ML-Agents Release 13

Package Versions

NOTE: It is strongly recommended that you use packages from the same release together for the best experience.

Major Features and Improvements

com.unity.ml-agents / com.unity.ml-agents.extensions

• Add an InputActuatorComponent to allow the generation of Agent action spaces from an InputActionAsset.
  Projects wanting to use this feature will need to add the
  Input System Package at version 1.1.0-preview.3 or later. (#4881)

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

• TensorFlow trainers have been removed, please use the Torch trainers instead. (#4707)
• A plugin system for mlagents-learn has been added. You can now define custom
  StatsWriter implementations and register them to be called during training.
  More types of plugins will be added in the future. (#4788)

Minor Changes

com.unity.ml-agents / com.unity.ml-agents.extensions (C#)

• The ActionSpec constructor is now public. Previously, it was not possible to create an
  ActionSpec with both continuous and discrete actions from code. (#4896)
• StatAggregationMethod.Sum can now be passed to StatsRecorder.Add(). This
  will result in the values being summed (instead of averaged) when written to
  TensorBoard. Thanks to @brccabral for the contribution! (#4816)
• The upper limit for the time scale (by setting the --time-scale parameter in mlagents-learn) was
  removed when training with a player. The Editor still requires it to be clamped to 100. (#4867)
• Added the IHeuristicProvider interface to allow IActuators as well as Agent implement the Heuristic function to generate actions.
  Updated the Basic example and the Match3 Example to use Actuators.
  Changed the namespace and file names of classes in com.unity.ml-agents.extensions. (#4849)
• Added VectorSensor.AddObservation(IList<float>). VectorSensor.AddObservation(IEnumerable<float>)
  is deprecated. The IList version is recommended, as it does not generate any
  additional memory allocations. (#4887)
• Added ObservationWriter.AddList() and deprecated ObservationWriter.AddRange().
  AddList() is recommended, as it does not generate any additional memory allocations. (#4887)
• The Barracuda dependency was upgraded to 1.3.0. (#4898)
• Added ActuatorComponent.CreateActuators, and deprecated ActuatorComponent.CreateActuator. The
  default implementation will wrap ActuatorComponent.CreateActuator in an array and return that. (#4899)
• InferenceDevice.Burst was added, indicating that Agent's model will be run using Barracuda's Burst backend.
  This is the default for new Agents, but existing ones that use InferenceDevice.CPU should update to
  InferenceDevice.Burst. (#4925)

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

• Tensorboard now logs the Environment Reward as both a scalar and a histogram. (#4878)
• Added a --torch-device commandline option to mlagents-learn, which sets the default
  torch.device used for training. (#4888)
• The --cpu commandline option had no effect and was removed. Use --torch-device=cpu to force CPU training. (#4888)
• The mlagents_env API has changed, BehaviorSpec now has a observation_specs property containing a list of ObservationSpec. For more information on ObservationSpec see here. (#4763, #4825)

Bug Fixes

com.unity.ml-agents (C#)

• Fix a compile warning about using an obsolete enum in GrpcExtensions.cs. (#4812)
• CameraSensor now logs an error if the GraphicsDevice is null. (#4880)
• Removed unnecessary memory allocations in ActuatorManager.UpdateActionArray() (#4877)
• Removed unnecessary memory allocations in SensorShapeValidator.ValidateSensors() (#4879)
• Removed unnecessary memory allocations in SideChannelManager.GetSideChannelMessage() (#4886)
• Removed several memory allocations that happened during inference. On a test scene, this
  reduced the amount of memory allocated by approximately 25%. (#4887)
• Removed several memory allocations that happened during inference with discrete actions. (#4922)
• Properly catch permission errors when writing timer files. (#4921)
• Unexpected exceptions during training initialization and shutdown are now logged. If you see
  "noisy" logs, please let us know! (#4930, #4935)

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

• Fixed a bug that would cause an exception when RunOptions was deserialized via pickle. (#4842)
• Fixed a bug that can cause a crash if a behavior can appear during training in multi-environment training. (#4872)
• Fixed the computation of entropy for continuous actions. (#4869)
• Fixed a bug that would cause UnityEnvironment to wait the full timeout
  period and report a misleading error message if the executable crashed
  without closing the connection. It now periodically checks the process status
  while waiting for a connection, and raises a better error message if it crashes. (#4880)
• Passing a -logfile option in the --env-args option to mlagents-learn is
  no longer overwritten. (#4880)
• The load_weights function was being called unnecessarily often in the Ghost Trainer leading to training slowdowns. (#4934)