How to obtain pose of a mesh that I added as a collision object?

edit

I am trying to obtain pose of a collision object that I added to the scene.

I have two nodes (node1 and node2), I also have a launch file which launches a custom world.

node1 does all the planning and collision checking stuff. Works well

node2 is to spawn a part into my custom world and attach it to a link(not a manipulator link). I'm using planning_scene_interface to add a mesh collision object to the scene and also updating the collision between the link and the part using setEntry() for allowedCollisionMatrix. I am then using using planning_scene_monitor to publish the updates into the scene. All this works well.

Now, in the node1 I want to obtain the pose of the collision object that I added from node2. I found that I can use move_group/monitored_planning_scene topic to get the information of the complete scene. From this answer I read that move_group/monitored_planning_scene topic publish msgs only if there is a change in the scene or if we explicitly make a service request to update the scene and get information out of it.

My question is how do I access the pose of a collision object after making that request? do I need to write a subscriber and callback for the move_group/monitored_planning_scene topic to read the pose information?

EDIT: I tried making a planning_scene_monitor->requestPlanningSceneState("/get_planning_scene") to get a response on move_group/monitored_planning_scene topic, msgs are being published on the topic whenever I make a request, but those msgs does not show the information of the added collision object.

My end goal for getting this pose information is to transform this pose using a transformation_matrix to rotate and/or translate this collision object from node1 itself.

Is this the right way of doing it? or is there a more straight-forward way to read the pose of the collision object? I see there is a topic being published /collision_object, does this topic publish any useful information that I'm trying to find? I don't see anything being published to it