realsense D435 + turtlebot2

edit

Hi, I am an absolute beginner in ROS I have a turtlebot2 mounted by velodyne laser scanner this turtlebot can built a map and can also perform autonomous navigation. (gmapping used) Now my objective is replacing the laser scanner with realsense d435 and do the same job. I can start the camera node and make it publish the RGBD point cloud using aligned depth topic by this command roslaunch realsense2_camera rs_rgbd.launch so my question is how to replace the velodyne laser scanner by the d435 to be used in gmapping to do the same job of mapping environment.