Implementation of a custom OmnyGraph node in Python

[pme1976]

Hello.
I’m trying to write an Omnigraph node implementation that subscribes to a custom ROS message. I want the node state to reset to its initial state when the model is stopped. I have a few questions:

1. Isaac Sim guide describes one function (compute), which is called (probably) when a signal arrives at the execution input. What are other functions exist?

2. What node functions are called when opening/closing the graph, starting the model, stopping the model? I would like to get a description like this:
   Simulink Engine Interaction with C S-Functions - MATLAB & Simulink

3. I have met the release and initialize functions in the code of other OmnyGraph nodes. What are their functional purposes? When are they called?

[Hammad_M]

this tutorial lists all of the ABIs that can be overridden
https://docs.omniverse.nvidia.com/py/kit/source/extensions/omni.graph.tutorials/tutorials/tutorial12/tutorial12.html

In isaac sim we use this base class for nodes that need to reset when simulation is stopped.

#
# NVIDIA CORPORATION and its licensors retain all intellectual property
# and proprietary rights in and to this software, related documentation
# and any modifications thereto.  Any use, reproduction, disclosure or
# distribution of this software and related documentation without an express
# license agreement from NVIDIA CORPORATION is strictly prohibited.
#

import omni.usd
import carb.events


class BaseResetNode:
    """
        Base class for nodes that automatically reset when stop is pressed.
    """

    def __init__(self, initialize=False):
        self.initialized = initialize

        stage = omni.usd.get_context()

        self.stage_event_sub = stage.get_stage_event_stream().create_subscription_to_pop(
            self.on_stage_event, name="IsaacSimOGNCoreNodesStageEventHandler"
        )

    def on_stage_event(self, event: carb.events.IEvent):
        if event.type == int(omni.usd.StageEventType.SIMULATION_STOP_PLAY):
            self.custom_reset()
            self.initialized = False

    # Defined by subclass
    def custom_reset(self):
        pass

    def reset(self):
        self.stage_event_sub = None
        self.initialized = None

[pme1976]

Hammad_M, thank you so much for your helpness.