What topics is my nodelet listening to? (For RGBD6D playback)

Question

Hello folks,

Background:

I'm playing around with openni_camera_unstable, hoping to get a two-pass pointcloud-generation system going (in the first pass, I record the image and depth data; in the second, I generate the registered pointclouds; limited hardware on my robot makes this handy).

Question:

If I fire up unstable's openni.launch, I get nice pointclouds exactly like I would expect. What I'd like to do is figure out what topics I need to bag in order to be able to run the point-cloud projection nodelet in a second pass. rosnode list shows /camera/points_xyzrgb_depth_rgb, which is the nodelet doing this work, but rosnode info on that node just lists a bunch of bond topics. The node actually publishing the point clouds is the manager (which I suppose makes sense, as I understand that to be the actual owning process of the various nodelets).

So: how do I figure out which topics my nodelet is subscribing to? (Alternatively, which topics do I need to accomplish what I'm after?)

Thanks!

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Originally posted by Mac on ROS Answers with karma: 4119 on 2011-05-20

Post score: 2

Answer 1

To answer your specific use case: you need to bag /camera/depth_registered/image_rect_raw, /camera/rgb/image_rect_color, and /camera/rgb/camera_info.

As for the more general question, I have the same frustration. We need nodelet equivalents of rosnode info and rxgraph, but that tooling doesn't exist yet.

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Originally posted by Patrick Mihelich with karma: 4336 on 2011-05-25

This answer was ACCEPTED on the original site

Post score: 6

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Original comments

Comment by JFReuter on 2011-08-31:
If you have the bag file playing, run this to get the point cloud: ROS_NAMESPACE=camera rosrun nodelet nodelet standalone openni_camera/point_cloud_xyzrgb

Comment by Patrick Mihelich on 2011-05-26:
At the bottom of http://www.ros.org/wiki/common (stack containing the nodelet package) there's a "request features" link to create a ticket in the right Trac.

Comment by Mac on 2011-05-26:
Thanks for posting; I had, in fact, figured that out by source-code perusal, but failed to post the results. What's the right way to request said features? File a bug? Organize a mob, with signs and patriotic music?

Answer 2

I think if you do rosnode info on the nodelet manager you'll see the topics all of the nodlets running under it are subscribed to.

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Originally posted by Asomerville with karma: 2743 on 2011-05-20

This answer was NOT ACCEPTED on the original site

Post score: 1

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Original comments

Comment by Mac on 2011-05-23:
Yeah, I did that. No luck. I see a long list of publications (none of which are inter-nodelet; the manager is publishing everything all of the nodelets produce), and a huge number of Bonds, and nothing else.

Comment by Asomerville on 2011-05-20:
I've use it with success for stere_image_proc which is a collection of nodelets and saw subscriptions between nodelets (other than bond). The key was that I did it on the nodelet manager rather than the nodelet.

Comment by Mac on 2011-05-20:
Nope (at least, not what I want). I get the "external" plumbing information (the manager is publishing all of the various topics assembled by the nodelets), plus a whole bunch of bond subscriptions. What I want, so to speak, is the "internal" plumbing, showing how the nodelets are connected up.