How to integrate PCL library into an existing project?

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Suppose I clone the hector_slam project in my catkin_ws:

1. cd ~/catkin_ws/src/ && git clone https://github.com/tu-darmstadt-ros-pkg/hector_slam.
2. cd .. && catkin_make

Those two steps work perfectly and I can launch the program.

Now, I need to extend the project and need the PCL library pcl_roshttps://wiki.ros.org/pcl_ros to create new point clouds objects (for clustering and filtering), since hector_slam doesn't depend on the pcl_ros. hector_slam utilized laser_geometry::LaserProjection::projectLaser() to create a sensor_msgs::PointCloud.

Adding #include <pcl_conversions/pcl_conversions.h> in a source file returns this error fatal error: pcl_conversions/pcl_conversions.h: No such file or directory #include <pcl_conversions/pcl_conversions.h>

After adding pcl_conversions in the find_package line of CMakeLists.txt, it returns a CMake error of no package found.

Shall I install the package using sudo apt install ros-melodic-pcl-conversions or sudo apt install pcl-rosor clone the this github repo https://github.com/ros-perception/per... in my catkin_ws/src?

It is a little bit confusing since the name in the Wiki https://wiki.ros.org/pcl_ros called pcl_ros but the repo name is perception_pcl.