Hi all! At our company we are trying to use MoveIt2 (MoveGroupInteface) to plan trajectories for our robots. As of now, we are not using ros2control to communicate with the real hardware, and hence we don't use jointstatebroadcaster to publish joint states. Instead, we are publishing them from our own ros2 node. This seems to break fcl collision check and we often get messages like the following: ``` [moveitcollisiondetectionfcl.collisioncommon]: Found a contact between 'link1' (type 'Robot link') and 'link2' (type 'Robot link'), which constitutes a collision. Contact information is not stored. `` Even though the srdf disables collisions between these links. This seems to happen only when a planning scene is published. Trying with several options, again, it seems that if the planning scene is published using a publisher ofPlanningScene` message to the /planningscene topic, this error happens. Instead, if PlanningSceneInterface is used with the method addCollisionObjects, the planning is successful.

In general, the documentation or the tutorials explain only the case in which ros2control is used to publish joint states. We seem to have understood that this problem has something to do with getting properly the state of the robot. However, it is not entirely clear and we believe it would be interesting to understand how to keep MoveIt2 planning independent from ros2control while publishing joint states on our own. What are the specifications that such a joint state publisher should meet in order to work with MoveIt2?

Our environment

• ROS Distro: Humble
• OS Version: Ubuntu 22.04
• Docker Image: ykrobotics/humble-dev

Steps to reproduce

To reproduce the issue, we have prepared a working demo.

• Clone the repo and open in container.
• In a terminal, run ros2 launch moveit_debug demo.launch.py
• Then, in a separate terminal ros2 launch moveit_debug collision.launch.py

Lines 100 or 101 of src/moveit_collision.cpp can be commented to try publishing planning scene through a classic publisher or PlanningSceneInterface.

Expected behaviour

The planning produced valid trajectories and are "executed" in RViz.

Actual behaviour

When publishing using a publisher to the /planning_scene topic, unexpected collisions are found. This is not the case when using planning_scene_interface.addCollisionObjects(collision_objects);.

We believe this is quite a common and important issue, which is not receiving the deserved interest from the community.