::Ptr cloud (new pcl::PointCloud<pcl::PointXYZRGBA>);
   pcl::io::loadPCDFile ("my_point_cloud.pcd", *cloud);
   
   //可视化对象
   pcl::visualization::CloudViewer viewer("Cloud Viewer");
   
   //停在此处，直到渲染出点云
   viewer.showCloud(cloud);
   
   //use the following functions to get access to the underlying more advanced/powerful
   //PCLVisualizer
   
  //在可视化的时候，创建球的函数，只调用一次
   viewer.runOnVisualizationThreadOnce (viewerOneOff);
   
  //在渲染输出时每一次都调用
   viewer.runOnVisualizationThread (viewerPsycho);
   while (!viewer.wasStopped ())
   {
   //you can also do cool processing here
   //FIXME: Note that this is running in a separate thread from viewerPsycho
   //and you should guard against race conditions yourself...
   user_data++;
   }
   return 0;
}

1.3编译报错
1.编译警告

error C4996: 'std::uninitialized_copy::_Unchecked_iterators::_Deprecate': Call to 'std::uninitialized_copy' with parameters that may be unsafe - this call relies on the caller to check that the passed values are correct. To disable this warning, use -D_SCL_SECURE_NO_WARNINGS. See documentation on how to use Visual C++ 'Checked Iterators

解决：属性-> c/c++ -> 预处理器 -> 预处理器定义 里添加_SCL_SECURE_NO_WARNINGS
2.error LNK2019: 无法解析的外部符号，lib文件未引入，添加

#pragma comment(lib,"User32.lib")
#pragma comment(lib,"ws2_32.lib")
#pragma comment(lib, "gdi32.lib")

3.运行vtk文件库的时候出现错误,分别添加

#include "vtkAutoInit.h"  //vtk库
VTK_MODULE_INIT(vtkRenderingOpenGL); 
VTK_MODULE_INIT(vtkInteractionStyle);

二、可视化深度图像

#include <iostream>

#include <pcl/common/common_headers.h>
#include <pcl/range_image/range_image.h>
#include <pcl/io/pcd_io.h>
#include <pcl/visualization/range_image_visualizer.h>
#include <pcl/visualization/pcl_visualizer.h>
#include <pcl/console/parse.h>
#include "vtkAutoInit.h"  //vtk库



typedef pcl::PointXYZ PointType;

//全局参数-
float angular_resolution_x = 0.5f,
angular_resolution_y = angular_resolution_x;
pcl::RangeImage::CoordinateFrame coordinate_frame = pcl::RangeImage::CAMERA_FRAME;
bool live_update = false;

// 打印帮助
void  printUsage(const char* progName)
{
	std::cout << "\n\nUsage: " << progName << " [options] <scene.pcd>\n\n"
		<< "Options:\n"
		<< "-------------------------------------------\n"
		<< "-rx <float>  angular resolution in degrees (default " << angular_resolution_x << ")\n"
		<< "-ry <float>  angular resolution in degrees (default " << angular_resolution_y << ")\n"
		<< "-c <int>     coordinate frame (default " << (int)coordinate_frame << ")\n"
		<< "-l           live update - update the range image according to the selected view in the 3D viewer.\n"
		<< "-h           this help\n"
		<< "\n\n";
}

//设置视点
void  setViewerPose(pcl::visualization::PCLVisua