Reintroduce MLAgents.Sensors namespace (#3509)

* Reintroduced the namespace MLAgents.Sensors

* Documentation changes

* updated the changelog

Project/Assets/ML-Agents/Examples/3DBall/Scripts/Ball3DAgent.cs

 using UnityEngine;
 using MLAgents;
+using MLAgents.Sensors;
 
 public class Ball3DAgent : Agent
 {

Project/Assets/ML-Agents/Examples/3DBall/Scripts/Ball3DHardAgent.cs

 using UnityEngine;
 using MLAgents;
+using MLAgents.Sensors;
 
 public class Ball3DHardAgent : Agent
 {

Project/Assets/ML-Agents/Examples/Basic/Scripts/BasicAgent.cs

 using UnityEngine;
 using MLAgents;
+using MLAgents.Sensors;
 
 public class BasicAgent : Agent
 {

Project/Assets/ML-Agents/Examples/Bouncer/Scripts/BouncerAgent.cs

 using UnityEngine;
 using MLAgents;
+using MLAgents.Sensors;
 
 public class BouncerAgent : Agent
 {

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

 using UnityEngine;
 using MLAgents;
 using MLAgentsExamples;
+using MLAgents.Sensors;
 
 [RequireComponent(typeof(JointDriveController))] // Required to set joint forces
 public class CrawlerAgent : Agent

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

 using UnityEngine;
 using MLAgents;
+using MLAgents.Sensors;
 
 public class FoodCollectorAgent : Agent
 {

Project/Assets/ML-Agents/Examples/GridWorld/Scripts/GridAgent.cs

 using UnityEngine;
 using System.Linq;
 using MLAgents;
+using MLAgents.Sensors;
 using UnityEngine.Serialization;
 
 public class GridAgent : Agent

Project/Assets/ML-Agents/Examples/Hallway/Scripts/HallwayAgent.cs

 using System.Collections;
 using UnityEngine;
 using MLAgents;
+using MLAgents.Sensors;
 
 public class HallwayAgent : Agent
 {

Project/Assets/ML-Agents/Examples/Pyramids/Scripts/PyramidAgent.cs

 using UnityEngine;
 using Random = UnityEngine.Random;
 using MLAgents;
+using MLAgents.Sensors;
 
 public class PyramidAgent : Agent
 {

Project/Assets/ML-Agents/Examples/Reacher/Scripts/ReacherAgent.cs

 using UnityEngine;
 using MLAgents;
+using MLAgents.Sensors;
 
 public class ReacherAgent : Agent
 {

Project/Assets/ML-Agents/Examples/Template/Scripts/TemplateAgent.cs

 using UnityEngine;
 using MLAgents;
+using MLAgents.Sensors;
 
 public class TemplateAgent : Agent
 {

Project/Assets/ML-Agents/Examples/Tennis/Scripts/TennisAgent.cs

 using UnityEngine;
 using UnityEngine.UI;
 using MLAgents;
+using MLAgents.Sensors;
 
 public class TennisAgent : Agent
 {

Project/Assets/ML-Agents/Examples/Walker/Scripts/WalkerAgent.cs

 using UnityEngine;
 using MLAgents;
 using MLAgentsExamples;
+using MLAgents.Sensors;
 
 public class WalkerAgent : Agent
 {

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

 using UnityEngine;
 using MLAgents;
 using Barracuda;
-
+using MLAgents.Sensors;
 
 public class WallJumpAgent : Agent
 {

com.unity.ml-agents/CHANGELOG.md

  - Beta support for ONNX export was added. If the `tf2onnx` python package is installed, models will be saved to `.onnx` as well as `.nn` format.
  Note that Barracuda 0.6.0 or later is required to import the `.onnx` files properly
  - Multi-GPU training and the `--multi-gpu` option has been removed temporarily. (#3345)
+ - All Sensor related code has been moved to the namespace `MLAgents.Sensors`.
 
 ### Minor Changes
  - Monitor.cs was moved to Examples. (#3372)

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

-using UnityEngine;
+using MLAgents.Sensors;
 using UnityEditor;
 using Barracuda;
 

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

 using UnityEngine;
 using UnityEditor;
-using Barracuda;
+using MLAgents.Sensors;
 
 namespace MLAgents
 {

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

 using System.Collections.Generic;
 using UnityEngine;
 using Barracuda;
+using MLAgents.Sensors;
 
 namespace MLAgents
 {

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

 using MLAgents.CommunicatorObjects;
 using UnityEngine;
 using System.Runtime.CompilerServices;
+using MLAgents.Sensors;
 
 [assembly: InternalsVisibleTo("Unity.ML-Agents.Editor")]
 [assembly: InternalsVisibleTo("Unity.ML-Agents.Editor.Tests")]

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

 using System;
 using System.Collections.Generic;
 using UnityEngine;
+using MLAgents.Sensors;
 
 namespace MLAgents
 {

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

 using System.Linq;
 using UnityEngine;
 using MLAgents.CommunicatorObjects;
+using MLAgents.Sensors;
 using System.IO;
 using Google.Protobuf;
 

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

 using System.IO;
 using Google.Protobuf;
 using System.Collections.Generic;
+using MLAgents.Sensors;
 
 namespace MLAgents
 {

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

 using System.Collections.Generic;
 using System.Linq;
 using Barracuda;
-using UnityEngine;
+using MLAgents.Sensors;
 
 namespace MLAgents.InferenceBrain
 {

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

 using Barracuda;
 using MLAgents.InferenceBrain.Utils;
 using UnityEngine;
+using MLAgents.Sensors;
 
 namespace MLAgents.InferenceBrain
 {

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

 using System.Collections.Generic;
 using Barracuda;
 using UnityEngine.Profiling;
-using System;
+using MLAgents.Sensors;
 
 namespace MLAgents.InferenceBrain
 {

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

 using System.Collections.Generic;
 using Barracuda;
+using MLAgents.Sensors;
 
 namespace MLAgents.InferenceBrain
 {

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

 using System.Collections.Generic;
 using MLAgents.InferenceBrain;
 using System;
+using MLAgents.Sensors;
 
 namespace MLAgents
 {

com.unity.ml-agents/Runtime/Policy/HeuristicPolicy.cs

 using System.Collections.Generic;
 using System;
+using MLAgents.Sensors;
 
 namespace MLAgents
 {

com.unity.ml-agents/Runtime/Policy/IPolicy.cs

 using System;
 using System.Collections.Generic;
+using MLAgents.Sensors;
 
 namespace MLAgents
 {

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

 using UnityEngine;
 using System.Collections.Generic;
 using System;
+using MLAgents.Sensors;
 
 namespace MLAgents
 {

com.unity.ml-agents/Runtime/Sensor/CameraSensor.cs

 using UnityEngine;
 
-namespace MLAgents
+namespace MLAgents.Sensors
 {
     /// <summary>
     /// A sensor that wraps a Camera object to generate visual observations for an agent.

com.unity.ml-agents/Runtime/Sensor/CameraSensorComponent.cs

 using UnityEngine;
 
-namespace MLAgents
+namespace MLAgents.Sensors
 {
     /// <summary>
     /// A SensorComponent that creates a <see cref="CameraSensor"/>.

com.unity.ml-agents/Runtime/Sensor/ISensor.cs

-namespace MLAgents
+namespace MLAgents.Sensors
 {
     /// <summary>
     /// The compression setting for visual/camera observations.

com.unity.ml-agents/Runtime/Sensor/Observation.cs

 using System;
-using UnityEngine;
-namespace MLAgents
+namespace MLAgents.Sensors
 {
     internal struct Observation
     {

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

 using System.Collections.Generic;
 using UnityEngine;
 
-namespace MLAgents
+namespace MLAgents.Sensors
 {
     /// <summary>
     /// Determines which dimensions the sensor will perform the casts in.

com.unity.ml-agents/Runtime/Sensor/RayPerceptionSensorComponent2D.cs

 using UnityEngine;
 
-namespace MLAgents
+namespace MLAgents.Sensors
 {
     /// <summary>
     /// A component for 2D Ray Perception.

com.unity.ml-agents/Runtime/Sensor/RayPerceptionSensorComponent3D.cs

 using UnityEngine;
 using UnityEngine.Serialization;
 
-namespace MLAgents
+namespace MLAgents.Sensors
 {
     /// <summary>
     /// A component for 3D Ray Perception.

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

 using UnityEngine;
 using UnityEngine.Serialization;
 
-namespace MLAgents
+namespace MLAgents.Sensors
 {
     /// <summary>
     /// A base class to support sensor components for raycast-based sensors.

com.unity.ml-agents/Runtime/Sensor/RenderTextureSensor.cs

 using UnityEngine;
 
-namespace MLAgents
+namespace MLAgents.Sensors
 {
     /// <summary>
     /// Sensor class that wraps a <see cref="RenderTexture"/> instance.

com.unity.ml-agents/Runtime/Sensor/RenderTextureSensorComponent.cs

 using UnityEngine;
 
-namespace MLAgents
+namespace MLAgents.Sensors
 {
     /// <summary>
     /// Component that wraps a <see cref="RenderTextureSensor"/>.

com.unity.ml-agents/Runtime/Sensor/SensorBase.cs

-namespace MLAgents
+namespace MLAgents.Sensors
 {
     /// <summary>
     /// A base sensor that provides a number default implementations.

com.unity.ml-agents/Runtime/Sensor/SensorComponent.cs

 using UnityEngine;
 
-namespace MLAgents
+namespace MLAgents.Sensors
 {
     /// <summary>
     /// Editor components for creating Sensors. Generally an ISensor implementation should have a

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

 using System.Collections.Generic;
 using UnityEngine;
 
-namespace MLAgents
+namespace MLAgents.Sensors
 {
     internal class SensorShapeValidator
     {

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

-namespace MLAgents
+namespace MLAgents.Sensors
 {
     /// <summary>
     /// Sensor that wraps around another Sensor to provide temporal stacking.

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

 using System.Collections.Generic;
 using UnityEngine;
 
-namespace MLAgents
+namespace MLAgents.Sensors
 {
     /// <summary>
     /// A sensor implementation for vector observations.

com.unity.ml-agents/Runtime/Sensor/WriteAdapter.cs

 using Barracuda;
 using MLAgents.InferenceBrain;
 
-namespace MLAgents
+namespace MLAgents.Sensors
 {
     /// <summary>
     /// Allows sensors to write to both TensorProxy and float arrays/lists.

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

 using System;
 using UnityEngine;
+using MLAgents.Sensors;
 
 namespace MLAgents
 {

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

 using System.IO.Abstractions.TestingHelpers;
 using System.Reflection;
 using MLAgents.CommunicatorObjects;
+using MLAgents.Sensors;
 
 namespace MLAgents.Tests
 {

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

 using NUnit.Framework;
 using System.Reflection;
 using System.Collections.Generic;
+using MLAgents.Sensors;
 
 namespace MLAgents.Tests
 {

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

 using NUnit.Framework;
-using UnityEngine;
+using MLAgents.Sensors;
 
 namespace MLAgents.Tests
 {

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

 using System.Collections.Generic;
 using NUnit.Framework;
 using UnityEngine;
+using MLAgents.Sensors;
 
 namespace MLAgents.Tests
 {

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

 using NUnit.Framework;
-using UnityEngine;
+using MLAgents.Sensors;
 
 namespace MLAgents.Tests
 {

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

 using NUnit.Framework;
 using UnityEngine;
+using MLAgents.Sensors;
 
 namespace MLAgents.Tests
 {

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

 using NUnit.Framework;
-using UnityEngine;
+using MLAgents.Sensors;
 using Barracuda;
 using MLAgents.InferenceBrain;
 

docs/Learning-Environment-Create-New.md

 
 1. In the Unity Project window, double-click the `RollerAgent` script to open it
    in your code editor.
-2. In the editor, add the `using MLAgents;` statement and then change the base
+2. In the editor, add the `using MLAgents;` and `using MLAgents.Sensors` statements and then change the base
     class from `MonoBehaviour` to `Agent`.
 3. Delete the `Update()` method, but we will use the `Start()` function, so
     leave it alone for now.
 using System.Collections.Generic;
 using UnityEngine;
 using MLAgents;
+using MLAgents.Sensors;
 
 public class RollerAgent : Agent
 {

docs/Migrating.md

 * The `--multi-gpu` option has been removed temporarily.
 
 ### Steps to Migrate
+* Add the `using MLAgents.Sensors;` in addition to `using MLAgents;` on top of your Agent's script.
 * Replace your Agent's implementation of `CollectObservations()` with `CollectObservations(VectorSensor sensor)`. In addition, replace all calls to `AddVectorObs()` with `sensor.AddObservation()` or `sensor.AddOneHotObservation()` on the `VectorSensor` passed as argument.
 * Replace your calls to `SetActionMask` on your Agent to `ActionMasker.SetActionMask` in `CollectObservations`
 * If you call `RayPerceptionSensor.PerceiveStatic()` manually, add your inputs to a `RayPerceptionInput`. To get the previous float array output, use `RayPerceptionOutput.ToFloatArray()`