Ubuntu16.04在QT或ROS环境中安装并使用PCL,实现点云曲面重建

• 记录并分享一下安装PCL的安装和使用过程，很大概率以后还要配置环境，以免再次踩坑。刚开始进行点云处理的时候，是直接使用ROS(Kinetic版本)中自带的pcl，后来需要实现基于B样条曲线的点云曲面重建，发现了一些问题。ROS中安装的PCL没有开启BUILD_sruface_on_nurbs 选项，没法使用NURBS曲面相关的功能，所以需要重新安装PCL。

源码安装PCL1.9.1

• 源码安装之前需要安转一些其他的库，可参考博客:安装电脑里没有的依赖

• 下载PCL1.9.1的源码:下载链接，然后解压到/home目录下，并更改解压后的文件夹名为pcl-1.9.1。进入该文件目录下，新建build文件夹。

• 新建终端并切换到刚刚新建的build目录下面，执行命令 cmake-gui.

• where is the source code选择解压后的pcl1.9.1的路径，where to build the binaries选择新建的build路径。然后点击configure选项。

• 选中BUILD_sruface_on_nurbs选项，再次点击configure，选择USE_UMFPACK选项。选择CMAKE_INSTALL_PREFIX的路径为/usr/local/pcl-1.9。(选择路径前需要先在/usr/local/目录下新建pcl-1.9文件夹)。 最后点击generate选项。

• 依然在build目录下新建终端，执行指令make -j2(j后面的数字可以指定，越大程序编译的越快，不过电脑也容易卡死，最大为CPU的核数)。完成之后，执行指令sudo make install将安装到刚刚在cmake-gui中指定的路径/usr/local/pcl-1.9.

安装PCL到指定路径下之后如何使用

修改.bashrc文件

• 安装到/usr/local/pcl-1.9是为了后期安装其他版本，而且卸载的时候也方便，以后如果安装其他开源库也可这样设置路径，比如/usr/local/opencv-3.4
• 在.bashrc文件后面添加如下两行,指定PCL库的路径.

export PKG_CONFIG_PATH=/usr/local/pcl-1.9/lib/pkgconfig:$PKG_CONFIG_PATH
export LD_LIBRARY_PATH=/usr/local/pcl-1.9/lib:$LD_LIBRARY_PATH

QT中使用PCL

• 新建demo文件夹,然后新建CMakeLists.txt和bspline_fitting.cpp文件,其中bspline_fitting.cpp写曲面重建等程序以及对应的头文件,CMakeLists.txt文件的内容如下,配置完文件之后用QT打开CMakeLists.txt,然后在QT中做后续开发即可.

cmake_minimum_required(VERSION 2.4.6)

project(bspline_fitting)

set(PCL_DIR "/usr/local/pcl-1.9/share/pcl-1.9")

find_package(PCL 1.9 REQUIRED)
include_directories(${PCL_INCLUDE_DIRS})
link_directories(${PCL_LIBRARY_DIRS})
add_definitions(${PCL_DEFINITIONS})

add_executable (bspline_fitting bspline_fitting.cpp)
target_link_libraries (bspline_fitting ${PCL_LIBRARIES})

ROS中使用PCL

• 新建ROS的工作空间catkin_PCL和对应的功能包名称test，目录如下所示
  
• CMakeLists.txt文件的内容如下:

cmake_minimum_required(VERSION 2.4.8)
project(test)

#指定PCL库的路径
set(PCL_DIR "/usr/local/pcl-1.9/share/pcl-1.9")
find_package(PCL 1.9 REQUIRED COMPONENTS)
include_directories(${PCL_INCLUDE_DIRS})
link_directories(${PCL_LIBRARY_DIRS})
add_definitions(${PCL_DEFINITIONS})

#ROS相关,不要添加pcl_ros等ROS中自带的PCL功能包,使用PCL1.9即可
find_package(catkin REQUIRED COMPONENTS roscpp)
catkin_package()
include_directories(include ${catkin_INCLUDE_DIRS})

#生成可执行文件的依赖
add_executable(app src/app.cpp)
add_dependencies(app ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
#后面的${PCL_LIBRARIES}一定要加,否则会出现函数未定义的错误,容易忘记.
target_link_libraries(app ${catkin_LIBRARIES} ${PCL_LIBRARIES})

基于B样条曲线的点云曲面重建

• 如下是PCL提供的一个实现示例(.cpp文件),编译之后,运行生成可执行文件需要有.pcd文件,并将.pcd文件完整路径这个参数输入给主函数main.

#include 
#include 
#include 

#include 
#include 
#include 
#include 
#include 
using namespace pcl::console;
typedef pcl::PointXYZ Point;

void
PointCloud2Vector3d (pcl::PointCloud<Point>::Ptr cloud, pcl::on_nurbs::vector_vec3d &data);

void
visualizeCurve (ON_NurbsCurve &curve,
                ON_NurbsSurface &surface,
                pcl::visualization::PCLVisualizer &viewer);

int
main (int argc, char *argv[])
{
  std::string pcd_file, file_3dm;

  if (argc < 2)
  {
    printf ("\nUsage: pcl_example_nurbs_fitting_surface pcd-in-file -o 3 -rn 4 -in 10 -mr 128 -td 1\n\n");
    exit (0);
  }
  pcd_file = argv[1];
  //file_3dm = argv[2];
 
  pcl::visualization::PCLVisualizer viewer ("点云库PCL学习教程第二版-B样条曲面拟合点云数据");
  viewer.setBackgroundColor(255,255,255);
  viewer.setSize (800, 600);

  // ############################################################################
  // load point cloud

  printf ("  loading %s\n", pcd_file.c_str ());
  pcl::PointCloud<Point>::Ptr cloud (new pcl::PointCloud<Point>);
  pcl::PCLPointCloud2 cloud2;
  pcl::on_nurbs::NurbsDataSurface data;

  if (pcl::io::loadPCDFile (pcd_file, cloud2) == -1)
    throw std::runtime_error ("  PCD file not found.");

  fromPCLPointCloud2 (cloud2, *cloud);
  PointCloud2Vector3d (cloud, data.interior);
  pcl::visualization::PointCloudColorHandlerCustom<Point> handler (cloud, 0, 255, 0);
  viewer.addPointCloud<Point> (cloud, handler, "cloud_cylinder");
  printf ("  %lu points in data set\n", cloud->size ());

  // ############################################################################
  // fit B-spline surface

  // parameters
  unsigned order (3);
  unsigned refinement (4);
  unsigned iterations (10);
  unsigned mesh_resolution (128);
  bool two_dim=true;
  parse_argument (argc, argv, "-o", order);
  parse_argument (argc, argv, "-rn", refinement);
  parse_argument (argc, argv, "-in", iterations);
  parse_argument (argc, argv, "-mr", mesh_resolution);
  parse_argument (argc, argv, "-td", two_dim);
  pcl::on_nurbs::FittingSurface::Parameter params;
  params.interior_smoothness = 0.2;
  params.interior_weight = 1.0;
  params.boundary_smoothness = 0.2;
  params.boundary_weight = 0.0;

  // initialize
  printf ("  surface fitting ...\n");
  ON_NurbsSurface nurbs = pcl::on_nurbs::FittingSurface::initNurbsPCABoundingBox (order, &data);
  pcl::on_nurbs::FittingSurface fit (&data, nurbs);
  //  fit.setQuiet (false); // enable/disable debug output

  // mesh for visualization
  pcl::PolygonMesh mesh;
  pcl::PointCloud<pcl::PointXYZ>::Ptr mesh_cloud (new pcl::PointCloud<pcl::PointXYZ>);
  std::vector<pcl::Vertices> mesh_vertices;
  std::string mesh_id = "mesh_nurbs";
  pcl::on_nurbs::Triangulation::convertSurface2PolygonMesh (fit.m_nurbs, mesh, mesh_resolution);
  viewer.addPolygonMesh (mesh, mesh_id);
  std::cout<<"Before refine"<<endl;
  viewer.spinOnce (3000);
  // surface refinement
  for (unsigned i = 0; i < refinement; i++)
  {
    fit.refine (0);
    if(two_dim)fit.refine (1);
    fit.assemble (params);
    fit.solve ();
    pcl::on_nurbs::Triangulation::convertSurface2Vertices (fit.m_nurbs, mesh_cloud, mesh_vertices, mesh_resolution);
    viewer.updatePolygonMesh<pcl::PointXYZ> (mesh_cloud, mesh_vertices, mesh_id);
    viewer.spinOnce (3000);
	std::cout<<"refine: "<<i<<endl;
  }

  // surface fitting with final refinement level
  for (unsigned i = 0; i < iterations; i++)
  {
    fit.assemble (params);
    fit.solve ();
    pcl::on_nurbs::Triangulation::convertSurface2Vertices (fit.m_nurbs, mesh_cloud, mesh_vertices, mesh_resolution);
    viewer.updatePolygonMesh<pcl::PointXYZ> (mesh_cloud, mesh_vertices, mesh_id);
    viewer.spinOnce (3000);
	std::cout<<"iterations: "<<i<<endl;
  }

  // ############################################################################
  // fit B-spline curve

  // parameters
  pcl::on_nurbs::FittingCurve2dAPDM::FitParameter curve_params;
  curve_params.addCPsAccuracy = 5e-2;
  curve_params.addCPsIteration = 3;
  curve_params.maxCPs = 200;
  curve_params.accuracy = 1e-3;
  curve_params.iterations = 100;

  curve_params.param.closest_point_resolution = 0;
  curve_params.param.closest_point_weight = 1.0;
  curve_params.param.closest_point_sigma2 = 0.1;
  curve_params.param.interior_sigma2 = 0.00001;
  curve_params.param.smooth_concavity = 1.0;
  curve_params.param.smoothness = 1.0;

  // initialisation (circular)
  printf ("  curve fitting ...\n");
  pcl::on_nurbs::NurbsDataCurve2d curve_data;
  curve_data.interior = data.interior_param;
  curve_data.interior_weight_function.push_back (true);
  ON_NurbsCurve curve_nurbs = pcl::on_nurbs::FittingCurve2dAPDM::initNurbsCurve2D (order, curve_data.interior);

  // curve fitting
  pcl::on_nurbs::FittingCurve2dASDM curve_fit (&curve_data, curve_nurbs);
  // curve_fit.setQuiet (false); // enable/disable debug output
  curve_fit.fitting (curve_params);
  visualizeCurve (curve_fit.m_nurbs, fit.m_nurbs, viewer);

  // ############################################################################
  // triangulation of trimmed surface

  printf ("  triangulate trimmed surface ...\n");
  viewer.removePolygonMesh (mesh_id);
  pcl::on_nurbs::Triangulation::convertTrimmedSurface2PolygonMesh (fit.m_nurbs, curve_fit.m_nurbs, mesh,
                                                                   mesh_resolution);
  viewer.addPolygonMesh (mesh, mesh_id);


  // save trimmed B-spline surface
  /*if ( fit.m_nurbs.IsValid() )
  {
    ONX_Model model;
    ONX_Model_Object& surf = model.m_object_table.AppendNew();
    surf.m_object = new ON_NurbsSurface(fit.m_nurbs);
    surf.m_bDeleteObject = true;
    surf.m_attributes.m_layer_index = 1;
    surf.m_attributes.m_name = "surface";

    ONX_Model_Object& curv = model.m_object_table.AppendNew();
    curv.m_object = new ON_NurbsCurve(curve_fit.m_nurbs);
    curv.m_bDeleteObject = true;
    curv.m_attributes.m_layer_index = 2;
    curv.m_attributes.m_name = "trimming curve";

    model.Write(file_3dm.c_str());
    printf("  model saved: %s\n", file_3dm.c_str());
  }*/

  printf ("  ... done.\n");

  viewer.spin ();
  return 0;
}

void
PointCloud2Vector3d (pcl::PointCloud<Point>::Ptr cloud, pcl::on_nurbs::vector_vec3d &data)
{
  for (unsigned i = 0; i < cloud->size (); i++)
  {
    Point &p = cloud->at (i);
    if (!pcl_isnan (p.x) && !pcl_isnan (p.y) && !pcl_isnan (p.z))
      data.push_back (Eigen::Vector3d (p.x, p.y, p.z));
  }
}

void
visualizeCurve (ON_NurbsCurve &curve, ON_NurbsSurface &surface, pcl::visualization::PCLVisualizer &viewer)
{
  pcl::PointCloud<pcl::PointXYZRGB>::Ptr curve_cloud (new pcl::PointCloud<pcl::PointXYZRGB>);

  pcl::on_nurbs::Triangulation::convertCurve2PointCloud (curve, surface, curve_cloud, 4);
  for (std::size_t i = 0; i < curve_cloud->size () - 1; i++)
  {
    pcl::PointXYZRGB &p1 = curve_cloud->at (i);
    pcl::PointXYZRGB &p2 = curve_cloud->at (i + 1);
    std::ostringstream os;
    os << "line" << i;
    viewer.removeShape (os.str ());
    viewer.addLine<pcl::PointXYZRGB> (p1, p2, 1.0, 0.0, 0.0, os.str ());
  }

  pcl::PointCloud<pcl::PointXYZRGB>::Ptr curve_cps (new pcl::PointCloud<pcl::PointXYZRGB>);
  for (int i = 0; i < curve.CVCount (); i++)
  {
    ON_3dPoint p1;
    curve.GetCV (i, p1);

    double pnt[3];
    surface.Evaluate (p1.x, p1.y, 0, 3, pnt);
    pcl::PointXYZRGB p2;
    p2.x = float (pnt[0]);
    p2.y = float (pnt[1]);
    p2.z = float (pnt[2]);

    p2.r = 255;
    p2.g = 0;
    p2.b = 0;

    curve_cps->push_back (p2);
  }
  viewer.removePointCloud ("cloud_cps");
  viewer.addPointCloud (curve_cps, "cloud_cps");
}