Re: rtabmap_ros outdoor 3D mapping

Posted by matlabbe on
URL: http://official-rtab-map-forum.206.s1.nabble.com/rtabmap-ros-outdoor-3D-mapping-tp6104p6149.html

acp wrote

     * I guess this is to give more robustness to the zed/odometer rotations, right? and  how to obtained the TF between IMU and ZED :)

     * And, why using TF if I am using rtabmap node and not using TF if I am using rtabmap.launch

Depending on the frame of the ZED and the IMU, you can set a static_transform_publisher with the correct orientation between those frames. TF is used for both (that remark applies to two previous sentences).

acp wrote

* What does it mean the graph to be aligned with gravity :)

The orientation of the point clouds created will be aligned with the horizon. For example, if the ground is flat, it should appear flat in the resulting map.

acp wrote

      * How can the featureless interpolation surface can cause multiple walls?

      * I have sent a mail to the stereolabs about the issue of featureless surfaces and I got the following replay [..] Based on the previous answer, what can be done to solve that issue?

If the depth estimation is poor on textureless surfaces, this could create your doublewall effect. As I said in the previous post, it is possible to try another disparity estimation approach on rtabmap side with cv::StereoBM. To do that that, you should use stereo mode of rtabmap with left/right images of zed, not the rgb/depth images. See stereo demo with zed here.