Package Versions

As part of ML-Agents Release 1, we will be versioning the different packages that make up the release.
NOTE: It is strongly recommended that you use packages from the same release together for the best experience.

Major Changes

com.unity.ml-agents (C#)

• The MLAgents C# namespace was renamed to Unity.MLAgents, and other nested namespaces were similarly renamed. (#3843)
• The offset logic was removed from DecisionRequester. (#3716)
• The signature of Agent.Heuristic() was changed to take a float array as a parameter, instead of returning the array. This was done to prevent a common source of error where users would return arrays of the wrong size. (#3765)
• The communication API version has been bumped up to 1.0.0 and will use Semantic Versioning to do compatibility checks for communication between Unity and the Python process. (#3760)
• The obsolete Agent methods GiveModel, Done, InitializeAgent, AgentAction and AgentReset have been removed. (#3770)
• The SideChannel API has changed:
  • Introduced the SideChannelManager to register, unregister and access side channels. (#3807)
  • Academy.FloatProperties was replaced by Academy.EnvironmentParameters. See the Migration Guide for more details on upgrading. (#3807)
  • SideChannel.OnMessageReceived is now a protected method (was public). (#3807)
  • SideChannel IncomingMessages methods now take an optional default argument, which is used when trying to read more data than the message contains. (#3751)
  • Added a feature to allow sending stats from C# environments to TensorBoard (and other python StatsWriters). To do this from your code, use Academy.Instance.StatsRecorder.Add(key, value). (#3660)
• CameraSensorComponent.m_Grayscale and RenderTextureSensorComponent.m_Grayscale were changed from public to private. These can still be accessed via their corresponding properties. (#3808)
• Public fields and properties on several classes were renamed to follow Unity's C# style conventions. All public fields and properties now use "PascalCase" instead of "camelCase"; for example, Agent.maxStep was renamed to Agent.MaxStep. For a full list of changes, see the pull request. (#3828)
• WriteAdapter was renamed to ObservationWriter. If you have a custom ISensor implementation, you will need to change the signature of its Write() method. (#3834)
• The Barracuda dependency was upgraded to 0.7.0-preview (which has breaking namespace and assembly name changes). (#3875)

ml-agents / ml-agents-envs / gym-unity (Python)

• The --load and --train command-line flags have been deprecated. Training now happens by default, and use --resume to resume training instead of --load. (#3705)
• The Jupyter notebooks have been removed from the repository. (#3704)
• The multi-agent gym option was removed from the gym wrapper. For multi-agent scenarios, use the Low Level Python API. (#3681)
• The low level Python API has changed. You can look at the document Low Level Python API documentation for more information. If you use mlagents-learn for training, this should be a transparent change. (#3681)
• Added ability to start training (initialize model weights) from a previous run ID. (#3710)
• The GhostTrainer has been extended to support asymmetric games and the asymmetric example environment Strikers Vs. Goalie has been added. (#3653)
• The UnityEnv class from the gym-unity package was renamed UnityToGymWrapper and no longer creates the UnityEnvironment. Instead, the UnityEnvironment must be passed as input to the constructor of UnityToGymWrapper (#3812)

Minor Changes

com.unity.ml-agents (C#)

• Added new 3-joint Worm ragdoll environment. (#3798)
• StackingSensor was changed from internal visibility to public. (#3701)
• The internal event Academy.AgentSetStatus was renamed to Academy.AgentPreStep and made public. (#3716)
• Academy.InferenceSeed property was added. This is used to initialize the random number generator in ModelRunner, and is incremented for each ModelRunner. (#3823)
• Agent.GetObservations() was added, which returns a read-only view of the observations added in CollectObservations(). (#3825)
• UnityRLCapabilities was added to help inform users when RL features are mismatched between C# and Python packages. (#3831)

ml-agents / ml-agents-envs / gym-unity (Python)

• Format of console output has changed slightly and now matches the name of the model/summary directory. (#3630, #3616)
• Renamed 'Generalization' feature to 'Environment Parameter Randomization'. (#3646)
• Timer files now contain a dictionary of metadata, including things like the package version numbers. (#3758)
• The way that UnityEnvironment decides the port was changed. If no port is specified, the behavior will depend on the file_name parameter. If it is None, 5004 (the editor port) will be used; otherwise 5005 (the base environment port) will be used. (#3673)
• Running mlagents-learn with the same --run-id twice will no longer overwrite the existing files. (#3705)
• Model updates can now happen asynchronously with environment steps for better performance. (#3690)
• num_updates and train_interval for SAC were replaced with steps_per_update. (#3690)
• The maximum compatible version of tensorflow was changed to allow tensorflow 2.1 and 2.2. This will allow use with python 3.8 using tensorflow 2.2.0rc3. (#3830)
• mlagents-learn will no longer set the width and height of the executable window to 84x84 when no width nor height arguments are given. (#3867)

Bug Fixes

com.unity.ml-agents (C#)

• Fixed a display bug when viewing Demonstration files in the inspector. The shapes of the observations in the file now display correctly. (#3771)

ml-agents / ml-agents-envs / gym-unity (Python)

• Fixed an issue where exceptions from environments provided a return code of 0. (#3680)