downward force tennis agent

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

     float m_InvertMult;
     FloatPropertiesChannel m_ResetParams;
     float m_BallTouch;
+    Vector3 down = new Vector3(0f, -60f, 0f);
 
     // Looks for the scoreboard based on the name of the gameObjects.
     // Do not modify the names of the Score GameObjects
             AddReward(.2f * m_BallTouch);
         }
     }
+
+    void FixedUpdate()
+    {   
+        m_AgentRb.AddForce(down);
+    }   
+
     public override void OnEpisodeBegin()
     {