I am building a differential-wheel robot with rplidar and I am wondering if there is any reason to use the robot state publisher. My questions:

• Why incorporate robotstatepublisher in my launch file? Does it pick the geometric robot and lidar data from the urdf and then broadcast their odometry transforms as a parent-child relation?
• If yes, couldn't I better add that parent-child transform broadcast to my own C++ code instead of using robotstatepublisher with an urdf file?

thanks