New SceneSettingsManager based on a stack. Also commited updated .meta since last folder rename.

Assets/ScriptableRenderPipeline.meta

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+guid: 403e54624681147459c529bbda90360e
 folderAsset: yes
 timeCreated: 1466769773
 licenseType: Pro

Assets/ScriptableRenderPipeline/HDRenderPipeline.meta

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 folderAsset: yes
 timeCreated: 1483548930
 licenseType: Pro

Assets/ScriptableRenderPipeline/HDRenderPipeline/Editor.meta

 fileFormatVersion: 2
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 folderAsset: yes
 timeCreated: 1479127051
 licenseType: Pro

Assets/ScriptableRenderPipeline/HDRenderPipeline/Editor/HDRenderPipelineMenuItems.cs

 using UnityEngine;
+using UnityEditor;
+using UnityEngine.SceneManagement;
+using UnityEngine.Experimental.Rendering.HDPipeline;
 
 namespace UnityEditor.Experimental.Rendering.HDPipeline
 {
                     LayeredLitGUI.SynchronizeAllLayers(mat);
                 }
             }
+        }
+
+        [MenuItem("HDRenderPipeline/Create Scene Settings")]
+        public static void CreateSceneSettings()
+        {
+            var allSettings = Object.FindObjectsOfType<SceneSettings>();
+            var activeScene = SceneManager.GetActiveScene();
+            foreach (SceneSettings setting in allSettings)
+            {
+                if (setting.gameObject.scene == activeScene)
+                {
+                    EditorUtility.DisplayDialog("Create Scene Settings", "Scene settings already exist on scene " + activeScene.name + ". \n\n If you want to create on another scene, set it active (double click) first, then select this option in the menu.", "Got It!");
+                    return;
+                }
+            }
+
+            var manager = new GameObject();
+            manager.name = "Scene Settings";
+            manager.AddComponent<SceneSettings>();
         }
     }
 }

Assets/ScriptableRenderPipeline/HDRenderPipeline/HDRenderPipeline.asset

     type: 2}
   globalDebugParameters:
     debugOverlayRatio: 0.33
-    displayMaterialDebug: 0
-    displayRenderingDebug: 0
-    displayLightingDebug: 0
+    displayMaterialDebug: 1
+    displayRenderingDebug: 1
+    displayLightingDebug: 1
     materialDebugParameters:
       debugViewMaterial: 0
     lightingDebugParameters:
     enabled: 1
     shadowAtlasWidth: 4096
     shadowAtlasHeight: 4096
-    maxShadowDistance: 1000
+    maxShadowDistance: 400
     directionalLightCascadeCount: 4
     directionalLightCascades: {x: 0.05, y: 0.2, z: 0.3}
     directionalLightNearPlaneOffset: 5

Assets/ScriptableRenderPipeline/HDRenderPipeline/Lighting.meta

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+guid: 3002976b0b09954499dd1f6e00169b06
 folderAsset: yes
 timeCreated: 1474297943
 licenseType: Pro

Assets/ScriptableRenderPipeline/HDRenderPipeline/Lighting/Resources.meta

 fileFormatVersion: 2
-guid: 8d7b73e3debb13b46a544563ce8f4a64
+guid: 0823a45531ce4ee45ab39bcbe1ea52a6
 folderAsset: yes
 timeCreated: 1479129942
 licenseType: Pro

Assets/ScriptableRenderPipeline/HDRenderPipeline/Lighting/TilePass.meta

 fileFormatVersion: 2
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+guid: 8d0d2ae5d51ae6e42a81b92e8693272f
 folderAsset: yes
 timeCreated: 1479218330
 licenseType: Pro

Assets/ScriptableRenderPipeline/HDRenderPipeline/Material.meta

 fileFormatVersion: 2
-guid: 96af336cb096f854ea18990a1c0a4e19
+guid: 49844bc6823848a4087668ebd3367436
 folderAsset: yes
 timeCreated: 1474297943
 licenseType: Pro

Assets/ScriptableRenderPipeline/HDRenderPipeline/Material/LayeredLit.meta

 fileFormatVersion: 2
-guid: e173dfe6cd75d954b95306237244f6de
+guid: c526d3e6d7f3ce1408308bb431089d2d
 folderAsset: yes
 timeCreated: 1476653183
 licenseType: Pro

Assets/ScriptableRenderPipeline/HDRenderPipeline/Material/Lit.meta

 fileFormatVersion: 2
-guid: d6cadd3aaf3ad6641b86e85a0929b245
+guid: 0d05f89ce69203543914d745c388e6bb
 folderAsset: yes
 timeCreated: 1476653183
 licenseType: Pro

Assets/ScriptableRenderPipeline/HDRenderPipeline/SceneSettings/SceneSettings.cs

     [ExecuteInEditMode]
     public class SceneSettings : MonoBehaviour
     {
-        public CommonSettings SceneCommonSettings
+        public CommonSettings commonSettings
-            set { m_CommonSettings = value; ApplySettings(); }
-        public SkyParameters SceneSkyParameters
+        public SkyParameters skyParameters
-            set { m_SkyParameters = value; ApplySettings(); }
-        [SerializeField]
-        private CommonSettings m_CommonSettings;
-        [SerializeField]
-        private SkyParameters m_SkyParameters;
+        [SerializeField] private CommonSettings m_CommonSettings;
+        [SerializeField] private SkyParameters  m_SkyParameters;
-            ApplySettings();
+            SceneSettingsManager.instance.AddSceneSettings(this);
-        void OnValidate()
+        void OnDisable()
-            ApplySettings();
+            SceneSettingsManager.instance.RemoveSceneSettings(this);
-        private void ApplySettings()
+        void OnValidate()
-            if (m_CommonSettings != null)
-                CommonSettingsSingleton.overrideSettings = m_CommonSettings;
+            // If the setting is already the one currently used we need to tell the manager to reapply it.
+            if(SceneSettingsManager.instance.GetCurrentSceneSetting())
+            {
+                SceneSettingsManager.instance.UpdateCurrentSceneSetting();
+            }
+        }
-            if (m_SkyParameters != null)
-                SkyParametersSingleton.overrideSettings = m_SkyParameters;
-        }
     }
 }

Assets/ScriptableRenderPipeline/HDRenderPipeline/ShaderPass.meta

 fileFormatVersion: 2
-guid: e3b3ad4462341ec4b86566ec1fd82c7c
+guid: 057d8506536500045b3047320a4d6122
 folderAsset: yes
 timeCreated: 1476885561
 licenseType: Pro

Assets/ScriptableRenderPipeline/HDRenderPipeline/Sky.meta

 fileFormatVersion: 2
-guid: 066ab4d03bd03384f81c9d82b479f8dd
+guid: 99e8d5bd81663624399d10e3fc27571c
 folderAsset: yes
 timeCreated: 1479239906
 licenseType: Pro

Assets/ScriptableRenderPipeline/HDRenderPipeline/Sky/Resources.meta

 fileFormatVersion: 2
-guid: 4cdc45a9a65126a42aca158413a5b089
+guid: 920208451db81a846ae1c2d55f7b50b4
 folderAsset: yes
 timeCreated: 1479239906
 licenseType: Pro

Assets/ScriptableRenderPipeline/HDRenderPipeline/Editor/SceneSettingsManagementWindow.cs

+using UnityEngine.Experimental.Rendering.HDPipeline;
+using UnityEngine;
+
+namespace UnityEditor.Experimental.Rendering.HDPipeline
+{
+    public class SceneSettingsManagementWindow : EditorWindow
+    {
+        [MenuItem("HDRenderPipeline/Scene Settings Management")]
+        static void SceneSettingsManagement()
+        {
+            GetWindow<SceneSettingsManagementWindow>().Show();
+        }
+
+        static private string m_LastCreationPath = "Assets";
+
+        void CreateAsset<AssetType>(string assetName) where AssetType : ScriptableObject
+        {
+            string assetPath = EditorUtility.SaveFilePanel("Create new Asset", m_LastCreationPath, assetName, "asset");
+            if (!string.IsNullOrEmpty(assetPath))
+            {
+                assetPath = assetPath.Substring(assetPath.LastIndexOf("Assets"));
+                m_LastCreationPath = System.IO.Path.GetDirectoryName(assetPath);
+                var instance = CreateInstance<AssetType>();
+                AssetDatabase.CreateAsset(instance, assetPath);
+            }
+        }
+
+        void OnGUI()
+        {
+            // Keep it there temporarily until it's back to an "engine" setting in the HDRenderPipeline asset.
+            SubsurfaceScatteringSettings.overrideSettings = (SubsurfaceScatteringParameters)EditorGUILayout.ObjectField(new GUIContent("SSS Settings"), SubsurfaceScatteringSettings.overrideSettings, typeof(SubsurfaceScatteringParameters), false);
+            EditorGUILayout.Space();
+
+            if (GUILayout.Button("Create new Common Settings"))
+            {
+                CreateAsset<CommonSettings>("NewCommonSettings");
+            }
+
+            if (GUILayout.Button("Create new HDRI sky params"))
+            {
+                CreateAsset<HDRISkyParameters>("NewHDRISkyParameters");
+            }
+
+            if (GUILayout.Button("Create new Procedural sky params"))
+            {
+                CreateAsset<ProceduralSkyParameters>("NewProceduralSkyParameters");
+            }
+
+            if (GUILayout.Button("Create new SSS params"))
+            {
+                CreateAsset<SubsurfaceScatteringParameters>("NewSssParameters");
+            }
+        }
+    }
+}

Assets/ScriptableRenderPipeline/HDRenderPipeline/SceneSettings/SceneSettingsManager.cs

+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+namespace UnityEngine.Experimental.Rendering.HDPipeline
+{
+    public class SceneSettingsManager
+    {
+        static private SceneSettingsManager s_Instance = null;
+        static public SceneSettingsManager instance
+        {
+            get
+            {
+                if(s_Instance == null)
+                    s_Instance = new SceneSettingsManager();
+
+                return s_Instance;
+            }
+        }
+
+        private List<SceneSettings> m_SceneSettingsList = new List<SceneSettings>();
+
+        void OnEnable()
+        {
+
+        }
+
+        void OnDisable()
+        {
+
+        }
+
+        public SceneSettings GetCurrentSceneSetting()
+        {
+            if (m_SceneSettingsList.Count == 0)
+                return null;
+            else
+                return m_SceneSettingsList[m_SceneSettingsList.Count - 1];
+        }
+
+        // This can be needed in the editor in case the current setting is being changed. In this case we need to reapply it.
+        public void UpdateCurrentSceneSetting()
+        {
+            if (m_SceneSettingsList.Count != 0)
+                ApplySettings(GetCurrentSceneSetting());
+        }
+
+        public void AddSceneSettings(SceneSettings settings)
+        {
+            m_SceneSettingsList.Add(settings);
+            ApplySettings(settings);
+        }
+
+        public void RemoveSceneSettings(SceneSettings settings)
+        {
+            m_SceneSettingsList.Remove(settings);
+
+            // Always reapply the settings at the top of the list
+            // (this way if the setting being removed was the active one we switch to the next one)
+            ApplySettings(GetCurrentSceneSetting());
+        }
+
+        private void ApplySettings(SceneSettings settings)
+        {
+            if(settings)
+            {
+                if (settings.commonSettings != null)
+                    CommonSettingsSingleton.overrideSettings = settings.commonSettings;
+
+                if (settings.skyParameters != null)
+                    SkyParametersSingleton.overrideSettings = settings.skyParameters;
+            }
+            else
+            {
+                CommonSettingsSingleton.overrideSettings = null;
+                SkyParametersSingleton.overrideSettings = null;
+            }
+        }
+
+    }
+}

Assets/ScriptableRenderPipeline/HDRenderPipeline/SceneSettings/SceneSettingsManager.cs.meta

+fileFormatVersion: 2
+guid: f31f023dee834de44993536e71ee27ac
+timeCreated: 1487241314
+licenseType: Pro
+MonoImporter:
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/ScriptableRenderPipeline/HDRenderPipeline/Editor/HDRenderPipeWindow.cs

-using UnityEngine.Experimental.Rendering.HDPipeline;
-using UnityEngine;
-
-namespace UnityEditor.Experimental.Rendering.HDPipeline
-{
-    public class HDRenderPipeWindow : EditorWindow
-    {
-        [MenuItem("HDRenderPipeline/Configure Overrides")]
-        static void ConfigureOverrides()
-        {
-            GetWindow<HDRenderPipeWindow>().Show();
-        }
-
-        void OnGUI()
-        {
-            CommonSettingsSingleton.overrideSettings = (CommonSettings)EditorGUILayout.ObjectField(new GUIContent("Common Settings"), CommonSettingsSingleton.overrideSettings, typeof(CommonSettings), false);
-            SkyParametersSingleton.overrideSettings = (SkyParameters)EditorGUILayout.ObjectField(new GUIContent("Sky Settings"), SkyParametersSingleton.overrideSettings, typeof(SkyParameters), false);
-            SubsurfaceScatteringSettings.overrideSettings = (SubsurfaceScatteringParameters)EditorGUILayout.ObjectField(new GUIContent("Subsurface Scattering Settings"), SubsurfaceScatteringSettings.overrideSettings, typeof(SubsurfaceScatteringParameters), false);
-
-            if (GUILayout.Button("Create new common settings"))
-            {
-                var instance = CreateInstance<CommonSettings>();
-                AssetDatabase.CreateAsset(instance, "Assets/NewCommonSettings.asset");
-            }
-
-            if (GUILayout.Button("Create new HDRI sky params"))
-            {
-                var instance = CreateInstance<HDRISkyParameters>();
-                AssetDatabase.CreateAsset(instance, "Assets/NewHDRISkyParameters.asset");
-            }
-
-            if (GUILayout.Button("Create new Procedural sky params"))
-            {
-                var instance = CreateInstance<ProceduralSkyParameters>();
-                AssetDatabase.CreateAsset(instance, "Assets/NewProceduralSkyParameters.asset");
-            }
-
-            if (GUILayout.Button("Create new SSS params"))
-            {
-                var instance = CreateInstance<SubsurfaceScatteringParameters>();
-                AssetDatabase.CreateAsset(instance, "Assets/NewSssParameters.asset");
-            }
-        }
-    }
-}