added xml docs to sample randomizers

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

 
 namespace UnityEngine.Experimental.Perception.Randomization.Randomizers.SampleRandomizers
 {
+    /// <summary>
+    /// Creates multiple layers of evenly distributed but randomly placed objects
+    /// </summary>
+        List<GameObject> m_SpawnedObjects = new List<GameObject>();
+
+        /// <summary>
+        /// The Z offset component applied to all generated background layers
+        /// </summary>
+
+        /// <summary>
+        /// The number of background layers to generate
+        /// </summary>
+
+        /// <summary>
+        /// The minimum distance between placed background objects
+        /// </summary>
+
+        /// <summary>
+        /// The 2D size of the generated background layers
+        /// </summary>
+
+        /// <summary>
+        /// A categorical parameter for sampling random prefabs to place
+        /// </summary>
-        List<GameObject> m_SpawnedObjects = new List<GameObject>();
+        /// <summary>
+        /// Generates background layers of objects at the start of each scenario iteration
+        /// </summary>
         protected override void OnIterationStart()
         {
             for (var i = 0; i < layerCount; i++)
             }
         }
 
+        /// <summary>
+        /// Deletes generated background objects after each scenario iteration is complete
+        /// </summary>
         protected override void OnIterationEnd()
         {
             foreach (var spawnedObject in m_SpawnedObjects)

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

 
 namespace UnityEngine.Experimental.Perception.Randomization.Randomizers.SampleRandomizers
 {
+    /// <summary>
+    /// Randomizes the material color of objects tagged with a ColorRandomizerTag
+    /// </summary>
+
+        /// <summary>
+        /// Describes the range of random colors to assign to tagged objects
+        /// </summary>
+        /// <summary>
+        /// Randomizes the colors of tagged objects at the start of each scenario iteration
+        /// </summary>
         protected override void OnIterationStart()
         {
             var taggedObjects = tagManager.Query<ColorRandomizerTag>();

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

 
 namespace UnityEngine.Experimental.Perception.Randomization.Randomizers.SampleRandomizers
 {
+    /// <summary>
+    /// Creates a 2D layer of of evenly spaced GameObjects from a given list of prefabs
+    /// </summary>
+        List<GameObject> m_SpawnedObjects = new List<GameObject>();
+
+        /// <summary>
+        /// The Z offset component applied to the generated layer of GameObjects
+        /// </summary>
+
+        /// <summary>
+        /// The minimum distance between all placed objects
+        /// </summary>
+
+        /// <summary>
+        /// The size of the 2D area designated for object placement
+        /// </summary>
+
+        /// <summary>
+        /// The list of prefabs sample and randomly place
+        /// </summary>
-        List<GameObject> m_SpawnedObjects = new List<GameObject>();
+        /// <summary>
+        /// Generates a foreground layer of objects at the start of each scenario iteration
+        /// </summary>
         protected override void OnIterationStart()
         {
             var seed = SamplerUtility.IterateSeed((uint)scenario.currentIteration, SamplerUtility.largePrime);
             placementSamples.Dispose();
         }
 
+        /// <summary>
+        /// Deletes generated foreground objects after each scenario iteration is complete
+        /// </summary>
         protected override void OnIterationEnd()
         {
             foreach (var spawnedObject in m_SpawnedObjects)

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

 
 namespace UnityEngine.Experimental.Perception.Randomization.Randomizers.SampleRandomizers
 {
+    /// <summary>
+    /// Randomizes the rotation of objects tagged with a RotationRandomizerTag
+    /// </summary>
+        /// <summary>
+        /// Defines the range of random rotations that can be assigned to tagged objects
+        /// </summary>
+        /// <summary>
+        /// Randomizes the rotation of tagged objects at the start of each scenario iteration
+        /// </summary>
         protected override void OnIterationStart()
         {
             var taggedObjects = tagManager.Query<RotationRandomizerTag>();

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

 
 namespace UnityEngine.Experimental.Perception.Randomization.Randomizers.SampleRandomizers
 {
+    /// <summary>
+    /// Randomizes the material texture of objects tagged with a TextureRandomizerTag
+    /// </summary>
+
+        /// <summary>
+        /// The list of textures to sample and apply to tagged objects
+        /// </summary>
+        /// <summary>
+        /// Randomizes the material texture of tagged objects at the start of each scenario iteration
+        /// </summary>
         protected override void OnIterationStart()
         {
             var taggedObjects = tagManager.Query<TextureRandomizerTag>();

com.unity.perception/Runtime/Randomization/Randomizers/SampleRandomizers/Tags/ColorRandomizerTag.cs

 namespace UnityEngine.Experimental.Perception.Randomization.Randomizers.SampleRandomizers.Tags
 {
+    /// <summary>
+    /// Used in conjunction with a ColorRandomizer to vary the material color of GameObjects
+    /// </summary>
     [AddComponentMenu("Perception/RandomizerTags/ColorRandomizerTag")]
     public class ColorRandomizerTag : RandomizerTag { }
 }

com.unity.perception/Runtime/Randomization/Randomizers/SampleRandomizers/Tags/RotationRandomizerTag.cs

 namespace UnityEngine.Experimental.Perception.Randomization.Randomizers.SampleRandomizers.Tags
 {
+    /// <summary>
+    /// Used in conjunction with a RotationRandomizer to vary the rotation of GameObjects
+    /// </summary>
     [AddComponentMenu("Perception/RandomizerTags/RotationRandomizerTag")]
     public class RotationRandomizerTag : RandomizerTag { }
 }

com.unity.perception/Runtime/Randomization/Randomizers/SampleRandomizers/Tags/TextureRandomizerTag.cs

 namespace UnityEngine.Experimental.Perception.Randomization.Randomizers.SampleRandomizers.Tags
 {
+    /// <summary>
+    /// Used in conjunction with a TextureRandomizer to vary the material texture of GameObjects
+    /// </summary>
     [AddComponentMenu("Perception/RandomizerTags/TextureRandomizerTag")]
     public class TextureRandomizerTag : RandomizerTag { }
 }

com.unity.perception/Runtime/Randomization/Randomizers/SampleRandomizers/Utilities/PoissonDiskSampling.cs

 
 namespace UnityEngine.Experimental.Perception.Randomization.Randomizers.SampleRandomizers
 {
+    /// <summary>
+    /// Utility for generating lists of poisson disk sampled points
+    /// </summary>
     public static class PoissonDiskSampling
     {
         const int k_DefaultSamplingResolution = 30;
         /// <summary>
-        ///   <para>Returns a list of poisson disc sampled points for a given area and density</para>
+        /// Returns a list of poisson disc sampled points for a given area and density
         /// </summary>
         /// <param name="width">Width of the sampling area</param>
         /// <param name="height">Height of the sampling area</param>
+        /// <returns>The list of generated poisson points</returns>
         public static NativeList<float2> GenerateSamples(
             float width,
             float height,
             }
         }
 
-        public static NativeList<float2> Sample(
+        static NativeList<float2> Sample(
             float width,
             float height,
             float minimumRadius,