Re: Transformations between Maps

Posted by matlabbe on
URL: http://official-rtab-map-forum.206.s1.nabble.com/Transformations-between-Maps-tp1126p1129.html

Hi Kaifei,

Sure, it is the best place to ask them!

1. Yes, and even if they are in the same map (unless odometry is perfect).
2. The Link table contains all transformations between nodes in a map and between maps (on loop closures).
3. The relative transformation between two maps is implicitly saved in loop closure links. There could be many loop closures between two maps. On graph optimization, all nodes are transformed in the coordinate system of the first map if "RGBD/OptimizeFromGraphEnd=false" or the last map if "RGBD/OptimizeFromGraphEnd=true". In "rtabmap-databaseViewer", you can specify exactly the root node of the optimization under Graph View panel so that all maps/nodes are transformed accordingly to this node.

cheers,
Mathieu