Visualization / Transforms with rosbridge and erratic

Question

I'm trying to create a website that displays the current progress of a robot (in this case erratic) running SLAM. With rosbridge I've been able to set up the subscriptions that I need, I think and I can draw all of the data in a similar way that rviz does.

The trouble is that each topic I've subscribed to has a lot of fields and I'm not sure how to get the transforms from each frame to line up when visualizing the slam map, the senses obstacles and the robot.

The topics of interest are:

/move_base_node/local_costmap/robot_footprint
/move_base_node/local_costmap/inflated_obstacles
/map

Obviously it makes sense that the topics under /move_base_node/local_costmap are in the same frame, but obviously /map is not.

Do I need to use tf to accomplish this? I couldn't find a tutorial for this kind of thing.

Any help or direction is greatly appreciated.

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Originally posted by skiesel on ROS Answers with karma: 549 on 2012-08-16

Post score: 0

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Original comments

Comment by skiesel on 2012-08-22:
This was my solution in the end

Answer 1

Yes, you need tf.

In the Header of each topic there is a frame_id, naming the frame of reference for each message. This command should show the origins of each frame (assuming they are being published correctly somewhere).

$ rosrun tf tf_monitor

Rviz should be able to display your data in some appropriate frame of reference (probably /map).

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Originally posted by joq with karma: 25443 on 2012-08-16

This answer was ACCEPTED on the original site

Post score: 0