Camera image bridge from Gazebo to ROS 2 failing with OakD-Lite in PX4 SITL simulation

[sidharthmohannair]

Description

When using the ros_gz_bridge package to connect Gazebo camera topics to ROS 2 for visualization, the bridge establishes but no data flows through. The camera topics exist in Gazebo and appear in ROS 2 after bridging, but no messages are received by ROS 2 subscribers. This prevents visualization and use of camera data in ROS 2 applications.

Environment

• OS: Ubuntu 22.04
• ROS 2: Humble
• Gazebo: Garden/Harmonic
• PX4 Version: Latest main branch
• Hardware: GPU-based system
• ROS_GZ Packages: ros-humble-ros-gz-bridge, ros-humble-ros-gz-image

Drone Model

Using x500_depth which includes the OakD-Lite camera:

<?xml version="1.0" encoding="UTF-8"?>
<sdf version='1.9'>
  <model name='x500_depth'>
    <include merge='true'>
      <uri>x500</uri>
    </include>
    <include merge='true'>
      <uri>model://OakD-Lite</uri>
      <pose>.12 .03 .242 0 0 0</pose>
    </include>
    <joint name="CameraJoint" type="fixed">
      <parent>base_link</parent>
      <child>camera_link</child>
      <pose relative_to="base_link">.12 .03 .242 0 0 0</pose>
    </joint>
  </model>
</sdf>

Steps to Reproduce

1. Start PX4 SITL with the depth camera model:

   cd ~/PX4-Autopilot
   make px4_sitl gz_x500_depth

2. Verify camera topics exist in Gazebo:

   gz topic -l | grep -i camera

   Output includes:

   /camera_info
   /depth_camera
   /depth_camera/points
   /gui/camera/pose
   /world/default/model/x500_depth_0/link/camera_link/sensor/IMX214/camera_info
   /world/default/model/x500_depth_0/link/camera_link/sensor/IMX214/image
   /world/default/model/x500_depth_0/link/camera_link/sensor/camera_imu/imu
   

3. Start the ROS-Gazebo bridge:

   # Using parameter_bridge with a config file containing:
   - topic_name: "/world/default/model/x500_depth_0/link/camera_link/sensor/IMX214/image"
     ros_type_name: "sensor_msgs/msg/Image"
     gz_type_name: "gz.msgs.Image"
     direction: GZ_TO_ROS
     lazy: false
   
   - topic_name: "/depth_camera"
     ros_type_name: "sensor_msgs/msg/Image"
     gz_type_name: "gz.msgs.Image"
     direction: GZ_TO_ROS
     lazy: false

4. Check that ROS 2 topics are created:

   ros2 topic list | grep -E 'camera|depth'

   Output includes:

   /camera/camera_info
   /camera/image_raw
   /depth_camera
   

5. Attempt to monitor message frequency:

   ros2 topic hz /camera/image_raw
   # or
   ros2 topic hz /depth_camera
   # or
   ros2 topic hz /world/default/model/x500_depth_0/link/camera_link/sensor/IMX214/image

   No messages are detected.

6. Launch rqt_image_view and select the camera topics:

   ros2 run rqt_image_view rqt_image_view

   Window appears but shows no images.

Error Messages

From the bridge:

[parameter_bridge-1] Unknown message type [8].
[parameter_bridge-1] Unknown message type [9].
[parameter_bridge-1] Unknown message type [9].

When trying to use ros_gz_image:

2025-03-12 11:49:32.647 [RTPS_TRANSPORT_SHM Error] Failed init_port fastrtps_port7415: open_and_lock_file failed -> Function open_port_internal

Expected Behavior

• Camera topics should bridge successfully from Gazebo to ROS 2
• ROS 2 subscribers should receive camera image data
• rqt_image_view should display the camera feed when selecting the appropriate topic

Actual Behavior

• Bridge starts without errors but reports "Unknown message type" warnings
• No messages flow through the bridge
• rqt_image_view shows no images
• ros2 topic hz reports no messages received

Attempted Solutions

1. Using parameter_bridge with different topic configurations
2. Using ros_gz_image directly with the image topics
3. Trying alternative topic names
4. Cleaning shared memory: sudo rm -rf /dev/shm/rtps*
5. Ensuring correct permissions: sudo chmod 777 /dev/shm

Possible Related Issues

• Message type compatibility between Gazebo and ROS 2
• Shared memory transport issues
• Potential mismatch in image format or encoding

Any guidance or solutions to get the camera feed working properly would be greatly appreciated.