ROS2 Camera topic publish Hz control (Camera FPS Fix problem using ros2)

[phr0201]

I want to get the camera topic of fixed fps ( 30 ) when i publish the camera topic(/carter1/rgb_left, /carter1/rgb_right) using ros2.

1. At first, I set the “FPS Limit” ( =10 _ just test ) But like below figure, It does not apply.
   ( In figure, FPS Limit is 10, but camera fps published is 22.34 )
   
   

And then, What should i do if i want to get the fixed fps of camera topic using ros2 in isaac sim?
Now I am using the omnigraph for getting the ros topics ( camera, imu, lidar etc ).
And also when the scene is more complicated or I open multiple viewport, FPS decreased.

2. Second, I found the RTX Option(real time & interactive & accurate ), What is differences between them? When i choose “Interactive option” like below, scene looks like blurry and dark. ( But real-time looks good )
   

   

3. Is it possible to get the topic of fixed fps if i use the Enterprise version?

4. Lastly, I want to publish various sensor topic ( imu, camera, lidar ). In this case, Can i get it at a fixed fps for each topic? ( like camera = 30 fps, IMU = 110hz )

Thank you so much for reading. If anyone knows, Please reply me… !!

Thank you

[smoon]

@Hammad_M Can you help to respond this thread? @phr0201 can elaborate more on the question if this is not clear to you. She is looking for a way to set FPS Limit forthe camera topic. Thank you!

[Hammad_M]

@phr0201 Are you using isaac-sim.sh or python.sh + SImulationApp?
There are different ways of fixing the rendering FPS based on the simulation method.

There are also additional options mentioned here if you want to reduce the publishing rate by a fixed multiple.

https://docs.omniverse.nvidia.com/app_isaacsim/app_isaacsim/tutorial_ros_migration.html#periodic-image-publishing

If you want to Publish at an increased rate that is possible in certain circumstances. For example to publish a simulation clock message every physics step you can take a look at
standalone_examples/api/omni.isaac.quadruped/go1_ros1_standalone.py

Where a specific graph like

 try:
            keys = og.Controller.Keys
            (self._clock_graph, _, _, _) = og.Controller.edit(
                {
                    "graph_path": "/ROS_Clock",
                    "evaluator_name": "push",
                    "pipeline_stage": og.GraphPipelineStage.GRAPH_PIPELINE_STAGE_ONDEMAND,
                },
                {
                    keys.CREATE_NODES: [
                        ("OnTick", "omni.graph.action.OnTick"),
                        ("readSimTime", "omni.isaac.core_nodes.IsaacReadSimulationTime"),
                        ("publishClock", "omni.isaac.ros_bridge.ROS1PublishClock"),
                    ],
                    keys.CONNECT: [
                        ("OnTick.outputs:tick", "publishClock.inputs:execIn"),
                        ("readSimTime.outputs:simulationTime", "publishClock.inputs:timeStamp"),
                    ],
                },
            )
        except Exception as e:
            print(e)
            simulation_app.close()
            exit()

is then manually run each physics step:

og.Controller.evaluate_sync(self._clock_graph)

Also take a look at standalone_examples/api/omni.isaac.core/time_stepping.py

For various options on stepping time forward at specific frequencies/step sizes.

[phr0201]

Thank you for replying me!

By the way, Your examples are all based on ros1, but i want to use ros2.
Because i want to get the 30 fps camera topics(e.g /carter1/rgb_left) in isaac sim (2022.1.1 release version) based on ros2.
Is it possible applying above examples in ros2 environment?

Thank you!

[Hammad_M]

Yes the same applies to ROS2 Omnigraph nodes as well.
Note that if your current FPS is lower than 30, there is no way to increase this because its GPU/CPU limited performance wise.

You can however run slower than realtime and use the sim_time clock message from isaac sim to keep things in sync.