Re: grid_map versus proj_map for same bag data

Posted by matlabbe on
URL: http://official-rtab-map-forum.206.s1.nabble.com/grid-map-versus-proj-map-for-same-bag-data-tp1779p1781.html

Hi Patrick,

for the arc, it may be because the lidar is upside down. Either set:

<param name="flip_scan" type="bool" value="true"/>

or

<param name="map_negative_poses_ignored" type="bool" value="true"/>

under rtabmap node. I think with "map_negative_poses_ignored=true", you would get something similar to gmapping.

The algorithm used to create occupancy map from projection is labeling ground points as empty and obstacle points as occupied. The camera needs to "see" the ground to add empty cells.

You may try "octomap_proj" topic instead of "proj_map", which is the projection of the OctoMap on the ground. In this version, OctoMap does ray tracing in 3D, so empty voxels just in front of the camera will be projected as empty cells on the ground, this would fill the unknown space in the middle of the map.

cheers,
Mathieu