Merge branch 'develop-add-fire' into develop-add-fire-sac-lst

.pre-commit-config.yaml

     hooks:
     -   id: pyupgrade
         args: [--py3-plus, --py36-plus]
-        exclude: .*barracuda.py
+        exclude: >
+            (?x)^(
+                .*barracuda.py|
+                .*_pb2.py|
+                .*_pb2_grpc.py
+            )$
 
 -   repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v2.5.0

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

   variables:
     UNITY_VERSION: {{ editor.version }}
   commands:
-    - python -m pip install unity-downloader-cli --extra-index-url https://artifactory.eu-cph-1.unityops.net/api/pypi/common-python/simple
+    - python -m pip install unity-downloader-cli --index-url https://artifactory.prd.it.unity3d.com/artifactory/api/pypi/pypi/simple
     - unity-downloader-cli -u {{ editor.version }} -c editor --wait --fast
     - curl -s https://artifactory.internal.unity3d.com/core-automation/tools/utr-standalone/utr --output utr
     - chmod +x ./utr

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

     image: {{ platform.image }}
     flavor: {{ platform.flavor}}
   commands:
-    - python -m pip install unity-downloader-cli --extra-index-url https://artifactory.prd.it.unity3d.com/artifactory/api/pypi/unity-pypi-local/simple --upgrade
+    - python -m pip install unity-downloader-cli --index-url https://artifactory.prd.it.unity3d.com/artifactory/api/pypi/pypi/simple --upgrade
     - 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 project test -u {{ editor.version }} --project-path Project --package-filter {{ package.name }} {{ coverageOptions }}

.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:
     expression: |
       (pull_request.target eq "master" 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 
+      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/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/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
     expression: |
       (pull_request.target eq "master" 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 
+      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/standalone-build-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.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

.yamato/training-int-tests.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.training_int_tests
     # Backwards-compatibility tests.
     # If we make a breaking change to the communication protocol, these will need

Project/Assets/ML-Agents/Examples/Crawler/Prefabs/Crawler.prefab

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   m_Name: Crawler
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   m_Name: 
   m_EditorClassIdentifier: 
   m_BrainParameters:
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+    VectorObservationSize: 21
     NumStackedVectorObservations: 1
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     VectorActionDescriptions: []
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   m_EditorClassIdentifier: 
   debugCommandLineOverride: 
+--- !u!114 &4622120667686875944
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+  m_Name: 
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+  VirtualRoot: {fileID: 2270141184585723037}
+  Settings:
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+    UseModelSpaceRotations: 1
+    UseLocalSpaceTranslations: 0
+    UseLocalSpaceRotations: 1
+    UseModelSpaceLinearVelocity: 1
+    UseLocalSpaceLinearVelocity: 0
+    UseJointPositionsAndAngles: 0
+    UseJointForces: 0
+  sensorName: 
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+  m_GameObject: {fileID: 2270141184585723037}
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Project/Assets/ML-Agents/Examples/Crawler/Prefabs/FixedPlatform.prefab

       propertyPath: targetToLookAt
       value: 
       objectReference: {fileID: 2673081981996998229}
+    - target: {fileID: 4622120667686875944, guid: 0456c89e8c9c243d595b039fe7aa0bf9,
+        type: 3}
+      propertyPath: Settings.UseLocalSpaceLinearVelocity
+      value: 1
+      objectReference: {fileID: 0}
     - target: {fileID: 4845971000000621469, guid: 0456c89e8c9c243d595b039fe7aa0bf9,
         type: 3}
       propertyPath: m_ConnectedAnchor.x

Project/Assets/ML-Agents/Examples/Crawler/Scripts/CrawlerAgent.cs

         //GROUND CHECK
         sensor.AddObservation(bp.groundContact.touchingGround); // Is this bp touching the ground
 
-        //Get velocities in the context of our orientation cube's space
-        //Note: You can get these velocities in world space as well but it may not train as well.
-        sensor.AddObservation(orientationCube.transform.InverseTransformDirection(bp.rb.velocity));
-        sensor.AddObservation(orientationCube.transform.InverseTransformDirection(bp.rb.angularVelocity));
-
-        //Get position relative to hips in the context of our orientation cube's space
-        sensor.AddObservation(orientationCube.transform.InverseTransformDirection(bp.rb.position - body.position));
-
-            sensor.AddObservation(bp.rb.transform.localRotation);
             sensor.AddObservation(bp.currentStrength / m_JdController.maxJointForceLimit);
         }
     }
     /// </summary>
     public override void CollectObservations(VectorSensor sensor)
     {
-        //Add body rotation delta relative to orientation cube
-        sensor.AddObservation(Quaternion.FromToRotation(body.forward, orientationCube.transform.forward));
-
         //Add pos of target relative to orientation cube
         sensor.AddObservation(orientationCube.transform.InverseTransformPoint(target.transform.position));
 

Project/Assets/ML-Agents/Examples/PushBlock/Prefabs/PushBlockVisualArea.prefab

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-    numStackedVectorObservations: 1
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+    VectorObservationSize: 0
+    NumStackedVectorObservations: 1
+    VectorActionSize: 07000000
+    VectorActionDescriptions: []
+    VectorActionSpaceType: 0
-  m_BehaviorName: VisualHallway
-  m_TeamID: 0
-  m_useChildSensors: 1
+  m_BehaviorName: VisualPushBlock
+  TeamId: 0
+  m_UseChildSensors: 1
+  m_ObservableAttributeHandling: 0
 --- !u!114 &114812843792483960
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   m_Name: 
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-  maxStep: 5000
+  agentParameters:
+    maxStep: 0
+  hasUpgradedFromAgentParameters: 1
+  MaxStep: 5000
   ground: {fileID: 1913379827958244}
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   areaBounds:
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-  sensorName: CameraSensor
-  width: 84
-  height: 84
-  grayscale: 0
-  compression: 1
+  m_Camera: {fileID: 20961401228419460}
+  m_SensorName: CameraSensor
+  m_Width: 84
+  m_Height: 84
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Project/ProjectSettings/ProjectVersion.txt

-m_EditorVersion: 2018.4.20f1
+m_EditorVersion: 2018.4.24f1

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_4_docs/docs/)
+[![docs badge](https://img.shields.io/badge/docs-reference-blue.svg)](https://github.com/Unity-Technologies/ml-agents/tree/release_5_docs/docs/)
 
 [![license badge](https://img.shields.io/badge/license-Apache--2.0-green.svg)](LICENSE)
 
 
 ## Releases & Documentation
 
-**Our latest, stable release is `Release 4`. Click
-[here](https://github.com/Unity-Technologies/ml-agents/tree/release_4_docs/docs/Readme.md)
+**Our latest, stable release is `Release 5`. Click
+[here](https://github.com/Unity-Technologies/ml-agents/tree/release_5_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
 | **Version** | **Release Date** | **Source** | **Documentation** | **Download** |
 |:-------:|:------:|:-------------:|:-------:|:------------:|
 | **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 4** | **July 15, 2020** | **[source](https://github.com/Unity-Technologies/ml-agents/tree/release_4)** | **[docs](https://github.com/Unity-Technologies/ml-agents/tree/release_4_docs/docs/Readme.md)** | **[download](https://github.com/Unity-Technologies/ml-agents/archive/release_4.zip)** |
+| **Release 5** | **July 31, 2020** | **[source](https://github.com/Unity-Technologies/ml-agents/tree/release_5)** | **[docs](https://github.com/Unity-Technologies/ml-agents/tree/release_5_docs/docs/Readme.md)** | **[download](https://github.com/Unity-Technologies/ml-agents/archive/release_5.zip)** |
+| **Release 4** | July 15, 2020 | [source](https://github.com/Unity-Technologies/ml-agents/tree/release_4) | [docs](https://github.com/Unity-Technologies/ml-agents/tree/release_4_docs/docs/Readme.md) | [download](https://github.com/Unity-Technologies/ml-agents/archive/release_4.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) |
 
 ## Citation
 

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

 # ML-Agents Extensions
 
 This is a source-only package for new features based on ML-Agents.
+
+More details coming soon.

com.unity.ml-agents.extensions/Runtime/Sensors/ArticulationBodyPoseExtractor.cs

                 parentIndices[i] = bodyToIndex[parentArticBody];
             }
 
-            SetParentIndices(parentIndices);
+            Setup(parentIndices);
-        protected override Vector3 GetLinearVelocityAt(int index)
+        protected internal override Vector3 GetLinearVelocityAt(int index)
-        protected override Pose GetPoseAt(int index)
+        protected internal override Pose GetPoseAt(int index)
         {
             var body = m_Bodies[index];
             var go = body.gameObject;

com.unity.ml-agents.extensions/Runtime/Sensors/PhysicsBodySensor.cs

         /// <summary>
         ///  Construct a new PhysicsBodySensor
         /// </summary>
-        /// <param name="rootBody"></param>
+        /// <param name="rootBody">The root Rigidbody. This has no Joints on it (but other Joints may connect to it).</param>
+        /// <param name="rootGameObject">Optional GameObject used to find Rigidbodies in the hierarchy.</param>
+        /// <param name="virtualRoot">Optional GameObject used to determine the root of the poses,
-        public PhysicsBodySensor(Rigidbody rootBody, GameObject rootGameObject, PhysicsSensorSettings settings, string sensorName=null)
+        public PhysicsBodySensor(
+            Rigidbody rootBody,
+            GameObject rootGameObject,
+            GameObject virtualRoot,
+            PhysicsSensorSettings settings,
+            string sensorName=null
+        )
-            var poseExtractor = new RigidBodyPoseExtractor(rootBody, rootGameObject);
+            var poseExtractor = new RigidBodyPoseExtractor(rootBody, rootGameObject, virtualRoot);
             m_PoseExtractor = poseExtractor;
             m_SensorName = string.IsNullOrEmpty(sensorName) ? $"PhysicsBodySensor:{rootBody?.name}" : sensorName;
             m_Settings = settings;

com.unity.ml-agents.extensions/Runtime/Sensors/PhysicsSensorSettings.cs

 using System;
-
 using Unity.MLAgents.Sensors;
 
 namespace Unity.MLAgents.Extensions.Sensors
             var offset = baseOffset;
             if (settings.UseModelSpace)
             {
-                var poses = poseExtractor.ModelSpacePoses;
-                var vels = poseExtractor.ModelSpaceVelocities;
-
-                for(var i=0; i<poseExtractor.NumPoses; i++)
+                foreach (var pose in poseExtractor.GetEnabledModelSpacePoses())
-                    var pose = poses[i];
-                    if(settings.UseModelSpaceTranslations)
+                    if (settings.UseModelSpaceTranslations)
+
+                }
+
+                foreach(var vel in poseExtractor.GetEnabledModelSpaceVelocities())
+                {
-                        writer.Add(vels[i], offset);
+                        writer.Add(vel, offset);
                         offset += 3;
                     }
                 }
             {
-                var poses = poseExtractor.LocalSpacePoses;
-                var vels = poseExtractor.LocalSpaceVelocities;
-
-                for(var i=0; i<poseExtractor.NumPoses; i++)
+                foreach (var pose in poseExtractor.GetEnabledLocalSpacePoses())
-                    var pose = poses[i];
-                    if(settings.UseLocalSpaceTranslations)
+                    if (settings.UseLocalSpaceTranslations)
+
+                }
+
+                foreach(var vel in poseExtractor.GetEnabledLocalSpaceVelocities())
+                {
-                        writer.Add(vels[i], offset);
+                        writer.Add(vel, offset);
                         offset += 3;
                     }
                 }

com.unity.ml-agents.extensions/Runtime/Sensors/PoseExtractor.cs

         Vector3[] m_ModelSpaceLinearVelocities;
         Vector3[] m_LocalSpaceLinearVelocities;
 
+        bool[] m_PoseEnabled;
+
-        /// Read access to the model space transforms.
+        /// Read iterator for the enabled model space transforms.
-        public IList<Pose> ModelSpacePoses
+        public IEnumerable<Pose> GetEnabledModelSpacePoses()
-            get { return m_ModelSpacePoses;  }
+            if (m_ModelSpacePoses == null)
+            {
+                yield break;
+            }
+
+            for (var i = 0; i < m_ModelSpacePoses.Length; i++)
+            {
+                if (m_PoseEnabled[i])
+                {
+                    yield return m_ModelSpacePoses[i];
+                }
+            }
-        /// Read access to the local space transforms.
+        /// Read iterator for the enabled local space transforms.
-        public IList<Pose> LocalSpacePoses
+        public IEnumerable<Pose> GetEnabledLocalSpacePoses()
-            get { return m_LocalSpacePoses;  }
+            if (m_LocalSpacePoses == null)
+            {
+                yield break;
+            }
+
+            for (var i = 0; i < m_LocalSpacePoses.Length; i++)
+            {
+                if (m_PoseEnabled[i])
+                {
+                    yield return m_LocalSpacePoses[i];
+                }
+            }
-        /// Read access to the model space linear velocities.
+        /// Read iterator for the enabled model space linear velocities.
-        public IList<Vector3> ModelSpaceVelocities
+        public IEnumerable<Vector3> GetEnabledModelSpaceVelocities()
-            get { return m_ModelSpaceLinearVelocities;  }
+            if (m_ModelSpaceLinearVelocities == null)
+            {
+                yield break;
+            }
+
+            for (var i = 0; i < m_ModelSpaceLinearVelocities.Length; i++)
+            {
+                if (m_PoseEnabled[i])
+                {
+                    yield return m_ModelSpaceLinearVelocities[i];
+                }
+            }
-        /// Read access to the local space linear velocities.
+        /// Read iterator for the enabled local space linear velocities.
+        /// </summary>
+        public IEnumerable<Vector3> GetEnabledLocalSpaceVelocities()
+        {
+            if (m_LocalSpaceLinearVelocities == null)
+            {
+                yield break;
+            }
+
+            for (var i = 0; i < m_LocalSpaceLinearVelocities.Length; i++)
+            {
+                if (m_PoseEnabled[i])
+                {
+                    yield return m_LocalSpaceLinearVelocities[i];
+                }
+            }
+        }
+
+        /// <summary>
+        /// Number of enabled poses in the hierarchy (read-only).
-        public IList<Vector3> LocalSpaceVelocities
+        public int NumEnabledPoses
-            get { return m_LocalSpaceLinearVelocities;  }
+            get
+            {
+                if (m_PoseEnabled == null)
+                {
+                    return 0;
+                }
+
+                var numEnabled = 0;
+                for (var i = 0; i < m_PoseEnabled.Length; i++)
+                {
+                    numEnabled += m_PoseEnabled[i] ? 1 : 0;
+                }
+
+                return numEnabled;
+            }
-        /// Number of poses in the hierarchy (read-only).
+        /// Number of total poses in the hierarchy (read-only).
-            get { return m_ModelSpacePoses?.Length ?? 0;  }
+            get { return m_ModelSpacePoses?.Length ?? 0; }
         }
 
         /// <summary>
             }
 
             return m_ParentIndices[index];
+        }
+
+        /// <summary>
+        /// Set whether the pose at the given index is enabled or disabled for observations.
+        /// </summary>
+        /// <param name="index"></param>
+        /// <param name="val"></param>
+        public void SetPoseEnabled(int index, bool val)
+        {
+            m_PoseEnabled[index] = val;
         }
 
         /// <summary>
         /// <param name="parentIndices"></param>
-        protected void SetParentIndices(int[] parentIndices)
+        protected void Setup(int[] parentIndices)
+#if DEBUG
+            if (parentIndices[0] != -1)
+            {
+                throw new UnityAgentsException($"Expected parentIndices[0] to be -1, got {parentIndices[0]}");
+            }
+#endif
-            var numTransforms = parentIndices.Length;
-            m_ModelSpacePoses = new Pose[numTransforms];
-            m_LocalSpacePoses = new Pose[numTransforms];
+            var numPoses = parentIndices.Length;
+            m_ModelSpacePoses = new Pose[numPoses];
+            m_LocalSpacePoses = new Pose[numPoses];
+
+            m_ModelSpaceLinearVelocities = new Vector3[numPoses];
+            m_LocalSpaceLinearVelocities = new Vector3[numPoses];
-            m_ModelSpaceLinearVelocities = new Vector3[numTransforms];
-            m_LocalSpaceLinearVelocities = new Vector3[numTransforms];
+            m_PoseEnabled = new bool[numPoses];
+            // All poses are enabled by default. Generally we'll want to disable the root though.
+            for (var i = 0; i < numPoses; i++)
+            {
+                m_PoseEnabled[i] = true;
+            }
         }
 
         /// <summary>
         /// <returns></returns>
-        protected abstract Pose GetPoseAt(int index);
+        protected internal abstract Pose GetPoseAt(int index);
 
         /// <summary>
         /// Return the world space linear velocity of the i'th object.
-        protected abstract Vector3 GetLinearVelocityAt(int index);
+        protected internal abstract Vector3 GetLinearVelocityAt(int index);
 
 
         /// <summary>
         {
-            if (m_ModelSpacePoses == null)
+            using (TimerStack.Instance.Scoped("UpdateModelSpacePoses"))
-                return;
-            }
+                if (m_ModelSpacePoses == null)
+                {
+                    return;
+                }
-            var rootWorldTransform = GetPoseAt(0);
-            var worldToModel = rootWorldTransform.Inverse();
-            var rootLinearVel = GetLinearVelocityAt(0);
+                var rootWorldTransform = GetPoseAt(0);
+                var worldToModel = rootWorldTransform.Inverse();
+                var rootLinearVel = GetLinearVelocityAt(0);
-            for (var i = 0; i < m_ModelSpacePoses.Length; i++)
-            {
-                var currentWorldSpacePose = GetPoseAt(i);
-                var currentModelSpacePose = worldToModel.Multiply(currentWorldSpacePose);
-                m_ModelSpacePoses[i] = currentModelSpacePose;
+                for (var i = 0; i < m_ModelSpacePoses.Length; i++)
+                {
+                    var currentWorldSpacePose = GetPoseAt(i);
+                    var currentModelSpacePose = worldToModel.Multiply(currentWorldSpacePose);
+                    m_ModelSpacePoses[i] = currentModelSpacePose;
-                var currentBodyLinearVel = GetLinearVelocityAt(i);
-                var relativeVelocity = currentBodyLinearVel - rootLinearVel;
-                m_ModelSpaceLinearVelocities[i] = worldToModel.rotation * relativeVelocity;
+                    var currentBodyLinearVel = GetLinearVelocityAt(i);
+                    var relativeVelocity = currentBodyLinearVel - rootLinearVel;
+                    m_ModelSpaceLinearVelocities[i] = worldToModel.rotation * relativeVelocity;
+                }
             }
         }
 
         public void UpdateLocalSpacePoses()
         {
-            if (m_LocalSpacePoses == null)
-            {
-                return;
-            }
-
-            for (var i = 0; i < m_LocalSpacePoses.Length; i++)
+            using (TimerStack.Instance.Scoped("UpdateLocalSpacePoses"))
-                if (m_ParentIndices[i] != -1)
+                if (m_LocalSpacePoses == null)
-                    var parentTransform = GetPoseAt(m_ParentIndices[i]);
-                    // This is slightly inefficient, since for a body with multiple children, we'll end up inverting
-                    // the transform multiple times. Might be able to trade space for perf here.
-                    var invParent = parentTransform.Inverse();
-                    var currentTransform = GetPoseAt(i);
-                    m_LocalSpacePoses[i] = invParent.Multiply(currentTransform);
-
-                    var parentLinearVel = GetLinearVelocityAt(m_ParentIndices[i]);
-                    var currentLinearVel = GetLinearVelocityAt(i);
-                    m_LocalSpaceLinearVelocities[i] = invParent.rotation * (currentLinearVel - parentLinearVel);
+                    return;
-                else
+
+                for (var i = 0; i < m_LocalSpacePoses.Length; i++)
-                    m_LocalSpacePoses[i] = Pose.identity;
-                    m_LocalSpaceLinearVelocities[i] = Vector3.zero;
+                    if (m_ParentIndices[i] != -1)
+                    {
+                        var parentTransform = GetPoseAt(m_ParentIndices[i]);
+                        // This is slightly inefficient, since for a body with multiple children, we'll end up inverting
+                        // the transform multiple times. Might be able to trade space for perf here.
+                        var invParent = parentTransform.Inverse();
+                        var currentTransform = GetPoseAt(i);
+                        m_LocalSpacePoses[i] = invParent.Multiply(currentTransform);
+
+                        var parentLinearVel = GetLinearVelocityAt(m_ParentIndices[i]);
+                        var currentLinearVel = GetLinearVelocityAt(i);
+                        m_LocalSpaceLinearVelocities[i] = invParent.rotation * (currentLinearVel - parentLinearVel);
+                    }
+                    else
+                    {
+                        m_LocalSpacePoses[i] = Pose.identity;
+                        m_LocalSpaceLinearVelocities[i] = Vector3.zero;
+                    }
                 }
             }
         }
             obsPerPose += settings.UseModelSpaceLinearVelocity ? 3 : 0;
             obsPerPose += settings.UseLocalSpaceLinearVelocity ? 3 : 0;
 
-            return NumPoses * obsPerPose;
+            return NumEnabledPoses * obsPerPose;
         }
 
         internal void DrawModelSpace(Vector3 offset)

com.unity.ml-agents.extensions/Runtime/Sensors/RigidBodyPoseExtractor.cs

         Rigidbody[] m_Bodies;
 
         /// <summary>
+        /// Optional game object used to determine the root of the poses, separate from the actual Rigidbodies
+        /// in the hierarchy. For locomotion
+        /// </summary>
+        GameObject m_VirtualRoot;
+
+        /// <summary>
-        /// <param name="rootBody"></param>
-        public RigidBodyPoseExtractor(Rigidbody rootBody, GameObject rootGameObject = null)
+        /// <param name="rootBody">The root Rigidbody. This has no Joints on it (but other Joints may connect to it).</param>
+        /// <param name="rootGameObject">Optional GameObject used to find Rigidbodies in the hierarchy.</param>
+        /// <param name="virtualRoot">Optional GameObject used to determine the root of the poses,
+        /// separate from the actual Rigidbodies in the hierarchy. For locomotion tasks, with ragdolls, this provides
+        /// a stabilized refernece frame, which can improve learning.</param>
+        public RigidBodyPoseExtractor(Rigidbody rootBody, GameObject rootGameObject = null, GameObject virtualRoot = null)
         {
             if (rootBody == null)
             {
             {
                 rbs = rootGameObject.GetComponentsInChildren<Rigidbody>();
             }
-            var bodyToIndex = new Dictionary<Rigidbody, int>(rbs.Length);
-            var parentIndices = new int[rbs.Length];
+
+            if (rbs == null || rbs.Length == 0)
+            {
+                Debug.Log("No rigid bodies found!");
+                return;
+            }
-            if (rbs[0] != rootBody)
+                if (rbs[0] != rootBody)
+            // Adjust the array if we have a virtual root.
+            // This will be at index 0, and the "real" root will be parented to it.
+            if (virtualRoot != null)
+            {
+                var extendedRbs = new Rigidbody[rbs.Length + 1];
+                for (var i = 0; i < rbs.Length; i++)
+                {
+                    extendedRbs[i + 1] = rbs[i];
+                }
+
+                rbs = extendedRbs;
+            }
+
+            var bodyToIndex = new Dictionary<Rigidbody, int>(rbs.Length);
+            var parentIndices = new int[rbs.Length];
+            parentIndices[0] = -1;
+
-                bodyToIndex[rbs[i]] = i;
+                if(rbs[i] != null)
+                {
+                    bodyToIndex[rbs[i]] = i;
+                }
             }
 
             var joints = rootBody.GetComponentsInChildren <Joint>();
                 parentIndices[childIndex] = parentIndex;
             }
 
+            if (virtualRoot != null)
+            {
+                // Make sure the original root treats the virtual root as its parent.
+                parentIndices[1] = 0;
+                m_VirtualRoot = virtualRoot;
+            }
+
-            SetParentIndices(parentIndices);
+            Setup(parentIndices);
+
+            // By default, ignore the root
+            SetPoseEnabled(0, false);
-        protected override Vector3 GetLinearVelocityAt(int index)
+        protected internal override Vector3 GetLinearVelocityAt(int index)
+            if (index == 0 && m_VirtualRoot != null)
+            {
+                // No velocity on the virtual root
+                return Vector3.zero;
+            }
-        protected override Pose GetPoseAt(int index)
+        protected internal override Pose GetPoseAt(int index)
+            if (index == 0 && m_VirtualRoot != null)
+            {
+                // Use the GameObject's world transform
+                return new Pose
+                {
+                    rotation = m_VirtualRoot.transform.rotation,
+                    position = m_VirtualRoot.transform.position
+                };
+            }
+
             var body = m_Bodies[index];
             return new Pose { rotation = body.rotation, position = body.position };
         }

com.unity.ml-agents.extensions/Runtime/Sensors/RigidBodySensorComponent.cs

         public Rigidbody RootBody;
 
         /// <summary>
+        /// Optional GameObject used to determine the root of the poses.
+        /// </summary>
+        public GameObject VirtualRoot;
+
+        /// <summary>
         /// Settings defining what types of observations will be generated.
         /// </summary>
         [SerializeField]
         /// <returns></returns>
         public override ISensor CreateSensor()
         {
-            return new PhysicsBodySensor(RootBody, gameObject, Settings, sensorName);
+            return new PhysicsBodySensor(RootBody, gameObject, VirtualRoot, Settings, sensorName);
         }
 
         /// <inheritdoc/>
 
             // TODO static method in PhysicsBodySensor?
             // TODO only update PoseExtractor when body changes?
-            var poseExtractor = new RigidBodyPoseExtractor(RootBody, gameObject);
+            var poseExtractor = new RigidBodyPoseExtractor(RootBody, gameObject, VirtualRoot);
             var numPoseObservations = poseExtractor.GetNumPoseObservations(Settings);
 
             var numJointObservations = 0;

com.unity.ml-agents.extensions/Tests/Editor/Sensors/ArticulationBodySensorTests.cs

 
                 // Local space
                 0f, 0f, 0f, // Root pos
+                13.37f, 0f, 0f, // Attached pos
+                4.2f, 0f, 0f, // Leaf pos
+
-#endif
-
-                13.37f, 0f, 0f, // Attached pos
-#if UNITY_2020_2_OR_NEWER
-#endif
-
-                4.2f, 0f, 0f, // Leaf pos
-#if UNITY_2020_2_OR_NEWER
                 0f, -1f, 1f // Leaf vel
 #endif
             };

com.unity.ml-agents.extensions/Tests/Editor/Sensors/PoseExtractorTests.cs

     {
         class UselessPoseExtractor : PoseExtractor
         {
-            protected override Pose GetPoseAt(int index)
+            protected internal override Pose GetPoseAt(int index)
-            protected override Vector3 GetLinearVelocityAt(int index)
+            protected internal override Vector3 GetLinearVelocityAt(int index)
             {
                 return Vector3.zero;
             }
-                SetParentIndices(parentIndices);
+                Setup(parentIndices);
             }
         }
 
                 {
                     parents[i] = i - 1;
                 }
-                SetParentIndices(parents);
+                Setup(parents);
-            protected override Pose GetPoseAt(int index)
+            protected internal override Pose GetPoseAt(int index)
             {
                 var rotation = Quaternion.identity;
                 var translation = offset + new Vector3(index, index, index);
                 };
             }
 
-            protected override Vector3 GetLinearVelocityAt(int index)
+            protected  internal override Vector3 GetLinearVelocityAt(int index)
             {
                 return Vector3.zero;
             }
             chain.UpdateModelSpacePoses();
             chain.UpdateLocalSpacePoses();
 
-            // Root transforms are currently always the identity.
-            Assert.IsTrue(chain.ModelSpacePoses[0] == Pose.identity);
-            Assert.IsTrue(chain.LocalSpacePoses[0] == Pose.identity);
-            // Check the non-root transforms
-            for (var i = 1; i < size; i++)
+            var modelPoseIndex = 0;
+            foreach (var modelSpace in chain.GetEnabledModelSpacePoses())
-                var modelSpace = chain.ModelSpacePoses[i];
-                var expectedModelTranslation = new Vector3(i, i, i);
-                Assert.IsTrue(expectedModelTranslation == modelSpace.position);
+                if (modelPoseIndex == 0)
+                {
+                    // Root transforms are currently always the identity.
+                    Assert.IsTrue(modelSpace == Pose.identity);
+                }
+                else
+                {
+                    var expectedModelTranslation = new Vector3(modelPoseIndex, modelPoseIndex, modelPoseIndex);
+                    Assert.IsTrue(expectedModelTranslation == modelSpace.position);
-                var localSpace = chain.LocalSpacePoses[i];
-                var expectedLocalTranslation = new Vector3(1, 1, 1);
-                Assert.IsTrue(expectedLocalTranslation == localSpace.position);
+                }
+                modelPoseIndex++;
+            Assert.AreEqual(size, modelPoseIndex);
+
+            var localPoseIndex = 0;
+            foreach (var localSpace in chain.GetEnabledLocalSpacePoses())
+            {
+                if (localPoseIndex == 0)
+                {
+                    // Root transforms are currently always the identity.
+                    Assert.IsTrue(localSpace == Pose.identity);
+                }
+                else
+                {
+                    var expectedLocalTranslation = new Vector3(1, 1, 1);
+                    Assert.IsTrue(expectedLocalTranslation == localSpace.position, $"{expectedLocalTranslation} != {localSpace.position}");
+                }
+
+                localPoseIndex++;
+            }
+            Assert.AreEqual(size, localPoseIndex);
+        class BadPoseExtractor : PoseExtractor
+        {
+            public BadPoseExtractor()
+            {
+                var size = 2;
+                var parents = new int[size];
+                // Parents are intentionally invalid - expect -1 at root
+                for (var i = 0; i < size; i++)
+                {
+                    parents[i] = i;
+                }
+                Setup(parents);
+            }
+
+            protected internal override Pose GetPoseAt(int index)
+            {
+                return Pose.identity;
+            }
+
+            protected  internal override Vector3 GetLinearVelocityAt(int index)
+            {
+                return Vector3.zero;
+            }
+        }
+
+        [Test]
+        public void TestExpectedRoot()
+        {
+            Assert.Throws<UnityAgentsException>(() =>
+            {
+                var bad = new BadPoseExtractor();
+            });
+        }
     }
 
     public class PoseExtensionTests

com.unity.ml-agents.extensions/Tests/Editor/Sensors/RigidBodyPoseExtractorTests.cs

 using UnityEngine;
 using NUnit.Framework;
 using Unity.MLAgents.Extensions.Sensors;
+using UnityEditor;
 
 namespace Unity.MLAgents.Extensions.Tests.Sensors
 {
 
             var poseExtractor = new RigidBodyPoseExtractor(rb1);
             Assert.AreEqual(2, poseExtractor.NumPoses);
+
+            rb1.position = new Vector3(1, 0, 0);
+            rb1.rotation = Quaternion.Euler(0, 13.37f, 0);
+            rb1.velocity = new Vector3(2, 0, 0);
+
+            Assert.AreEqual(rb1.position, poseExtractor.GetPoseAt(0).position);
+            Assert.IsTrue(rb1.rotation == poseExtractor.GetPoseAt(0).rotation);
+            Assert.AreEqual(rb1.velocity, poseExtractor.GetLinearVelocityAt(0));
+        }
+
+        [Test]
+        public void TestTwoBodiesVirtualRoot()
+        {
+            // * virtualRoot
+            // * rootObj
+            //   - rb1
+            //   * go2
+            //     - rb2
+            //     - joint
+            var virtualRoot = new GameObject("I am vroot");
+
+            var rootObj = new GameObject();
+            var rb1 = rootObj.AddComponent<Rigidbody>();
+
+            var go2 = new GameObject();
+            var rb2 = go2.AddComponent<Rigidbody>();
+            go2.transform.SetParent(rootObj.transform);
+
+            var joint = go2.AddComponent<ConfigurableJoint>();
+            joint.connectedBody = rb1;
+
+            var poseExtractor = new RigidBodyPoseExtractor(rb1, null, virtualRoot);
+            Assert.AreEqual(3, poseExtractor.NumPoses);
+
+            // "body" 0 has no parent
+            Assert.AreEqual(-1, poseExtractor.GetParentIndex(0));
+
+            // body 1 has parent 0
+            Assert.AreEqual(0, poseExtractor.GetParentIndex(1));
+
+            var virtualRootPos = new Vector3(0,2,0);
+            var virtualRootRot = Quaternion.Euler(0, 42, 0);
+            virtualRoot.transform.position = virtualRootPos;
+            virtualRoot.transform.rotation = virtualRootRot;
+
+            Assert.AreEqual(virtualRootPos, poseExtractor.GetPoseAt(0).position);
+            Assert.IsTrue(virtualRootRot == poseExtractor.GetPoseAt(0).rotation);
+            Assert.AreEqual(Vector3.zero, poseExtractor.GetLinearVelocityAt(0));
+
+            // Same as above test, but using index 1
+            rb1.position = new Vector3(1, 0, 0);
+            rb1.rotation = Quaternion.Euler(0, 13.37f, 0);
+            rb1.velocity = new Vector3(2, 0, 0);
+
+            Assert.AreEqual(rb1.position, poseExtractor.GetPoseAt(1).position);
+            Assert.IsTrue(rb1.rotation == poseExtractor.GetPoseAt(1).rotation);
+            Assert.AreEqual(rb1.velocity, poseExtractor.GetLinearVelocityAt(1));
         }
     }
 }

com.unity.ml-agents.extensions/Tests/Editor/Sensors/RigidBodySensorTests.cs

 
             var sensor = sensorComponent.CreateSensor();
             sensor.Update();
-            var expected = new[]
-            {
-                0f, 0f, 0f, // ModelSpaceLinearVelocity
-                0f, 0f, 0f, // LocalSpaceTranslations
-                0f, 0f, 0f, 1f // LocalSpaceRotations
-            };
-            SensorTestHelper.CompareObservation(sensor, expected);
+
+            // The root body is ignored since it always generates identity values
+            // and there are no other bodies to generate observations.
+            var expected = new float[0];
+            SensorTestHelper.CompareObservation(sensor, expected);
         }
 
         [Test]
             var joint2 = leafGameObj.AddComponent<ConfigurableJoint>();
             joint2.connectedBody = middleRb;
 
+            var virtualRoot = new GameObject();
 
             var sensorComponent = rootObj.AddComponent<RigidBodySensorComponent>();
             sensorComponent.RootBody = rootRb;
                 UseLocalSpaceTranslations = true,
                 UseLocalSpaceLinearVelocity = true
             };
+            sensorComponent.VirtualRoot = virtualRoot;
+
+            // Note that the VirtualRoot is ignored from the observations
             var expected = new[]
             {
                 // Model space
 
                 // Local space
                 0f, 0f, 0f, // Root pos
-                0f, 0f, 0f, // Root vel
-
-                -1f, 1f, 0f, // Attached vel
+                4.2f, 0f, 0f, // Leaf pos
-                4.2f, 0f, 0f, // Leaf pos
+                1f, 0f, 0f, // Root vel (relative to virtual root)
+                -1f, 1f, 0f, // Attached vel
+            Assert.AreEqual(expected.Length, sensorComponent.GetObservationShape()[0]);
-            Assert.AreEqual(expected.Length, sensorComponent.GetObservationShape()[0]);
 
             // Update the settings to only process joint observations
             sensorComponent.Settings = new PhysicsSensorSettings

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

   "unity": "2018.4",
   "description": "A source-only package for new features based on ML-Agents",
   "dependencies": {
-    "com.unity.ml-agents": "1.2.0-preview"
+    "com.unity.ml-agents": "1.3.0-preview"
   }
 }

com.unity.ml-agents/CHANGELOG.md

 ### Major Changes
 #### com.unity.ml-agents (C#)
 #### ml-agents / ml-agents-envs / gym-unity (Python)
-- The minimum supported python version for ml-agents-envs was changed to 3.6.1. (#4244)
+
+### Minor Changes
+#### com.unity.ml-agents (C#)
+#### ml-agents / ml-agents-envs / gym-unity (Python)
+
+### Bug Fixes
+#### com.unity.ml-agents (C#)
+#### ml-agents / ml-agents-envs / gym-unity (Python)
+
+## [1.3.0-preview] 2020-08-12
+
+### Major Changes
+#### com.unity.ml-agents (C#)
+#### ml-agents / ml-agents-envs / gym-unity (Python)
+- The minimum supported Python version for ml-agents-envs was changed to 3.6.1. (#4244)
 - The interaction between EnvManager and TrainerController was changed; EnvManager.advance() was split into to stages,
 and TrainerController now uses the results from the first stage to handle new behavior names. This change speeds up
 Python training by approximately 5-10%. (#4259)
-#### ml-agents / ml-agents-envs / gym-unity (Python)
+#### ml-agents / ml-agents-envs / gym-unity (Python)
+- The versions of `numpy` supported by ml-agents-envs were changed to disallow 1.19.0 or later. This was done to reflect
+a similar change in TensorFlow's requirements. (#4274)
+- CSV statistics writer was removed (#4300).
 
 ### Bug Fixes
 #### com.unity.ml-agents (C#)
 - `max_step` in the `TerminalStep` and `TerminalSteps` objects was renamed `interrupted`.
 - `beta` and `epsilon` in `PPO` are no longer decayed by default but follow the same schedule as learning rate. (#3940)
 - `get_behavior_names()` and `get_behavior_spec()` on UnityEnvironment were replaced by the `behavior_specs` property. (#3946)
-- The first version of the Unity Environment Registry (Experimental) has been released. More information [here](https://github.com/Unity-Technologies/ml-agents/blob/release_4_docs/docs/Unity-Environment-Registry.md)(#3967)
+- The first version of the Unity Environment Registry (Experimental) has been released. More information [here](https://github.com/Unity-Technologies/ml-agents/blob/release_5_docs/docs/Unity-Environment-Registry.md)(#3967)
 - `use_visual` and `allow_multiple_visual_obs` in the `UnityToGymWrapper` constructor
 were replaced by `allow_multiple_obs` which allows one or more visual observations and
 vector observations to be used simultaneously. (#3981) Thank you @shakenes !
 - The format for trainer configuration has changed, and the "default" behavior has been deprecated.
-  See the [Migration Guide](https://github.com/Unity-Technologies/ml-agents/blob/release_4_docs/docs/Migrating.md) for more details. (#3936)
+  See the [Migration Guide](https://github.com/Unity-Technologies/ml-agents/blob/release_5_docs/docs/Migrating.md) for more details. (#3936)
 - Training artifacts (trained models, summaries) are now found in the `results/`
   directory. (#3829)
 - When using Curriculum, the current lesson will resume if training is quit and resumed. As such,

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

 [unity ML-Agents Toolkit]: https://github.com/Unity-Technologies/ml-agents
 [unity inference engine]: https://docs.unity3d.com/Packages/com.unity.barracuda@latest/index.html
 [package manager documentation]: https://docs.unity3d.com/Manual/upm-ui-install.html
-[installation instructions]: https://github.com/Unity-Technologies/ml-agents/blob/release_4_docs/docs/Installation.md
+[installation instructions]: https://github.com/Unity-Technologies/ml-agents/blob/release_5_docs/docs/Installation.md
 [github repository]: https://github.com/Unity-Technologies/ml-agents
 [python package]: https://github.com/Unity-Technologies/ml-agents
 [execution order of event functions]: https://docs.unity3d.com/Manual/ExecutionOrder.html

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_4_docs/docs/
+ * https://github.com/Unity-Technologies/ml-agents/tree/release_5_docs/docs/
  */
 
 namespace Unity.MLAgents
     /// 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_4_docs/" +
+    [HelpURL("https://github.com/Unity-Technologies/ml-agents/tree/release_5_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 = "1.2.0-preview";
+        internal const string k_PackageVersion = "1.3.0-preview";
 
         const int k_EditorTrainingPort = 5004;
 

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_4_docs/docs/Learning-Environment-Design-Agents.md
-    /// [Reinforcement Learning in Unity]: https://github.com/Unity-Technologies/ml-agents/blob/release_4_docs/docs/Learning-Environment-Design.md
+    /// [Agents]: https://github.com/Unity-Technologies/ml-agents/blob/release_5_docs/docs/Learning-Environment-Design-Agents.md
+    /// [Reinforcement Learning in Unity]: https://github.com/Unity-Technologies/ml-agents/blob/release_5_docs/docs/Learning-Environment-Design.md
-    /// [Unity ML-Agents Toolkit manual]: https://github.com/Unity-Technologies/ml-agents/blob/release_4_docs/docs/Readme.md
+    /// [Unity ML-Agents Toolkit manual]: https://github.com/Unity-Technologies/ml-agents/blob/release_5_docs/docs/Readme.md
-    [HelpURL("https://github.com/Unity-Technologies/ml-agents/blob/release_4_docs/" +
+    [HelpURL("https://github.com/Unity-Technologies/ml-agents/blob/release_5_docs/" +
         "docs/Learning-Environment-Design-Agents.md")]
     [Serializable]
     [RequireComponent(typeof(BehaviorParameters))]
         /// 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_4_docs/docs/Learning-Environment-Design-Agents.md#rewards
-        /// [Reward Signals]: https://github.com/Unity-Technologies/ml-agents/blob/release_4_docs/docs/ML-Agents-Overview.md#a-quick-note-on-reward-signals
+        /// [Agents - Rewards]: https://github.com/Unity-Technologies/ml-agents/blob/release_5_docs/docs/Learning-Environment-Design-Agents.md#rewards
+        /// [Reward Signals]: https://github.com/Unity-Technologies/ml-agents/blob/release_5_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_4_docs/docs/Learning-Environment-Design-Agents.md#rewards
-        /// [Reward Signals]: https://github.com/Unity-Technologies/ml-agents/blob/release_4_docs/docs/ML-Agents-Overview.md#a-quick-note-on-reward-signals
+        /// [Agents - Rewards]: https://github.com/Unity-Technologies/ml-agents/blob/release_5_docs/docs/Learning-Environment-Design-Agents.md#rewards
+        /// [Reward Signals]: https://github.com/Unity-Technologies/ml-agents/blob/release_5_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)
         /// 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_4_docs/docs/Learning-Environment-Design-Agents.md#recording-demonstrations
-        /// [Actions]: https://github.com/Unity-Technologies/ml-agents/blob/release_4_docs/docs/Learning-Environment-Design-Agents.md#actions
+        /// [Demonstration Recorder]: https://github.com/Unity-Technologies/ml-agents/blob/release_5_docs/docs/Learning-Environment-Design-Agents.md#recording-demonstrations
+        /// [Actions]: https://github.com/Unity-Technologies/ml-agents/blob/release_5_docs/docs/Learning-Environment-Design-Agents.md#actions
         /// [GameObject]: https://docs.unity3d.com/Manual/GameObjects.html
         /// </remarks>
         /// <example>
         /// 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_4_docs/docs/Learning-Environment-Design-Agents.md#observations-and-sensors
+        /// [Observations and Sensors]: https://github.com/Unity-Technologies/ml-agents/blob/release_5_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_4_docs/docs/Learning-Environment-Design-Agents.md#actions
+        /// [Agents - Actions]: https://github.com/Unity-Technologies/ml-agents/blob/release_5_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_4_docs/docs/Learning-Environment-Design-Agents.md#actions
+        /// [Agents - Actions]: https://github.com/Unity-Technologies/ml-agents/blob/release_5_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

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

 
 [assembly: InternalsVisibleTo("Unity.ML-Agents.Editor.Tests")]
 [assembly: InternalsVisibleTo("Unity.ML-Agents.Editor")]
+[assembly: InternalsVisibleTo("Unity.ML-Agents.Extensions")]

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_4_docs/docs//Learning-Environment-Design-Agents.md#recording-demonstrations
+    /// [Imitation Learning - Recording Demonstrations]: https://github.com/Unity-Technologies/ml-agents/blob/release_5_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_4_docs/docs/Learning-Environment-Design-Agents.md#actions
+        /// [Agents - Actions]: https://github.com/Unity-Technologies/ml-agents/blob/release_5_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/package.json

 {
   "name": "com.unity.ml-agents",
   "displayName": "ML Agents",
-  "version": "1.2.0-preview",
+  "version": "1.3.0-preview",
   "unity": "2018.4",
   "description": "Use state-of-the-art machine learning to create intelligent character behaviors in any Unity environment (games, robotics, film, etc.).",
   "dependencies": {

docs/Installation-Anaconda-Windows.md

 the ml-agents Conda environment by typing `activate ml-agents`)_:
 
 ```sh
-git clone --branch release_4 https://github.com/Unity-Technologies/ml-agents.git
+git clone --branch release_5 https://github.com/Unity-Technologies/ml-agents.git
-The `--branch release_4` option will switch to the tag of the latest stable
+The `--branch release_5` option will switch to the tag of the latest stable
 release. Omitting that will get the `master` branch which is potentially
 unstable.
 

docs/Installation.md

 of our tutorials / guides assume you have access to our example environments).
 
 ```sh
-git clone --branch release_4 https://github.com/Unity-Technologies/ml-agents.git
+git clone --branch release_5 https://github.com/Unity-Technologies/ml-agents.git
-The `--branch release_4` option will switch to the tag of the latest stable
+The `--branch release_5` option will switch to the tag of the latest stable
 release. Omitting that will get the `master` branch which is potentially
 unstable.
 
 ML-Agents Toolkit for your purposes. If you plan to contribute those changes
-back, make sure to clone the `master` branch (by omitting `--branch release_4`
+back, make sure to clone the `master` branch (by omitting `--branch release_5`
 from the command above). See our
 [Contributions Guidelines](../com.unity.ml-agents/CONTRIBUTING.md) for more
 information on contributing to the ML-Agents Toolkit.

docs/Training-Configuration-File.md

 | `hyperparameters -> beta`      | (default