ZeroMQ remote API

The ZeroMQ remote API is one of several ways an application can connect with CoppeliaSim.

The ZeroMQ remote API allows to control a simulation (or the simulator itself) from an external application or a remote hardware (e.g. real robot, remote computer, etc.). It offers all API functions also available via a CoppeliaSim script: this includes all regular API functions (i.e. sim.* -type functions), but also all API functions provided by plugins (e.g. simOMPL.*, simUI.*, simIK.*, etc.), if enabled.

The ZeroMQ remote API functions are interacting with CoppeliaSim via ZeroMQ and its interface plugin to CoppeliaSim and the ZMQ remote API add-on. All this happens in a hidden fashion to the user. The remote API can let one or several external applications interact with CoppeliaSim in a stepping (i.e. synchronized with each simulation step) or non-stepping way (i.e. the normal operation mode), and even remote control of the simulator is supported (e.g. remotely loading a scene, starting, pausing or stopping a simulation for instance).

See programming/zmqRemoteApi folder or its related repository for examples.

Python client

Install client package:

$ python3 -m pip install coppeliasim-zmqremoteapi-client

(the ZeroMQ and CBOR dependencies will be automatically installed with the above command).

Following is a very simple example ZeroMQ remote API client code, which starts then runs a stepping simulation for 3 seconds:

from coppeliasim_zmqremoteapi_client import RemoteAPIClient client = RemoteAPIClient() sim = client.require('sim') sim.setStepping(True) sim.startSimulation() while (t := sim.getSimulationTime()) < 3: print(f'Simulation time: {t:.2f} [s]') sim.step() sim.stopSimulation()

C++ client

Any C++ client requires the jsoncons and cppzmq package: those are automatically downloaded and used when compiling via cmake. The boost and ZMQ libraries need to be installed. For details see programming/zmqRemoteApi/clients/cpp/, which contains several examples.

Build them with:

$ mkdir build $ cd build $ cmake .. $ cmake --build . --config Release

Following is a very simple C++ ZeroMQ remote API client code, which starts then runs a stepping simulation for 3 seconds:

#include "RemoteAPIClient.h" int main(int argc,char* argv[]) { RemoteAPIClient client; auto sim = client.getObject().sim(); sim.setStepping(true); sim.startSimulation(); double t = 0.0; do { t = sim.getSimulationTime(); printf("Simulation time: %.2f [s]\n", t); sim.step(); } while (t < 3.0); sim.stopSimulation(); return(0); }

Java client

Any Java client requires Apache Maven. For details see programming/zmqRemoteApi/clients/java/src/main/java, which contains several examples.

Make sure that your folder names do not contain any spaces, and have CoppeliaSim running (API function are fetched from CoppeliaSim). Build with:

$ export COPPELIASIM_ROOT_DIR=path/to/CoppeliaSim/exec/folder/or/resources/folder/on/macOS $ cd zmqRemoteApi/clients/java $ mvn package -D"GENERATE_INCLUDE_OBJECTS=sim,simIK"

In above, only the sim and simIK namespaces are considered, you may add more when needed. Following is a very simple Java ZeroMQ remote API client code, which starts then runs a stepping simulation for 3 seconds:

import java.util.Arrays; import com.coppeliarobotics.remoteapi.zmq.*; public class Example { public static void main(String[] _args) throws, { var client = new RemoteAPIClient(); var sim = client.getObject().sim(); sim.setStepping(true); sim.startSimulation(); double simTime = 0.0; while((simTime = sim.getSimulationTime()) < 3) { System.out.printf("Simulation time: %.2f [s]%n", simTime); sim.step(); } sim.stopSimulation(); } }

Matlab & Octave clients

Matlab clients require the bundled JeroMQ, which installs automatically if not yet present.

Octave clients require Octave 6.4+, the octave communications and zeromq packages. Those can be installed with:

pkg install -forge communications pkg install -forge zeromq

Following is a very simple Matlab/Octave ZeroMQ remote API client code, which starts then runs a stepping simulation for 3 seconds:

client = RemoteAPIClient(); sim = client.require('sim'); sim.setStepping(true); sim.startSimulation(); while true t = sim.getSimulationTime(); if t >= 3; break; end fprintf('Simulation time: %.2f [s]\n', t); sim.step(); end sim.stopSimulation();

Lua client

Currently, a Lua client is only supported from within a CoppeliaSim script, e.g. in order to connect 2 or more CoppeliaSim instances.

Following is a very simple Lua ZeroMQ remote API client code, which synchronizes the simulation steps with another CoppeliaSim instance:

function sysCall_init() remoteApiClient = require('luaZmqRemoteApi') remoteApiClient.init('', 23002) simx = remoteApiClient.getObject('sim') remoteApiClient.setStepping(true) simx.startSimulation() end function sysCall_sensing() remoteApiClient.step() end function sysCall_cleanup() simx.stopSimulation() remoteApiClient.cleanup() end

Rust client

The Rust ZeroMQ remote API is courtesy of Samuel Cavalcanti. Following is a very simple example ZeroMQ remote API client code, which starts then runs a stepping simulation for 3 seconds:

use std::rc::Rc; use zmq_remote_api::{sim::Sim, RemoteAPIError, RemoteApiClientParams}; /* Example based on Example.cpp */ fn main() -> Result<(), RemoteAPIError> { // use the env variable RUST_LOG="trace" or RUST_LOG="debug" to observe the zmq communication env_logger::init(); let client = zmq_remote_api::RemoteApiClient::new(RemoteApiClientParams { host: "localhost".to_string(), ..RemoteApiClientParams::default() })?; // Rc means Reference counter, is a smart pointer that counter the number of references let client = Rc::new(client); let sim = Sim::new(client.clone()); client.set_stepping(true)?; sim.start_simulation()?; let mut time = sim.get_simulation_time()?; while time < 3.0 { println!("Simulation time: {:.3} [s]", time); client.step(true)?; time = sim.get_simulation_time()?; } sim.stop_simulation()?; Ok(()) }