ros noetic moveit中订阅点云话题将所有点云组合成一个整体后转换成环境scene的Python非类函数

以下是一个Python函数，可以订阅点云话题并将其转换为MoveIt中的场景（scene）：

import rospy
from moveit_msgs.msg import CollisionObject
from sensor_msgs.msg import PointCloud2
import sensor_msgs.point_cloud2 as pc2
import numpy as np
import scipy.spatial
import geometry_msgs.msg
import shape_msgs.msg

def point_cloud_to_scene():
    points = []
    cloud_frame = ""
    cloud_time = None
    scene_pub = rospy.Publisher("/collision_object", CollisionObject, queue_size=10)

    def callback(data):
        nonlocal points
        nonlocal cloud_frame
        nonlocal cloud_time
        if cloud_frame != data.header.frame_id:
            points = []
            cloud_frame = data.header.frame_id
        cloud_time = data.header.stamp
        for p in pc2.read_points(data, field_names=("x", "y", "z"), skip_nans=True):
            points.append(p)
        publish_scene()

    def publish_scene():
        nonlocal points
        if not points:
            return
        # Combine all points into a single numpy array
        points_np = np.array(points)
        # Create CollisionObject message
        obj = CollisionObject()
        obj.header.frame_id = cloud_frame
        obj.header.stamp = cloud_time
        obj.operation = CollisionObject.ADD
        obj.id = "point_cloud_scene"
        # Create mesh of convex hull of the points
        hull_indices = scipy.spatial.ConvexHull(points_np).vertices
        hull_points = points_np[hull_indices]
        obj.mesh_poses.append(geometry_msgs.msg.Pose())
        obj.meshes.append(create_mesh(hull_points))
        # Publish the scene message
        scene_pub.publish(obj)
        # Clear the points list
        points = []

    def create_mesh(points):
        mesh = shape_msgs.msg.Mesh()
        vertices = []
        for p in points:
            vertices.append(geometry_msgs.msg.Point(p[0], p[1], p[2]))
        triangles = []
        for i in range(1, len(points)-1):
            triangles.append(shape_msgs.msg.MeshTriangle(0, i, i+1))
        mesh.vertices = vertices
        mesh.triangles = triangles
        return mesh

    rospy.init_node('point_cloud_to_scene')
    pc_sub = rospy.Subscriber("/your/point_cloud_topic", PointCloud2, callback)

    rospy.spin()

该函数使用了内部函数的概念，将订阅点云话题和发布场景消息的代码封装在了callback()和publish_scene()函数内。在收到新的点云消息时，callback()函数将点云中的所有点组合成一个单独的numpy数组，并将其转换为一个具有凸包网格的CollisionObject消息。最后，publish_scene()函数将CollisionObject消息发布到MoveIt的场景（CollisionScene）中，并清空点云列表。

注意：在使用此代码之前，您需要安装moveit_msgs，sensor_msgs和numpy等必要的依赖项。