add discount for team reward

Project/Assets/ML-Agents/Examples/PushBlock/Scripts/PushBlockTeamManager.cs

 using UnityEngine;
 using Unity.MLAgents.Extensions.Teams;
 using Unity.MLAgents.Sensors;
+using System;
-    Dictionary<Agent, bool> m_AgentDoneState = new Dictionary<Agent, bool> { };
+    float m_rewardDiscount = 1;
+
+    // -1 means not done
+    Dictionary<Agent, int> m_AgentDoneStep = new Dictionary<Agent, int> { };
+    Dictionary<Agent, float> m_AgentRewardDiscount = new Dictionary<Agent, float> { };
+
+    public PushBlockTeamManager()
+    {
+    }
+
+    public PushBlockTeamManager(float rewardDiscount)
+    {
+        m_rewardDiscount = rewardDiscount;
+    }
-        m_AgentDoneState[agent] = false;
+        m_AgentDoneStep[agent] = -1;
-        m_AgentDoneState[agent] = true;
+        m_AgentDoneStep[agent] = agent.StepCount;
-        foreach (var agent in m_AgentDoneState.Keys.ToList())
+        foreach (var agent in m_AgentDoneStep.Keys.ToList())
-            if (m_AgentDoneState[agent])
+            if (m_AgentDoneStep[agent] >= 0)
-                m_AgentDoneState[agent] = false;
+                m_AgentDoneStep[agent] = -1;
             }
         }
     }
-        foreach (var agent in m_AgentDoneState.Keys)
+        int maxAgentStep = m_AgentDoneStep.Values.Max();
+        foreach (var agent in m_AgentDoneStep.Keys)
-            if (m_AgentDoneState[agent])
+            if (m_AgentDoneStep[agent] >= 0)
-                agent.AddRewardAfterDeath(reward);
+                agent.AddRewardAfterDeath(reward * (float)Math.Pow(m_rewardDiscount, maxAgentStep - m_AgentDoneStep[agent]));
             }
             else
             {

Project/Assets/ML-Agents/Examples/PushBlock/Scripts/ZombiePushBlockDeathEnvController.cs

     public bool UseRandomBlockPosition = true;
     public bool UseTeamManager = true;
     public bool UseTeamReward = true;
+    public float TeamRewardDiscountRate = 1;
     PushBlockSettings m_PushBlockSettings;
 
     private int m_NumberOfRemainingBlocks;
         {
             if (UseTeamReward)
             {
-                m_TeamManager = new PushBlockTeamManager();
+                m_TeamManager = new PushBlockTeamManager(TeamRewardDiscountRate);
             }
             else
             {