# Single camera This guide provides instructions on how to launch the camera node with a colored point cloud feature enabled using ROS 2. - Table of contents - [Start single camera](#start-single-camera) - [Visualizing data in rviz2](#visualizing-data-in-rviz2) - [Display view topics service](#display-view-topics-service) - [Example visualizations](#example-visualizations) - [TF tree diagram](#tf-tree-diagram) ## Start single camera For how to compile and build methods, please refer to Chapter `Installation/Build_the_package `documentation and follow the steps provided [build_the_package](../2_installation/build_the_package.md) - Command to start single camera node On terminal 1: Launch camera node, example of gemini330 series : ```bash cd ~/ros2_ws/ source /opt/ros/$ROS_DISTRO/setup.bash source install/setup.bash ros2 launch orbbec_camera orbbec_camera.launch.py config_file_path:=gemini330_series.yaml ``` ## Visualizing data in rviz2 - view_display launch `view_display.launch.py` supports loading different `.rviz` files through yaml configuration. For example, loading the default `.rviz` file to display four streams. config in different `.model.yaml `files through yaml configuration. On terminal 2: ```bash cd ~/ros2_ws/ source /opt/ros/$ROS_DISTRO/setup.bash source install/setup.bash ros2 launch orbbec_description view_display.launch.py camera_model:=gemini335_336 ```  - view_model launch `view_model.launch.py` supports loading different `.model.yaml `files through yaml configuration. For example, loading the default model file to display gemini335_336 model . On terminal 3: ```bash cd ~/ros2_ws/ source /opt/ros/$ROS_DISTRO/setup.bash source install/setup.bash ros2 launch orbbec_description view_model.launch.py camera_model:=gemini335_336 ```  - Or you can run rviz2 and configure it by yourself ```bash cd ~/ros2_ws/ source /opt/ros/$ROS_DISTRO/setup.bash source install/setup.bash rviz2 ``` When runing rviz2, select the topic you wish to visualize from the list of published topics. Add the selected topic to rviz2 to start viewing the data. ## Display view topic/service/param Once the camera node is running, it will publish data on several ROS topics. Below is a list of the available topics: By executing `ros2 topic list`, the following topics are displayed: On terminal 4: ```bash ros2 topic list ``` Other , to display services/ parameters , example as follows ```bash ros2 service list ros2 param list ``` Get device info: ```bash ros2 service call /camera/get_device_info orbbec_camera_msgs/srv/GetDeviceInfo '{}' ``` Get SDK version: ```bash ros2 service call /camera/get_sdk_version orbbec_camera_msgs/srv/GetString '{}' ``` Set auto exposure: ```bash ros2 service call /camera/set_color_auto_exposure std_srvs/srv/SetBool '{data: false}' ``` Save point cloud: ```bash ros2 service call /camera/save_point_cloud std_srvs/srv/Empty "{}" ```   ## Example visualizations Here are examples of how the visualization might appear in rviz2: - **PointCloud Visualization**    - **Image Data Visualization**    ## TF tree diagram To get the TF tree ```bash ros2 run rqt_tf_tree rqt_tf_tree --force-discover ```   The TF tree diagram for the OrbbecSDK_ROS2 is illustrated below: