added generic seed generator apis to ScenarioBase

com.unity.perception/Runtime/Randomization/Randomizers/AddRandomizerMenuAttribute.cs

 
 namespace UnityEngine.Experimental.Perception.Randomization.Randomizers
 {
+    /// <summary>
+    /// The AddRandomizerMenu attribute allows you to organize randomizers under different menu paths
+    /// </summary>
+        /// <summary>
+        /// The assigned randomizer menu path. Path directories should be separated using forward slash characters.
+        /// </summary>
+        /// <summary>
+        /// Add a randomizer to the AddRandomizerMenus
+        /// </summary>
+        /// <param name="menuPath">The assigned randomizer menu path</param>
         public AddRandomizerMenuAttribute(string menuPath)
         {
             this.menuPath = menuPath;

com.unity.perception/Runtime/Randomization/Randomizers/SampleRandomizers/Randomizers/BackgroundObjectPlacementRandomizer.cs

         {
             for (var i = 0; i < layerCount; i++)
             {
-                var seed = SamplerUtility.IterateSeed((uint)scenario.currentIteration, (uint)i);
+                var seed = scenario.GenerateIterativeRandomSeed(i);
                 var placementSamples = PoissonDiskSampling.GenerateSamples(
                     placementArea.x, placementArea.y, separationDistance, seed);
                 var offset = new Vector3(placementArea.x, placementArea.y, 0f) * -0.5f;

com.unity.perception/Runtime/Randomization/Randomizers/SampleRandomizers/Randomizers/ForegroundObjectPlacementRandomizer.cs

 using System;
 using System.Collections.Generic;
 using UnityEngine.Experimental.Perception.Randomization.Parameters;
-using UnityEngine.Experimental.Perception.Randomization.Samplers;
 
 namespace UnityEngine.Experimental.Perception.Randomization.Randomizers.SampleRandomizers
 {
         /// </summary>
         protected override void OnIterationStart()
         {
-            var seed = SamplerUtility.IterateSeed((uint)scenario.currentIteration, SamplerUtility.largePrime);
+            var seed = scenario.GenerateRandomSeed();
             var placementSamples = PoissonDiskSampling.GenerateSamples(
                 placementArea.x, placementArea.y, separationDistance, seed);
             var offset = new Vector3(placementArea.x, placementArea.y, 0f) * -0.5f;

com.unity.perception/Runtime/Randomization/Scenarios/ScenarioBase.cs

 using Unity.Simulation;
 using UnityEngine;
 using UnityEngine.Experimental.Perception.Randomization.Randomizers;
+using UnityEngine.Experimental.Perception.Randomization.Samplers;
 using UnityEngine.Perception.GroundTruth;
 
 namespace UnityEngine.Experimental.Perception.Randomization.Scenarios
             var randomizer = m_Randomizers[currentIndex];
             m_Randomizers.RemoveAt(currentIndex);
             m_Randomizers.Insert(nextIndex, randomizer);
+        }
+
+        /// <summary>
+        /// Generates a random seed by hashing the current scenario iteration with a given base random seed
+        /// </summary>
+        /// <param name="baseSeed">Used to offset the seed generator</param>
+        /// <returns>The generated random seed</returns>
+        public uint GenerateRandomSeed(uint baseSeed = SamplerUtility.largePrime)
+        {
+            var seed = SamplerUtility.IterateSeed((uint)currentIteration, baseSeed);
+            return SamplerUtility.IterateSeed((uint)currentIteration, seed);
+        }
+
+        /// <summary>
+        /// Generates a random seed by hashing three values together: an arbitrary iteration value,
+        /// the current scenario iteration, and a base random seed
+        /// </summary>
+        /// <param name="iteration">An offset value hashed inside the seed generator</param>
+        /// <param name="baseSeed">An offset value hashed inside the seed generator</param>
+        /// <returns>The generated random seed</returns>
+        public uint GenerateIterativeRandomSeed(int iteration, uint baseSeed = SamplerUtility.largePrime)
+        {
+            return SamplerUtility.IterateSeed((uint)iteration, baseSeed);
         }
 
         void ValidateParameters()