ml-agents/docs/Learning-Environment-Executable.md

Using an Environment Executable

This section will help you create and use built environments rather than the Editor to interact with an environment. Using an executable has some advantages over using the Editor:

• You can exchange executable with other people without having to share your entire repository.
• You can put your executable on a remote machine for faster training.
• You can use Headless mode for faster training.
• You can keep using the Unity Editor for other tasks while the agents are training.

Building the 3DBall environment

The first step is to open the Unity scene containing the 3D Balance Ball environment:

1. Launch Unity.
2. On the Projects dialog, choose the Open option at the top of the window.
3. Using the file dialog that opens, locate the MLAgentsSDK folder within the ML-Agents project and click Open.
4. In the Project window, navigate to the folder Assets/ML-Agents/Examples/3DBall/.
5. Double-click the 3DBall file to load the scene containing the Balance Ball environment.

Make sure the Brains in the scene have the right type. For example, if you want to be able to control your agents from Python, you will need to set the corresponding brain to External.

1. In the Scene window, click the triangle icon next to the Ball3DAcademy object.
2. Select its child object Ball3DBrain.
3. In the Inspector window, set Brain Type to External.

Next, we want the set up scene to play correctly when the training process launches our environment executable. This means:

• The environment application runs in the background.
• No dialogs require interaction.
• The correct scene loads automatically.

1. Open Player Settings (menu: Edit > Project Settings > Player).
2. Under Resolution and Presentation:
   • Ensure that Run in Background is Checked.
   • Ensure that Display Resolution Dialog is set to Disabled.
3. Open the Build Settings window (menu:File > Build Settings).
4. Choose your target platform.
   • (optional) Select “Development Build” to log debug messages.
5. If any scenes are shown in the Scenes in Build list, make sure that the 3DBall Scene is the only one checked. (If the list is empty, than only the current scene is included in the build).
6. Click Build:
   • In the File dialog, navigate to your ML-Agents directory.
   • Assign a file name and click Save.
   • (For Windows）With Unity 2018.1, it will ask you to select a folder instead of a file name. Create a subfolder within the ML-Agents folder and select that folder to build. In the following steps you will refer to this subfolder's name as env_name.

Now that we have a Unity executable containing the simulation environment, we can interact with it.

Interacting with the Environment

If you want to use the Python API to interact with your executable, you can pass the name of the executable with the argument 'file_name' of the UnityEnvironment. For instance:

from mlagents.envs import UnityEnvironment
env = UnityEnvironment(file_name=<env_name>)

Training the Environment

1. Open a command or terminal window.
2. Nagivate to the folder where you installed ML-Agents.
3. Change to the python directory.
4. Run mlagents-learn <trainer-config-file> --env=<env_name> --run-id=<run-identifier> --train Where:
   • <trainer-config-file> is the filepath of the trainer configuration yaml.
   • <env_name> is the name and path to the executable you exported from Unity (without extension)
   • <run-identifier> is a string used to separate the results of different training runs
   • And the --train tells mlagents-learn to run a training session (rather than inference)

For example, if you are training with a 3DBall executable you exported to the ml-agents/python directory, run:

mlagents-learn config/trainer_config.yaml --env=3DBall --run-id=firstRun --train

Note: If you're using Anaconda, don't forget to activate the ml-agents environment first.

If mlagents-learn runs correctly and starts training, you should see something like this:

You can press Ctrl+C to stop the training, and your trained model will be at models/<run-identifier>/<env_name>_<run-identifier>.bytes, which corresponds to your model's latest checkpoint. You can now embed this trained model into your internal brain by following the steps below:

1. Move your model file into MLAgentsSDK/Assets/ML-Agents/Examples/3DBall/TFModels/.
2. Open the Unity Editor, and select the 3DBall scene as described above.
3. Select the Ball3DBrain object from the Scene hierarchy.
4. Change the Type of Brain to Internal.
5. Drag the <env_name>_<run-identifier>.bytes file from the Project window of the Editor to the Graph Model placeholder in the Ball3DBrain inspector window.
6. Press the Play button at the top of the editor.