Modify ROS camera timestamp

Omniverse Isaac Sim
1

I’m trying to change the timestamp of ros camera topic from simulator time to cpu time, and I did the following:

def publish_rgb(self, camera: Camera, freq):
render_product = camera.get_render_product_path()
step_size = int(1)
topic_name = camera.prim_path.split(“/”)[-1] + self._camera_topic
queue_size = 1
node_namespace = “”
frame_id = camera.prim_path.split(“/”)[-1]

rv = omni.syntheticdata.SyntheticData.convert_sensor_type_to_rendervar(sd.SensorType.Rgb.name)
writer = rep.writers.get(rv + "ROS1PublishImage")
writer.initialize(
    frameId=frame_id,
    nodeNamespace=node_namespace,
    queueSize=queue_size,
    topicName=topic_name,
)
writer.attach([render_product])

# Modify the graph to add a CPU time provider for the timestamp
keys = og.Controller.Keys
(graph, nodes, _, _) = og.Controller.edit(
    {"graph_path": f"/World/{camera.prim_path.split('/')[-1]}_rgb_graph", "evaluator_name": "execution"},
    {
        keys.CREATE_NODES: [
            ("OnPlaybackTick", "omni.graph.action.OnPlaybackTick"),
            ("ReadTimes", "omni.isaac.core_nodes.IsaacReadTimes"),  # Use IsaacReadTimes for CPU time
            ("ReadRenderProduct", "omni.syntheticdata.SyntheticDataRenderProduct"),
            ("PublishImage", "omni.isaac.ros_bridge.ROS1PublishImage"),
        ],
        keys.SET_VALUES: [
            ("PublishImage.inputs:topicName", topic_name),
            ("PublishImage.inputs:frameId", frame_id),
            ("ReadRenderProduct.inputs:renderProductPath", render_product),
        ],
        keys.CONNECT: [
            ("OnPlaybackTick.outputs:tick", "ReadRenderProduct.inputs:execIn"),
            ("OnPlaybackTick.outputs:tick", "ReadTimes.inputs:execIn"),
            ("ReadRenderProduct.outputs:image", "PublishImage.inputs:image"),
            ("ReadTimes.outputs:execOut", "PublishImage.inputs:execIn"),
            ("ReadTimes.outputs:systemTime", "PublishImage.inputs:timeStamp"),  # Connect system time here
        ],
    },
)

return

however it doesn’t work as expected and I’m wondering is there something I might doing incorrectly here?

2

Same question here. Anyone could help?