Merge branch 'soccer-2v1' into asymm-envs

Project/Assets/ML-Agents/Examples/Tennis/Prefabs/TennisArea.prefab

   m_GameObject: {fileID: 1273406647218856}
   serializedVersion: 2
   m_Mass: 0.75
-  m_Drag: 0
+  m_Drag: 0.1
   m_AngularDrag: 0.05
   m_UseGravity: 1
   m_IsKinematic: 0

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

     TennisArea m_Area;
     float m_InvertMult;
     FloatPropertiesChannel m_ResetParams;
+    float m_BallTouch;
 
     // Looks for the scoreboard based on the name of the gameObjects.
     // Do not modify the names of the Score GameObjects
         return action;
     }
 
+    void OnCollisionEnter(Collision c)
+    {
+        if (c.gameObject.CompareTag("ball"))
+        {
+            AddReward(.1f * m_BallTouch);
+        }
+    }
+        m_BallTouch = SideChannelUtils.GetSideChannel<FloatPropertiesChannel>().GetPropertyWithDefault("ball_touch", 0);
         m_InvertMult = invertX ? -1f : 1f;
         if (m_InvertMult == 1f)
         {

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

     void FixedUpdate()
     {
         var rgV = m_BallRb.velocity;
-        m_BallRb.velocity = new Vector3(Mathf.Clamp(rgV.x, -9f, 9f), Mathf.Clamp(rgV.y, -9f, 9f), rgV.z);
+        //m_BallRb.velocity = new Vector3(Mathf.Clamp(rgV.x, -9f, 9f), Mathf.Clamp(rgV.y, -9f, 9f), rgV.z);
     }
 }

config/curricula/tennis.yaml

+Tennis:
+  measure: progress
+  thresholds: [0.05, 0.1]
+  min_lesson_length: 100
+  signal_smoothing: true
+  parameters:
+    ball_touch: [1.0, 0.5, 0.0]