update to 1.0.8 (#5395)

* update to 1.0.8

* remove com.unity.purchasing dep from project

* remove 2018.4 from tests, make sure to user 2020.3

* copy yamato util from main

* test 2020.3 (not .2)

* use downloader in standalone build test

* remove trunk tests, fix version parsing in unit test

* add 2018.4 back to package tests

.circleci/config.yml

       - image: circleci/python:3.8.2
 
 jobs:
-  build_python:
-    parameters:
-      executor:
-        type: executor
-      pyversion:
-        type: string
-        description: python version to being used (currently only affects caching).
-      pip_constraints:
-        type: string
-        description: Constraints file that is passed to "pip install". We constraint older versions of libraries for older python runtime, in order to help ensure compatibility.
-      enforce_onnx_conversion:
-        type: integer
-        default: 0
-        description: Whether to raise an exception if ONNX models couldn't be saved.
-    executor: << parameters.executor >>
-    working_directory: ~/repo
-
-    # Run additional numpy checks on unit tests
-    environment:
-      TEST_ENFORCE_NUMPY_FLOAT32: 1
-      TEST_ENFORCE_ONNX_CONVERSION: << parameters.enforce_onnx_conversion >>
-
-    steps:
-      - checkout
-
-      - run:
-          # Combine all the python dependencies into one file so that we can use that for the cache checksum
-          name: Combine pip dependencies for caching
-          command: cat ml-agents/setup.py ml-agents-envs/setup.py gym-unity/setup.py test_requirements.txt << parameters.pip_constraints >> > python_deps.txt
-
-      - restore_cache:
-          keys:
-          # Parameterize the cache so that different python versions can get different versions of the packages
-          - v1-dependencies-py<< parameters.pyversion >>-{{ checksum "python_deps.txt" }}
-
-      - run:
-          name: Install Dependencies
-          command: |
-            python3 -m venv venv
-            . venv/bin/activate
-            pip install --upgrade pip
-            pip install --upgrade setuptools
-            pip install --progress-bar=off -e ./ml-agents-envs -c << parameters.pip_constraints >>
-            pip install --progress-bar=off -e ./ml-agents -c << parameters.pip_constraints >>
-            pip install --progress-bar=off -r test_requirements.txt -c << parameters.pip_constraints >>
-            pip install --progress-bar=off -e ./gym-unity -c << parameters.pip_constraints >>
-
-      - save_cache:
-          paths:
-            - ./venv
-          key: v1-dependencies-py<< parameters.pyversion >>-{{ checksum "python_deps.txt" }}
-
-      - run:
-          name: Run Tests for ml-agents and gym_unity
-          # This also dumps the installed pip packages to a file, so we can see what versions are actually being used.
-          command: |
-            . venv/bin/activate
-            mkdir test-reports
-            pip freeze > test-reports/pip_versions.txt
-            pytest -n 2 --cov=ml-agents --cov=ml-agents-envs --cov=gym-unity --cov-report html --junitxml=test-reports/junit.xml -p no:warnings
-
-      - run:
-          name: Verify there are no hidden/missing metafiles.
-          # Renaming files or deleting files can leave metafiles behind that makes Unity very unhappy.
-          command: |
-            . venv/bin/activate
-            python utils/validate_meta_files.py
-
-      - store_test_results:
-          path: test-reports
-
-      - store_artifacts:
-          path: test-reports
-          destination: test-reports
-
-      - store_artifacts:
-          path: htmlcov
-          destination: htmlcov
-
-  pre-commit:
-    docker:
-      - image: circleci/python:3.7.3
-    working_directory: ~/repo/
-
-    steps:
-      - checkout
-      - run:
-          name: Combine precommit config and python versions for caching
-          command: |
-            cat .pre-commit-config.yaml > pre-commit-deps.txt
-            python -VV >> pre-commit-deps.txt
-
-      - restore_cache:
-          keys:
-          - v1-precommit-deps-{{ checksum "pre-commit-deps.txt" }}
-
-      - run:
-          name: Install Dependencies
-          command: |
-            # Need ruby for search-and-replace
-            sudo apt-get update
-            sudo apt-get install ruby-full
-            python3 -m venv venv
-            . venv/bin/activate
-            pip install --upgrade pip
-            pip install --upgrade setuptools
-            pip install pre-commit
-            # Install the hooks now so that they'll be cached
-            pre-commit install-hooks
-
-      - save_cache:
-          paths:
-            - ~/.cache/pre-commit
-            - ./venv
-          key: v1-precommit-deps-{{ checksum "pre-commit-deps.txt" }}
-
-      - run:
-          name: Check Code Style using pre-commit
-          command: |
-            . venv/bin/activate
-            pre-commit run --show-diff-on-failure --all-files
-
-  markdown_link_check:
-    parameters:
-      precommit_command:
-        type: string
-        description: precommit hook to run
-        default: markdown-link-check
-    docker:
-      - image: circleci/node:12.6.0
-    working_directory: ~/repo
-
-    steps:
-      - checkout
-
-      - restore_cache:
-          keys:
-          - v1-node-dependencies-{{ checksum ".pre-commit-config.yaml" }}
-          # fallback to using the latest cache if no exact match is found
-          - v1-node-dependencies-
-
-      - run:
-          name: Install Dependencies
-          command: |
-            sudo apt-get install python3-venv
-            python3 -m venv venv
-            . venv/bin/activate
-            pip install pre-commit
-      - run: sudo npm install -g markdown-link-check
-
-      - save_cache:
-          paths:
-            - ./venv
-          key: v1-node-dependencies-{{ checksum ".pre-commit-config.yaml" }}
-
-      - run:
-          name: Run markdown-link-check via precommit
-          command: |
-            . venv/bin/activate
-            pre-commit run --hook-stage manual << parameters.precommit_command >> --all-files
-
   deploy:
     parameters:
       directory:
   version: 2
   workflow:
     jobs:
-      - build_python:
-          name: python_3.6.1
-          executor: python361
-          pyversion: 3.6.1
-          # Test python 3.6 with the oldest supported versions
-          pip_constraints: test_constraints_min_version.txt
-      - build_python:
-          name: python_3.7.3
-          executor: python373
-          pyversion: 3.7.3
-          # Test python 3.7 with the newest supported versions
-          pip_constraints: test_constraints_max_tf1_version.txt
-          # Make sure ONNX conversion passes here (recent version of tensorflow 1.x)
-          enforce_onnx_conversion: 1
-      - build_python:
-          name: python_3.7.3+tf2
-          executor: python373
-          pyversion: 3.7.3
-          # Test python 3.7 with the newest supported versions
-          pip_constraints: test_constraints_max_tf2_version.txt
-      - build_python:
-          name: python_3.8.2+tf2.2
-          executor: python382
-          pyversion: 3.8.2
-          # Test python 3.8 with the newest edge versions
-          pip_constraints: test_constraints_max_tf2_version.txt
-      - markdown_link_check
-      - pre-commit
       # The first deploy jobs are the "real" ones that upload to pypi
       - deploy:
           name: deploy ml-agents-envs
               only: /^release_[0-9]+_test[0-9]+$/
             branches:
               ignore: /.*/
-  nightly:
-    triggers:
-      - schedule:
-          cron: "0 0 * * *"
-          filters:
-            branches:
-              only:
-                - develop
-    jobs:
-      - markdown_link_check:
-          name: markdown-link-check full
-          precommit_command: markdown-link-check-full

.pre-commit-config.yaml

         files: "gym-unity/.*"
         args: [--ignore-missing-imports, --disallow-incomplete-defs]
 
+-   repo: https://gitlab.com/pycqa/flake8
+    rev: 3.8.1
+    hooks:
+    -   id: flake8
+        exclude: >
+            (?x)^(
+                .*_pb2.py|
+                .*_pb2_grpc.py
+            )$
+        # flake8-tidy-imports is used for banned-modules, not actually tidying
+        additional_dependencies: [flake8-comprehensions==3.2.2, flake8-tidy-imports==4.1.0, flake8-bugbear==20.1.4]
+
+-   repo: https://github.com/asottile/pyupgrade
+    rev: v2.7.0
+    hooks:
+    -   id: pyupgrade
+        args: [--py3-plus, --py36-plus]
+        exclude: >
+            (?x)^(
+                .*barracuda.py|
+                .*_pb2.py|
+                .*_pb2_grpc.py
+            )$
+
-    rev: v2.4.0
+    rev: v2.5.0
     hooks:
     -   id: mixed-line-ending
         exclude: >
                 .*.meta
             )$
         args: [--fix=lf]
-    -   id: flake8
-        exclude: >
-            (?x)^(
-                .*_pb2.py|
-                .*_pb2_grpc.py
-            )$
-        # flake8-tidy-imports is used for banned-modules, not actually tidying
-        additional_dependencies: [flake8-comprehensions==3.1.4, flake8-tidy-imports==4.0.0, flake8-bugbear==20.1.2]
+
     -   id: trailing-whitespace
         name: trailing-whitespace-markdown
         types: [markdown]
         # Won't handle the templating in yamato
-        exclude: \.yamato/*
+        exclude: \.yamato/.*
-
--   repo: https://github.com/pre-commit/mirrors-pylint
-    rev: v2.4.4
-    hooks:
-    -   id: pylint
-        exclude: >
-            (?x)^(
-                .*_pb2.py|
-                .*_pb2_grpc.py|
-                .*/tests/.*
-            )$
-        args: [--score=n]
 
 - repo: https://github.com/mattlqx/pre-commit-search-and-replace
   rev: v1.0.3

test_requirements.txt

 # Test-only dependencies should go here, not in setup.py
 pytest>4.0.0,<6.0.0
 pytest-cov==2.6.1
-pytest-xdist
+pytest-xdist==1.34.0
 
 # onnx doesn't currently have a wheel for 3.8
 tf2onnx>=1.5.5;python_version<'3.8'

gym-unity/gym_unity/__init__.py

 # Version of the library that will be used to upload to pypi
-__version__ = "0.16.0"
+__version__ = "0.16.1"
-__release_tag__ = "release_1"
+__release_tag__ = "release_2"

gym-unity/gym_unity/envs/__init__.py

             self._env.step()
 
         self.visual_obs = None
-        self._n_agents = -1
 
         # Save the step result from the last time all Agents requested decisions.
         self._previous_decision_step: DecisionSteps = None
 
         self._env.step()
         decision_step, terminal_step = self._env.get_steps(self.name)
+        self._check_agents(max(len(decision_step), len(terminal_step)))
         if len(terminal_step) != 0:
             # The agent is done
             self.game_over = True
         logger.warning("Could not seed environment %s", self.name)
         return
 
-    def _check_agents(self, n_agents: int) -> None:
-        if self._n_agents > 1:
+    @staticmethod
+    def _check_agents(n_agents: int) -> None:
+        if n_agents > 1:
-                "There can only be one Agent in the environment but {n_agents} were detected."
+                f"There can only be one Agent in the environment but {n_agents} were detected."
             )
 
     @property
     @property
     def observation_space(self):
         return self._observation_space
-
-    @property
-    def number_agents(self):
-        return self._n_agents
 
 
 class ActionFlattener:

gym-unity/setup.py

         tag = os.getenv("CIRCLE_TAG")
 
         if tag != EXPECTED_TAG:
-            info = "Git tag: {0} does not match the expected tag of this app: {1}".format(
+            info = "Git tag: {} does not match the expected tag of this app: {}".format(
                 tag, EXPECTED_TAG
             )
             sys.exit(info)
     author_email="ML-Agents@unity3d.com",
     url="https://github.com/Unity-Technologies/ml-agents",
     packages=find_packages(),
-    install_requires=["gym", "mlagents_envs=={}".format(VERSION)],
+    install_requires=["gym", f"mlagents_envs=={VERSION}"],
     cmdclass={"verify": VerifyVersionCommand},
 )

ml-agents-envs/mlagents_envs/__init__.py

 # Version of the library that will be used to upload to pypi
-__version__ = "0.16.0"
+__version__ = "0.16.1"
-__release_tag__ = "release_1"
+__release_tag__ = "release_2"

ml-agents-envs/mlagents_envs/base_env.py

         :returns: The DecisionStep
         """
         if agent_id not in self.agent_id_to_index:
-            raise KeyError(
-                "agent_id {} is not present in the DecisionSteps".format(agent_id)
-            )
+            raise KeyError(f"agent_id {agent_id} is not present in the DecisionSteps")
         agent_index = self._agent_id_to_index[agent_id]  # type: ignore
         agent_obs = []
         for batched_obs in self.obs:
         specific agent
         """
         if agent_id not in self.agent_id_to_index:
-            raise KeyError(
-                "agent_id {} is not present in the TerminalSteps".format(agent_id)
-            )
+            raise KeyError(f"agent_id {agent_id} is not present in the TerminalSteps")
         agent_index = self._agent_id_to_index[agent_id]  # type: ignore
         agent_obs = []
         for batched_obs in self.obs:

ml-agents-envs/mlagents_envs/communicator.py

 from mlagents_envs.communicator_objects.unity_input_pb2 import UnityInputProto
 
 
-class Communicator(object):
+class Communicator:
     def __init__(self, worker_id=0, base_port=5005):
         """
         Python side of the communication. Must be used in pair with the right Unity Communicator equivalent.

ml-agents-envs/mlagents_envs/environment.py

             for _sc in side_channels:
                 if _sc.channel_id in self.side_channels:
                     raise UnityEnvironmentException(
-                        "There cannot be two side channels with the same channel id {0}.".format(
+                        "There cannot be two side channels with the same channel id {}.".format(
                             _sc.channel_id
                         )
                     )
             .replace(".x86", "")
         )
         true_filename = os.path.basename(os.path.normpath(env_path))
-        logger.debug("The true file name is {}".format(true_filename))
+        logger.debug(f"The true file name is {true_filename}")
 
         if not (glob.glob(env_path) or glob.glob(env_path + ".*")):
             return None
                 f"Couldn't launch the {file_name} environment. Provided filename does not match any environments."
             )
         else:
-            logger.debug("This is the launch string {}".format(launch_string))
+            logger.debug(f"This is the launch string {launch_string}")
             # Launch Unity environment
             subprocess_args = [launch_string]
             if no_graphics:
     def _assert_behavior_exists(self, behavior_name: str) -> None:
         if behavior_name not in self._env_specs:
             raise UnityActionException(
-                "The group {0} does not correspond to an existing agent group "
+                "The group {} does not correspond to an existing agent group "
                 "in the environment".format(behavior_name)
             )
 
         expected_shape = (len(self._env_state[behavior_name][0]), spec.action_size)
         if action.shape != expected_shape:
             raise UnityActionException(
-                "The behavior {0} needs an input of dimension {1} but received input of dimension {2}".format(
-                    behavior_name, expected_shape, action.shape
-                )
+                "The behavior {} needs an input of dimension {} for "
+                "(<number of agents>, <action size>) but received input of "
+                "dimension {}".format(behavior_name, expected_shape, action.shape)
             )
         if action.dtype != expected_type:
             action = action.astype(expected_type)
         expected_shape = (spec.action_size,)
         if action.shape != expected_shape:
             raise UnityActionException(
-                f"The Agent {0} with BehaviorName {1} needs an input of dimension "
-                f"{2} but received input of dimension {3}".format(
-                    agent_id, behavior_name, expected_shape, action.shape
-                )
+                f"The Agent {agent_id} with BehaviorName {behavior_name} needs an input of dimension "
+                f"{expected_shape} but received input of dimension {action.shape}"
             )
         expected_type = np.float32 if spec.is_action_continuous() else np.int32
         if action.dtype != expected_type:
                 )
             if len(message_data) != message_len:
                 raise UnityEnvironmentException(
-                    "The message received by the side channel {0} was "
+                    "The message received by the side channel {} was "
                     "unexpectedly short. Make sure your Unity Environment "
                     "sending side channel data properly.".format(channel_id)
                 )
             else:
                 logger.warning(
                     "Unknown side channel data received. Channel type "
-                    ": {0}.".format(channel_id)
+                    ": {}.".format(channel_id)
                 )
 
     @staticmethod

ml-agents-envs/mlagents_envs/exception.py

 
     def __init__(self, worker_id):
         message = self.MESSAGE_TEMPLATE.format(str(worker_id))
-        super(UnityWorkerInUseException, self).__init__(message)
+        super().__init__(message)

ml-agents-envs/mlagents_envs/rpc_communicator.py

         s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         try:
             s.bind(("localhost", port))
-        except socket.error:
+        except OSError:
             raise UnityWorkerInUseException(self.worker_id)
         finally:
             s.close()

ml-agents-envs/mlagents_envs/side_channel/environment_parameters_channel.py

         FLOAT = 0
 
     def __init__(self) -> None:
-        channel_id = uuid.UUID(("534c891e-810f-11ea-a9d0-822485860400"))
+        channel_id = uuid.UUID("534c891e-810f-11ea-a9d0-822485860400")
         super().__init__(channel_id)
 
     def on_message_received(self, msg: IncomingMessage) -> None:

ml-agents-envs/mlagents_envs/side_channel/float_properties_channel.py

     def __init__(self, channel_id: uuid.UUID = None) -> None:
         self._float_properties: Dict[str, float] = {}
         if channel_id is None:
-            channel_id = uuid.UUID(("60ccf7d0-4f7e-11ea-b238-784f4387d1f7"))
+            channel_id = uuid.UUID("60ccf7d0-4f7e-11ea-b238-784f4387d1f7")
         super().__init__(channel_id)
 
     def on_message_received(self, msg: IncomingMessage) -> None:

ml-agents-envs/mlagents_envs/tests/test_side_channel.py

     sender = RawBytesChannel(guid)
     receiver = RawBytesChannel(guid)
 
-    sender.send_raw_data("foo".encode("ascii"))
-    sender.send_raw_data("bar".encode("ascii"))
+    sender.send_raw_data(b"foo")
+    sender.send_raw_data(b"bar")
 
     data = UnityEnvironment._generate_side_channel_data({sender.channel_id: sender})
     UnityEnvironment._parse_side_channel_message({receiver.channel_id: receiver}, data)

ml-agents-envs/setup.py

         tag = os.getenv("CIRCLE_TAG")
 
         if tag != EXPECTED_TAG:
-            info = "Git tag: {0} does not match the expected tag of this app: {1}".format(
+            info = "Git tag: {} does not match the expected tag of this app: {}".format(
                 tag, EXPECTED_TAG
             )
             sys.exit(info)

README.md

 
 # Unity ML-Agents Toolkit
 
-[![docs badge](https://img.shields.io/badge/docs-reference-blue.svg)](https://github.com/Unity-Technologies/ml-agents/tree/release_1_docs/docs/)
+[![docs badge](https://img.shields.io/badge/docs-reference-blue.svg)](https://github.com/Unity-Technologies/ml-agents/tree/release_2_verified_docs/docs/)
 
 [![license badge](https://img.shields.io/badge/license-Apache--2.0-green.svg)](LICENSE)
 
 
 ## Releases & Documentation
 
-**Our latest, stable release is `Release 1`. Click [here](docs/Readme.md) to
-get started with the latest release of ML-Agents.**
+**Our latest, stable release is `Release 2`. Click
+[here](https://github.com/Unity-Technologies/ml-agents/tree/release_2_verified_docs/docs/Readme.md)
+to get started with the latest release of ML-Agents.**
-The table below lists all our releases, including our `master` branch which is under active
-development and may be unstable. A few helpful guidelines:
-* The docs links in the table below include installation and usage instructions specific to each
-release. Remember to always use the documentation that corresponds to the release version you're
-using.
-* See the [GitHub releases](https://github.com/Unity-Technologies/ml-agents/releases) for more
-details of the changes between versions.
-* If you have used an earlier version of the ML-Agents Toolkit, we strongly recommend our
-[guide on migrating from earlier versions](docs/Migrating.md).
+The table below lists all our releases, including our `main` branch which is
+under active development and may be unstable. A few helpful guidelines:
+- The [Versioning page](docs/Versioning.md) overviews how we manage our GitHub
+  releases and the versioning process for each of the ML-Agents components.
+- The [Releases page](https://github.com/Unity-Technologies/ml-agents/releases)
+  contains details of the changes between releases.
+- The [Migration page](docs/Migrating.md) contains details on how to upgrade
+  from earlier releases of the ML-Agents Toolkit.
+- The **Documentation** links in the table below include installation and usage
+  instructions specific to each release. Remember to always use the
+  documentation that corresponds to the release version you're using.
-| **master (unstable)** | -- | [source](https://github.com/Unity-Technologies/ml-agents/tree/master) | [docs](https://github.com/Unity-Technologies/ml-agents/tree/master/docs/Readme.md) | [download](https://github.com/Unity-Technologies/ml-agents/archive/master.zip) |
-| **Release 1** | **April 30, 2020** | **[source](https://github.com/Unity-Technologies/ml-agents/tree/release_1)** | **[docs](https://github.com/Unity-Technologies/ml-agents/tree/release_1/docs/Readme.md)** | **[download](https://github.com/Unity-Technologies/ml-agents/archive/release_1.zip)** |
+| **main (unstable)** | -- | [source](https://github.com/Unity-Technologies/ml-agents/tree/main) | [docs](https://github.com/Unity-Technologies/ml-agents/tree/main/docs/Readme.md) | [download](https://github.com/Unity-Technologies/ml-agents/archive/main.zip) |
+| **Release 2** | **May 19, 2020** | **[source](https://github.com/Unity-Technologies/ml-agents/tree/release_2)** | **[docs](https://github.com/Unity-Technologies/ml-agents/tree/release_2/docs/Readme.md)** | **[download](https://github.com/Unity-Technologies/ml-agents/archive/release_2.zip)** |
+| **Release 1** | April 30, 2020 | [source](https://github.com/Unity-Technologies/ml-agents/tree/release_1) | [docs](https://github.com/Unity-Technologies/ml-agents/tree/release_1/docs/Readme.md) | [download](https://github.com/Unity-Technologies/ml-agents/archive/release_1.zip) |
 | **0.15.1** | March 30, 2020 | [source](https://github.com/Unity-Technologies/ml-agents/tree/0.15.1) | [docs](https://github.com/Unity-Technologies/ml-agents/tree/0.15.1/docs/Readme.md) | [download](https://github.com/Unity-Technologies/ml-agents/archive/0.15.1.zip) |
 | **0.15.0** | March 18, 2020 | [source](https://github.com/Unity-Technologies/ml-agents/tree/0.15.0) | [docs](https://github.com/Unity-Technologies/ml-agents/tree/0.15.0/docs/Readme.md) | [download](https://github.com/Unity-Technologies/ml-agents/archive/0.15.0.zip) |
 | **0.14.1** | February 26, 2020 | [source](https://github.com/Unity-Technologies/ml-agents/tree/0.14.1) | [docs](https://github.com/Unity-Technologies/ml-agents/tree/0.14.1/docs/Readme.md) | [download](https://github.com/Unity-Technologies/ml-agents/archive/0.14.1.zip) |
-| **0.12.1** | December 11, 2019 | [source](https://github.com/Unity-Technologies/ml-agents/tree/0.12.1) | [docs](https://github.com/Unity-Technologies/ml-agents/tree/0.12.1/docs/Readme.md) | [download](https://github.com/Unity-Technologies/ml-agents/archive/0.12.1.zip) |
-| **0.12.0** | December 2, 2019 | [source](https://github.com/Unity-Technologies/ml-agents/tree/0.12.0) | [docs](https://github.com/Unity-Technologies/ml-agents/tree/0.12.0/docs/Readme.md) | [download](https://github.com/Unity-Technologies/ml-agents/archive/0.12.0.zip) |
-
 ## Citation
 
 If you are a researcher interested in a discussion of Unity as an AI platform,
 If you use Unity or the ML-Agents Toolkit to conduct research, we ask that you
 cite the following paper as a reference:
 
-Juliani, A., Berges, V., Vckay, E., Gao, Y., Henry, H., Mattar, M., Lange, D.
-(2018). Unity: A General Platform for Intelligent Agents. _arXiv preprint
-arXiv:1809.02627._ https://github.com/Unity-Technologies/ml-agents.
+Juliani, A., Berges, V., Teng, E., Cohen, A., Harper, J., Elion, C., Goy, C.,
+Gao, Y., Henry, H., Mattar, M., Lange, D. (2020). Unity: A General Platform for
+Intelligent Agents. _arXiv preprint
+[arXiv:1809.02627](https://arxiv.org/abs/1809.02627)._
+https://github.com/Unity-Technologies/ml-agents.
+- (May 12, 2020)
+  [Announcing ML-Agents Unity Package v1.0!](https://blogs.unity3d.com/2020/05/12/announcing-ml-agents-unity-package-v1-0/)
 - (February 28, 2020)
   [Training intelligent adversaries using self-play with ML-Agents](https://blogs.unity3d.com/2020/02/28/training-intelligent-adversaries-using-self-play-with-ml-agents/)
 - (November 11, 2019)
 
 For any other questions or feedback, connect directly with the ML-Agents team at
 ml-agents@unity3d.com.
+
+## Privacy
+
+In order to improve the developer experience for Unity ML-Agents Toolkit, we have added in-editor analytics.
+Please refer to "Information that is passively collected by Unity" in the
+[Unity Privacy Policy](https://unity3d.com/legal/privacy-policy).
 
 ## License
 

docs/Using-Tensorboard.md

 the --port option.
 
 **Note:** If you don't assign a `run-id` identifier, `mlagents-learn` uses the
-default string, "ppo". All the statistics will be saved to the same sub-folder
-and displayed as one session in TensorBoard. After a few runs, the displays can
-become difficult to interpret in this situation. You can delete the folders
-under the `summaries` directory to clear out old statistics.
+default string, "ppo". You can delete the folders under the `results` directory
+to clear out old statistics.
 
 On the left side of the TensorBoard window, you can select which of the training
 runs you want to display. You can select multiple run-ids to compare statistics.
 
 ```csharp
 var statsRecorder = Academy.Instance.StatsRecorder;
-statsSideChannel.Add("MyMetric", 1.0);
+statsRecorder.Add("MyMetric", 1.0);
 ```

docs/Learning-Environment-Create-New.md

   learning_rate: 3.0e-4
   learning_rate_schedule: linear
   max_steps: 5.0e4
+  memory_size: 128
   normalize: false
   num_epoch: 3
   num_layers: 2

docs/Training-ML-Agents.md

   normalize: false
   num_layers: 2
   time_horizon: 64
+  summary_freq: 10000
+  init_path: null
 
   # PPO-specific configs
   beta: 5.0e-3
     batch_size: 512
     num_epoch: 3
     samples_per_update: 0
-    init_path:
 
   reward_signals:
     # environment reward
       strength: 0.02
       gamma: 0.99
       encoding_size: 256
-      learning_rate: 3e-4
+      learning_rate: 3.0e-4
 
     # GAIL
     gail:
       demo_path: Project/Assets/ML-Agents/Examples/Pyramids/Demos/ExpertPyramid.demo
-      learning_rate: 3e-4
+      learning_rate: 3.0e-4
       use_actions: false
       use_vail: false
 
     `interval_2_max`], ...]
   - **sub-arguments** - `intervals`
 
-The implementation of the samplers can be found at
-`ml-agents-envs/mlagents_envs/sampler_class.py`.
+The implementation of the samplers can be found in the
+[sampler_class.py file](../ml-agents/mlagents/trainers/sampler_class.py).
 
 #### Defining a New Sampler Type
 

docs/Installation-Anaconda-Windows.md

 the ml-agents Conda environment by typing `activate ml-agents`)_:
 
 ```sh
-git clone --branch release_1 https://github.com/Unity-Technologies/ml-agents.git
+git clone --branch release_2 https://github.com/Unity-Technologies/ml-agents.git
-The `--branch release_1` option will switch to the tag of the latest stable
-release. Omitting that will get the `master` branch which is potentially
+The `--branch release_2` option will switch to the tag of the latest stable
+release. Omitting that will get the `main` branch which is potentially
 unstable.
 
 If you don't want to use Git, you can find download links on the
 connected to the Internet and then type in the Anaconda Prompt:
 
 ```console
-pip install mlagents
+pip install mlagents==0.16.1
 ```
 
 This will complete the installation of all the required Python packages to run
 this, you can try:
 
 ```console
-pip install mlagents --no-cache-dir
+pip install mlagents==0.16.1 --no-cache-dir
 ```
 
 This `--no-cache-dir` tells the pip to disable the cache.

docs/Installation.md

 of our tutorials / guides assume you have access to our example environments).
 
 ```sh
-git clone --branch release_1 https://github.com/Unity-Technologies/ml-agents.git
+git clone --branch release_2 https://github.com/Unity-Technologies/ml-agents.git
-The `--branch release_1` option will switch to the tag of the latest stable
-release. Omitting that will get the `master` branch which is potentially
+The `--branch release_2` option will switch to the tag of the latest stable
+release. Omitting that will get the `main` branch which is potentially
 unstable.
 
 #### Advanced: Local Installation for Development
-back, make sure to clone the `master` branch (by omitting `--branch release_1`
+back, make sure to clone the `main` branch (by omitting `--branch release_2`
 from the command above). See our
 [Contributions Guidelines](../com.unity.ml-agents/CONTRIBUTING.md) for more
 information on contributing to the ML-Agents Toolkit.
 run from the command line:
 
 ```sh
-pip3 install mlagents
+pip3 install mlagents==0.16.1
 ```
 
 Note that this will install `mlagents` from PyPi, _not_ from the cloned

utils/validate_versions.py

 
 def extract_version_string(filename):
     with open(filename) as f:
-        for l in f.readlines():
-            if l.startswith(VERSION_LINE_START):
-                return l.replace(VERSION_LINE_START, "").strip()
+        for line in f.readlines():
+            if line.startswith(VERSION_LINE_START):
+                return line.replace(VERSION_LINE_START, "").strip()
     return None
 
 
 
 
 def set_package_version(new_version: str) -> None:
-    with open(UNITY_PACKAGE_JSON_PATH, "r") as f:
+    with open(UNITY_PACKAGE_JSON_PATH) as f:
         package_json = json.load(f)
     if "version" in package_json:
         package_json["version"] = new_version
         f.writelines(lines)
 
 
+def print_release_tag_commands(
+    python_version: str, csharp_version: str, release_tag: str
+):
+    python_tag = f"python-packages_{python_version}"
+    csharp_tag = f"com.unity.ml-agents_{csharp_version}"
+    docs_tag = f"{release_tag}_docs"
+    print(
+        f"""
+###
+Use these commands to create the tags after the release:
+###
+git checkout {release_tag}
+git tag -f latest_release
+git push -f origin latest_release
+git tag -f {docs_tag}
+git push -f origin {docs_tag}
+git tag {python_tag}
+git push -f origin {python_tag}
+git tag {csharp_tag}
+git push -f origin {csharp_tag}
+"""
+    )
+
+
 if __name__ == "__main__":
     parser = argparse.ArgumentParser()
     parser.add_argument("--python-version", default=None)
         if args.csharp_version:
             print(f"Updating C# package to version {args.csharp_version}")
         set_version(args.python_version, args.csharp_version, args.release_tag)
+        if args.release_tag is not None:
+            print_release_tag_commands(
+                args.python_version, args.csharp_version, args.release_tag
+            )
     else:
         ok = check_versions()
         return_code = 0 if ok else 1

utils/validate_meta_files.py

 
 
 def main():
-    asset_path = "Project/Assets"
+    asset_paths = [
+        "Project/Assets",
+        "DevProject/Assets",
+        "com.unity.ml-agents",
+        "com.unity.ml-agents.extensions",
+    ]
+    allow_list = frozenset(
+        [
+            "com.unity.ml-agents/.editorconfig",
+            "com.unity.ml-agents/.gitignore",
+            "com.unity.ml-agents/.npmignore",
+            "com.unity.ml-agents/Tests/.tests.json",
+            "com.unity.ml-agents.extensions/.gitignore",
+            "com.unity.ml-agents.extensions/.npmignore",
+            "com.unity.ml-agents.extensions/Tests/.tests.json",
+        ]
+    )
+    ignored_dirs = {"Documentation~"}
-    for root, dirs, files in os.walk(asset_path):
-        dirs = set(dirs)
-        files = set(files)
+    for asset_path in asset_paths:
+        for root, dirs, files in os.walk(asset_path):
+            # Modifying the dirs list with topdown=True (the default) will prevent us from recursing those directories
+            for ignored in ignored_dirs:
+                try:
+                    dirs.remove(ignored)
+                except ValueError:
+                    pass
-        combined = dirs | files
-        for f in combined:
-            if f.endswith(python_suffix):
-                # Probably this script; skip it
-                continue
+            dirs = set(dirs)
+            files = set(files)
+
+            combined = dirs | files
+            for f in combined:
+
+                if f.endswith(python_suffix):
+                    # Probably this script; skip it
+                    continue
-            # We expect each non-.meta file to have a .meta file, and each .meta file to have a non-.meta file
-            if f.endswith(meta_suffix):
-                expected = f.replace(meta_suffix, "")
-            else:
-                expected = f + meta_suffix
+                full_path = os.path.join(root, f)
+                if full_path in allow_list:
+                    continue
+
+                # We expect each non-.meta file to have a .meta file, and each .meta file to have a non-.meta file
+                if f.endswith(meta_suffix):
+                    expected = f.replace(meta_suffix, "")
+                else:
+                    expected = f + meta_suffix
-            if expected not in combined:
-                unmatched.add(os.path.join(root, f))
-            else:
-                num_matched += 1
+                if expected not in combined:
+                    unmatched.add(full_path)
+                else:
+                    num_matched += 1
 
     if unmatched:
         raise Exception(

utils/make_readme_table.py

     ReleaseInfo.from_simple_tag("0.15.0", "March 18, 2020"),
     ReleaseInfo.from_simple_tag("0.15.1", "March 30, 2020"),
     ReleaseInfo("release_1", "1.0.0", "0.16.0", "April 30, 2020"),
+    ReleaseInfo("release_2", "1.0.1", "0.16.1", "May 19, 2020"),
-print(table_line("master (unstable)", "master", "--"))
+print(table_line("main (unstable)", "main", "--"))
 highlight = True  # whether to bold the line or not
 for version_info in sorted_versions:
     if version_info.elapsed_days <= MAX_DAYS:

DevProject/ProjectSettings/EditorBuildSettings.asset

 EditorBuildSettings:
   m_ObjectHideFlags: 0
   serializedVersion: 2
-  m_Scenes: []
+  m_Scenes:
+  - enabled: 1
+    path: Assets/ML-Agents/Scripts/Tests/Runtime/AcademyTest/AcademyStepperTestScene.unity
+    guid: 9bafc50b1e55b43b2b1ae9620f1f8311
   m_configObjects: {}

DevProject/ProjectSettings/ProjectVersion.txt

-m_EditorVersion: 2019.3.3f1
-m_EditorVersionWithRevision: 2019.3.3f1 (7ceaae5f7503)
+m_EditorVersion: 2019.4.17f1
+m_EditorVersionWithRevision: 2019.4.17f1 (667c8606c536)

DevProject/Packages/manifest.json

   "dependencies": {
     "com.unity.2d.sprite": "1.0.0",
     "com.unity.2d.tilemap": "1.0.0",
-    "com.unity.ads": "2.0.8",
+    "com.unity.ads": "3.5.2",
-    "com.unity.ide.vscode": "1.1.4",
+    "com.unity.ide.vscode": "1.2.3",
-    "com.unity.multiplayer-hlapi": "1.0.4",
-    "com.unity.package-manager-doctools": "1.1.1-preview.3",
-    "com.unity.package-validation-suite": "0.7.15-preview",
-    "com.unity.purchasing": "2.0.6",
-    "com.unity.test-framework": "1.1.11",
-    "com.unity.testtools.codecoverage": "0.2.2-preview",
+    "com.unity.multiplayer-hlapi": "1.0.6",
+    "com.unity.package-manager-doctools": "1.7.0-preview",
+    "com.unity.package-validation-suite": "0.19.0-preview",
+    "com.unity.purchasing": "2.2.1",
+    "com.unity.test-framework": "1.1.19",
+    "com.unity.test-framework.performance": "2.2.0-preview",
+    "com.unity.testtools.codecoverage": "1.0.0-pre.3",
-    "com.unity.xr.legacyinputhelpers": "1.3.8",
+    "com.unity.xr.legacyinputhelpers": "2.1.6",
     "com.unity.modules.ai": "1.0.0",
     "com.unity.modules.androidjni": "1.0.0",
     "com.unity.modules.animation": "1.0.0",

.yamato/protobuf-generation-test.yml

       nuget install Grpc.Tools -Version $GRPC_VERSION -OutputDirectory protobuf-definitions/
       python3 -m venv venv
       . venv/bin/activate
-      pip install --upgrade pip
-      pip install grpcio-tools==1.13.0  --progress-bar=off
-      pip install mypy-protobuf==1.16.0 --progress-bar=off
+      pip install --upgrade pip --index-url https://artifactory.prd.it.unity3d.com/artifactory/api/pypi/pypi/simple
+      pip install grpcio==1.28.1 grpcio-tools==1.13.0 protobuf==3.11.3 six==1.14.0 mypy-protobuf==1.16.0  --progress-bar=off --index-url https://artifactory.prd.it.unity3d.com/artifactory/api/pypi/pypi/simple
       cd protobuf-definitions
       chmod +x Grpc.Tools.$GRPC_VERSION/tools/macosx_x64/protoc
       chmod +x Grpc.Tools.$GRPC_VERSION/tools/macosx_x64/grpc_csharp_plugin

.yamato/com.unity.ml-agents-promotion.yml

+test_editors:
+  - version: 2019.3
+test_platforms:
+  - name: win
+    type: Unity::VM
+    image: package-ci/win10:stable
+    flavor: b1.large
+---
+
+{% for editor in test_editors %}
+{% for platform in test_platforms %}
+promotion_test_{{ platform.name }}_{{ editor.version }}:
+  name : Promotion Test {{ editor.version }} on {{ platform.name }}
+  agent:
+    type: {{ platform.type }}
+    image: {{ platform.image }}
+    flavor: {{ platform.flavor}}
+  variables:
+    UPMCI_PROMOTION: 1
+  commands:
+    - npm install upm-ci-utils@stable -g --registry https://artifactory.prd.cds.internal.unity3d.com/artifactory/api/npm/upm-npm
+    - upm-ci package test --unity-version {{ editor.version }} --package-path com.unity.ml-agents
+  artifacts:
+    logs:
+      paths:
+        - "upm-ci~/test-results/**/*"
+  dependencies:
+    - .yamato/com.unity.ml-agents-pack.yml#pack
+{% endfor %}
+{% endfor %}
+
+promotion_test_trigger:
+  name: Promotion Tests Trigger
+  dependencies:
+{% for editor in test_editors %}
+{% for platform in test_platforms %}
+    - .yamato/com.unity.ml-agents-promotion.yml#promotion_test_{{platform.name}}_{{editor.version}}
+{% endfor %}
+{% endfor %}
+
+
 promote:
   name: Promote to Production
   agent:
         - "upm-ci~/packages/*.tgz"
   dependencies:
     - .yamato/com.unity.ml-agents-pack.yml#pack
-    - .yamato/com.unity.ml-agents-test.yml#all_package_tests
+{% for editor in test_editors %}
+{% for platform in test_platforms %}
+    - .yamato/com.unity.ml-agents-promotion.yml#promotion_test_{{ platform.name }}_{{ editor.version }}
+{% endfor %}
+{% endfor %}

.yamato/gym-interface-test.yml

   variables:
     UNITY_VERSION: {{ editor.version }}
   commands:
-    - pip install pyyaml
+    - pip install pyyaml --index-url https://artifactory.prd.it.unity3d.com/artifactory/api/pypi/pypi/simple
     - python -u -m ml-agents.tests.yamato.setup_venv
     - ./venv/bin/python ml-agents/tests/yamato/scripts/run_gym.py --env=artifacts/testPlayer-Basic
   dependencies:
-    changes:
-      only:
-        - "com.unity.ml-agents/**"
-        - "Project/**"
-        - "ml-agents/**"
-        - "ml-agents-envs/**"
-        - ".yamato/gym-interface-test.yml"
-      except:
-        - "*.md"
-        - "com.unity.ml-agents/*.md"
-        - "com.unity.ml-agents/**/*.md"
+    expression: |
+      (pull_request.target eq "main" OR
+      pull_request.target match "release.+") AND
+      NOT pull_request.draft AND
+      (pull_request.changes.any match "com.unity.ml-agents/**" OR
+      pull_request.changes.any match "Project/**" OR
+      pull_request.changes.any match "ml-agents/**" OR
+      pull_request.changes.any match "ml-agents-envs/**" OR
+      pull_request.changes.any match "gym-unity/**" OR
+      pull_request.changes.any match ".yamato/gym-interface-test.yml") AND
+      NOT pull_request.changes.all match "**/*.md"
 {% endfor %}

.yamato/python-ll-api-test.yml

   variables:
     UNITY_VERSION: {{ editor.version }}
   commands:
-    - pip install pyyaml
+    - pip install pyyaml --index-url https://artifactory.prd.it.unity3d.com/artifactory/api/pypi/pypi/simple
-    - ./venv/bin/python ml-agents/tests/yamato/scripts/run_llapi.py 
+    - ./venv/bin/python ml-agents/tests/yamato/scripts/run_llapi.py
     - ./venv/bin/python ml-agents/tests/yamato/scripts/run_llapi.py --env=artifacts/testPlayer-Basic
     - ./venv/bin/python ml-agents/tests/yamato/scripts/run_llapi.py --env=artifacts/testPlayer-WallJump
     - ./venv/bin/python ml-agents/tests/yamato/scripts/run_llapi.py --env=artifacts/testPlayer-Bouncer
     cancel_old_ci: true
-    changes:
-      only:
-        - "com.unity.ml-agents/**"
-        - "Project/**"
-        - "ml-agents/**"
-        - "ml-agents-envs/**"
-        - ".yamato/python-ll-api-test.yml"
-      except:
-        - "*.md"
-        - "com.unity.ml-agents/*.md"
-        - "com.unity.ml-agents/**/*.md"
+    expression: |
+      (pull_request.target eq "main" OR
+      pull_request.target match "release.+") AND
+      NOT pull_request.draft AND
+      (pull_request.changes.any match "com.unity.ml-agents/**" OR
+      pull_request.changes.any match "Project/**" OR
+      pull_request.changes.any match "ml-agents/**" OR
+      pull_request.changes.any match "ml-agents-envs/**" OR
+      pull_request.changes.any match ".yamato/python-ll-api-test.yml") AND
+      NOT pull_request.changes.all match "**/*.md"
 {% endfor %}

.yamato/com.unity.ml-agents-test.yml

     # 2018.4 doesn't support code-coverage
     coverageOptions:
     minCoveragePct: 0
+    # We want some scene tests to run in the DevProject, but packages there only support 2019+
+    testProject: Project
+    testProject: DevProject
-  - version: 2020.2
+    testProject: DevProject
+  - version: 2020.3
-trunk_editor:
-  - version: trunk
-    coverageOptions: --enable-code-coverage --code-coverage-options 'generateHtmlReport;assemblyFilters:+Unity.ML-Agents'
-    minCoveragePct: 72
+    testProject: DevProject
 test_platforms:
   - name: win
     type: Unity::VM
     {% endfor %}
   {% endfor %}
 
-  {% for editor in trunk_editor %}
-    {% for platform in test_platforms %}
-  - .yamato/com.unity.ml-agents-test.yml#test_{{ platform.name }}_{{ editor.version }}
-    {% endfor %}
-  {% endfor %}
-      - branch: master
+      - branch: main
         frequency: daily
 
 {% for editor in test_editors %}
     flavor: {{ platform.flavor}}
   commands:
     - npm install upm-ci-utils@stable -g --registry https://artifactory.prd.cds.internal.unity3d.com/artifactory/api/npm/upm-npm
-    - upm-ci package test -u {{ editor.version }} --package-path com.unity.ml-agents {{ editor.coverageOptions }}
-    - python ml-agents/tests/yamato/check_coverage_percent.py upm-ci~/test-results/ {{ editor.minCoveragePct }}
+    - upm-ci project test -u {{ editor.version }} --project-path {{ editor.testProject }} {{ editor.coverageOptions }} --extra-utr-arg "reruncount=2"
+    - python3 ml-agents/tests/yamato/check_coverage_percent.py upm-ci~/test-results/ {{ editor.minCoveragePct }}
   artifacts:
     logs:
       paths:
     changes:
       only:
         - "com.unity.ml-agents/**"
+        - "{{ editor.testProject }}/**"
-
-{% for editor in trunk_editor %}
-  {% for platform in test_platforms %}
-test_{{ platform.name }}_trunk:
-  name : com.unity.ml-agents test {{ editor.version }} on {{ platform.name }}
-  agent:
-    type: {{ platform.type }}
-    image: {{ platform.image }}
-    flavor: {{ platform.flavor}}
-  commands:
-    - python -m pip install unity-downloader-cli --extra-index-url https://artifactory.eu-cph-1.unityops.net/api/pypi/common-python/simple
-    - unity-downloader-cli -u trunk -c editor --wait --fast
-    - npm install upm-ci-utils@stable -g --registry https://artifactory.prd.cds.internal.unity3d.com/artifactory/api/npm/upm-npm
-    - upm-ci package test -u {{ editor.version }} --package-path com.unity.ml-agents {{ editor.coverageOptions }}
-    - python ml-agents/tests/yamato/check_coverage_percent.py upm-ci~/test-results/ {{ editor.minCoveragePct }}
-  artifacts:
-    logs:
-      paths:
-        - "upm-ci~/test-results/**/*"
-  dependencies:
-    - .yamato/com.unity.ml-agents-pack.yml#pack
-  triggers:
-    cancel_old_ci: true
-    {% endfor %}
-  {% endfor %}

.yamato/standalone-build-test.yml

 test_editors:
-  - version: 2018.4
+  - version: 2020.3
 ---
 {% for editor in test_editors %}
 test_mac_standalone_{{ editor.version }}:
-    image: ml-agents/ml-agents-bokken-mac:0.1.4-492264
+    image: package-ci/mac:stable
-    - pip install pyyaml
-    - python -u -m ml-agents.tests.yamato.standalone_build_tests
-    - python -u -m ml-agents.tests.yamato.standalone_build_tests --scene=Assets/ML-Agents/Examples/Basic/Scenes/Basic.unity
-    - python -u -m ml-agents.tests.yamato.standalone_build_tests --scene=Assets/ML-Agents/Examples/Bouncer/Scenes/Bouncer.unity 
-    - python -u -m ml-agents.tests.yamato.standalone_build_tests --scene=Assets/ML-Agents/Examples/WallJump/Scenes/WallJump.unity 
+    - python3 -m pip install pyyaml --index-url https://artifactory.prd.it.unity3d.com/artifactory/api/pypi/pypi/simple
+    - python3 -m pip install unity-downloader-cli --index-url https://artifactory.prd.it.unity3d.com/artifactory/api/pypi/pypi/simple --upgrade
+    - unity-downloader-cli -u {{ editor.version }} -c editor --wait --fast
+
+    - python3 -u -m ml-agents.tests.yamato.standalone_build_tests
+    - python3 -u -m ml-agents.tests.yamato.standalone_build_tests --scene=Assets/ML-Agents/Examples/Basic/Scenes/Basic.unity
+    - python3 -u -m ml-agents.tests.yamato.standalone_build_tests --scene=Assets/ML-Agents/Examples/Bouncer/Scenes/Bouncer.unity
+    - python3 -u -m ml-agents.tests.yamato.standalone_build_tests --scene=Assets/ML-Agents/Examples/WallJump/Scenes/WallJump.unity
   triggers:
     cancel_old_ci: true
     changes:

.yamato/training-int-tests.yml

 test_editors:
-  - version: 2018.4
+  - version: 2020.3
 ---
 {% for editor in test_editors %}
 test_mac_training_int_{{ editor.version }}:
   variables:
     UNITY_VERSION: {{ editor.version }}
   commands:
-    - pip install pyyaml
+    - pip install pyyaml --index-url https://artifactory.prd.it.unity3d.com/artifactory/api/pypi/pypi/simple
     - python -u -m ml-agents.tests.yamato.training_int_tests
     # Backwards-compatibility tests.
     # If we make a breaking change to the communication protocol, these will need

Project/Assets/ML-Agents/Examples/FoodCollector/Scripts/FoodCollectorAgent.cs

 
     public override void Heuristic(float[] actionsOut)
     {
+        actionsOut[0] = 0f;
+        actionsOut[1] = 0f;
+        actionsOut[2] = 0f;
         if (Input.GetKey(KeyCode.D))
         {
             actionsOut[2] = 2f;

Project/Assets/ML-Agents/Examples/Soccer/Scripts/AgentSoccer.cs

 
     public override void Heuristic(float[] actionsOut)
     {
+        Array.Clear(actionsOut, 0, actionsOut.Length);
         //forward
         if (Input.GetKey(KeyCode.W))
         {

Project/Assets/ML-Agents/Examples/WallJump/Scripts/WallJumpAgent.cs

 
     public override void Heuristic(float[] actionsOut)
     {
+        System.Array.Clear(actionsOut, 0, actionsOut.Length);
         if (Input.GetKey(KeyCode.D))
         {
             actionsOut[1] = 2f;

Project/Packages/manifest.json

     "com.unity.analytics": "3.2.3",
     "com.unity.collab-proxy": "1.2.15",
     "com.unity.ml-agents": "file:../../com.unity.ml-agents",
-    "com.unity.package-manager-ui": "2.0.8",
+    "com.unity.package-manager-ui": "2.0.13",
-    "com.unity.purchasing": "2.0.3",
     "com.unity.textmeshpro": "1.4.1",
     "com.unity.modules.ai": "1.0.0",
     "com.unity.modules.animation": "1.0.0",

Project/ProjectSettings/ProjectVersion.txt

-m_EditorVersion: 2018.4.17f1
+m_EditorVersion: 2018.4.35f1

Project/ProjectSettings/UnityConnectSettings.asset

 UnityConnectSettings:
   m_ObjectHideFlags: 0
   serializedVersion: 1
-  m_Enabled: 1
+  m_Enabled: 0
   m_TestMode: 0
   m_EventOldUrl: https://api.uca.cloud.unity3d.com/v1/events
   m_EventUrl: https://cdp.cloud.unity3d.com/v1/events

com.unity.ml-agents/CONTRIBUTING.md

 ## Communication
 
 First, please read through our
-[code of conduct](https://github.com/Unity-Technologies/ml-agents/blob/master/CODE_OF_CONDUCT.md),
+[code of conduct](https://github.com/Unity-Technologies/ml-agents/blob/main/CODE_OF_CONDUCT.md),
 as we expect all our contributors to follow it.
 
 Second, before starting on a project that you intend to contribute to the
 
 ## Git Branches
 
-The master branch corresponds to the most recent version of the project. Note
+The `main` branch corresponds to the most recent version of the project. Note
 that this may be newer that the
 [latest release](https://github.com/Unity-Technologies/ml-agents/releases/tag/latest_release).
 

com.unity.ml-agents/Editor/BrainParametersDrawer.cs

         static void DrawContinuousVectorAction(Rect position, SerializedProperty property)
         {
             var vecActionSize = property.FindPropertyRelative(k_ActionSizePropName);
-            vecActionSize.arraySize = 1;
+
+            // This check is here due to:
+            // https://fogbugz.unity3d.com/f/cases/1246524/
+            // If this case has been resolved, please remove this if condition.
+            if (vecActionSize.arraySize != 1)
+            {
+                vecActionSize.arraySize = 1;
+            }
             var continuousActionSize =
                 vecActionSize.GetArrayElementAtIndex(0);
             EditorGUI.PropertyField(
         static void DrawDiscreteVectorAction(Rect position, SerializedProperty property)
         {
             var vecActionSize = property.FindPropertyRelative(k_ActionSizePropName);
-            vecActionSize.arraySize = EditorGUI.IntField(
+            var newSize = EditorGUI.IntField(
+
+            // This check is here due to:
+            // https://fogbugz.unity3d.com/f/cases/1246524/
+            // If this case has been resolved, please remove this if condition.
+            if (newSize != vecActionSize.arraySize)
+            {
+                vecActionSize.arraySize = newSize;
+            }
+
             position.y += k_LineHeight;
             position.x += 20;
             position.width -= 20;

com.unity.ml-agents/Editor/DemonstrationImporter.cs

 using Unity.MLAgents.CommunicatorObjects;
 using UnityEditor;
 using UnityEngine;
+#if UNITY_2020_2_OR_NEWER
+using UnityEditor.AssetImporters;
+#else
+#endif
 using Unity.MLAgents.Demonstrations;
 
 namespace Unity.MLAgents.Editor

com.unity.ml-agents/Documentation~/com.unity.ml-agents.md

 Manager documentation].
 
 To install the companion Python package to enable training behaviors, follow the
-[installation instructions] on our [GitHub repository].
+[installation instructions] on our [GitHub repository]. It is strongly recommended that you
+use the Python package that corresponds to this release (version 0.16.1) for the best experience;
+versions between 0.16.1 and 0.20.0 are supported. Versions after 0.25.1 cannot be used.
 
 ## Requirements
 
 the documentation, you can checkout our [GitHUb Repository], which also includes
 a number of ways to [connect with us] including our [ML-Agents Forum].
 
-[unity ML-Agents Toolkit]: https://github.com/Unity-Technologies/ml-agents
+In order to improve the developer experience for Unity ML-Agents Toolkit, we have added in-editor analytics.
+Please refer to "Information that is passively collected by Unity" in the
+[Unity Privacy Policy](https://unity3d.com/legal/privacy-policy).
+
+[unity ML-Agents Toolkit]: https://github.com/Unity-Technologies/ml-agents/tree/release_2_verified_docs
-[installation instructions]: https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/docs/Installation.md
-[github repository]: https://github.com/Unity-Technologies/ml-agents
-[python package]: https://github.com/Unity-Technologies/ml-agents
+[installation instructions]: https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/docs/Installation.md
+[github repository]: https://github.com/Unity-Technologies/ml-agents/tree/release_2_verified_docs
+[python package]: https://github.com/Unity-Technologies/ml-agents/tree/release_2_verified_docs
-[connect with us]: https://github.com/Unity-Technologies/ml-agents#community-and-feedback
+[connect with us]: https://github.com/Unity-Technologies/ml-agents/tree/release_2_verified_docs#community-and-feedback
 [ml-agents forum]: https://forum.unity.com/forums/ml-agents.453/

com.unity.ml-agents/CHANGELOG.md

 and this project adheres to
 [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [1.0.8] - 2021-05-26
+### Bug Fixes
+#### com.unity.ml-agents (C#)
+- Fixed a null reference exception that occurred when loading an ONNX model file that was generated with a new
+version of the Python trainer (0.26.0 or newer). (#5350)
+- Added checked to prevent training with incompatible versions of the python trainer (0.26.0 or newer). (#5370)
+
+## [1.0.7] - 2021-03-04
+### Minor Changes
+#### com.unity.ml-agents (C#)
+In order to improve the developer experience for Unity ML-Agents Toolkit, we have added in-editor analytics.
+Please refer to "Information that is passively collected by Unity" in the
+[Unity Privacy Policy](https://unity3d.com/legal/privacy-policy).
+
+### Bug Fixes
+#### com.unity.ml-agents (C#)
+- Removed unnecessary memory allocations in `SensorShapeValidator.ValidateSensors()` (#4915)
+- Removed unnecessary memory allocations in `SideChannelManager.GetSideChannelMessage()` (#4915)
+- Removed several memory allocations that happened during inference. On a test scene, this
+  reduced the amount of memory allocated by approximately 25%. (#4916)
+
+## [1.0.6] - 2020-11-13
+### Minor Changes
+#### com.unity.ml-agents (C#)
+- Update documentation with recommended version of Python trainer. (#4535)
+- Log a warning if a version of the Python trainer is used that is newer than expected. (#4535)
+- Update Barracuda to 1.0.4. (#4644)
+
+### Bug Fixes
+#### com.unity.ml-agents (C#)
+- Fixed a bug with visual observations using .onnx model files and newer versions of Barracuda (1.1.0 or later). (#4533)
+- `Agent.CollectObservations()`, `Agent.EndEpisode()`, and `Academy.EnvironmentStep()` will now throw an exception
+if they are called recursively (for example, if they call `Agent.EndEpisode()`).
+Previously, this would result in an infinite loop and cause the editor to hang. (#4638)
+- Fixed a bug where accessing the Academy outside of play mode would cause the Academy to get stepped multiple times when in play mode. (#4637)
+
+## [1.0.5] - 2020-09-23
+### Minor Changes
+#### com.unity.ml-agents (C#)
+- Update Barracuda to 1.0.3. (#4506)
+
+## [1.0.4] - 2020-08-19
+### Minor Changes
+#### com.unity.ml-agents (C#)
+- Update Barracuda to 1.0.2. (#4385)
+- Explicitly call out dependencies in package.json.
+
+## [1.0.3] - 2020-07-07
+### Minor Changes
+#### com.unity.ml-agents (C#)
+- Update Barracuda to 1.0.1. (#4187)
+### Bug Fixes
+#### com.unity.ml-agents (C#)
+- 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)
+#### ml-agents / ml-agents-envs / gym-unity (Python)
+- Fixed issue with FoodCollector, Soccer, and WallJump when playing with keyboard. (#4147, #4174)
+
+## [1.0.2] - 2020-06-04
+### Minor Changes
+#### com.unity.ml-agents (C#)
+- Remove 'preview' tag.
+
+## [1.0.2-preview] - 2020-05-19
+### Bug Fixes
+#### com.unity.ml-agents (C#)
+- Fix missing .meta file
+
+## [1.0.1-preview] - 2020-05-19
+### Bug Fixes
+#### com.unity.ml-agents (C#)
+- A bug that would cause the editor to go into a loop when a prefab was selected was fixed. (#3949)
+- BrainParameters.ToProto() no longer throws an exception if none of the fields have been set. (#3930)
+- The Barracuda dependency was upgraded to 0.7.1-preview. (#3977)
+#### ml-agents / ml-agents-envs / gym-unity (Python)
+- An issue was fixed where using `--initialize-from` would resume from the past step count. (#3962)
+- The gym wrapper error for the wrong number of agents now fires more consistently, and more details
+  were added to the error message when the input dimension is wrong. (#3963)
+
 ## [1.0.0-preview] - 2020-05-06
 
 ### Major Changes
   - Introduced the `SideChannelManager` to register, unregister and access side
     channels. (#3807)
   - `Academy.FloatProperties` was replaced by `Academy.EnvironmentParameters`.
-    See the [Migration Guide](https://github.com/Unity-Technologies/ml-agents/blob/master/docs/Migrating.md)
+    See the [Migration Guide](https://github.com/Unity-Technologies/ml-agents/blob/main/docs/Migrating.md)
     for more details on upgrading. (#3807)
   - `SideChannel.OnMessageReceived` is now a protected method (was public)
   - SideChannel IncomingMessages methods now take an optional default argument,
   `--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](https://github.com/Unity-Technologies/ml-agents/blob/master/docs/Python-API.md). (#3681)
+  scenarios, use the [Low Level Python API](https://github.com/Unity-Technologies/ml-agents/blob/main/docs/Python-API.md). (#3681)
-  [Low Level Python API](https://github.com/Unity-Technologies/ml-agents/blob/master/docs/Python-API.md)
+  [Low Level Python API](https://github.com/Unity-Technologies/ml-agents/blob/main/docs/Python-API.md)
   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

com.unity.ml-agents/Runtime/SideChannels/SideChannelsManager.cs

         /// <returns></returns>
         internal static byte[] GetSideChannelMessage(Dictionary<Guid, SideChannel> sideChannels)
         {
+            if (!HasOutgoingMessages(sideChannels))
+            {
+                // Early out so that we don't create the MemoryStream or BinaryWriter.
+                // This is the most common case.
+                return Array.Empty<byte>();
+            }
+
             using (var memStream = new MemoryStream())
             {
                 using (var binaryWriter = new BinaryWriter(memStream))
                     return memStream.ToArray();
                 }
             }
+        }
+
+        /// <summary>
+        /// Check whether any of the sidechannels have queued messages.
+        /// </summary>
+        /// <param name="sideChannels"></param>
+        /// <returns></returns>
+        static bool HasOutgoingMessages(Dictionary<Guid, SideChannel> sideChannels)
+        {
+            foreach (var sideChannel in sideChannels.Values)
+            {
+                var messageList = sideChannel.MessageQueue;
+                if (messageList.Count > 0)
+                {
+                    return true;
+                }
+            }
+
+            return false;
         }
 
         /// <summary>

com.unity.ml-agents/Runtime/Agent.cs

     /// [OnDisable()]: https://docs.unity3d.com/ScriptReference/MonoBehaviour.OnDisable.html]
     /// [OnBeforeSerialize()]: https://docs.unity3d.com/ScriptReference/MonoBehaviour.OnBeforeSerialize.html
     /// [OnAfterSerialize()]: https://docs.unity3d.com/ScriptReference/MonoBehaviour.OnAfterSerialize.html
-    /// [Agents]: https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/docs/Learning-Environment-Design-Agents.md
-    /// [Reinforcement Learning in Unity]: https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/docs/Learning-Environment-Design.md
+    /// [Agents]: https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/docs/Learning-Environment-Design-Agents.md
+    /// [Reinforcement Learning in Unity]: https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/docs/Learning-Environment-Design.md
-    /// [Unity ML-Agents Toolkit manual]: https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/docs/Readme.md
+    /// [Unity ML-Agents Toolkit manual]: https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/docs/Readme.md
-    [HelpURL("https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/" +
+    [HelpURL("https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/" +
         "docs/Learning-Environment-Design-Agents.md")]
     [Serializable]
     [RequireComponent(typeof(BehaviorParameters))]
         /// </summary>
         internal VectorSensor collectObservationsSensor;
 
+        private RecursionChecker m_CollectObservationsChecker = new RecursionChecker("CollectObservations");
+        private RecursionChecker m_OnEpisodeBeginChecker = new RecursionChecker("OnEpisodeBegin");
+
         /// <summary>
         /// Called when the attached [GameObject] becomes enabled and active.
         /// [GameObject]: https://docs.unity3d.com/Manual/GameObjects.html
             // episode when initializing until after the Academy had its first reset.
             if (Academy.Instance.TotalStepCount != 0)
             {
-                OnEpisodeBegin();
+                using (m_OnEpisodeBeginChecker.Start())
+                {
+                    OnEpisodeBegin();
+                }
             }
         }
 
             {
                 // Make sure the latest observations are being passed to training.
                 collectObservationsSensor.Reset();
-                CollectObservations(collectObservationsSensor);
+                using (m_CollectObservationsChecker.Start())
+                {
+                    CollectObservations(collectObservationsSensor);
+                }
             }
             // Request the last decision with no callbacks
             // We request a decision so Python knows the Agent is done immediately
         /// for information about mixing reward signals from curiosity and Generative Adversarial
         /// Imitation Learning (GAIL) with rewards supplied through this method.
         ///
-        /// [Agents - Rewards]: https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/docs/Learning-Environment-Design-Agents.md#rewards
-        /// [Reward Signals]: https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/docs/ML-Agents-Overview.md#a-quick-note-on-reward-signals
+        /// [Agents - Rewards]: https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/docs/Learning-Environment-Design-Agents.md#rewards
+        /// [Reward Signals]: https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/docs/ML-Agents-Overview.md#a-quick-note-on-reward-signals
         /// </remarks>
         /// <param name="reward">The new value of the reward.</param>
         public void SetReward(float reward)
         /// for information about mixing reward signals from curiosity and Generative Adversarial
         /// Imitation Learning (GAIL) with rewards supplied through this method.
         ///
-        /// [Agents - Rewards]: https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/docs/Learning-Environment-Design-Agents.md#rewards
-        /// [Reward Signals]: https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/docs/ML-Agents-Overview.md#a-quick-note-on-reward-signals
+        /// [Agents - Rewards]: https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/docs/Learning-Environment-Design-Agents.md#rewards
+        /// [Reward Signals]: https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/docs/ML-Agents-Overview.md#a-quick-note-on-reward-signals
         ///</remarks>
         /// <param name="increment">Incremental reward value.</param>
         public void AddReward(float increment)
         ///
         /// Your heuristic implementation can use any decision making logic you specify. Assign decision
         /// values to the float[] array, <paramref name="actionsOut"/>, passed to your function as a parameter.
+        /// The same array will be reused between steps. It is up to the user to initialize
+        /// the values on each call, for example by calling `Array.Clear(actionsOut, 0, actionsOut.Length);`.
         /// Add values to the array at the same indexes as they are used in your
         /// <seealso cref="OnActionReceived(float[])"/> function, which receives this array and
         /// implements the corresponding agent behavior. See [Actions] for more information
         /// implementing a simple heuristic function can aid in debugging agent actions and interactions
         /// with its environment.
         ///
-        /// [Demonstration Recorder]: https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/docs/Learning-Environment-Design-Agents.md#recording-demonstrations
-        /// [Actions]: https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/docs/Learning-Environment-Design-Agents.md#actions
+        /// [Demonstration Recorder]: https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/docs/Learning-Environment-Design-Agents.md#recording-demonstrations
+        /// [Actions]: https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/docs/Learning-Environment-Design-Agents.md#actions
         /// [GameObject]: https://docs.unity3d.com/Manual/GameObjects.html
         /// </remarks>
         /// <example>
             UpdateSensors();
             using (TimerStack.Instance.Scoped("CollectObservations"))
             {
-                CollectObservations(collectObservationsSensor);
+                using (m_CollectObservationsChecker.Start())
+                {
+                    CollectObservations(collectObservationsSensor);
+                }
             }
             using (TimerStack.Instance.Scoped("CollectDiscreteActionMasks"))
             {
         /// For more information about observations, see [Observations and Sensors].
         ///
         /// [GameObject]: https://docs.unity3d.com/Manual/GameObjects.html
-        /// [Observations and Sensors]: https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/docs/Learning-Environment-Design-Agents.md#observations-and-sensors
+        /// [Observations and Sensors]: https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/docs/Learning-Environment-Design-Agents.md#observations-and-sensors
         /// </remarks>
         public virtual void CollectObservations(VectorSensor sensor)
         {
         ///
         /// See [Agents - Actions] for more information on masking actions.
         ///
-        /// [Agents - Actions]: https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/docs/Learning-Environment-Design-Agents.md#actions
+        /// [Agents - Actions]: https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/docs/Learning-Environment-Design-Agents.md#actions
         /// </remarks>
         /// <seealso cref="OnActionReceived(float[])"/>
         public virtual void CollectDiscreteActionMasks(DiscreteActionMasker actionMasker)
         ///
         /// For more information about implementing agent actions see [Agents - Actions].
         ///
-        /// [Agents - Actions]: https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/docs/Learning-Environment-Design-Agents.md#actions
+        /// [Agents - Actions]: https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/docs/Learning-Environment-Design-Agents.md#actions
         /// </remarks>
         /// <param name="vectorAction">
         /// An array containing the action vector. The length of the array is specified
         {
             ResetData();
             m_StepCount = 0;
-            OnEpisodeBegin();
+            using (m_OnEpisodeBeginChecker.Start())
+            {
+                OnEpisodeBegin();
+            }
+
         }
 
         /// <summary>

com.unity.ml-agents/Runtime/Demonstrations/DemonstrationRecorder.cs

     /// See [Imitation Learning - Recording Demonstrations] for more information.
     ///
     /// [GameObject]: https://docs.unity3d.com/Manual/GameObjects.html
-    /// [Imitation Learning - Recording Demonstrations]: https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/docs//Learning-Environment-Design-Agents.md#recording-demonstrations
+    /// [Imitation Learning - Recording Demonstrations]: https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/docs//Learning-Environment-Design-Agents.md#recording-demonstrations
     /// </remarks>
     [RequireComponent(typeof(Agent))]
     [AddComponentMenu("ML Agents/Demonstration Recorder", (int)MenuGroup.Default)]

com.unity.ml-agents/Runtime/DiscreteActionMasker.cs

         ///
         /// See [Agents - Actions] for more information on masking actions.
         ///
-        /// [Agents - Actions]: https://github.com/Unity-Technologies/ml-agents/blob/release_1_docs/docs/Learning-Environment-Design-Agents.md#actions
+        /// [Agents - Actions]: https://github.com/Unity-Technologies/ml-agents/blob/release_2_verified_docs/docs/Learning-Environment-Design-Agents.md#actions
         /// </remarks>
         /// <param name="branch">The branch for which the actions will be masked.</param>
         /// <param name="actionIndices">The indices of the masked actions.</param>

com.unity.ml-agents/Runtime/Policies/BarracudaPolicy.cs

         /// </summary>
         List<int[]> m_SensorShapes;
 
+        private string m_BehaviorName;
+        private BrainParameters m_BrainParameters;
+
+        /// <summary>
+        /// Whether or not we've tried to send analytics for this model. We only ever try to send once per policy,
+        /// and do additional deduplication in the analytics code.
+        /// </summary>
+        private bool m_AnalyticsSent;
+
-            InferenceDevice inferenceDevice)
+            InferenceDevice inferenceDevice,
+            string behaviorName
+        )
+            m_BehaviorName = behaviorName;
+            m_BrainParameters = brainParameters;
+
+            if (!m_AnalyticsSent)
+            {
+                m_AnalyticsSent = true;
+                Analytics.InferenceAnalytics.InferenceModelSet(
+                    m_ModelRunner.Model,
+                    m_BehaviorName,
+                    m_ModelRunner.InferenceDevice,
+                    sensors,
+                    m_BrainParameters
+                );
+            }
             m_AgentId = info.episodeId;
             m_ModelRunner?.PutObservations(info, sensors);
         }

com.unity.ml-agents/Runtime/Policies/BehaviorParameters.cs

                             "Either assign a model, or change to a different Behavior Type."
                         );
                     }
-                    return new BarracudaPolicy(m_BrainParameters, m_Model, m_InferenceDevice);
+                    return new BarracudaPolicy(m_BrainParameters, m_Model, m_InferenceDevice, m_BehaviorName);
                 }
                 case BehaviorType.Default:
                     if (Academy.Instance.IsCommunicatorOn)
                     if (m_Model != null)
                     {
-                        return new BarracudaPolicy(m_BrainParameters, m_Model, m_InferenceDevice);
+                        return new BarracudaPolicy(m_BrainParameters, m_Model, m_InferenceDevice, m_BehaviorName);
                     }
                     else
                     {

com.unity.ml-agents/Runtime/Policies/RemotePolicy.cs

 using UnityEngine;
 using System.Collections.Generic;
 using System;
+using Unity.MLAgents.Analytics;
 using Unity.MLAgents.Sensors;
 
 namespace Unity.MLAgents.Policies
         int m_AgentId;
         string m_FullyQualifiedBehaviorName;
 
+        private bool m_AnalyticsSent = false;
+        private BrainParameters m_BrainParameters;
+
         internal ICommunicator m_Communicator;
 
         /// <inheritdoc />
         {
             m_FullyQualifiedBehaviorName = fullyQualifiedBehaviorName;
             m_Communicator = Academy.Instance.Communicator;
-            m_Communicator.SubscribeBrain(m_FullyQualifiedBehaviorName, brainParameters);
+            m_Communicator?.SubscribeBrain(m_FullyQualifiedBehaviorName, brainParameters);
+            m_BrainParameters = brainParameters;
+
+            if (!m_AnalyticsSent)
+            {
+                m_AnalyticsSent = true;
+                TrainingAnalytics.RemotePolicyInitialized(
+                    m_FullyQualifiedBehaviorName,
+                    sensors,
+                    m_BrainParameters
+                );
+            }
             m_AgentId = info.episodeId;
             m_Communicator?.PutObservations(m_FullyQualifiedBehaviorName, info, sensors);
         }

com.unity.ml-agents/Runtime/Sensors/SensorShapeValidator.cs

             {
                 // Check for compatibility with the other Agents' Sensors
                 // TODO make sure this only checks once per agent
-                Debug.Assert(m_SensorShapes.Count == sensors.Count, $"Number of Sensors must match. {m_SensorShapes.Count} != {sensors.Count}");
+                Debug.AssertFormat(
+                    m_SensorShapes.Count == sensors.Count,
+                    "Number of Sensors must match. {0} != {1}",
+                    m_SensorShapes.Count,
+                    sensors.Count
+                );
                 for (var i = 0; i < Mathf.Min(m_SensorShapes.Count, sensors.Count); i++)
                 {
                     var cachedShape = m_SensorShapes[i];
                     {
-                        Debug.Assert(cachedShape[j] == sensorShape[j], "Sensor sizes much match.");
+                        Debug.Assert(cachedShape[j] == sensorShape[j], "Sensor sizes must match.");
                     }
                 }
             }

com.unity.ml-agents/Runtime/Sensors/RayPerceptionSensorComponentBase.cs

             else
             {
                 var rayInput = GetRayPerceptionInput();
+                // We don't actually need the tags here, since they don't affect the display of the rays.
+                // Additionally, the user might be in the middle of typing the tag name when this is called,
+                // and there's no way to turn off the "Tag ... is not defined" error logs.
+                // So just don't use any tags here.
+                rayInput.DetectableTags = null;
                 for (var rayIndex = 0; rayIndex < rayInput.Angles.Count; rayIndex++)
                 {
                     DebugDisplayInfo.RayInfo debugRay;

com.unity.ml-agents/Runtime/Sensors/ObservationWriter.cs

         }
 
         /// <summary>
-        /// 1D write access at a specified index. Use AddRange if possible instead.
+        /// 1D write access at a specified index. Use AddList if possible instead.
         /// </summary>
         /// <param name="index">Index to write to.</param>
         public float this[int index]
                 {
                     m_Proxy.data[m_Batch, index + m_Offset + writeOffset] = val;
                     index++;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Write the range of floats
+        /// </summary>
+        /// <param name="data"></param>
+        /// <param name="writeOffset">Optional write offset.</param>
+        internal void AddList(IList<float> data, int writeOffset = 0)
+
+        {
+            if (m_Data != null)
+            {
+                for (var index = 0; index < data.Count; index++)
+                {
+                    var val = data[index];
+                    m_Data[index + m_Offset + writeOffset] = val;
+
+                }
+            }
+            else
+            {
+                for (var index = 0; index < data.Count; index++)
+                {
+                    var val = data[index];
+                    m_Proxy.data[m_Batch, index + m_Offset + writeOffset] = val;
                 }
             }
         }

com.unity.ml-agents/Runtime/Sensors/RayPerceptionSensor.cs

                     rayOutput.ToFloatArray(numDetectableTags, rayIndex, m_Observations);
                 }
                 // Finally, add the observations to the ObservationWriter
-                writer.AddRange(m_Observations);
+                writer.AddList(m_Observations);
             }
             return m_Observations.Length;
         }
             if (castHit)
             {
                 // Find the index of the tag of the object that was hit.
-                for (var i = 0; i < input.DetectableTags.Count; i++)
+                var numTags = input.DetectableTags?.Count ?? 0;
+                for (var i = 0; i < numTags; i++)
-                    if (hitObject.CompareTag(input.DetectableTags[i]))
+                    var tagsEqual = false;
+                    try
+                    {
+                        var tag = input.DetectableTags[i];
+                        if (!string.IsNullOrEmpty(tag))
+                        {
+                            tagsEqual = hitObject.CompareTag(tag);
+                        }
+                    }
+                    catch (UnityException)
+                    {
+                        // If the tag is null, empty, or not a valid tag, just ignore it.
+                    }
+
+                    if (tagsEqual)
                     {
                         rayOutput.HitTaggedObject = true;
                         rayOutput.HitTagIndex = i;

com.unity.ml-agents/Runtime/Sensors/StackingSensor.cs

             for (var i = 0; i < m_NumStackedObservations; i++)
             {
                 var obsIndex = (m_CurrentIndex + 1 + i) % m_NumStackedObservations;
-                writer.AddRange(m_StackedObservations[obsIndex], numWritten);
+                writer.AddList(m_StackedObservations[obsIndex], numWritten);
                 numWritten += m_UnstackedObservationSize;
             }
 
         {
             return SensorCompressionType.None;
         }
+
+        internal ISensor GetWrappedSensor()
+        {
+            return m_WrappedSensor;
+        }
+
 
         // TODO support stacked compressed observations (byte stream)
     }

com.unity.ml-agents/Runtime/Sensors/VectorSensor.cs

                     m_Observations.Add(0);
                 }
             }
-            writer.AddRange(m_Observations);
+            writer.AddList(m_Observations);
             return expectedObservations;
         }
 

com.unity.ml-agents/Runtime/Communicator/GrpcExtensions.cs

         {
             var agentInfoProto = ai.ToAgentInfoProto();
 
-            var agentActionProto = new AgentActionProto
+            var agentActionProto = new AgentActionProto();
+            if(ai.storedVectorActions != null)
-                VectorActions = { ai.storedVectorActions }
-            };
+                agentActionProto.VectorActions.AddRange(ai.storedVectorActions);
+            }
 
             return new AgentInfoActionPairProto
             {
             var brainParametersProto = new BrainParametersProto
             {
                 VectorActionSize = { bp.VectorActionSize },
-                VectorActionSpaceType =
-                    (SpaceTypeProto)bp.VectorActionSpaceType,
+                VectorActionSpaceType = (SpaceTypeProto) bp.VectorActionSpaceType,
-            brainParametersProto.VectorActionDescriptions.AddRange(bp.VectorActionDescriptions);
+            if(bp.VectorActionDescriptions != null)
+            {
+                brainParametersProto.VectorActionDescriptions.AddRange(bp.VectorActionDescriptions);
+            }
             return brainParametersProto;
         }
 
         /// </summary>
         public static DemonstrationMetaProto ToProto(this DemonstrationMetaData dm)
         {
+            var demonstrationName = dm.demonstrationName ?? "";
             var demoProto = new DemonstrationMetaProto
             {
                 ApiVersion = DemonstrationMetaData.ApiVersion,
-                DemonstrationName = dm.demonstrationName
+                DemonstrationName = demonstrationName
             };
             return demoProto;
         }

com.unity.ml-agents/Runtime/Communicator/RpcCommunicator.cs

 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Text.RegularExpressions;
+using Unity.MLAgents.Analytics;
 using Unity.MLAgents.CommunicatorObjects;
 using Unity.MLAgents.Sensors;
 using Unity.MLAgents.Policies;
     /// Responsible for communication with External using gRPC.
     internal class RpcCommunicator : ICommunicator
     {
+
         public event QuitCommandHandler QuitCommandReceived;
         public event ResetCommandHandler ResetCommandReceived;
 
             return true;
         }
 
+        internal static bool CheckPythonPackageVersionIsCompatible(string pythonLibraryVersion)
+        {
+            // Try to extract the numerical values from the pythonLibraryVersion, e.g. remove the ".dev0" suffix
+            var versionMatch = Regex.Match(pythonLibraryVersion, @"[0-9]+\.[0-9]+\.[0-9]");
+            if (versionMatch.Success)
+            {
+                pythonLibraryVersion = versionMatch.Value;
+            }
+
+            Version pythonVersion;
+            try
+            {
+                pythonVersion = new Version(pythonLibraryVersion);
+            }
+            catch
+            {
+                // Unparseable version.
+                // Anything like 0.42.0.dev0 should have been caught with the regex above, so anything here
+                // is totally bogus. For now, ignore these and let CheckPythonPackageVersionIsSupported handle it.
+                return true;
+            }
+
+            if (pythonVersion > PythonTrainerVersions.s_MaxCompatibleVersion)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        /// <summary>
+        /// Check if the package is in the supported range. Note that some versions might be unsupported but
+        /// still compatible.
+        /// </summary>
+        /// <param name="pythonLibraryVersion"></param>
+        /// <returns></returns>
+        internal static bool CheckPythonPackageVersionIsSupported(string pythonLibraryVersion)
+        {
+            Version pythonVersion;
+            try
+            {
+                pythonVersion = new Version(pythonLibraryVersion);
+            }
+            catch
+            {
+                // Unparseable - this also catches things like "0.20.0.dev0" which we don't want to support
+                return false;
+            }
+
+            if (pythonVersion < PythonTrainerVersions.s_MinSupportedVersion ||
+                pythonVersion > PythonTrainerVersions.s_MaxSupportedVersion)
+            {
+                return false;
+            }
+            return true;
+        }
+
         /// <summary>
         /// Sends the initialization parameters through the Communicator.
         /// Is used by the academy to send initialization parameters to the communicator.
                 var pythonCommunicationVersion = initializationInput.RlInitializationInput.CommunicationVersion;
                 var pythonPackageVersion = initializationInput.RlInitializationInput.PackageVersion;
                 var unityCommunicationVersion = initParameters.unityCommunicationVersion;
+
+                TrainingAnalytics.SetTrainerInformation(pythonPackageVersion, pythonCommunicationVersion);
 
                 var communicationIsCompatible = CheckCommunicationVersionsAreCompatible(unityCommunicationVersion,
                     pythonCommunicationVersion,
                     }
 
                     throw new UnityAgentsException("ICommunicator.Initialize() failed.");
+                }
+
+                var packageVersionCompatible = CheckPythonPackageVersionIsCompatible(pythonPackageVersion);
+                if (!packageVersionCompatible)
+                {
+                    Debug.LogErrorFormat(
+                        "Python package version ({0}) will produce model files that are incompatible with this " +
+                        "version of the com.unity.ml-agents Unity package. Please downgrade to a Python package " +
+                        "between {1} and {2}, or update to a new version of com.unity.ml-agents.",
+                        pythonPackageVersion,
+                        PythonTrainerVersions.s_MinSupportedVersion,
+                        PythonTrainerVersions.s_MaxSupportedVersion
+                    );
+                    throw new UnityAgentsException("Incompatible trainer version.");
+                }
+
+                var packageVersionSupported = CheckPythonPackageVersionIsSupported(pythonPackageVersion);
+                if (!packageVersionSupported)
+                {
+                    Debug.LogWarningFormat(
+                        "Python package version ({0}) is out of the supported range or not from an official release. " +
+                        "It is strongly recommended that you use a Python package between {1} and {2}. " +
+                        "Training will proceed, but the output format may be different.",
+                        pythonPackageVersion,
+                        PythonTrainerVersions.s_MinSupportedVersion,
+                        PythonTrainerVersions.s_MaxSupportedVersion
+                    );
                 }
             }
             catch

com.unity.ml-agents/Runtime/Constants.cs

+using System;
+
 namespace Unity.MLAgents
 {
     /// <summary>
         Default = 0,
         Sensors = 50
     }
+
+    internal static class PythonTrainerVersions
+    {
+        // The python package version should be >= s_MinSupportedVersion
+        // and <= s_MaxSupportedVersion.
+        internal static Version s_MinSupportedVersion = new Version("0.16.1");
+        internal static Version s_MaxSupportedVersion = new Version("0.20.0");
+
+        // Any version > to this is known to be incompatible and we will block training.
+        // Covers any patch to the release before the 2.0.0 package release.
+        internal static Version s_MaxCompatibleVersion = new Version("0.25.999");
+    }
+
 }

com.unity.ml-agents/Runtime/Inference/ApplierImpl.cs

 using System;
+using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
 using Unity.MLAgents.Inference.Utils;
     /// </summary>
     internal class ContinuousActionOutputApplier : TensorApplier.IApplier
     {
-        public void Apply(TensorProxy tensorProxy, IEnumerable<int> actionIds, Dictionary<int, float[]> lastActions)
+        public void Apply(TensorProxy tensorProxy, IList<int> actionIds, Dictionary<int, float[]> lastActions)
-            foreach (int agentId in actionIds)
+            for (var i = 0; i < actionIds.Count; i++)
+                var agentId = actionIds[i];
                 if (lastActions.ContainsKey(agentId))
                 {
                     var actionValue = lastActions[agentId];
             m_Allocator = allocator;
         }
 
-        public void Apply(TensorProxy tensorProxy, IEnumerable<int> actionIds, Dictionary<int, float[]> lastActions)
+        public void Apply(TensorProxy tensorProxy, IList<int> actionIds, Dictionary<int, float[]> lastActions)
         {
             //var tensorDataProbabilities = tensorProxy.Data as float[,];
             var idActionPairList = actionIds as List<int> ?? actionIds.ToList();
                 outputTensor.data.Dispose();
             }
             var agentIndex = 0;
-            foreach (int agentId in actionIds)
+            for (var i = 0; i < actionIds.Count; i++)
+                var agentId = actionIds[i];
                 if (lastActions.ContainsKey(agentId))
                 {
                     var actionVal = lastActions[agentId];
             m_Memories = memories;
         }
 
-        public void Apply(TensorProxy tensorProxy, IEnumerable<int> actionIds, Dictionary<int, float[]> lastActions)
+        public void Apply(TensorProxy tensorProxy, IList<int> actionIds, Dictionary<int, float[]> lastActions)
-            foreach (int agentId in actionIds)
+            for (var i = 0; i < actionIds.Count; i++)
+                var agentId = actionIds[i];
                 List<float> memory;
                 if (!m_Memories.TryGetValue(agentId, out memory)
                     || memory.Count < memorySize)
             m_Memories = memories;
         }
 
-        public void Apply(TensorProxy tensorProxy, IEnumerable<int> actionIds, Dictionary<int, float[]> lastActions)
+        public void Apply(TensorProxy tensorProxy, IList<int> actionIds, Dictionary<int, float[]> lastActions)
-            foreach (int agentId in actionIds)
+            for (var i = 0; i < actionIds.Count; i++)
+                var agentId = actionIds[i];
                 List<float> memory;
                 if (!m_Memories.TryGetValue(agentId, out memory)
                     || memory.Count < memorySize * m_MemoriesCount)

com.unity.ml-agents/Runtime/Inference/GeneratorImpl.cs

             m_Allocator = allocator;
         }
 
-        public void Generate(TensorProxy tensorProxy, int batchSize, IEnumerable<AgentInfoSensorsPair> infos)
+        public void Generate(TensorProxy tensorProxy, int batchSize, IList<AgentInfoSensorsPair> infos)
         {
             TensorUtils.ResizeTensor(tensorProxy, batchSize, m_Allocator);
         }
             m_Allocator = allocator;
         }
 
-        public void Generate(TensorProxy tensorProxy, int batchSize, IEnumerable<AgentInfoSensorsPair> infos)
+        public void Generate(TensorProxy tensorProxy, int batchSize, IList<AgentInfoSensorsPair> infos)
         {
             tensorProxy.data?.Dispose();
             tensorProxy.data = m_Allocator.Alloc(new TensorShape(1, 1));
             m_Allocator = allocator;
         }
 
-        public void Generate(TensorProxy tensorProxy, int batchSize, IEnumerable<AgentInfoSensorsPair> infos)
+        public void Generate(TensorProxy tensorProxy, int batchSize, IList<AgentInfoSensorsPair> infos)
         {
             tensorProxy.shape = new long[0];
             tensorProxy.data?.Dispose();
             m_SensorIndices.Add(sensorIndex);
         }
 
-        public void Generate(TensorProxy tensorProxy, int batchSize, IEnumerable<AgentInfoSensorsPair> infos)
+        public void Generate(TensorProxy tensorProxy, int batchSize, IList<AgentInfoSensorsPair> infos)
-            foreach (var info in infos)
+            for (var infoIndex = 0; infoIndex < infos.Count; infoIndex++)
+                var info = infos[infoIndex];
                 if (info.agentInfo.done)
                 {
                     // If the agent is done, we might have a stale reference to the sensors
                 {
                     var tensorOffset = 0;
                     // Write each sensor consecutively to the tensor
-                    foreach (var sensorIndex in m_SensorIndices)
+                    // TOOD
+                    for (var sensorIndexIndex = 0; sensorIndexIndex < m_SensorIndices.Count; sensorIndexIndex++)
+                        var sensorIndex = m_SensorIndices[sensorIndexIndex];
                         var sensor = info.sensors[sensorIndex];
                         m_ObservationWriter.SetTarget(tensorProxy, agentIndex, tensorOffset);
                         var numWritten = sensor.Write(m_ObservationWriter);
         }
 
         public void Generate(
-            TensorProxy tensorProxy, int batchSize, IEnumerable<AgentInfoSensorsPair> infos)
+            TensorProxy tensorProxy, int batchSize, IList<AgentInfoSensorsPair> infos)
-            foreach (var infoSensorPair in infos)
+            for (var infoIndex = 0; infoIndex < infos.Count; infoIndex++)
+                var infoSensorPair = infos[infoIndex];
                 var info = infoSensorPair.agentInfo;
                 List<float> memory;
 
             m_Memories = memories;
         }
 
-        public void Generate(TensorProxy tensorProxy, int batchSize, IEnumerable<AgentInfoSensorsPair> infos)
+        public void Generate(TensorProxy tensorProxy, int batchSize, IList<AgentInfoSensorsPair> infos)
-            foreach (var infoSensorPair in infos)
+            for (var infoIndex = 0; infoIndex < infos.Count; infoIndex++)
+                var infoSensorPair = infos[infoIndex];
+
                 var info = infoSensorPair.agentInfo;
                 var offset = memorySize * m_MemoryIndex;
                 List<float> memory;
             m_Allocator = allocator;
         }
 
-        public void Generate(TensorProxy tensorProxy, int batchSize, IEnumerable<AgentInfoSensorsPair> infos)
+        public void Generate(TensorProxy tensorProxy, int batchSize, IList<AgentInfoSensorsPair> infos)
-            foreach (var infoSensorPair in infos)
+            for (var infoIndex = 0; infoIndex < infos.Count; infoIndex++)
+                var infoSensorPair = infos[infoIndex];
+
                 var info = infoSensorPair.agentInfo;
                 var pastAction = info.storedVectorActions;
                 if (pastAction != null)
             m_Allocator = allocator;
         }
 
-        public void Generate(TensorProxy tensorProxy, int batchSize, IEnumerable<AgentInfoSensorsPair> infos)
+        public void Generate(TensorProxy tensorProxy, int batchSize, IList<AgentInfoSensorsPair> infos)
-            foreach (var infoSensorPair in infos)
+            for (var infoIndex = 0; infoIndex < infos.Count; infoIndex++)
+                var infoSensorPair = infos[infoIndex];
+
                 var agentInfo = infoSensorPair.agentInfo;
                 var maskList = agentInfo.discreteActionMasks;
                 for (var j = 0; j < maskSize; j++)
             m_Allocator = allocator;
         }
 
-        public void Generate(TensorProxy tensorProxy, int batchSize, IEnumerable<AgentInfoSensorsPair> infos)
+        public void Generate(TensorProxy tensorProxy, int batchSize, IList<AgentInfoSensorsPair> infos)
         {
             TensorUtils.ResizeTensor(tensorProxy, batchSize, m_Allocator);
             TensorUtils.FillTensorWithRandomNormal(tensorProxy, m_RandomNormal);
             m_Allocator = allocator;
         }
 
-        public void Generate(TensorProxy tensorProxy, int batchSize, IEnumerable<AgentInfoSensorsPair> infos)
+        public void Generate(TensorProxy tensorProxy, int batchSize, IList<AgentInfoSensorsPair> infos)
-            foreach (var infoSensorPair in infos)
+            for (var infoIndex = 0; infoIndex < infos.Count; infoIndex++)
+                var infoSensorPair = infos[infoIndex];
+
                 var sensor = infoSensorPair.sensors[m_SensorIndex];
                 if (infoSensorPair.agentInfo.done)
                 {

com.unity.ml-agents/Runtime/Inference/TensorApplier.cs

             /// </param>
             /// <param name="actionIds"> List of Agents Ids that will be updated using the tensor's data</param>
             /// <param name="lastActions"> Dictionary of AgentId to Actions to be updated</param>
-            void Apply(TensorProxy tensorProxy, IEnumerable<int> actionIds, Dictionary<int, float[]> lastActions);
+            void Apply(TensorProxy tensorProxy, IList<int> actionIds, Dictionary<int, float[]> lastActions);
         }
 
         readonly Dictionary<string, IApplier> m_Dict = new Dictionary<string, IApplier>();
         /// <exception cref="UnityAgentsException"> One of the tensor does not have an
         /// associated applier.</exception>
         public void ApplyTensors(
-            IEnumerable<TensorProxy> tensors, IEnumerable<int> actionIds, Dictionary<int, float[]> lastActions)
+            IReadOnlyList<TensorProxy> tensors, IList<int> actionIds, Dictionary<int, float[]> lastActions)
-            foreach (var tensor in tensors)
+            for (var tensorIndex = 0; tensorIndex < tensors.Count; tensorIndex++)
+                var tensor = tensors[tensorIndex];
                 if (!m_Dict.ContainsKey(tensor.name))
                 {
                     throw new UnityAgentsException(

com.unity.ml-agents/Runtime/Inference/TensorGenerator.cs

             /// the tensor's data.
             /// </param>
             void Generate(
-                TensorProxy tensorProxy, int batchSize, IEnumerable<AgentInfoSensorsPair> infos);
+                TensorProxy tensorProxy, int batchSize, IList<AgentInfoSensorsPair> infos);
         }
 
         readonly Dictionary<string, IGenerator> m_Dict = new Dictionary<string, IGenerator>();
         /// <exception cref="UnityAgentsException"> One of the tensor does not have an
         /// associated generator.</exception>
         public void GenerateTensors(
-            IEnumerable<TensorProxy> tensors, int currentBatchSize, IEnumerable<AgentInfoSensorsPair> infos)
+            IReadOnlyList<TensorProxy> tensors, int currentBatchSize, IList<AgentInfoSensorsPair> infos)
-            foreach (var tensor in tensors)
+            for (var tensorIndex = 0; tensorIndex < tensors.Count; tensorIndex++)
+                var tensor = tensors[tensorIndex];
                 if (!m_Dict.ContainsKey(tensor.name))
                 {
                     throw new UnityAgentsException(

com.unity.ml-agents/Runtime/Inference/TensorProxy.cs

         public Type DataType => k_TypeMap[valueType];
         public long[] shape;
         public Tensor data;
+
+        public long Height
+        {
+            get { return shape.Length == 4 ? shape[1] : shape[5]; }
+        }
+
+        public long Width
+        {
+            get { return shape.Length == 4 ? shape[2] : shape[6]; }
+        }
+
+        public long Channels
+        {
+            get { return shape.Length == 4 ? shape[3] : shape[7]; }
+        }
     }
 
     internal static class TensorUtils
             tensor.data?.Dispose();
             tensor.shape[0] = batch;
 
-            if (tensor.shape.Length == 4)
+            if (tensor.shape.Length == 4 || tensor.shape.Length == 8)
-                        (int)tensor.shape[1],
-                        (int)tensor.shape[2],
-                        (int)tensor.shape[3]));
+                        (int)tensor.Height,
+                        (int)tensor.Width,
+                        (int)tensor.Channels));
             }
             else
             {

com.unity.ml-agents/Runtime/Inference/ModelRunner.cs

         bool m_Verbose = false;
         string[] m_OutputNames;
         IReadOnlyList<TensorProxy> m_InferenceInputs;
-        IReadOnlyList<TensorProxy> m_InferenceOutputs;
+        List<TensorProxy> m_InferenceOutputs;
+        Dictionary<string, Tensor> m_InputsByName;
         Dictionary<int, List<float>> m_Memories = new Dictionary<int, List<float>>();
 
         SensorShapeValidator m_SensorShapeValidator = new SensorShapeValidator();
                 seed, m_TensorAllocator, m_Memories, barracudaModel);
             m_TensorApplier = new TensorApplier(
                 brainParameters, seed, m_TensorAllocator, m_Memories, barracudaModel);
+            m_InputsByName = new Dictionary<string, Tensor>();
+            m_InferenceOutputs = new List<TensorProxy>();
-        static Dictionary<string, Tensor> PrepareBarracudaInputs(IEnumerable<TensorProxy> infInputs)
+        public InferenceDevice InferenceDevice
+        {
+            get { return m_InferenceDevice; }
+        }
+
+        public NNModel Model
+        {
+            get { return m_Model; }
+        }
+
+        void PrepareBarracudaInputs(IReadOnlyList<TensorProxy> infInputs)
-            var inputs = new Dictionary<string, Tensor>();
-            foreach (var inp in infInputs)
+            m_InputsByName.Clear();
+            for (var i = 0; i < infInputs.Count; i++)
-                inputs[inp.name] = inp.data;
+                var inp = infInputs[i];
+                m_InputsByName[inp.name] = inp.data;
-
-            return inputs;
         }
 
         public void Dispose()
             m_TensorAllocator?.Reset(false);
         }
 
-        List<TensorProxy> FetchBarracudaOutputs(string[] names)
+        void FetchBarracudaOutputs(string[] names)
-            var outputs = new List<TensorProxy>();
+            m_InferenceOutputs.Clear();
-                outputs.Add(TensorUtils.TensorProxyFromBarracuda(output, n));
+                m_InferenceOutputs.Add(TensorUtils.TensorProxyFromBarracuda(output, n));
-
-            return outputs;
         }
 
         public void PutObservations(AgentInfo info, List<ISensor> sensors)
             Profiler.EndSample();
 
             Profiler.BeginSample($"MLAgents.{m_Model.name}.PrepareBarracudaInputs");
-            var inputs = PrepareBarracudaInputs(m_InferenceInputs);
+            PrepareBarracudaInputs(m_InferenceInputs);
-            m_Engine.Execute(inputs);
+            m_Engine.Execute(m_InputsByName);
-            m_InferenceOutputs = FetchBarracudaOutputs(m_OutputNames);
+            FetchBarracudaOutputs(m_OutputNames);
             Profiler.EndSample();
 
             Profiler.BeginSample($"MLAgents.{m_Model.name}.ApplyTensors");

com.unity.ml-agents/Runtime/Inference/BarracudaModelParamLoader.cs

             }
 
             var modelApiVersion = (int)model.GetTensorByName(TensorNames.VersionNumber)[0];
-            var memorySize = (int)model.GetTensorByName(TensorNames.MemorySize)[0];
-            var isContinuousInt = (int)model.GetTensorByName(TensorNames.IsContinuousControl)[0];
-            var isContinuous = GetActionType(isContinuousInt);
-            var actionSize = (int)model.GetTensorByName(TensorNames.ActionOutputShape)[0];
             if (modelApiVersion == -1)
             {
                 failedModelChecks.Add(
             }
-            if (modelApiVersion != k_ApiVersion)
+            if (modelApiVersion < k_ApiVersion)
             {
                 failedModelChecks.Add(
                     $"Version of the trainer the model was trained with ({modelApiVersion}) " +
+
+            if (modelApiVersion > k_ApiVersion)
+            {
+                var minTrainerVersion = PythonTrainerVersions.s_MinSupportedVersion;
+                var maxTrainerVersion = PythonTrainerVersions.s_MaxSupportedVersion;
+
+                failedModelChecks.Add(
+                    "Model was trained with a newer version of the trainer than is supported. " +
+                    $"Either retrain with an older trainer (between versions {minTrainerVersion} and {maxTrainerVersion}), " +
+                    $"or update to a newer version of com.unity.ml-agents.\n" +
+                    $"Model version: {modelApiVersion}  Supported version: {k_ApiVersion}"
+                );
+                return failedModelChecks;
+            }
+
+            var memorySize = (int)model.GetTensorByName(TensorNames.MemorySize)[0];
+            var isContinuousInt = (int)model.GetTensorByName(TensorNames.IsContinuousControl)[0];
+            var isContinuous = GetActionType(isContinuousInt);
+            var actionSize = (int)model.GetTensorByName(TensorNames.ActionOutputShape)[0];
 
             failedModelChecks.AddRange(
                 CheckIntScalarPresenceHelper(new Dictionary<string, int>()
             var heightBp = shape[0];
             var widthBp = shape[1];
             var pixelBp = shape[2];
-            var heightT = tensorProxy.shape[1];
-            var widthT = tensorProxy.shape[2];
-            var pixelT = tensorProxy.shape[3];
+            var heightT = tensorProxy.Height;
+            var widthT = tensorProxy.Width;
+            var pixelT = tensorProxy.Channels;
             if ((widthBp != widthT) || (heightBp != heightT) || (pixelBp != pixelT))
             {
                 return $"The visual Observation of the model does not match. " +

com.unity.ml-agents/Runtime/Academy.cs

  * API. For more information on each of these entities, in addition to how to
  * set-up a learning environment and train the behavior of characters in a
  * Unity scene, please browse our documentation pages on GitHub:
- * https://github.com/Unity-Technologies/ml-agents/tree/release_1_docs/docs/
+ * https://github.com/Unity-Technologies/ml-agents/tree/release_2_verified_docs/docs/
  */
 
 namespace Unity.MLAgents
     {
         void FixedUpdate()
         {
-            Academy.Instance.EnvironmentStep();
+            // Check if the stepper belongs to the current Academy and destroy it if it's not.
+            // This is to prevent from having leaked stepper from previous runs.
+            if (!Academy.IsInitialized || !Academy.Instance.IsStepperOwner(this))
+            {
+                Destroy(this.gameObject);
+            }
+            else
+            {
+                Academy.Instance.EnvironmentStep();
+            }
         }
     }
 
     /// fall back to inference or heuristic decisions. (You can also set agents to always use
     /// inference or heuristics.)
     /// </remarks>
-    [HelpURL("https://github.com/Unity-Technologies/ml-agents/tree/release_1_docs/" +
+    [HelpURL("https://github.com/Unity-Technologies/ml-agents/tree/release_2_verified_docs/" +
         "docs/Learning-Environment-Design.md")]
     public class Academy : IDisposable
     {
         /// Unity package version of com.unity.ml-agents.
         /// This must match the version string in package.json and is checked in a unit test.
         /// </summary>
-        internal const string k_PackageVersion = "1.0.0-preview";
+        internal const string k_PackageVersion = "1.0.8";
 
         const int k_EditorTrainingPort = 5004;
 
         // Flag used to keep track of the first time the Academy is reset.
         bool m_HadFirstReset;
 
+        // Detect an Academy step called by user code that is also called by the Academy.
+        private RecursionChecker m_StepRecursionChecker = new RecursionChecker("EnvironmentStep");
+
         // Random seed used for inference.
         int m_InferenceSeed;
 
             Application.quitting += Dispose;
 
             LazyInitialize();
+
+#if UNITY_EDITOR
+            EditorApplication.playModeStateChanged += HandleOnPlayModeChanged;
+#endif
+
+#if UNITY_EDITOR
+        /// <summary>
+        /// Clean up the Academy when switching from edit mode to play mode
+        /// </summary>
+        /// <param name="state">State.</param>
+        void HandleOnPlayModeChanged(PlayModeStateChange state)
+        {
+            if (state == PlayModeStateChange.ExitingEditMode)
+            {
+                Dispose();
+            }
+        }
+#endif
 
         /// <summary>
         /// Initialize the Academy if it hasn't already been initialized.
         /// </summary>
         public void EnvironmentStep()
         {
-            if (!m_HadFirstReset)
+            using (m_StepRecursionChecker.Start())
-                ForcedFullReset();
-            }
+
+
+                if (!m_HadFirstReset)
+                {
+                    ForcedFullReset();
+                }
-            AgentPreStep?.Invoke(m_StepCount);
+                AgentPreStep?.Invoke(m_StepCount);
-            m_StepCount += 1;
-            m_TotalStepCount += 1;
-            AgentIncrementStep?.Invoke();
+                m_StepCount += 1;
+                m_TotalStepCount += 1;
+                AgentIncrementStep?.Invoke();
-            using (TimerStack.Instance.Scoped("AgentSendState"))
-            {
-                AgentSendState?.Invoke();
-            }
+                using (TimerStack.Instance.Scoped("AgentSendState"))
+                {
+                    AgentSendState?.Invoke();
+                }
-            using (TimerStack.Instance.Scoped("DecideAction"))
-            {
-                DecideAction?.Invoke();
-            }
+                using (TimerStack.Instance.Scoped("DecideAction"))
+                {
+                    DecideAction?.Invoke();
+                }
-            // If the communicator is not on, we need to clear the SideChannel sending queue
-            if (!IsCommunicatorOn)
-            {
-                SideChannelsManager.GetSideChannelMessage();
-            }
+                // If the communicator is not on, we need to clear the SideChannel sending queue
+                if (!IsCommunicatorOn)
+                {
+                    SideChannelsManager.GetSideChannelMessage();
+                }
-            using (TimerStack.Instance.Scoped("AgentAct"))
-            {
-                AgentAct?.Invoke();
+                using (TimerStack.Instance.Scoped("AgentAct"))
+                {
+                    AgentAct?.Invoke();
+                }
             }
         }
 
 
             // Reset the Lazy instance
             s_Lazy = new Lazy<Academy>(() => new Academy());
+        }
+
+        /// <summary>
+        /// Check if the input AcademyFixedUpdateStepper belongs to this Academy.
+        /// </summary>
+        internal bool IsStepperOwner(AcademyFixedUpdateStepper stepper)
+        {
+            return GameObject.ReferenceEquals(stepper.gameObject, Academy.Instance.m_StepperObject);
         }
     }
 }

com.unity.ml-agents/Tests/Runtime/RuntimeAPITest.cs

         [SetUp]
         public static void Setup()
         {
+            if (Academy.IsInitialized)
+            {
+                Academy.Instance.Dispose();
+            }
             Academy.Instance.AutomaticSteppingEnabled = false;
         }
 

com.unity.ml-agents/Tests/Editor/PublicAPI/Unity.ML-Agents.Editor.Tests.PublicAPI.asmdef

     "references": [
         "Unity.ML-Agents.Editor",
         "Unity.ML-Agents",
-        "Barracuda",
+        "Unity.Barracuda",
         "Unity.ML-Agents.CommunicatorObjects"
     ],
     "optionalUnityReferences": [

com.unity.ml-agents/Tests/Editor/Communicator/RpcCommunicatorTests.cs

                 pythonPackageVerStr));
 
         }
+
+        [Test]
+        public void TestCheckPythonPackageVersionIsCompatible()
+        {
+            Assert.IsTrue(RpcCommunicator.CheckPythonPackageVersionIsCompatible("0.13.37")); // low is OK
+            Assert.IsFalse(RpcCommunicator.CheckPythonPackageVersionIsCompatible("0.26.0")); // too high
+
+            // These are fine
+            Assert.IsTrue(RpcCommunicator.CheckPythonPackageVersionIsCompatible("0.16.1"));
+            Assert.IsTrue(RpcCommunicator.CheckPythonPackageVersionIsCompatible("0.17.17"));
+            Assert.IsTrue(RpcCommunicator.CheckPythonPackageVersionIsCompatible("0.25.0"));
+            Assert.IsTrue(RpcCommunicator.CheckPythonPackageVersionIsCompatible("0.25.1"));
+            Assert.IsTrue(RpcCommunicator.CheckPythonPackageVersionIsCompatible("0.25.2"));
+
+            // "dev" strings should get removed before parsing
+            Assert.IsTrue(RpcCommunicator.CheckPythonPackageVersionIsCompatible("0.17.0.dev0"));
+            Assert.IsTrue(RpcCommunicator.CheckPythonPackageVersionIsCompatible("0.25.0.dev0"));
+            Assert.IsFalse(RpcCommunicator.CheckPythonPackageVersionIsCompatible("0.26.0.dev0"));
+
+            // otherwise unparseable - keep support for these
+            Assert.IsTrue(RpcCommunicator.CheckPythonPackageVersionIsCompatible("the airspeed velocity of an unladen swallow"));
+        }
+
+        [Test]
+        public void TestCheckPythonPackageVersionIsSupported()
+        {
+            Assert.IsFalse(RpcCommunicator.CheckPythonPackageVersionIsSupported("0.13.37")); // too low
+            Assert.IsFalse(RpcCommunicator.CheckPythonPackageVersionIsSupported("0.42.0")); // too high
+
+            // These are fine
+            Assert.IsTrue(RpcCommunicator.CheckPythonPackageVersionIsSupported("0.16.1"));
+            Assert.IsTrue(RpcCommunicator.CheckPythonPackageVersionIsSupported("0.17.17"));
+            Assert.IsTrue(RpcCommunicator.CheckPythonPackageVersionIsSupported("0.20.0"));
+
+            // "dev" string or otherwise unparseable
+            Assert.IsFalse(RpcCommunicator.CheckPythonPackageVersionIsSupported("0.17.0.dev0"));
+            Assert.IsFalse(RpcCommunicator.CheckPythonPackageVersionIsSupported("oh point seventeen point oh"));
+        }
     }
 }

com.unity.ml-agents/Tests/Editor/MLAgentsEditModeTest.cs

     {
         public Action OnRequestDecision;
         ObservationWriter m_ObsWriter = new ObservationWriter();
-        public void RequestDecision(AgentInfo info, List<ISensor> sensors) {
-            foreach(var sensor in sensors){
+        public void RequestDecision(AgentInfo info, List<ISensor> sensors)
+        {
+            foreach (var sensor in sensors)
+            {
                 sensor.GetObservationProto(m_ObsWriter);
             }
             OnRequestDecision?.Invoke();
             agent1.SetPolicy(policy);
 
             StackingSensor sensor = null;
-            foreach(ISensor s in agent1.sensors){
-                if (s is  StackingSensor){
+            foreach (ISensor s in agent1.sensors)
+            {
+                if (s is  StackingSensor)
+                {
                     sensor = s as StackingSensor;
                 }
             }
             {
                 agent1.RequestDecision();
                 aca.EnvironmentStep();
-
             }
 
             policy.OnRequestDecision = () =>  SensorTestHelper.CompareObservation(sensor, new[] {18f, 19f, 21f});
         public void TestAgentDontCallBaseOnEnable()
         {
             _InnerAgentTestOnEnableOverride();
+        }
+    }
+
+    [TestFixture]
+    public class AgentRecursionTests
+    {
+        [SetUp]
+        public void SetUp()
+        {
+            if (Academy.IsInitialized)
+            {
+                Academy.Instance.Dispose();
+            }
+        }
+
+        class CollectObsEndEpisodeAgent : Agent
+        {
+            public override void CollectObservations(VectorSensor sensor)
+            {
+                // NEVER DO THIS IN REAL CODE!
+                EndEpisode();
+            }
+        }
+
+        class OnEpisodeBeginEndEpisodeAgent : Agent
+        {
+            public override void OnEpisodeBegin()
+            {
+                // NEVER DO THIS IN REAL CODE!
+                EndEpisode();
+            }
+        }
+
+        void TestRecursiveThrows<T>() where T : Agent
+        {
+            var gameObj = new GameObject();
+            var agent = gameObj.AddComponent<T>();
+            agent.LazyInitialize();
+            agent.RequestDecision();
+
+            Assert.Throws<UnityAgentsException>(() =>
+            {
+                Academy.Instance.EnvironmentStep();
+            });
+        }
+
+        [Test]
+        public void TestRecursiveCollectObsEndEpisodeThrows()
+        {
+            TestRecursiveThrows<CollectObsEndEpisodeAgent>();
+        }
+
+        [Test]
+        public void TestRecursiveOnEpisodeBeginEndEpisodeThrows()
+        {
+            TestRecursiveThrows<OnEpisodeBeginEndEpisodeAgent>();
         }
     }
 }

com.unity.ml-agents/Tests/Editor/Sensor/SensorShapeValidatorTests.cs

             validator.ValidateSensors(sensorList1);
 
             var sensorList2 = new List<ISensor>() { new DummySensor(1), new DummySensor(2, 3), new DummySensor(4, 5, 7) };
-            LogAssert.Expect(LogType.Assert, "Sensor sizes much match.");
+            LogAssert.Expect(LogType.Assert, "Sensor sizes must match.");
-            LogAssert.Expect(LogType.Assert, "Sensor sizes much match.");
+            LogAssert.Expect(LogType.Assert, "Sensor sizes must match.");
             validator.ValidateSensors(sensorList1);
         }
 
             var sensorList2 = new List<ISensor>() { new DummySensor(1), new DummySensor(9) };
             LogAssert.Expect(LogType.Assert, "Number of Sensors must match. 3 != 2");
             LogAssert.Expect(LogType.Assert, "Sensor dimensions must match.");
-            LogAssert.Expect(LogType.Assert, "Sensor sizes much match.");
+            LogAssert.Expect(LogType.Assert, "Sensor sizes must match.");
             validator.ValidateSensors(sensorList2);
 
             // Add the sensors in the other order
             LogAssert.Expect(LogType.Assert, "Sensor dimensions must match.");
-            LogAssert.Expect(LogType.Assert, "Sensor sizes much match.");
+            LogAssert.Expect(LogType.Assert, "Sensor sizes must match.");
             validator.ValidateSensors(sensorList1);
         }
     }

com.unity.ml-agents/Tests/Editor/Sensor/RayPerceptionSensorTests.cs

 using System.Collections.Generic;
 using NUnit.Framework;
 using UnityEngine;
+using UnityEngine.TestTools;
 using Unity.MLAgents.Sensors;
 
 namespace Unity.MLAgents.Tests
                 // hit fraction is arbitrary but should be finite in [0,1]
                 Assert.GreaterOrEqual(outputBuffer[2], 0.0f);
                 Assert.LessOrEqual(outputBuffer[2], 1.0f);
+            }
+        }
+
+        [Test]
+        public void TestStaticPerceive()
+        {
+            SetupScene();
+            var obj = new GameObject("agent");
+            var perception = obj.AddComponent<RayPerceptionSensorComponent3D>();
+
+            perception.RaysPerDirection = 0; // single ray
+            perception.MaxRayDegrees = 45;
+            perception.RayLength = 20;
+            perception.DetectableTags = new List<string>();
+            perception.DetectableTags.Add(k_CubeTag);
+            perception.DetectableTags.Add(k_SphereTag);
+
+            var radii = new[] { 0f, .5f };
+            foreach (var castRadius in radii)
+            {
+                perception.SphereCastRadius = castRadius;
+                var castInput = perception.GetRayPerceptionInput();
+                var castOutput = RayPerceptionSensor.Perceive(castInput);
+
+                Assert.AreEqual(1, castOutput.RayOutputs.Length);
+
+                // Expected to hit the cube
+                Assert.AreEqual(0, castOutput.RayOutputs[0].HitTagIndex);
+            }
+        }
+
+        [Test]
+        public void TestStaticPerceiveInvalidTags()
+        {
+            SetupScene();
+            var obj = new GameObject("agent");
+            var perception = obj.AddComponent<RayPerceptionSensorComponent3D>();
+
+            perception.RaysPerDirection = 0; // single ray
+            perception.MaxRayDegrees = 45;
+            perception.RayLength = 20;
+            perception.DetectableTags = new List<string>();
+            perception.DetectableTags.Add("Bad tag");
+            perception.DetectableTags.Add(null);
+            perception.DetectableTags.Add("");
+            perception.DetectableTags.Add(k_CubeTag);
+
+            var radii = new[] { 0f, .5f };
+            foreach (var castRadius in radii)
+            {
+                perception.SphereCastRadius = castRadius;
+                var castInput = perception.GetRayPerceptionInput();
+
+                // There's no clean way that I can find to check for a defined tag without
+                // logging an error.
+                LogAssert.Expect(LogType.Error, "Tag: Bad tag is not defined.");
+                var castOutput = RayPerceptionSensor.Perceive(castInput);
+
+                Assert.AreEqual(1, castOutput.RayOutputs.Length);
+
+                // Expected to hit the cube
+                Assert.AreEqual(3, castOutput.RayOutputs[0].HitTagIndex);
+            }
+        }
+
+        [Test]
+        public void TestStaticPerceiveNoTags()
+        {
+            SetupScene();
+            var obj = new GameObject("agent");
+            var perception = obj.AddComponent<RayPerceptionSensorComponent3D>();
+
+            perception.RaysPerDirection = 0; // single ray
+            perception.MaxRayDegrees = 45;
+            perception.RayLength = 20;
+            perception.DetectableTags = null;
+
+            var radii = new[] { 0f, .5f };
+            foreach (var castRadius in radii)
+            {
+                perception.SphereCastRadius = castRadius;
+                var castInput = perception.GetRayPerceptionInput();
+                var castOutput = RayPerceptionSensor.Perceive(castInput);
+
+                Assert.AreEqual(1, castOutput.RayOutputs.Length);
+
+                // Expected to hit the cube
+                Assert.AreEqual(-1, castOutput.RayOutputs[0].HitTagIndex);
             }
         }
     }

com.unity.ml-agents/Tests/Editor/Sensor/ObservationWriterTests.cs

             writer[0] = 3f;
             Assert.AreEqual(new[] { 1f, 3f, 2f }, buffer);
 
-            // AddRange
+            // AddList
-            writer.AddRange(new[] {4f, 5f});
+            writer.AddList(new[] {4f, 5f});
-            // AddRange with offset
+            // AddList with offset
-            writer.AddRange(new[] {6f, 7f});
+            writer.AddList(new[] {6f, 7f});
             Assert.AreEqual(new[] { 4f, 6f, 7f }, buffer);
         }
 
             Assert.AreEqual(2f, t.data[1, 1]);
             Assert.AreEqual(3f, t.data[1, 2]);
 
-            // AddRange
+            // AddList
             t = new TensorProxy
             {
                 valueType = TensorProxy.TensorType.FloatingPoint,
             writer.SetTarget(t, 1, 1);
-            writer.AddRange(new[] {-1f, -2f});
+            writer.AddList(new[] {-1f, -2f});
             Assert.AreEqual(0f, t.data[0, 0]);
             Assert.AreEqual(0f, t.data[0, 1]);
             Assert.AreEqual(0f, t.data[0, 2]);

com.unity.ml-agents/Tests/Editor/TensorUtilsTest.cs

 using System;
+using System.Text.RegularExpressions;
 using Unity.MLAgents.Inference;
 using Unity.MLAgents.Inference.Utils;
 using Unity.Barracuda;
 {
     public class TensorUtilsTest
     {
+        [TestCase(4, TestName = "TestResizeTensor_4D")]
+        [TestCase(8, TestName = "TestResizeTensor_8D")]
+        public void TestResizeTensor(int dimension)
+        {
+            if (dimension == 8)
+            {
+                // Barracuda 1.0.x doesn't support 8D tensors
+                // Barracuda 1.1.x does but it initially broke ML-Agents support
+                // Unfortunately, the PackageInfo methods don't exist in earlier versions of the editor,
+                // so just skip that variant of the test then.
+                // It's unlikely, but possible that we'll upgrade to a newer dependency of Barracuda,
+                // in which case we should make sure this test is run then.
+#if UNITY_2019_3_OR_NEWER
+                var packageInfo = UnityEditor.PackageManager.PackageInfo.FindForAssembly(typeof(Tensor).Assembly);
+                Assert.AreEqual("com.unity.barracuda", packageInfo.name);
+                var barracuda8DSupport = new Version(1, 1, 0);
+
+                var versionMatch = Regex.Match(packageInfo.version, @"[0-9]+\.[0-9]+\.[0-9]");
+                if (!versionMatch.Success)
+                {
+                    // Couldn't parse barracuda version
+                    return;
+                }
+                var strippedBarracudaVersion = versionMatch.Value;
+                var version = new Version(strippedBarracudaVersion);
+                if (version <= barracuda8DSupport)
+                {
+                    return;
+                }
+#else
+                return;
+#endif
+            }
+            var alloc = new TensorCachingAllocator();
+            var height = 64;
+            var width = 84;
+            var channels = 3;
+
+            // Set shape to {1, ..., height, width, channels}
+            // For 8D, the ... are all 1's
+            var shape = new long[dimension];
+            for (var i = 0; i < dimension; i++)
+            {
+                shape[i] = 1;
+            }
+
+            shape[dimension - 3] = height;
+            shape[dimension - 2] = width;
+            shape[dimension - 1] = channels;
+
+            var intShape = new int[dimension];
+            for (var i = 0; i < dimension; i++)
+            {
+                intShape[i] = (int)shape[i];
+            }
+
+            var tensorProxy = new TensorProxy
+            {
+                valueType = TensorProxy.TensorType.Integer,
+                data = new Tensor(intShape),
+                shape = shape,
+            };
+
+            // These should be invariant after the resize.
+            Assert.AreEqual(height, tensorProxy.data.shape.height);
+            Assert.AreEqual(width, tensorProxy.data.shape.width);
+            Assert.AreEqual(channels, tensorProxy.data.shape.channels);
+
+            TensorUtils.ResizeTensor(tensorProxy, 42, alloc);
+
+            Assert.AreEqual(height, tensorProxy.shape[dimension - 3]);
+            Assert.AreEqual(width, tensorProxy.shape[dimension - 2]);
+            Assert.AreEqual(channels, tensorProxy.shape[dimension - 1]);
+
+            Assert.AreEqual(height, tensorProxy.data.shape.height);
+            Assert.AreEqual(width, tensorProxy.data.shape.width);
+            Assert.AreEqual(channels, tensorProxy.data.shape.channels);
+
+            alloc.Dispose();
+        }
+
         [Test]
         public void RandomNormalTestTensorInt()
         {

com.unity.ml-agents/package.json

 {
   "name": "com.unity.ml-agents",
   "displayName": "ML Agents",
-  "version": "1.0.0-preview",
+  "version": "1.0.8",
-    "com.unity.barracuda": "0.7.0-preview"
+    "com.unity.barracuda": "1.0.4",
+    "com.unity.modules.imageconversion": "1.0.0",
+    "com.unity.modules.jsonserialize": "1.0.0",
+    "com.unity.modules.physics": "1.0.0",
+    "com.unity.modules.physics2d": "1.0.0",
+    "com.unity.modules.unityanalytics": "1.0.0"
   }
 }

ml-agents/mlagents/trainers/__init__.py

 # Version of the library that will be used to upload to pypi
-__version__ = "0.16.0"
+__version__ = "0.16.1"
-__release_tag__ = "release_1"
+__release_tag__ = "release_2"

ml-agents/mlagents/trainers/subprocess_env_manager.py

         return self.env_workers[0].recv().payload
 
     def close(self) -> None:
-        logger.debug(f"SubprocessEnvManager closing.")
+        logger.debug("SubprocessEnvManager closing.")
         self.step_queue.close()
         self.step_queue.join_thread()
         for env_worker in self.env_workers:

ml-agents/mlagents/trainers/buffer.py

         super().__init__()
 
     def __str__(self):
-        return ", ".join(["'{0}' : {1}".format(k, str(self[k])) for k in self.keys()])
+        return ", ".join(["'{}' : {}".format(k, str(self[k])) for k in self.keys()])
 
     def reset_agent(self) -> None:
         """
             key_list = list(self.keys())
         if not self.check_length(key_list):
             raise BufferException(
-                "The length of the fields {0} were not of same length".format(key_list)
+                f"The length of the fields {key_list} were not of same length"
             )
         for field_key in key_list:
             target_buffer[field_key].extend(

ml-agents/mlagents/trainers/components/bc/model.py

 from mlagents.trainers.policy.tf_policy import TFPolicy
 
 
-class BCModel(object):
+class BCModel:
     def __init__(
         self, policy: TFPolicy, learning_rate: float = 3e-4, anneal_steps: int = 0
     ):

ml-agents/mlagents/trainers/components/bc/module.py

         for k in param_keys:
             if k not in config_dict:
                 raise UnityTrainerException(
-                    "The required pre-training hyper-parameter {0} was not defined. Please check your \
+                    "The required pre-training hyper-parameter {} was not defined. Please check your \
                     trainer YAML file.".format(
                         k
                     )

ml-agents/mlagents/trainers/components/reward_signals/__init__.py

         for k in param_keys:
             if k not in config_dict:
                 raise UnityTrainerException(
-                    "The hyper-parameter {0} could not be found for {1}.".format(
+                    "The hyper-parameter {} could not be found for {}.".format(
                         k, cls.__name__
                     )
                 )

ml-agents/mlagents/trainers/components/reward_signals/curiosity/model.py

 from mlagents.trainers.policy.tf_policy import TFPolicy
 
 
-class CuriosityModel(object):
+class CuriosityModel:
     def __init__(
         self, policy: TFPolicy, encoding_size: int = 128, learning_rate: float = 3e-4
     ):
                     self.encoding_size,
                     ModelUtils.swish,
                     1,
-                    "curiosity_stream_{}_visual_obs_encoder".format(i),
+                    f"curiosity_stream_{i}_visual_obs_encoder",
                     False,
                 )
 
                     ModelUtils.swish,
                     1,
-                    "curiosity_stream_{}_visual_obs_encoder".format(i),
+                    f"curiosity_stream_{i}_visual_obs_encoder",
                     True,
                 )
                 visual_encoders.append(encoded_visual)

ml-agents/mlagents/trainers/components/reward_signals/gail/model.py

 EPSILON = 1e-7
 
 
-class GAILModel(object):
+class GAILModel:
     def __init__(
         self,
         policy: TFPolicy,
                     self.encoding_size,
                     ModelUtils.swish,
                     1,
-                    "gail_stream_{}_visual_obs_encoder".format(i),
+                    f"gail_stream_{i}_visual_obs_encoder",
                     False,
                 )
 
                     ModelUtils.swish,
                     1,
-                    "gail_stream_{}_visual_obs_encoder".format(i),
+                    f"gail_stream_{i}_visual_obs_encoder",
                     True,
                 )
                 visual_policy_encoders.append(encoded_policy_visual)

ml-agents/mlagents/trainers/components/reward_signals/reward_signal_factory.py

     """
     rcls = NAME_TO_CLASS.get(name)
     if not rcls:
-        raise UnityTrainerException("Unknown reward signal type {0}".format(name))
+        raise UnityTrainerException(f"Unknown reward signal type {name}")
-            "Unknown parameters given for reward signal {0}".format(name)
+            f"Unknown parameters given for reward signal {name}"
         )
     return class_inst

ml-agents/mlagents/trainers/curriculum.py

                 for key in parameters:
                     config[key] = parameters[key][self.lesson_num]
                 logger.info(
-                    "{0} lesson changed. Now in lesson {1}: {2}".format(
+                    "{} lesson changed. Now in lesson {}: {}".format(
                         self.brain_name,
                         self.lesson_num,
                         ", ".join([str(x) + " -> " + str(config[x]) for x in config]),
         try:
             with open(config_path) as data_file:
                 return Curriculum._load_curriculum(data_file)
-        except IOError:
-            raise CurriculumLoadingError(
-                "The file {0} could not be found.".format(config_path)
-            )
+        except OSError:
+            raise CurriculumLoadingError(f"The file {config_path} could not be found.")
-            raise CurriculumLoadingError(
-                "There was an error decoding {}".format(config_path)
-            )
+            raise CurriculumLoadingError(f"There was an error decoding {config_path}")
 
     @staticmethod
     def _load_curriculum(fp: TextIO) -> Dict:

ml-agents/mlagents/trainers/ghost/controller.py

         """
         self._queue.append(self._learning_team)
         self._learning_team = self._queue.popleft()
-        logger.debug(
-            "Learning team {} swapped on step {}".format(self._learning_team, step)
-        )
+        logger.debug(f"Learning team {self._learning_team} swapped on step {step}")
         self._changed_training_team = True
 
     # Adapted from https://github.com/Unity-Technologies/ml-agents/pull/1975 and

ml-agents/mlagents/trainers/ghost/trainer.py

         :param run_id: The identifier of the current run
         """
 
-        super(GhostTrainer, self).__init__(
+        super().__init__(
             brain_name, trainer_parameters, training, run_id, reward_buff_cap
         )
 

ml-agents/mlagents/trainers/models.py

             )
         else:
             raise UnityTrainerException(
-                "The learning rate schedule {} is invalid.".format(lr_schedule)
+                f"The learning rate schedule {lr_schedule} is invalid."
             )
         return learning_rate
 
                     h_size,
                     activation=activation,
                     reuse=reuse,
-                    name="hidden_{}".format(i),
+                    name=f"hidden_{i}",
                     kernel_initializer=tf.initializers.variance_scaling(1.0),
                 )
         return hidden
         """
         value_heads = {}
         for name in stream_names:
-            value = tf.layers.dense(hidden_input, 1, name="{}_value".format(name))
+            value = tf.layers.dense(hidden_input, 1, name=f"{name}_value")
             value_heads[name] = value
         value = tf.reduce_mean(list(value_heads.values()), 0)
         return value_heads, value

ml-agents/mlagents/trainers/policy/tf_policy.py

             self.sequence_length = trainer_parameters["sequence_length"]
             if self.m_size == 0:
                 raise UnityPolicyException(
-                    "The memory size for brain {0} is 0 even "
+                    "The memory size for brain {} is 0 even "
-                    "The memory size for brain {0} is {1} "
+                    "The memory size for brain {} is {} "
                     "but it must be divisible by 2.".format(
                         brain.brain_name, self.m_size
                     )
             ckpt = tf.train.get_checkpoint_state(model_path)
             if ckpt is None:
                 raise UnityPolicyException(
-                    "The model {0} could not be loaded. Make "
+                    "The model {} could not be loaded. Make "
                     "sure you specified the right "
                     "--run-id and that the previous run you are loading from had the same "
                     "behavior names.".format(model_path)
             except tf.errors.NotFoundError:
                 raise UnityPolicyException(
-                    "The model {0} was found but could not be loaded. Make "
+                    "The model {} was found but could not be loaded. Make "
                     "sure the model is from the same version of ML-Agents, has the same behavior parameters, "
                     "and is using the same trainer configuration as the current run.".format(
                         model_path
+                self._set_step(0)
                 logger.info(
                     "Starting training from step 0 and saving to {}.".format(
                         self.model_path
-                logger.info(
-                    "Resuming training from step {}.".format(self.get_current_step())
-                )
+                logger.info(f"Resuming training from step {self.get_current_step()}.")
 
     def initialize_or_load(self):
         # If there is an initialize path, load from that. Else, load from the set model path.

ml-agents/mlagents/trainers/ppo/optimizer.py

         self.old_values = {}
         for name in value_heads.keys():
             returns_holder = tf.placeholder(
-                shape=[None], dtype=tf.float32, name="{}_returns".format(name)
+                shape=[None], dtype=tf.float32, name=f"{name}_returns"
-                shape=[None], dtype=tf.float32, name="{}_value_estimate".format(name)
+                shape=[None], dtype=tf.float32, name=f"{name}_value_estimate"
             )
             self.returns_holders[name] = returns_holder
             self.old_values[name] = old_value
             self.all_old_log_probs: mini_batch["action_probs"],
         }
         for name in self.reward_signals:
-            feed_dict[self.returns_holders[name]] = mini_batch[
-                "{}_returns".format(name)
-            ]
-            feed_dict[self.old_values[name]] = mini_batch[
-                "{}_value_estimates".format(name)
-            ]
+            feed_dict[self.returns_holders[name]] = mini_batch[f"{name}_returns"]
+            feed_dict[self.old_values[name]] = mini_batch[f"{name}_value_estimates"]
 
         if self.policy.output_pre is not None and "actions_pre" in mini_batch:
             feed_dict[self.policy.output_pre] = mini_batch["actions_pre"]

ml-agents/mlagents/trainers/ppo/trainer.py

         :param seed: The seed the model will be initialized with
         :param run_id: The identifier of the current run
         """
-        super(PPOTrainer, self).__init__(
+        super().__init__(
             brain_name, trainer_parameters, training, run_id, reward_buff_cap
         )
         self.param_keys = [
             trajectory.done_reached and not trajectory.max_step_reached,
         )
         for name, v in value_estimates.items():
-            agent_buffer_trajectory["{}_value_estimates".format(name)].extend(v)
+            agent_buffer_trajectory[f"{name}_value_estimates"].extend(v)
             self._stats_reporter.add_stat(
                 self.optimizer.reward_signals[name].value_name, np.mean(v)
             )
             evaluate_result = reward_signal.evaluate_batch(
                 agent_buffer_trajectory
             ).scaled_reward
-            agent_buffer_trajectory["{}_rewards".format(name)].extend(evaluate_result)
+            agent_buffer_trajectory[f"{name}_rewards"].extend(evaluate_result)
             # Report the reward signals
             self.collected_rewards[name][agent_id] += np.sum(evaluate_result)
 
         for name in self.optimizer.reward_signals:
             bootstrap_value = value_next[name]
 
-            local_rewards = agent_buffer_trajectory[
-                "{}_rewards".format(name)
-            ].get_batch()
+            local_rewards = agent_buffer_trajectory[f"{name}_rewards"].get_batch()
-                "{}_value_estimates".format(name)
+                f"{name}_value_estimates"
             ].get_batch()
             local_advantage = get_gae(
                 rewards=local_rewards,
             )
             local_return = local_advantage + local_value_estimates
             # This is later use as target for the different value estimates
-            agent_buffer_trajectory["{}_returns".format(name)].set(local_return)
-            agent_buffer_trajectory["{}_advantage".format(name)].set(local_advantage)
+            agent_buffer_trajectory[f"{name}_returns"].set(local_return)
+            agent_buffer_trajectory[f"{name}_advantage"].set(local_advantage)
             tmp_advantages.append(local_advantage)
             tmp_returns.append(local_return)
 
             self.update_buffer.shuffle(sequence_length=self.policy.sequence_length)
             buffer = self.update_buffer
             max_num_batch = buffer_length // batch_size
-            for l in range(0, max_num_batch * batch_size, batch_size):
+            for i in range(0, max_num_batch * batch_size, batch_size):
-                    buffer.make_mini_batch(l, l + batch_size), n_sequences
+                    buffer.make_mini_batch(i, i + batch_size), n_sequences
                 )
                 for stat_name, value in update_stats.items():
                     batch_update_stats[stat_name].append(value)

ml-agents/mlagents/trainers/sac/network.py

         """
         self.value_heads = {}
         for name in stream_names:
-            value = tf.layers.dense(hidden_input, 1, name="{}_value".format(name))
+            value = tf.layers.dense(hidden_input, 1, name=f"{name}_value")
             self.value_heads[name] = value
         self.value = tf.reduce_mean(list(self.value_heads.values()), 0)
 
 
             q1_heads = {}
             for name in stream_names:
-                _q1 = tf.layers.dense(q1_hidden, num_outputs, name="{}_q1".format(name))
+                _q1 = tf.layers.dense(q1_hidden, num_outputs, name=f"{name}_q1")
                 q1_heads[name] = _q1
 
             q1 = tf.reduce_mean(list(q1_heads.values()), axis=0)
 
             q2_heads = {}
             for name in stream_names:
-                _q2 = tf.layers.dense(q2_hidden, num_outputs, name="{}_q2".format(name))
+                _q2 = tf.layers.dense(q2_hidden, num_outputs, name=f"{name}_q2")
                 q2_heads[name] = _q2
 
             q2 = tf.reduce_mean(list(q2_heads.values()), axis=0)

ml-agents/mlagents/trainers/sac/optimizer.py

                 )
 
             rewards_holder = tf.placeholder(
-                shape=[None], dtype=tf.float32, name="{}_rewards".format(name)
+                shape=[None], dtype=tf.float32, name=f"{name}_rewards"
             )
             self.rewards_holders[name] = rewards_holder
 
             self.policy.mask_input: batch["masks"] * burn_in_mask,
         }
         for name in self.reward_signals:
-            feed_dict[self.rewards_holders[name]] = batch["{}_rewards".format(name)]
+            feed_dict[self.rewards_holders[name]] = batch[f"{name}_rewards"]
 
         if self.policy.use_continuous_act:
             feed_dict[self.policy_network.external_action_in] = batch["actions"]

ml-agents/mlagents/trainers/sac/trainer.py

         filename = os.path.join(
             self.trainer_parameters["model_path"], "last_replay_buffer.hdf5"
         )
-        logger.info("Saving Experience Replay Buffer to {}".format(filename))
+        logger.info(f"Saving Experience Replay Buffer to {filename}")
         with open(filename, "wb") as file_object:
             self.update_buffer.save_to_file(file_object)
 
         filename = os.path.join(
             self.trainer_parameters["model_path"], "last_replay_buffer.hdf5"
         )
-        logger.info("Loading Experience Replay Buffer from {}".format(filename))
+        logger.info(f"Loading Experience Replay Buffer from {filename}")
         with open(filename, "rb+") as file_object:
             self.update_buffer.load_from_file(file_object)
         logger.info(
 
         batch_update_stats: Dict[str, list] = defaultdict(list)
         while self.step / self.update_steps > self.steps_per_update:
-            logger.debug("Updating SAC policy at step {}".format(self.step))
+            logger.debug(f"Updating SAC policy at step {self.step}")
             buffer = self.update_buffer
             if (
                 self.update_buffer.num_experiences
                 )
                 # Get rewards for each reward
                 for name, signal in self.optimizer.reward_signals.items():
-                    sampled_minibatch[
-                        "{}_rewards".format(name)
-                    ] = signal.evaluate_batch(sampled_minibatch).scaled_reward
+                    sampled_minibatch[f"{name}_rewards"] = signal.evaluate_batch(
+                        sampled_minibatch
+                    ).scaled_reward
 
                 update_stats = self.optimizer.update(sampled_minibatch, n_sequences)
                 for stat_name, value in update_stats.items():
             # Get minibatches for reward signal update if needed
             reward_signal_minibatches = {}
             for name, signal in self.optimizer.reward_signals.items():
-                logger.debug("Updating {} at step {}".format(name, self.step))
+                logger.debug(f"Updating {name} at step {self.step}")
                 # Some signals don't need a minibatch to be sampled - so we don't!
                 if signal.update_dict:
                     reward_signal_minibatches[name] = buffer.sample_mini_batch(

ml-agents/mlagents/trainers/sampler_class.py

         for param_name, cur_param_dict in self.reset_param_dict.items():
             if "sampler-type" not in cur_param_dict:
                 raise SamplerException(
-                    "'sampler_type' argument hasn't been supplied for the {0} parameter".format(
+                    "'sampler_type' argument hasn't been supplied for the {} parameter".format(
                         param_name
                     )
                 )

ml-agents/mlagents/trainers/stats.py

             )
             if self.self_play and "Self-play/ELO" in values:
                 elo_stats = values["Self-play/ELO"]
-                logger.info("{} ELO: {:0.3f}. ".format(category, elo_stats.mean))
+                logger.info(f"{category} ELO: {elo_stats.mean:0.3f}. ")
         else:
             logger.info(
                 "{}: Step: {}. No episode was completed since last summary. {}".format(
     ) -> None:
         if property_type == StatsPropertyType.HYPERPARAMETERS:
             logger.info(
-                """Hyperparameters for behavior name {0}: \n{1}""".format(
+                """Hyperparameters for behavior name {}: \n{}""".format(
                     category, self._dict_to_str(value, 0)
                 )
             )
                 [
                     "\t"
                     + "  " * num_tabs
-                    + "{0}:\t{1}".format(
+                    + "{}:\t{}".format(
                         x, self._dict_to_str(param_dict[x], num_tabs + 1)
                     )
                     for x in param_dict
         self._maybe_create_summary_writer(category)
         for key, value in values.items():
             summary = tf.Summary()
-            summary.value.add(tag="{}".format(key), simple_value=value.mean)
+            summary.value.add(tag=f"{key}", simple_value=value.mean)
             self.summary_writers[category].add_summary(summary, step)
             self.summary_writers[category].flush()
 
         for file_name in os.listdir(directory_name):
             if file_name.startswith("events.out"):
                 logger.warning(
-                    "{} was left over from a previous run. Deleting.".format(file_name)
+                    f"{file_name} was left over from a previous run. Deleting."
                 )
                 full_fname = os.path.join(directory_name, file_name)
                 try:
                 s_op = tf.summary.text(
                     name,
                     tf.convert_to_tensor(
-                        ([[str(x), str(input_dict[x])] for x in input_dict])
+                        [[str(x), str(input_dict[x])] for x in input_dict]
                     ),
                 )
                 s = sess.run(s_op)