Troubleshoot transfer PingProto message from Isaac to ROS

I have experimented with the mechanism to transfer Isaac message to ROS using ros_bridge conversion patterns. The example involves simple Ping node (same one as used in the Ping example). It transmits PingProto message which is transferred further to ROS.

To do that, I extended examples in the ros_bridge package provided along with Isaac SDK by adding Proto to Ros converter class named PingToRos, and used it to convert PingProto message (containing string) to ROS’s std_msgs::String.

The application json files are here:


I get following error when running ping_to_ros app:

020-05-08 10:53:30.751 PANIC engine/alice/backend/application_json_loader.cpp@315: Could not load subgraph from file ‘/home/miro/.cache/bazel/_bazel_miro/22cc6ac8c5007e2c5f11433d0d03665f/execroot/com_nvidia_isaac/bazel-out/k8-opt/bin/packages/isaac_to_ros/ping_to_ros.runfiles/com_nvidia_isaac/packages/isaac_to_ros/ping_to_ros.subgraph.json’ (originally: ‘packages/isaac_to_ros/ping_to_ros.subgraph.json’)

What can cause the error? I tried to be careful when assigning variables. I am sending the zip with isaac-sdk/packages/isaac_to_ros (my test app) and isaac-sdk/packages/ros_bridge (where I added new message converter):!AsYocJ5K94iIi9ZzAcYFFd9zXu89BA?e=VsAu8D

Would anyone be able to assist? What is missing in this app? The error information I get is not too helpful.

Hi @miroslav.radojevic, after analyzing the BUILD file for the application, I can see that it has a missing target of type isaac_subgraph to accommodate for subgraph that you have created. Please refer to the detailed explanation of subgraph and how to use it in BUILD file here. Hope this helps!