在 ROS 中使用 pcl 和 python

Question

I'm new to the ROS and i have a problem.

I'm trying to visualize a point cloud using pcl library. At first i start my ros-realsense camera typing in a terminal "roslaunch realsense2_camera rs_camera.launch filters:=pointcloud" Then, i have made a catkin package where i have a listener.py script where i subscribe to the realsense and i get the point cloud information that i want. So far so good. Now i want to visualize this point cloud using the PCL library but when i run my package "rosrun pcl listener.py" i get the error

import pcl ImportError: No module named pcl

So my question is what do i miss? How do i import the pcl in a ros package? Do i have to add something on the CMakeLists.txt or/and package.xml?

I include my listener.py script.

#!/usr/bin/env python
import rospy
import pcl
import ros_numpy
import sensor_msgs.point_cloud2 as pc2
from sensor_msgs.msg import PointCloud2

def callback_ptclud(ptcloud_data):
    pc = ros_numpy.numpify(data)
    points=np.zeros((pc.shape[0],3))
    points[:,0]=pc['x']
    points[:,1]=pc['y']
    points[:,2]=pc['z']
    p = pcl.PointCloud(np.array(points, dtype=np.float32))

def listener():
    rospy.Subscriber("/camera/depth/color/points", PointCloud2, callback_ptclud)
    rospy.spin()

if __name__ == '__main__':
    rospy.init_node("realsense_subscriber", anonymous=True)
    listener()

Thank you in advance Any help is appreciated

Answer 1

About the pcl the most easiest way is to use it with C++. Its easy to install and there are a lot of documentations and examples. About the python_pcl for some reason its not easy to install (at least for me). What i did to use it was to download the library, put it somewhere in my pc and when i want to use it in my scripts i just import the absolute path of pcl.

By downloading the python_pcl files i mean find and download the init.py, _pcl.py, _pcl.so and all the necessary files of the library.

For example in my python scripts i use:

import sys
sys.path.append('~/path_to_downloaded_pcl') "it will find the __init__.py"
import pcl