PCL点云文件生成与读取
提要
PCL中创造了一种用于描述空间点集的文件 - PCD.关于PCD的简介，可以参考这里 - http://pointclouds.org/documentation/tutorials/pcd_file_format.php
今天要做的是最简单的事情 - PCD文件的生产与读取。
环境：Win7 64bit VS2010 PCL1.7
PCL编译参考这里 - Window7下手动编译最新版的PCL库
PCD文件生成
官网推荐的是用cmake来管理工程，在windows中，我们可以通过Cmakegui来生成VS2010的工程，然后导入。这样就免去了在VS中各种添加lib，头文件之苦了 ^^
首先创建主程序 pcd_write.cpp ，随便找个记事本写一下就可以了，代码如下：
#include
#include
#include
#include
#include
using namespace std;
int main (int argc, char** argv)
{
pcl::PointCloud cloud;
// Fill in the cloud data
cloud.width = 5;
cloud.height = 1;
cloud.is_dense = false;
cloud.points.resize (cloud.width * cloud.height);
for (size_t i = 0; i < cloud.points.size (); ++i)
{
cloud.points[i].x = 1024 * rand () / (RAND_MAX + 1.0f);
cloud.points[i].y = 1024 * rand () / (RAND_MAX + 1.0f);
cloud.points[i].z = 1024 * rand () / (RAND_MAX + 1.0f);
}
pcl::io::savePCDFileASCII ("test_pcd.pcd", cloud);
std::cerr << "Saved " << cloud.points.size () << " data points to test_pcd.pcd." << std::endl;
for (size_t i = 0; i < cloud.points.size (); ++i)
std::cerr << " " << cloud.points[i].x << " " << cloud.points[i].y << " " << cloud.points[i].z << std::endl;
getchar();
return (0);
}
再创建CMakeLists.txt
cmake_minimum_required(VERSION 2.6 FATAL_ERROR)
project(MY_GRAND_PROJECT)
find_package(PCL 1.3 REQUIRED COMPONENTS common io)
include_directories(${PCL_INCLUDE_DIRS})
link_directories(${PCL_LIBRARY_DIRS})
add_definitions(${PCL_DEFINITIONS})
add_executable(pcd_write_test pcd_write.cpp)
target_link_libraries(pcd_write_test ${PCL_COMMON_LIBRARIES} ${PCL_IO_LIBRARIES})在工程目录下创建一个build文件夹，接下来打开CMake-gui，将CMakeList.txt托进去，Configure->Generate.如果环境是配置好的话，结果就像这样：
如果报错了，基本是你环境没配置好，检查一下该装的东西是否都安装好了，环境变量是否设置好。
成功时候在build文件夹下就生成了对应的vs2010工程了，直接双击打开 MY_GRAND_PROJECT.sln
导入后在cloud_view上 右击->Set as StartUp Project,如下图：
直接运行，效果如下：
工程目录下就生成了一个 test_pcd.pcd 点云文件。
点云文件的读取
套路和上面的一样，贴一下代码就好。
cloud_viewer.cpp
#include
#include
#include
#include
int user_data;
void
viewerOneOff (pcl::visualization::PCLVisualizer& viewer)
{
viewer.setBackgroundColor (0.0, 0.0, 0.0);
pcl::PointXYZ o;
o.x = 1.0;
o.y = 0;
o.z = 0;
viewer.addSphere (o, 0.25, "sphere", 0);
std::cout << "i only run once" << std::endl;
}
void
viewerPsycho (pcl::visualization::PCLVisualizer& viewer)
{
static unsigned count = 0;
std::stringstream ss;
ss << "Once per viewer loop: " << count++;
viewer.removeShape ("text", 0);
viewer.addText (ss.str(), 200, 300, "text", 0);
//FIXME: possible race condition here:
user_data++;
}
int
main ()
{
pcl::PointCloud::Ptr cloud (new pcl::PointCloud);
pcl::io::loadPCDFile ("bunny.pcd", *cloud);
pcl::visualization::CloudViewer viewer("Cloud Viewer");
//blocks until the cloud is actually rendered
viewer.showCloud(cloud);
//use the following functions to get access to the underlying more advanced/powerful
//PCLVisualizer
//This will only get called once
viewer.runOnVisualizationThreadOnce (viewerOneOff);
//This will get called once per visualization iteration
viewer.runOnVisualizationThread (viewerPsycho);
while (!viewer.wasStopped ())
{
//you can also do cool processing here
//FIXME: Note that this is running in a separate thread from viewerPsycho
//and you should guard against race conditions yourself...
user_data++;
}
return 0;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8 FATAL_ERROR)
project(cloud_viewer)
find_package(PCL 1.2 REQUIRED)
include_directories(${PCL_INCLUDE_DIRS})
link_directories(${PCL_LIBRARY_DIRS})
add_definitions(${PCL_DEFINITIONS})
add_executable (cloud_viewer cloud_viewer.cpp)
target_link_libraries (cloud_viewer ${PCL_LIBRARIES})将刚才生成的pcd文件拷贝过来，运行的结果如下：
由于之前生成的pcd里面仅有一些离散的点，看的不是很明显，加载一个Stanford bunny 的点云（PCL目录下有）来看看。
参考
Using PCL in your own project - http://pointclouds.org/documentation/tutorials/using_pcl_pcl_config.php#using-pcl-pcl-config
讀取 pcd 檔並顯示三維影像 - http://coldnew.github.io/blog/2013/04/12_64cf9.html
The CloudViewer - http://pointclouds.org/documentation/tutorials/cloud_viewer.php#cloud-viewer