Package Versions

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

Major Features and Improvements

ml-agents (Python)

• The Parameter Randomization feature has been refactored and merged with the Curriculum. This enables sampling of new parameters per episode to improve robustness. The resampling-interval parameter has been removed and the config structure updated. More information here. (#4065)
• Curriculum has been refactored and is now specified at the level of the parameter, not the behavior. It is also now possible to specify a sampler in the lesson of a Curriculum. More information here.(#4160)

Breaking Changes

ml-agents (Python)

• The training configuration yaml file format has changed. In order to use curriculum or environment randomization, you must update your configuration file with the new section environment_parameters. We provide an update script to help this migration. Run python -m mlagents.trainers.upgrade_config -h with the latest version to see the script usage.

Bug Fixes and Minor Changes

com.unity.ml-agents (C#)

• SideChannelsManager was renamed to SideChannelManager. The old name is still supported, but deprecated. (#4137)
• RayPerceptionSensor.Perceive() now additionally stores the GameObject that was hit by the ray. (#4111)
• Fixed an issue where RayPerceptionSensor would raise an exception when the list of tags was empty, or a tag in the list was invalid (unknown, null, or empty string). (#4155)
• The Barracuda dependency was upgraded to 1.0.1 (#4188)

ml-agents-envs (Python)

• Added new Google Colab notebooks to show how to use UnityEnvironment. (#4117)

ml-agents (Python)

• Fixed an error when setting initialize_from in the trainer configuration YAML to null. (#4175)
• Fixed a rare crash in StatsReporter when using threaded trainers (#4201)

Example Environments (C#)

• Fixed issue with FoodCollector, Soccer, and WallJump when playing with keyboard. (#4147, #4174)

Known Issues

com.unity.ml-agents (C#)

• On macOS 10.15, if the ML-Agents package is installed from a website download, you may receive a “file cannot be opened issue” when running scenes that use ML-Agents. Workarounds include installing the package using the Unity Package Manager, or following the instructions here.

Acknowledgements

Thank you @StefanoCecere, @yongjun823, @poehlerflorian, @ChristianCoenen, @textarcana, @furkan-celik and everyone at Unity for their contributions to this release.