我想创建一个简单的 python 脚本来读取一些 .pcd 文件并为 rosbag 中的每个文件创建一个 sensor_msgs::PointCloud2 。
我尝试使用 python-pcl 库，但是在将点添加到数据字段时我可能做错了，因为在播放 rosbag 并检查 RViz 并回显主题时，我没有得到任何分数。
这是我设置 PointCloud2 msg 的部分。
pcl_data = pcl.load(metadata_dir + "/" + pcd_path)
# get data
pcl_msg = sensor_msgs.msg.PointCloud2()
pcl_msg.data = np.ndarray.tobytes(pcl_data.to_array())
pcl_msg.header.stamp = rospy.Time(t_us/10000000.0)
pcl_msg.header.frame_id = "robot_1/navcam_sensor"
# Pusblish Pointcloud2 msg
outbag.write("/robot_1/pcl_navcam", pcl_msg, rospy.Time(t_us/10000000.0))
我也尝试了 pypc，但没有任何运气。
你会怎么做？也许在 pcl 的 cpp 版本中有一个 ToROSMsg 方法？
cpp 中很容易获得的东西是否有 python 等价物： pcl::toROSMsg ？
谢谢
这是python脚本的完整代码：
#! /usr/bin/env python3
import rospy
import rosbag
import tf2_msgs.msg
import geometry_msgs.msg
import sensor_msgs.msg
import sys
import os
import json
import numpy as np
import tf.transformations as tf_transformations
import pcl
import json
import math
import pypcd
import sensor_msgs.point_cloud2 as pc2
import tf2_msgs.msg._TFMessage
def main():
output_bag_path = dataset_path + "rosbag.bag"
with rosbag.Bag(output_bag_path, 'w') as outbag:
# iterate metadata files with tfs
metadata_dir = dataset_path + "Pointcloud/metadata"
t_first_flag = False
# for filename in os.listdir(metadata_dir):
list_of_files = sorted( filter( lambda x: os.path.isfile(os.path.join(metadata_dir, x)),
os.listdir(metadata_dir) ) )
for filename in list_of_files:
# open json file
json_path = os.path.join(metadata_dir, filename)
json_file = open(json_path)
json_data = json.load(json_file)
# get timestamp
t_us = json_data \
["metadata"] \
["Timestamps"] \
["microsec"]
t_ns, t_s = math.modf(t_us/1000000)
# get camera tf
pos = geometry_msgs.msg.Vector3( \
json_data["metadata"] \
["pose_robotFrame_sensorFrame"] \
["data"] \
["translation"][0], \
json_data["metadata"] \
["pose_robotFrame_sensorFrame"] \
["data"] \
["translation"][1], \
json_data["metadata"] \
["pose_robotFrame_sensorFrame"] \
["data"] \
["translation"][2])
quat = geometry_msgs.msg.Quaternion( \
json_data["metadata"] \
["pose_robotFrame_sensorFrame"] \
["data"] \
["orientation"] \
["x"], \
json_data["metadata"] \
["pose_robotFrame_sensorFrame"] \
["data"] \
["orientation"] \
["y"], \
json_data["metadata"] \
["pose_robotFrame_sensorFrame"] \
["data"] \
["orientation"] \
["z"], \
json_data["metadata"] \
["pose_robotFrame_sensorFrame"] \
["data"] \
["orientation"] \
["w"], )
navcam_sensor_tf = geometry_msgs.msg.TransformStamped()
navcam_sensor_tf.header.frame_id = "reu_1/base_link"
navcam_sensor_tf.child_frame_id = "reu_1/navcam_sensor"
navcam_sensor_tf.header.stamp = rospy.Time(t_us/1000000.0)
navcam_sensor_tf.transform.translation = pos
navcam_sensor_tf.transform.rotation = quat
# get base_link tf
pos = geometry_msgs.msg.Vector3( \
json_data["metadata"] \
["pose_fixedFrame_robotFrame"] \
["data"] \
["translation"][0], \
json_data["metadata"] \
["pose_fixedFrame_robotFrame"] \
["data"] \
["translation"][1], \
json_data["metadata"] \
["pose_fixedFrame_robotFrame"] \
["data"] \
["translation"][2])
quat = geometry_msgs.msg.Quaternion( \
json_data["metadata"] \
["pose_fixedFrame_robotFrame"] \
["data"] \
["orientation"] \
["x"], \
json_data["metadata"] \
["pose_fixedFrame_robotFrame"] \
["data"] \
["orientation"] \
["y"], \
json_data["metadata"] \
["pose_fixedFrame_robotFrame"] \
["data"] \
["orientation"] \
["z"], \
json_data["metadata"] \
["pose_fixedFrame_robotFrame"] \
["data"] \
["orientation"] \
["w"], )
base_link_tf = geometry_msgs.msg.TransformStamped()
base_link_tf.header.frame_id = "map"
base_link_tf.child_frame_id = "reu_1/base_link"
base_link_tf.header.stamp = rospy.Time(t_us/1000000.0)
base_link_tf.transform.translation = pos
base_link_tf.transform.rotation = quat
# publish TFs
tf_msg = tf2_msgs.msg.TFMessage()
tf_msg.transforms = []
tf_msg.transforms.append(base_link_tf)
outbag.write("/tf", tf_msg, rospy.Time(t_us/1000000.0))
tf_msg = tf2_msgs.msg.TFMessage()
tf_msg.transforms = []
tf_msg.transforms.append(navcam_sensor_tf)
outbag.write("/tf", tf_msg, rospy.Time(t_us/1000000.0))
# open corresponding .pcd file
pcd_path = json_data["data"]["path"]
pcl_data = pcl.load(metadata_dir + "/" + pcd_path)
# pcl_data = pypcd.(metadata_dir + "/" + pcd_path)
# get data
pcl_msg = sensor_msgs.msg.PointCloud2()
pcl_msg.data = np.ndarray.tobytes(pcl_data.to_array())
pcl_msg.header.stamp = rospy.Time(t_us/1000000.0)# t_s, t_ns)
pcl_msg.header.frame_id = "reu_1/navcam_sensor"
# Pusblish Pointcloud2 msg
outbag.write("/reu_1/pcl_navcam", pcl_msg, rospy.Time(t_us/1000000.0))
pass
if __name__ == "__main__":
dataset_path = "/home/---/Documents/datasets/---/"
main()
base_link 和相机 tfs 来自一个 json 文件，该文件还存储一个字符串以关联 .pcd 文件。