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2013-12-22 05:07:24 -0500 answered a question Library roscpp does not load

Hi. I am not sure if this could be the problem you are facing, but I came across something similar with rosconsole messages - a third party library using its own version of log4cxx wasn't playing good with rosconsole, resulting in rosconsole messages being displayed wrongly. In short, is it possible that there is some mismatch in the version of other system libraries that you have linked ROS against? HTH.

2013-12-22 04:57:17 -0500 commented answer sensor_msgs::PointCloud2 not displaying in rviz

@bvbdort the point cloud's frame is /laser_link according to the message, but your tf tree does not seem to have it ... name mismatch? Also, if your fixed frame is /map, the point cloud message time stamp will need to match with that of the tf broadcasters. Is the point cloud visible when you set the fixed frame to laser_link?

2013-12-19 01:58:59 -0500 commented question Calling a function in a function

Could you post the error messages please?

2013-12-19 01:55:24 -0500 answered a question Publishing .bag file for different nodes

There are 2 ways you can access the data in the bag file

  1. Play back the bag file using rosbag play <bagfile>; your processing node can then subscribe to the topics and collect the data as it is published.
  2. Access the data in the bag file programmatically using the rosbag C++ API.
2013-12-17 13:38:08 -0500 answered a question Costmap's free-space depending on gmapping?

Hi Daniel. When you say you need to "get" the free space, I assume you mean it as a published topic similar to the obstacles and unknown space. We did this is in Costmap2DPublisher::updateCostmapData, similar to what is done for raw and inflated obstacles. Obstacle and inflated space are different from free space, from the processing perspective as well as the actual value representation in the map.

As far as gmapping goes, while not having worked on it directly, I understand that you will need to connect it up as a layer in the costmap, either as a static map obtained after an offline map building run, or as a online source. By default, AFAIK costmap_2d does not support nav_msgs/OccupancyGrid as a source, so you will need to do some coding in the latter case and actually process the output of gmapping to interpret it as obstacle/inflated/unknown/free space, since the underlying value representations in OccupancyGrid and Costmap2D are different. I don't think faster SLAM updates will help here, if I understand your question correctly.

HTH.

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2013-12-12 04:10:11 -0500 commented question Mirroring the ROS wiki

Yup, the wiki_mirror module is showing up now. Thanks to the team behind ROS once again!!

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2013-12-11 04:55:38 -0500 asked a question Mirroring the ROS wiki

I am trying to mirror the ROS API and wiki docs for a project with no internet access, by following the instructions on the wiki at http://wiki.ros.org/Mirrors#Creating_... .

The API docs seem to download fine, but mirroring the wiki:

rsync -azv wiki.ros.org::wiki_mirror wiki.ros.org --bwlimit=200 --delete

fails with

@ERROR: Unknown module 'wiki_mirror'

Am I missing something here or do the instructions need to be modified?