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[isaacsim.examples.ipc] IPC OmniGraph Node Examples#

Version: 1.0.1

Node Examples#

This extension ships tutorial-oriented OmniGraph nodes that use TCP/IP (BSD sockets only; no extra native dependencies) so you can stream a clock value to an external process or receive an external step command from Python or C++ clients.

See the Isaac Sim documentation: Omnigraph: Custom IPC nodes (omnigraph_custom_ipc_nodes) for prerequisites, wire format, and graph wiring.

Nodes#

Node

Language

Role

SimpleSendSimulationClockCpp / SimpleSendSimulationClockPy

C++ / Python

TCP client; takes simulationTime in seconds (e.g. from Isaac Read Simulation Time), converts to nanoseconds, sends int64 little-endian on the wire.

SimpleReceiveExternalStepCpp / SimpleReceiveExternalStepPy

C++ / Python

TCP server; non-blocking recv of uint32 little-endian step; execOut when a full message arrives.

Wire format#

  • Clock message: 8 bytes, signed int64, little-endian (round(simulationTime * 1e9) on the Python send node; C++ uses llround).

  • Step message: 4 bytes, unsigned int32, little-endian.

External tools can use the standard library only (e.g. Python socket + struct.pack / struct.unpack).

External scripts#

Runnable helper for this tutorial lives under source/extensions/isaacsim.examples.ipc/python/scripts/:

  • tcp_tutorial_playback_bridge.py — for On Playback Tick → Receive External Step → Send Simulation Clock (with Isaac Read Simulation Time on the send node): listens for each 8-byte clock, sends each 4-byte step so playback can advance. See --help and the user guide (Omnigraph: Custom IPC nodes).

Enable Extension#

The extension can be enabled (if not already) in one of the following ways:

Define the next entry as an application argument from a terminal.

APP_SCRIPT.(sh|bat) --enable isaacsim.examples.ipc

Define the next entry under [dependencies] in an experience (.kit) file or an extension configuration (extension.toml) file.

[dependencies]
"isaacsim.examples.ipc" = {}

Open the Window > Extensions menu in a running application instance and search for isaacsim.examples.ipc. Then, toggle the enable control button if it is not already active.

Omnigraph Nodes#

The extension exposes the following Omnigraph nodes: