RosNode¶
Inherits: RefCounted
A ROS 2 Node that manages publishers, subscribers, and other communication interfaces.
Description¶
The RosNode is the primary interface for interacting with the ROS 2 network. It provides factory methods to create publishers, subscribers, clients, and services, and allows management of node-level parameters and timers. Its ROS 2 logger is available through get_logger(), so messages reach the console and /rosout like any other ROS node's.
A node must be initialized using init() before it can be used to create other communication components.
Methods¶
count_publishers(topic: String) |
|
count_subscribers(topic: String) |
|
create_action_client(action_name: String, action_type: Variant, qos: RosQoS = null) |
|
create_action_server(action_name: String, action_type: Variant, execute_callback: Callable, goal_callback: Callable = Callable(), qos: RosQoS = null) |
|
create_client(srv_name: String, srv_type: Variant, qos: RosQoS = null) |
|
create_publisher(topic: String, type: Variant, qos: RosQoS = null) |
|
create_service(srv_name: String, srv_type: Variant, callback: Callable, qos: RosQoS = null) |
|
create_subscription(topic: String, type: Variant, callback: Callable, qos: RosQoS = null) |
|
create_tf_listener(cache_time_sec: float = 10.0) |
|
create_timer(seconds: float, callback: Callable) |
|
void |
declare_parameter(name: String, default_value: Variant) |
get_logger() const |
|
get_name() const |
|
get_namespace() const |
|
get_parameter(name: String) |
|
void |
|
now() |
|
resolve_frame(frame_id: String) |
|
void |
set_parameter(name: String, value: Variant) |
Signals¶
parameter_changed(name: String, value: Variant) 🔗
Emitted whenever a node parameter is updated by an external tool or by set_parameter() locally.
Method Descriptions¶
int count_publishers(topic: String) 🔗
Returns the number of publishers currently active on a specific topic in the ROS 2 graph.
int count_subscribers(topic: String) 🔗
Returns the number of subscribers currently active on a specific topic in the ROS 2 graph.
RosActionClient create_action_client(action_name: String, action_type: Variant, qos: RosQoS = null) 🔗
Creates and returns a RosActionClient for the specified action_name and action_type (e.g. "example_interfaces/action/Fibonacci"). Use qos to configure the Quality of Service for the action client.
RosActionServer create_action_server(action_name: String, action_type: Variant, execute_callback: Callable, goal_callback: Callable = Callable(), qos: RosQoS = null) 🔗
Creates and returns a RosActionServer for the specified action_name and action_type. Accepted goals are handed to execute_callback on the main thread as a RosServerGoalHandle, which must be driven to a terminal state. Goals are accepted by default; pass goal_callback to decide yourself: it receives the goal RosMsg and returns true to accept. goal_callback runs on a ROS executor thread, not the main thread, so it must not touch nodes or the scene tree. Cancel requests are always accepted. Use qos to configure the Quality of Service for the action server. See RosActionServer for a full example.
RosClient create_client(srv_name: String, srv_type: Variant, qos: RosQoS = null) 🔗
Creates and returns a RosClient for the specified service name and type. Use qos to configure the Quality of Service for the client.
RosPublisher create_publisher(topic: String, type: Variant, qos: RosQoS = null) 🔗
Creates and returns a RosPublisher to send messages to a specific topic. Use qos to configure the Quality of Service for the publisher.
RosService create_service(srv_name: String, srv_type: Variant, callback: Callable, qos: RosQoS = null) 🔗
Creates and returns a RosService server for the specified service name and type. The callback is triggered whenever a request is received. Use qos to configure the Quality of Service for the service server.
RosSubscriber create_subscription(topic: String, type: Variant, callback: Callable, qos: RosQoS = null) 🔗
Creates and returns a RosSubscriber to receive messages from a specific topic. The callback is triggered for every new message received, always on the Godot main thread. Use qos to configure the Quality of Service for the subscription.
RosTfBroadcaster create_tf_broadcaster() 🔗
Creates and returns a RosTfBroadcaster for publishing coordinate transforms into the TF2 system.
RosTfListener create_tf_listener(cache_time_sec: float = 10.0) 🔗
Creates and returns a RosTfListener for looking up coordinate transforms in the TF2 system.
cache_time_sec is how far back the buffer keeps transforms, which bounds how old a RosTfListener.lookup_transform() stamp may be. Raise it when replaying a bag or when data arrives well behind TF.
RosTimer create_timer(seconds: float, callback: Callable) 🔗
Creates and returns a RosTimer that triggers the callback at the specified seconds interval, synced with the ROS 2 executor's clock.
void declare_parameter(name: String, default_value: Variant) 🔗
Declares a parameter on the node with a default_value. Parameters must be declared before they can be retrieved or modified by external tools.
RosLogger get_logger() const 🔗
Returns the node's RosLogger, named after the node. Messages logged through it go to the console and /rosout. The same instance is returned on every call, so once, skip_first and throttle_duration_sec filter state is kept. Equivalent to rclpy's Node.get_logger().
var logger := ros_node.get_logger()
logger.info("Simulation started")
Returns the name of the node as registered in the ROS 2 graph.
String get_namespace() const 🔗
Returns the namespace of the node.
Variant get_parameter(name: String) 🔗
Returns the current value of the parameter with the specified name.
Dictionary get_topic_names_and_types() 🔗
Returns a Dictionary containing all currently active topic names as keys and their associated message types as values.
void init(node_name: String, namespace: String = "") 🔗
Initializes the node with a node_name and an optional namespace. This must be called before using any other functions of the node.
Returns the current ROS 2 system time as a RosMsg of type builtin_interfaces/msg/Time.
String resolve_frame(frame_id: String) 🔗
Prepends the node's namespace to a frame_id if it is not already absolute, helping resolve local frame names in multi-agent simulations.
void set_parameter(name: String, value: Variant) 🔗
Sets the value of a previously declared parameter on the node.