Added basic area manager to extensions.

com.unity.ml-agents.extensions/Runtime/Utils.meta

+fileFormatVersion: 2
+guid: 3857cb2a69864c82805a4b7ea4a65698
+timeCreated: 1623095341

com.unity.ml-agents.extensions/Runtime/Utils/AreaManager.cs

+using System;
+using System.Collections;
+using System.Collections.Generic;
+using Unity.MLAgents;
+using UnityEngine;
+
+namespace Unity.MLAgents.Extensions.Utils
+{
+    public class AreaManager : MonoBehaviour
+    {
+        public GameObject baseArea;
+        public int numAreas = 8;
+        public float separation = 20.0f;
+
+        public void Awake()
+        {
+            Academy.Instance.OnEnvironmentReset += AddEnvironments;
+        }
+
+        void AddEnvironments()
+        {
+            var envParameters = Academy.Instance.EnvironmentParameters;
+            int numAreas = (int) envParameters.GetWithDefault("num_areas", this.numAreas);
+
+            for (int i = 0; i < numAreas - 1; i++)
+            {
+                Instantiate(baseArea, new Vector3(0, 0, (i + 1) * separation), Quaternion.identity);
+            }
+        }
+    }
+}

com.unity.ml-agents.extensions/Runtime/Utils/AreaManager.cs.meta

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