1st attempt scan to point cloud

tuto_scan_echo.py

+#!python3
+import rclpy
+import math
+from rclpy.node import Node
+from sensor_msgs.msg import LaserScan, PointCloud2
+import sensor_msgs_py.point_cloud2
+from std_msgs.msg import Header
+
+rosNode= None
+
+def scan_callback(scanMsg):
+    global rosNode
+    obstacles = ranges_to_positions(scanMsg)
+    sample = [ [ round(p[0], 2), round(p[1], 2), round(p[2], 2) ] for p in  obstacles[10:20] ]
+
+
+    # Publish a msg
+    pointCloud = sensor_msgs_py.point_cloud2.create_cloud_xyz32(Header(frame_id='frame'), obstacles)
+    rosNode.get_logger().info( f"\nheader:\n{scanMsg.header}\nnumber of ranges: {len(scanMsg.ranges)}\nSample: {pointCloud}\n" )
+    point_publisher.publish(pointCloud)    
+
+
+def ranges_to_positions(scan_message: LaserScan) -> list:
+    obstacles= []
+    angle= scan_message.angle_min
+    for aDistance in scan_message.ranges :
+        if 0.1 < aDistance and aDistance < 5.0 :
+            aPoint= [
+                math.cos(angle) * aDistance,
+                math.sin(angle) * aDistance,
+                0
+            ]
+            obstacles.append(aPoint)
+        angle+= scan_message.angle_increment
+    return obstacles
+
+
+rclpy.init()
+rosNode= Node('scan_interpreter')
+# Initialize a subscriber:
+rosNode.create_subscription( LaserScan, 'scan', scan_callback, 10)
+# Initialize a publisher:
+point_publisher = rosNode.create_publisher(PointCloud2, '/scan_points', 10)
+
+while True :
+    rclpy.spin_once( rosNode )
+
+
+
+
+scanInterpret.destroy_node()
+rclpy.shutdown()
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