rtabmap+pose file
hi, i am following the tutorials of rtabmap and use this package for stereo vision. i created the map with stereo images from file (link:https://github.com/introlab/rtabmap/wiki/Stereo-mapping) for ros and saved RGBD_pose.txt file. the file's parameters is (x,y,z,qx,qy,qz,qw). but i don't know where is origin? and what is qw? please help me