SimplePendulumSimulation.java

Every SCS simulation requires an instance of us.ihmc.simulationconstructionset.SimulationConstructionSet and a Thread to run it. IHMC's convention is to create a 'simulation' class which performs this function.

1. Create the SimplePendulumSimulation Class

In the java directory of your project, src/main/java, create a new java class us.ihmc.exampleSimulations.simplePendulum.SimplePendulumSimulation. The simulation class is responsible for instantiating an instance of SimulationConstructionSet and starting a new Thread to run it.

The simplest version of this is as follows:

package us.ihmc.exampleSimulations.simplePendulum;

import us.ihmc.simulationconstructionset.SimulationConstructionSet;

/**
 * SimplePendulumSimulation
 */
public class SimplePendulumSimulation
{
   private SimulationConstructionSet sim;

   public SimplePendulumSimulation()
   {
      sim = new SimulationConstructionSet();

      Thread myThread = new Thread(sim);
      myThread.start();
   }

   public static void main(String[] args)
   {
      new SimplePendulumSimulation();
   }
}
  • Copy the Code and Run the Simulation Replace your class contents with the above and run the simulation. Don't forget to add -Xms4096m -Xmx4096m to your VM's run configuration as specified in the Quick Start. Since there is no robot in your simulation, you will just get an empty world as follows: blank simulation

2.Set the Simulation Parameters

Before we add a robot, there are some basic parameters and settings that you should apply to SimulationConstructionSet. Replace the simulation class contents with the following:


If you run the simulation now, it will not look any different, but what you have done is:

  • Create Simulation Parameters
  • SimulationConstructionSetParameters parameters = new SimulationConstructionSetParameters();
  • Instantiate a SimulationConstructionSetParameters object
  • parameters.setDataBufferSize(32000); sets the initial data buffer size to be 32000 bytes.
  • Create a new Simulation and set its properties
  • sim = new SimulationConstructionSet(parameters);
  • Instantiate a new Runnable SimulationConstructionSet object with default values and a buffer size of 32000 bytes as defined in parameters object
  • sim.setDT(DT, 20); sets the simulation's delta time value to be 20 milliseconds.
  • sim.setGroundVisible(true); sets the ground to be visible in the 3D view.
  • sim.setCameraPosition(0, -9.0, 0.6);
    sim.setCameraFix(0.0, 0.0, 0.70); sets the location and orientation of the camera in the 3D world.
  • sim.setSimulateDuration(60.0); specifies that the simulation will only run for a duration of 60 seconds. For this tutorial, this allows the simulation to run to a point where it does not overflow the data buffer.

Now it's time to add a robot.

← Create a New ProjectSimplePendulumRobot.java →