Navigation stack sensor sources

edit

Hi, I'm studying the navigation stack.
My question is, Will PointCloud Message be converted to LaserScan Mesassge?

In wiki, it's said that it accepts sensor data published using
either the sensor_msgs/LaserScan Message type or the sensor_msgs/PointCloud Message type.
However, in turtlebot_bringup, PointCloud Message is apparently converted to LaserScan Message
using pointcloud_to_laserscan package.

Then, does the above mean that
it accepts both Messages because PointCloud Message can be converted to LaserScan Message?
Only when building maps, will PointCloud Message be converted?

Thanks in advance.