how to use gmapping based on laser_scan_matcher?

edit

I now only have .pcap file collected by my velodyne. I want to test gampping without a moving robot.

Here are the steps I did:

roslaunch velodyne_pointcloud VLP16_points.launch pcap:=/home/soowon/Documents/County_Fair.pcap

...

rosrun pointcloud_to_laserscan pointcloud_to_laserscan_node cloud_in:=/velodyne_points

At this moment, I can see the laserscan in RVIZ with frame of "velodyne", then I run this to get fake /tf:

rosrun laser_scan_matcher laser_scan_matcher_node scan:=/scan

..

rosrun gmapping slam_gmapping scan:=/scan

No error occurs, but I cannot see anything new in RVIZ, I added the topic map, but it says "no map received". I tried different frames in RVIZ, like: velodyne, map, world. It does not work.

Can anybody tell me what is the reason? Thank you very much!