How to control simulation step size from API

Question

I can control the length of a Gazebo step size through the world's SDF. Example with max_step_size=4 ms :

<physics name="4ms" type="ode">
            <max_step_size>0.004</max_step_size>
            <real_time_factor>-1.0</real_time_factor>
            <real_time_update_rate>250</real_time_update_rate>
</physics>

But, can I also set this value through an API call ?

Another simulation parameter, the Update rate, can be controlled through the .SDF or programmatically with a call to gz::sim::ServerConfig::SetUpdateRate. Example:

// Object to pass custom configuration to the server
gz::sim::ServerConfig serverConfig;

// Populate with some configuration, for example, the SDF file to load
serverConfig.SetSdfFile(config["world_sdf_path"].as<std::string>());
serverConfig.SetUpdateRate(update_rate); // in Hz

I would like to do the same for max_step_size.

Note 1: Gazebo's SimulationRunner seem to have this capability (see this method), but I don't know how to access it from a "user" point of view.

Note 2: Transfer from unanswered answers.gazebosim question

Answer 1

The set_physics service is able to set the max_step_size using a gz::msgs::Physics. I don't see a tutorial for this, but some code from the user_commands integration test can be used as a reference:

• https://github.com/gazebosim/gz-sim/blob/gz-sim7/test/integration/user_commands.cc#L1081-L1103